Replication crisis

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Replication_crisis 

 

Ioannidis (2005), "Why Most Published Research Findings Are False".

The replication crisis (also called the replicability crisis and the reproducibility crisis) is an ongoing methodological crisis in which it has been found that many scientific studies are difficult or impossible to replicate or reproduce. The replication crisis most severely affects the social sciences and medicine. The phrase was coined in the early 2010s as part of a growing awareness of the problem. The replication crisis represents an important body of research in the field of metascience.

Because the reproducibility of experimental results is an essential part of the scientific method, an inability to replicate the studies of others has potentially grave consequences for many fields of science in which significant theories are grounded on unreproducible experimental work. The replication crisis has been particularly widely discussed in the fields of medicine, where a number of efforts have been made to re-investigate classic results, to determine both the reliability of the results and, if found to be unreliable, the reasons for the failure of replication.

Scope

Overall

A 2016 poll of 1,500 scientists reported that 70% of them had failed to reproduce at least one other scientist's experiment (50% had failed to reproduce one of their own experiments). In 2009, 2% of scientists admitted to falsifying studies at least once and 14% admitted to personally knowing someone who did. Misconducts were reported more frequently by medical researchers than others.

In psychology

Several factors have combined to put psychology at the center of the controversy. According to a 2018 survey of 200 meta-analyses, "psychological research is, on average, afflicted with low statistical power". Much of the focus has been on the area of social psychology, although other areas of psychology such as clinical psychology, developmental psychology, and educational research have also been implicated.

Firstly, questionable research practices (QRPs) have been identified as common in the field. Such practices, while not intentionally fraudulent, involve capitalizing on the gray area of acceptable scientific practices or exploiting flexibility in data collection, analysis, and reporting, often in an effort to obtain a desired outcome. Examples of QRPs include selective reporting or partial publication of data (reporting only some of the study conditions or collected dependent measures in a publication), optional stopping (choosing when to stop data collection, often based on statistical significance of tests), post-hoc storytelling (framing exploratory analyses as confirmatory analyses), and manipulation of outliers (either removing outliers or leaving outliers in a dataset to cause a statistical test to be significant). A survey of over 2,000 psychologists indicated that a majority of respondents admitted to using at least one QRP. The publication bias (see Section "Causes" below) leads to an elevated number of false positive results. It is augmented by the pressure to publish as well as the author's own confirmation bias and is an inherent hazard in the field, requiring a certain degree of skepticism on the part of readers.

Secondly, psychology and social psychology in particular, has found itself at the center of several scandals involving outright fraudulent research, most notably the admitted data fabrication by Diederik Stapel as well as allegations against others. However, most scholars acknowledge that fraud is, perhaps, the lesser contribution to replication crises.

Thirdly, several effects in psychological science have been found to be difficult to replicate even before the current replication crisis. For example, the scientific journal Judgment and Decision Making has published several studies over the years that fail to provide support for the unconscious thought theory. Replications appear particularly difficult when research trials are pre-registered and conducted by research groups not highly invested in the theory under questioning.

These three elements together have resulted in renewed attention for replication supported by psychologist Daniel Kahneman. Scrutiny of many effects have shown that several core beliefs are hard to replicate. A 2014 special edition of the journal Social Psychology focused on replication studies and a number of previously held beliefs were found to be difficult to replicate. A 2012 special edition of the journal Perspectives on Psychological Science also focused on issues ranging from publication bias to null-aversion that contribute to the replication crises in psychology. In 2015, the first open empirical study of reproducibility in psychology was published, called the Reproducibility Project. Researchers from around the world collaborated to replicate 100 empirical studies from three top psychology journals. Fewer than half of the attempted replications were successful at producing statistically significant results in the expected directions, though most of the attempted replications did produce trends in the expected directions.

Many research trials and meta-analyses are compromised by poor quality and conflicts of interest that involve both authors and professional advocacy organizations, resulting in many false positives regarding the effectiveness of certain types of psychotherapy.

Although the British newspaper The Independent wrote that the results of the reproducibility project show that much of the published research is just "psycho-babble", the replication crisis does not necessarily mean that psychology is unscientific. Rather this process is part of the scientific process in which old ideas or those that cannot withstand careful scrutiny are pruned, although this pruning process is not always effective. The consequence is that some areas of psychology once considered solid, such as social priming, have come under increased scrutiny due to failed replications.

Nobel laureate and professor emeritus in psychology Daniel Kahneman argued that the original authors should be involved in the replication effort because the published methods are often too vague. Others such as Dr. Andrew Wilson disagree and argue that the methods should be written down in detail. An investigation of replication rates in psychology in 2012 indicated higher success rates of replication in replication studies when there was author overlap with the original authors of a study (91.7% successful replication rates in studies with author overlap compared to 64.6% success replication rates without author overlap).

Focus on the replication crisis has led to other renewed efforts in the discipline to re-test important findings. In response to concerns about publication bias and p-hacking, more than 140 psychology journals have adopted result-blind peer review where studies are accepted not on the basis of their findings and after the studies are completed, but before the studies are conducted and upon the basis of the methodological rigor of their experimental designs and the theoretical justifications for their statistical analysis techniques before data collection or analysis is done. Early analysis of this procedure has estimated that 61 percent of result-blind studies have led to null results, in contrast to an estimated 5 to 20 percent in earlier research. In addition, large-scale collaborations between researchers working in multiple labs in different countries and that regularly make their data openly available for different researchers to assess have become much more common in the field.

Psychology replication rates

A report by the Open Science Collaboration in August 2015 that was coordinated by Brian Nosek estimated the reproducibility of 100 studies in psychological science from three high-ranking psychology journals. Overall, 36% of the replications yielded significant findings (p value below 0.05) compared to 97% of the original studies that had significant effects. The mean effect size in the replications was approximately half the magnitude of the effects reported in the original studies.

The same paper examined the reproducibility rates and effect sizes by journal (Journal of Personality and Social Psychology [JPSP], Journal of Experimental Psychology: Learning, Memory, and Cognition [JEP:LMC], Psychological Science [PSCI]) and discipline (social psychology, developmental psychology). Study replication rates were 23% for JPSP, 48% for JEP:LMC, and 38% for PSCI. Studies in the field of cognitive psychology had a higher replication rate (50%) than studies in the field of social psychology (25%).

An analysis of the publication history in the top 100 psychology journals between 1900 and 2012 indicated that approximately 1.6% of all psychology publications were replication attempts. Articles were considered a replication attempt if the term "replication" appeared in the text. A subset of those studies (500 studies) was randomly selected for further examination and yielded a lower replication rate of 1.07% (342 of the 500 studies [68.4%] were actually replications). In the subset of 500 studies, analysis indicated that 78.9% of published replication attempts were successful.

A study published in 2018 in Nature Human Behaviour sought to replicate 21 social and behavioral science papers from Nature and Science, finding that only 13 could be successfully replicated. Similarly, in a study conducted under the auspices of the Center for Open Science, a team of 186 researchers from 60 different laboratories (representing 36 different nationalities from 6 different continents) conducted replications of 28 classic and contemporary findings in psychology. The focus of the study was not only on whether or not the findings from the original papers replicated, but also on the extent to which findings varied as a function of variations in samples and contexts. Overall, 14 of the 28 findings failed to replicate despite massive sample sizes. However, if a finding replicated, it replicated in most samples, while if a finding was not replicated, it failed to replicate with little variation across samples and contexts. This evidence is inconsistent with a popular explanation that failures to replicate in psychology are likely due to changes in the sample between the original and replication study.

A disciplinary social dilemma

Highlighting the social structure that discourages replication in psychology, Brian D. Earp and Jim A. C. Everett enumerated five points as to why replication attempts are uncommon:

1. "Independent, direct replications of others' findings can be time-consuming for the replicating researcher"
2. "[Replications] are likely to take energy and resources directly away from other projects that reflect one's own original thinking"
3. "[Replications] are generally harder to publish (in large part because they are viewed as being unoriginal)"
4. "Even if [replications] are published, they are likely to be seen as 'bricklaying' exercises, rather than as major contributions to the field"
5. "[Replications] bring less recognition and reward, and even basic career security, to their authors"

For these reasons the authors advocated that psychology is facing a disciplinary social dilemma, where the interests of the discipline are at odds with the interests of the individual researcher.

"Methodological terrorism" controversy

With the replication crisis of psychology earning attention, Princeton University psychologist Susan Fiske drew controversy for calling out critics of psychology. She labeled these unidentified "adversaries" with names such as "methodological terrorist" and "self-appointed data police", and said that criticism of psychology should only be expressed in private or through contacting the journals. Columbia University statistician and political scientist Andrew Gelman, responded to Fiske, saying that she had found herself willing to tolerate the "dead paradigm" of faulty statistics and had refused to retract publications even when errors were pointed out. He added that her tenure as editor has been abysmal and that a number of published papers edited by her were found to be based on extremely weak statistics; one of Fiske's own published papers had a major statistical error and "impossible" conclusions.

In medicine

Out of 49 medical studies from 1990–2003 with more than 1000 citations, 45 claimed that the studied therapy was effective. Out of these studies, 16% were contradicted by subsequent studies, 16% had found stronger effects than did subsequent studies, 44% were replicated, and 24% remained largely unchallenged. The US Food and Drug Administration in 1977–1990 found flaws in 10–20% of medical studies. In a paper published in 2012, Glenn Begley, a biotech consultant working at Amgen, and Lee Ellis, at the University of Texas, found that only 11% of 53 pre-clinical cancer studies could be replicated. The irreproducible studies had a number of features in common, including that studies were not performed by investigators blinded to the experimental versus the control arms, there was a failure to repeat experiments, a lack of positive and negative controls, failure to show all the data, inappropriate use of statistical tests and use of reagents that were not appropriately validated.

A survey on cancer researchers found that half of them had been unable to reproduce a published result. A similar survey by Nature on 1,576 researchers who took a brief online questionnaire on reproducibility showed that more than 70% of researchers have tried and failed to reproduce another scientist's experiments, and more than half have failed to reproduce their own experiments. "Although 52% of those surveyed agree there is a significant 'crisis' of reproducibility, less than 31% think failure to reproduce published results means the result is probably wrong, and most say they still trust the published literature."

A 2016 article by John Ioannidis, Professor of Medicine and of Health Research and Policy at Stanford University School of Medicine and a Professor of Statistics at Stanford University School of Humanities and Sciences, elaborated on "Why Most Clinical Research Is Not Useful". In the article Ioannidis laid out some of the problems and called for reform, characterizing certain points for medical research to be useful again; one example he made was the need for medicine to be "patient centered" (e.g. in the form of the Patient-Centered Outcomes Research Institute) instead of the current practice to mainly take care of "the needs of physicians, investigators, or sponsors".

In marketing

Marketing is another discipline with a "desperate need" for replication. Many famous marketing studies fail to be repeated upon replication, a notable example being the "too-many-choices" effect, in which a high number of choices of product makes a consumer less likely to purchase. In addition to the previously mentioned arguments, replication studies in marketing are needed to examine the applicability of theories and models across countries and cultures, which is especially important because of possible influences of globalization.

In economics

A 2016 study in the journal Science found that one-third of 18 experimental studies from two top-tier economics journals (American Economic Review and the Quarterly Journal of Economics) failed to successfully replicate. A 2017 study in the Economic Journal suggested that "the majority of the average effects in the empirical economics literature are exaggerated by a factor of at least 2 and at least one-third are exaggerated by a factor of 4 or more".

In sports science

A 2018 study took the field of exercise and sports science to task for insufficient replication studies, limited reporting of both null and trivial results, and insufficient research transparency. Statisticians have criticized sports science for common use of a controversial statistical method called "magnitude-based inference" which has allowed sports scientists to extract apparently significant results from noisy data where ordinary hypothesis testing would have found none.

In water resource management

A 2019 study in Scientific Data suggested that only a small number of articles in water resources and management journals could be reproduced, while the majority of articles were not replicable due to data unavailability. The study estimated with 95% confidence that "results might be reproduced for only 0.6% to 6.8% of all 1,989 articles".

Political repercussions

In the US, science's reproducibility crisis has become a topic of political contention, linked to the attempt to diminish regulations – e.g. of emissions of pollutants, with the argument that these regulations are based on non-reproducible science. Previous attempts with the same aim accused studies used by regulators of being non-transparent.

Public awareness and perceptions

Concerns have been expressed within the scientific community that the general public may consider science less credible due to failed replications. Research supporting this concern is sparse, but a nationally representative survey in Germany showed that more than 75% of Germans have not heard of replication failures in science. The study also found that most Germans have positive perceptions of replication efforts: Only 18% think that non-replicability shows that science cannot be trusted, while 65% think that replication research shows that science applies quality control, and 80% agree that errors and corrections are part of science.

Causes 

A major cause of low reproducibility is the publication bias and the selection bias, in turn caused by the fact that statistically insignificant results are rarely published or discussed in publications on multiple potential effects. Among potential effects that are inexistent (or tiny), the statistical tests show significance (at the usual level) with 5% probability. If a large number of such effects are screened in a chase for significant results, these erroneously significant ones inundate the appropriately found ones, and they lead to (still erroneously) successful replications again with just 5% probability. An increasing proportion of such studies thus progressively lowers the replication rate corresponding to studies of plausibly relevant effects. Erroneously significant results may also come from questionable practices in data analysis called data dredging or P-hacking, HARKing, and researcher degrees of freedom.

Glenn Begley and John Ioannidis proposed these causes for the increase in the chase for significance:

• Generation of new data/publications at an unprecedented rate.
• Majority of these discoveries will not stand the test of time.
• Failure to adhere to good scientific practice and the desperation to publish or perish.
• Multiple varied stakeholders.

They conclude that no party is solely responsible, and no single solution will suffice.

These issues may lead to the canonization of false facts.

In fact, some predictions of an impending crisis in the quality control mechanism of science can be traced back several decades, especially among scholars in science and technology studies (STS). Derek de Solla Price – considered the father of scientometrics – predicted that science could reach 'senility' as a result of its own exponential growth. Some present day literature seems to vindicate this 'overflow' prophecy, lamenting the decay in both attention and quality.

Philosopher and historian of science Jerome R. Ravetz predicted in his 1971 book Scientific Knowledge and Its Social Problems that science – in its progression from "little" science composed of isolated communities of researchers, to "big" science or "techno-science" – would suffer major problems in its internal system of quality control. Ravetz recognized that the incentive structure for modern scientists could become dysfunctional, now known as the present 'publish or perish' challenge, creating perverse incentives to publish any findings, however dubious. According to Ravetz, quality in science is maintained only when there is a community of scholars linked by a set of shared norms and standards, all of whom are willing and able to hold one another accountable.

Historian Philip Mirowski offered a similar diagnosis in his 2011 book Science Mart (2011). In the title, the word 'Mart' is in reference to the retail giant 'Walmart', used by Mirowski as a metaphor for the commodification of science. In Mirowski's analysis, the quality of science collapses when it becomes a commodity being traded in a market. Mirowski argues his case by tracing the decay of science to the decision of major corporations to close their in-house laboratories. They outsourced their work to universities in an effort to reduce costs and increase profits. The corporations subsequently moved their research away from universities to an even cheaper option – Contract Research Organizations (CRO).

The crisis of science's quality control system is affecting the use of science for policy. This is the thesis of a recent work by a group of STS scholars, who identify in 'evidence based (or informed) policy' a point of present tension. Economist Noah Smith suggests that a factor in the crisis has been the overvaluing of research in academia and undervaluing of teaching ability, especially in fields with few major recent discoveries.

Social system theory, due to the German sociologist Niklas Luhmann offers another reading of the crisis . According to this theory each the systems such as 'economy', 'science', 'religion', 'media' and so on communicates using its own code, true/false for science, profit/loss for the economy, new/no-news for the media; according to some sociologists, science's mediatization, its commodification and its politicization – as a result of the structural coupling among systems – have led to a confusion of the original system codes. If science's code true/false is substituted for by those of the other systems, such as profit/loss, news/no-news, science's operation enters into an internal crisis.

Response 

Replication has been referred to as "the cornerstone of science". Replication studies attempt to evaluate whether published results reflect true findings or false positives. The integrity of scientific findings and reproducibility of research are important as they form the knowledge foundation on which future studies are built.

Metascience

Metascience is the use of scientific methodology to study science itself. Metascience seeks to increase the quality of scientific research while reducing waste. It is also known as "research on research" and "the science of science", as it uses research methods to study how research is done and where improvements can be made. Metascience concerns itself with all fields of research and has been described as "a bird's eye view of science." In the words of John Ioannidis, "Science is the best thing that has happened to human beings ... but we can do it better."

Meta-research continues to be conducted to identify the roots of the crisis and to address them. Methods of addressing the crisis include pre-registration of scientific studies and clinical trials as well as the founding of organizations such as CONSORT and the EQUATOR Network that issue guidelines for methodology and reporting. There are continuing efforts to reform the system of academic incentives, to improve the peer review process, to reduce the misuse of statistics, to combat bias in scientific literature, and to increase the overall quality and efficiency of the scientific process.

Tackling publication bias with pre-registration of studies

A recent innovation in scientific publishing to address the replication crisis is through the use of registered reports. The registered report format requires authors to submit a description of the study methods and analyses prior to data collection. Once the method and analysis plan is vetted through peer-review, publication of the findings is provisionally guaranteed, based on whether the authors follow the proposed protocol. One goal of registered reports is to circumvent the publication bias toward significant findings that can lead to implementation of questionable research practices and to encourage publication of studies with rigorous methods.

The journal Psychological Science has encouraged the preregistration of studies and the reporting of effect sizes and confidence intervals. The editor in chief also noted that the editorial staff will be asking for replication of studies with surprising findings from examinations using small sample sizes before allowing the manuscripts to be published.

Moreover, only a very small proportion of academic journals in psychology and neurosciences explicitly stated that they welcome submissions of replication studies in their aim and scope or instructions to authors. This phenomenon does not encourage the reporting or even attempt on replication studies.

Shift to a complex systems paradigm

It has been argued that research endeavours working within the conventional linear paradigm necessarily end up in replication difficulties. Problems arise if the causal processes in the system under study are "interaction-dominant" instead of "component dominant", multiplicative instead of additive, and with many small non-linear interactions producing macro-level phenomena, that are not reducible to their micro-level components. In the context of such complex systems, conventional linear models produce answers that are not reasonable, because it is not in principle possible to decompose the variance as suggested by the General Linear Model (GLM) framework – aiming to reproduce such a result is hence evidently problematic. The same questions are currently being asked in many fields of science, where researchers are starting to question assumptions underlying classical statistical methods.

Emphasizing replication attempts in teaching

Based on coursework in experimental methods at MIT, Stanford, and the University of Washington, it has been suggested that methods courses in psychology and other fields emphasize replication attempts rather than original studies. Such an approach would help students learn scientific methodology and provide numerous independent replications of meaningful scientific findings that would test the replicability of scientific findings. Some have recommended that graduate students should be required to publish a high-quality replication attempt on a topic related to their doctoral research prior to graduation.

Reducing the p-value required for claiming significance of new results

Many publications require a p-value of p < 0.05 to claim statistical significance. The paper "Redefine statistical significance", signed by a large number of scientists and mathematicians, proposes that in "fields where the threshold for defining statistical significance for new discoveries is p < 0.05, we propose a change to p < 0.005. This simple step would immediately improve the reproducibility of scientific research in many fields."

Their rationale is that "a leading cause of non-reproducibility (is that the) statistical standards of evidence for claiming new discoveries in many fields of science are simply too low. Associating 'statistically significant' findings with p < 0.05 results in a high rate of false positives even in the absence of other experimental, procedural and reporting problems."

This call was subsequently criticised by another large group, who argued that "redefining" the threshold would not fix current problems, would lead to some new ones, and that in the end, all thresholds needed to be justified case-by-case instead of following general conventions.

Addressing the misinterpretation of p-values

Although statisticians are unanimous that use of the p < 0.05 provides weaker evidence than is generally appreciated, there is a lack of unanimity about what should be done about it. Some have advocated that Bayesian methods should replace p-values. This has not happened on a wide scale, partly because it is complicated, and partly because many users distrust the specification of prior distributions in the absence of hard data. A simplified version of the Bayesian argument, based on testing a point null hypothesis was suggested by Colquhoun (2014, 2017). The logical problems of inductive inference were discussed in "The problem with p-values" (2016).

The hazards of reliance on p-values were emphasized by pointing out that even observation of p = 0.001 was not necessarily strong evidence against the null hypothesis. Despite the fact that the likelihood ratio in favour of the alternative hypothesis over the null is close to 100, if the hypothesis was implausible, with a prior probability of a real effect being 0.1, even the observation of p = 0.001 would have a false positive risk of 8 percent. It would not even reach the 5 percent level.

It was recommended that the terms "significant" and "non-significant" should not be used. p-values and confidence intervals should still be specified, but they should be accompanied by an indication of the false positive risk. It was suggested that the best way to do this is to calculate the prior probability that would be necessary to believe in order to achieve a false positive risk of, say, 5%. The calculations can be done with R scripts that are provided, or, more simply, with a web calculator. This so-called reverse Bayesian approach, which was suggested by Matthews (2001), is one way to avoid the problem that the prior probability is rarely known.

Encouraging larger sample sizes

To improve the quality of replications, larger sample sizes than those used in the original study are often needed. Larger sample sizes are needed because estimates of effect sizes in published work are often exaggerated due to publication bias and large sampling variability associated with small sample sizes in an original study. Further, using significance thresholds usually leads to inflated effects, because particularly with small sample sizes, only the largest effects will become significant.

Sharing raw data in online repositories

Online repositories where data, protocols, and findings can be stored and evaluated by the public seek to improve the integrity and reproducibility of research. Examples of such repositories include the Open Science Framework, Registry of Research Data Repositories, and Psychfiledrawer.org. Sites like Open Science Framework offer badges for using open science practices in an effort to incentivize scientists. However, there has been concern that those who are most likely to provide their data and code for analyses are the researchers that are likely the most sophisticated. John Ioannidis at Stanford University suggested that "the paradox may arise that the most meticulous and sophisticated and method-savvy and careful researchers may become more susceptible to criticism and reputation attacks by reanalyzers who hunt for errors, no matter how negligible these errors are".

Funding for replication studies

In July 2016 the Netherlands Organisation for Scientific Research made €3 million available for replication studies. The funding is for replication based on reanalysis of existing data and replication by collecting and analysing new data. Funding is available in the areas of social sciences, health research and healthcare innovation.

In 2013 the Laura and John Arnold Foundation funded the launch of The Center for Open Science with a $5.25 million grant and by 2017 had provided an additional $10 million in funding. It also funded the launch of the Meta-Research Innovation Center at Stanford at Stanford University run by John Ioannidis and Steven Goodman to study ways to improve scientific research. It also provided funding for the AllTrials initiative led in part by Ben Goldacre.

Emphasize triangulation, not just replication

Marcus R. Munafò and George Davey Smith argue, in a piece published by Nature, that research should emphasize triangulation, not just replication. They claim that,

replication alone will get us only so far (and) might actually make matters worse ... We believe that an essential protection against flawed ideas is triangulation. This is the strategic use of multiple approaches to address one question. Each approach has its own unrelated assumptions, strengths and weaknesses. Results that agree across different methodologies are less likely to be artefacts. ... Maybe one reason replication has captured so much interest is the often-repeated idea that falsification is at the heart of the scientific enterprise. This idea was popularized by Karl Popper's 1950s maxim that theories can never be proved, only falsified. Yet an overemphasis on repeating experiments could provide an unfounded sense of certainty about findings that rely on a single approach. ... philosophers of science have moved on since Popper. Better descriptions of how scientists actually work include what epistemologist Peter Lipton called in 1991 "inference to the best explanation".

Raise the overall standards of methods presentation

Some authors have argued that the insufficient communication of experimental methods is a major contributor to the reproducibility crisis and that improving the quality of how experimental design and statistical analyses are reported would help improve the situation. These authors tend to plea for both a broad cultural change in the scientific community of how statistics are considered and a more coercive push from scientific journals and funding bodies.

Implications for the pharmaceutical industry

Pharmaceutical companies and venture capitalists maintain research laboratories or contract with private research service providers (e.g. Envigo and Smart Assays Biotechnologies) whose job is to replicate academic studies, in order to test if they are accurate prior to investing or trying to develop a new drug based on that research. The financial stakes are high for the company and investors, so it is cost effective for them to invest in exact replications. Execution of replication studies consume resources. Further, doing an expert replication requires not only generic expertise in research methodology, but specific expertise in the often narrow topic of interest. Sometimes research requires specific technical skills and knowledge, and only researchers dedicated to a narrow area of research might have those skills. Right now, funding agencies are rarely interested in bankrolling replication studies, and most scientific journals are not interested in publishing such results. Amgen Oncology's cancer researchers were only able to replicate 11 percent of the innovative studies they selected to pursue over a 10-year period; a 2011 analysis by researchers with pharmaceutical company Bayer found that the company's in-house findings agreed with the original results only a quarter of the time, at the most. The analysis also revealed that, when Bayer scientists were able to reproduce a result in a direct replication experiment, it tended to translate well into clinical applications; meaning that reproducibility is a useful marker of clinical potential.

Apples and oranges

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Apples_and_oranges 

An apple and an orange, not to be practically compared

 

Apples and Oranges, by Paul Cézanne.

A comparison of apples and oranges occurs when two items or groups of items are compared that cannot be practically compared.

The idiom, comparing apples and oranges, refers to the apparent differences between items which are popularly thought to be incomparable or incommensurable, such as apples and oranges. The idiom may also be used to indicate that a false analogy has been made between two items, such as where an apple is faulted for not being a good orange.

Variants

The idiom is not unique to English. In Quebec French, it may take the form comparer des pommes avec des oranges (to compare apples with oranges), while in European French the idiom says comparer des pommes et des poires (to compare apples and pears) or comparer des choux et des carottes (to compare cabbages and carrots). In Latin American Spanish, it is usually comparar papas y boniatos (comparing potatoes and sweet potatoes) or commonly for all varieties of Spanish comparar peras con manzanas (comparing pears with apples). In some other languages the term for 'orange' derives from 'apple', suggesting not only that a direct comparison between the two is possible, but that it is implicitly present in their names. Fruit other than apples and oranges can also be compared; for example, apples and pears are compared in Danish, Dutch, German, Spanish, Swedish, Croatian, Czech, Romanian, Hungarian, Italian, Slovak, Slovene, Luxembourgish, Serbian, and Turkish. In fact, in the Spanish-speaking world, a common idiom is sumar peras con manzanas, that is, to add pears with apples; the same thing applies in Italian (sommare le mele con le pere) and Romanian (a aduna merele cu perele). In Portuguese, the expression is comparar laranjas com bananas (compare orange with banana). In Czech, the idiom míchat jablka s hruškami literally means 'to mix apples with pears'.

Not all apples are alike.

Some languages use completely different items, such as the Serbian Поредити бабе и жабе (comparing grandmothers and toads), or the Romanian baba şi mitraliera (the grandmother and the machine gun); vaca şi izmenele (the cow and the longjohns); or țiganul şi carioca (the gypsy and the marker), or the Welsh mor wahanol â mêl a menyn (as different as honey and butter), while some languages compare dissimilar properties of dissimilar items. For example, an equivalent Danish idiom, Hvad er højest, Rundetårn eller et tordenskrald? means "What is highest, the Round Tower or a thunderclap?", referring to the size of the former and the sound of the latter. In Russian, the phrase сравнивать тёплое с мягким (to compare warm and soft) is used. In Argentina, a common question is ¿En qué se parecen el amor y el ojo del hacha? (What do love and the eye of an axe have in common?) and emphasizes dissimilarity between two subjects; in Colombia, a similar (though more rude) version is common: confundir la mierda con la pomada (to confuse shit with ointment). In Polish, the expression co ma piernik do wiatraka? is used, meaning "What has (is) gingerbread for a windmill?". In Chinese, a phrase that has the similar meaning is 风马牛不相及 (fēng mǎ niú bù xiāng jí), literally meaning "horses and cattles won't mate with each other", and later used to describe things that are totally unrelated and incomparable.

A number of more exaggerated comparisons are sometimes made, in cases in which the speaker believes the two objects being compared are radically different. For example, "oranges with orangutans", "apples with dishwashers", and so on. In English, different fruits, such as pears, plums, or lemons are sometimes substituted for oranges in this context.

Sometimes the two words sound similar, for example, Romanian merele cu perele (apples with pears) and the Hungarian szezont a fazonnal (the season with the fashion).

Published comparisons

Scientific

Oranges, like apples, grow on trees.

At least two tongue-in-cheek scientific studies have been conducted on the subject, each of which concluded that apples can be compared with oranges fairly easily and on a low budget and the two fruits are quite similar.

The first study, conducted by Scott Sandford of the NASA Ames Research Center, used infrared spectroscopy to analyze both apples and oranges. The study, which was published in the satirical science magazine Annals of Improbable Research, concluded: "... the comparing apples and oranges defense should no longer be considered valid. This is a somewhat startling revelation. It can be anticipated to have a dramatic effect on the strategies used in arguments and discussions in the future."

A second study, written by Stamford Hospital's surgeon-in-chief James Barone and published in the British Medical Journal, noted that the phrase apples and oranges was appearing with increasing frequency in the medical literature, with some notable articles comparing "Desflurane and propofol" and "Salmeterol and ipratropium" with "apples and oranges". The study also found that both apples and oranges were sweet, similar in size, weight, and shape, that both are grown in orchards, and both may be eaten, juiced, and so on. The only significant differences found were in terms of seeds (the study used seedless oranges), the involvement of Johnny Appleseed, and color.

The Annals of Improbable Research subsequently noted that the "earlier investigation was done with more depth, more rigour, and, most importantly, more expensive equipment" than the British Medical Journal study.

Economic

On April Fools' Day 2014, The Economist compared worldwide production of apples and oranges from 1983 to 2013, however noted them to be "unrelated variables".

In teaching the use of units

While references to comparing apples and oranges are often a rhetorical device, references to adding apples and oranges are made in the case of teaching students the proper uses of units. Here, the admonition not to "add apples and oranges" refers to the requirement that two quantities with different units may not be combined by addition, although they may always be combined in ratio form by multiplication, so that multiplying ratios of apples and oranges is allowed. Similarly, the concept of this distinction is often used metaphorically in elementary algebra.

The admonition is really more of a mnemonic, since in general counts of objects have no intrinsic unit and, for example, a number count of apples may be dimensionless or have dimension fruit; in either of these two cases, apples and oranges may indeed be added.

Voyage of the James Caird (After Endurance Destroyed by Ice.)

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Voyage_of_the_James_Caird 

 

Launching the James Caird from the shore of Elephant Island, 24 April 1916

The voyage of the James Caird was a journey of 1,300 kilometres (800 mi) from Elephant Island in the South Shetland Islands through the Southern Ocean to South Georgia, undertaken by Sir Ernest Shackleton and five companions to obtain rescue for the main body of the stranded Imperial Trans-Antarctic Expedition of 1914–1917. Polar historians regard the voyage of the crew in a 22.5' lifeboat through the "Furious Fifties" as one of the greatest small-boat journeys ever completed.

In October 1915, pack ice in the Weddell Sea had sunk the main expedition ship Endurance, leaving Shackleton and his 27 companions adrift on a floe. They drifted northward until April 1916, when the floe they had encamped broke up, then made their way in the ship's lifeboats to Elephant Island. Shackleton decided to sail one of the lifeboats to South Georgia, not the closest human settlement but the only one not requiring sailing into the prevailing westerlies.

Of the three lifeboats, the James Caird was deemed the strongest and most likely to survive the journey. Shackleton had named it after Sir James Key Caird, a Dundee philanthropist whose sponsorship had helped finance the expedition. Before its voyage, the ship's carpenter, Harry McNish, strengthened and adapted the boat to withstand the seas of the Southern Ocean, sealing his makeshift wood and canvas deck with lamp wick, oil paint and seal blood.

Surviving a series of dangers, including a near capsizing, the boat reached the southern coast of South Georgia after a voyage that lasted 16 days. Shackleton and two companions then had to cross the island's mountainous interior to reach a whaling station on the northern side. Here he organised the relief of the three men left on the south side of the island and of the Elephant Island party, and the return of his men home without loss of life, then the rescue of the Ross Sea party of his expedition. After the First World War, in 1919, the James Caird was moved from South Georgia to England. It has been on regular display at Shackleton's old school, Dulwich College, since 1922.

Background

Endurance, listing heavily, shortly before being crushed by the ice, October 1915; photograph by Frank Hurley

On 5 December 1914, Shackleton's expedition ship Endurance left South Georgia for the Weddell Sea, on the first stage of the Imperial Trans-Antarctic Expedition. It was making for Vahsel Bay, the southernmost explored point of the Weddell Sea at 77° 49' S, where a shore party was to land and prepare for a transcontinental crossing of Antarctica. Before it could reach its destination the ship was trapped in pack ice, and by 14 February 1915 was held fast, despite prolonged efforts to free her. During the following eight months she drifted northward until, on 27 October, she was crushed by the pack's pressure, finally sinking on 21 November.

As his 27-man crew set up camp on the slowly moving ice, Shackleton's focus shifted to how best to save his party. His first plan was to march across the ice to the nearest land, and try to reach a point that ships were known to visit. The march began, but progress was hampered by the nature of the ice's surface, later described by Shackleton as "soft, much broken up, open leads intersecting the floes at all angles".

After struggling to make headway over several days, the march was abandoned; the party established "Patience Camp" on a flat ice floe, and waited as the drift carried them further north, towards open water. They had managed to salvage three lifeboats, which Shackleton had named after the principal backers of the expedition: Stancomb-Wills, Dudley Docker and James Caird. The party waited until 8 April 1916, when they finally took to the boats as the ice started to break up. Over a perilous period of seven days they sailed and rowed through stormy seas and dangerous loose ice, to reach the temporary haven of Elephant Island on 15 April.

Elephant Island

Shackleton's party arriving at Elephant Island, April 1916, after the loss of Endurance

Elephant Island, on the eastern limits of the South Shetland Islands, was remote from anywhere that the expedition had planned to go, and far beyond normal shipping routes. No relief ship would search for them there, and the likelihood of rescue from any other outside agency was equally negligible. The island was bleak and inhospitable, and its terrain devoid of vegetation, although it had fresh water, and a relative abundance of seals and penguins to provide food and fuel for immediate survival. The rigours of an Antarctic winter were fast approaching; the narrow shingle beach where they were camped was already being swept by almost continuous gales and blizzards, which destroyed one of the tents in their temporary camp, and knocked others flat. The pressures and hardships of the previous months were beginning to tell on the men, many of whom were in a run-down state both mentally and physically.

In these conditions, Shackleton decided to try to reach help, using one of the boats. The nearest port was Stanley in the Falkland Islands, 570 nautical miles (1,100 km; 660 mi) away, but made unreachable by the prevailing westerly winds. A better option was to head for Deception Island, 200 nautical miles (370 km; 230 mi) away at the western end of the South Shetland chain. Although it was uninhabited, Admiralty records indicated that this island held stores for shipwrecked mariners, and was also visited from time to time by whalers. However, reaching it would also involve a journey against the prevailing winds—though in less open seas—with ultimately no certainty when or if rescue would arrive. After discussions with the expedition's second-in-command, Frank Wild, and ship's captain Frank Worsley, Shackleton decided to attempt to reach the whaling stations of South Georgia, to the north-east. This would mean a much longer boat journey, of 700 nautical miles (1,300 km; 810 mi) across the Southern Ocean, in conditions of rapidly approaching winter, but with the help of following winds it appeared feasible. Shackleton thought that "a boat party might make the voyage and be back with relief within a month, provided that the sea was clear of ice, and the boat survive the great seas".

Preparations

General route of the James Caird to Elephant Island and to South Georgia

The South Georgia boat party could expect to meet hurricane-force winds and waves—the notorious Cape Horn Rollers—measuring from trough to crest as much as 18 m (60 ft). Shackleton therefore selected the heaviest and strongest of the three boats, the 22.5-foot (6.9 m) long James Caird. It had been built as a whaleboat in London to Worsley's orders, designed on the "double-ended" principle pioneered by Norwegian shipbuilder Colin Archer. Knowing that a heavily-laden open sea voyage was now unavoidable, Shackleton had already asked the expedition's carpenter, Harry McNish to modify the boats during the weeks the expedition spent at Patience Camp. Using material taken from Endurance's fourth boat, a small motor launch which had been broken up with this purpose in mind before the ship's final loss, McNish had raised the sides of the James Caird and the Dudley Docker by 8–10 inches (20–25 cm). Now in the primitive camp on Elephant Island, McNish was again asked if he could make the James Caird more seaworthy. Using improvised tools and materials, McNish built a makeshift deck of wood and canvas, sealing his work with oil paints, lamp wick, and seal blood. The craft was strengthened by having the mast of the Dudley Docker lashed inside, along the length of her keel. She was then fitted as a ketch, with her own mainmast and a mizzenmast made by cutting down the mainmast from the Stancomb-Wills, rigged to carry lug sails and a jib. The weight of the boat was increased by the addition of approximately 1 long ton (1 tonne) of ballast, to lessen the risk of capsizing in the high seas that Shackleton knew they would encounter.

The boat was loaded with provisions to last six men one month; as Shackleton later wrote, "if we did not make South Georgia in that time we were sure to go under". They took ration packs that had been intended for the transcontinental crossing, biscuits, Bovril, sugar and dried milk. They also took two 18-gallon (68-litre) casks of water (one of which was damaged during the loading and let in sea water), two Primus stoves, paraffin, oil, candles, sleeping bags and odd items of spare clothing.

Shackleton's first choices for the boat's crew were Worsley and Tom Crean, who had apparently "begged to go". Crean was a shipmate from the Discovery Expedition, 1901–04, and had also been with Scott's Terra Nova Expedition in 1910–13, where he had distinguished himself on the fatal polar march. Shackleton was confident that Crean would persevere to the bitter end, and had great faith in Worsley's skills as a navigator, especially his ability to work out positions in difficult circumstances. Worsley later wrote: "We knew it would be the hardest thing we had ever undertaken, for the Antarctic winter had set in, and we were about to cross one of the worst seas in the world".

For the remaining places Shackleton requested volunteers, and of the many who came forward he chose two strong sailors in John Vincent and Timothy McCarthy. He offered the final place to the carpenter, McNish. "He was over fifty years of age", wrote Shackleton of McNish (he was in fact 41), "but he had a good knowledge of sailing boats and was very quick". Vincent and McNish had each proved their worth during the difficult boat journey from the ice to Elephant Island. They were both somewhat awkward characters, and their selection may have reflected Shackleton's wish to keep potential troublemakers under his personal charge rather than leaving them on the island where personal animosities could fester.

Open-boat journey

Elephant Island party waving goodbye to sailors on the James Caird, 24 April 1916

Before leaving, Shackleton instructed Frank Wild that he was to assume full command as soon as the James Caird departed, and that should the journey fail, he was to attempt to take the party to Deception Island the following spring. The James Caird was launched from Elephant Island on 24 April 1916. The wind was a moderate south-westerly, which aided a swift getaway, and the boat was quickly out of sight of the land.

Shackleton ordered Worsley to set a course due north, instead of directly for South Georgia, to get clear of the menacing ice-fields that were beginning to form. By midnight they had left the immediate ice behind, but the sea swell was rising. At dawn the next day, they were 45 nautical miles (83 km; 52 mi) from Elephant Island, sailing in heavy seas and force 9 winds. Shackleton established an on-board routine: two three-man watches, with one man at the helm, another at the sails, and the third on bailing duty. The off-watch trio rested in the tiny covered space in the bows. The difficulties of exchanging places as each watch ended would, Shackleton wrote, "have had its humorous side if it had not involved us in so many aches and pains". Their clothing, designed for Antarctic sledging rather than open-boat sailing, was far from waterproof; repeated contact with the icy seawater left their skins painfully raw.

Success depended on Worsley's navigation, based on sightings attempted during the very brief appearances of the sun, as the boat pitched and rolled. The first observation was made after two days, and showed them to be 128 nautical miles (237 km; 147 mi) north of Elephant Island. The course was now changed to head directly for South Georgia. They were clear of the dangers of floating ice but had reached the dangerous seas of the Drake Passage, where giant waves sweep round the globe, unimpeded by any land. The movement of the ship made preparing hot food on the Primus nearly impossible, but Crean, who acted as cook, somehow kept the men fed.

The next observation, on 29 April, showed that they had travelled 238 nautical miles (441 km; 274 mi). Thereafter, navigation became, in Worsley's words, "a merry jest of guesswork", as they encountered the worst of the weather. The James Caird was taking on water in heavy seas and in danger of sinking, kept afloat by continuous bailing. The temperature fell sharply, and a new danger presented itself in the accumulations of frozen spray, which threatened to capsize the boat. In turns, they had to crawl out on to the pitching deck with an axe and chip away the ice from deck and rigging. For 48 hours they were stopped, held by a sea anchor, until the wind dropped sufficiently for them to raise sail and proceed. Despite their travails, Worsley's third observation, on 4 May, put them only 250 nautical miles (460 km; 290 mi) from South Georgia.

On 5 May the worst of the weather returned, and brought them close to disaster in the largest seas so far. Shackleton later wrote: "We felt our boat lifted and flung forward like a cork in breaking surf". The crew bailed frantically to keep afloat. Nevertheless, they were still moving towards their goal, and a dead reckoning calculation by Worsley on the next day, 6 May, suggested that they were now 115 nautical miles (213 km; 132 mi) from the western point of South Georgia. The strains of the past two weeks were by now taking their toll on the men. Shackleton observed that Vincent had collapsed and ceased to be an active member of the crew, McCarthy was "weak, but happy", McNish was weakening but still showing "grit and spirit".

Depiction of the James Caird nearing South Georgia (from Shackleton's expedition account, South)

On 7 May Worsley advised Shackleton that he could not be sure of their position within ten miles. To avoid the possibility of being swept past the island by the fierce south-westerly winds, Shackleton ordered a slight change of course so that the James Caird would reach land on the uninhabited south-west coast. They would then try to work the boat round to the whaling stations on the northern side of the island. "Things were bad for us in those days", wrote Shackleton. "The bright moments were those when we each received our one mug of hot milk during the long, bitter watches of the night". Late on the same day floating seaweed was spotted, and the next morning there were birds, including cormorants which were known never to venture far from land. Shortly after noon on 8 May came the first sighting of South Georgia.

A depiction of the James Caird landing at South Georgia at the end of its voyage on 10 May 1916

As they approached the high cliffs of the coastline, heavy seas made immediate landing impossible. For more than 24 hours they were forced to stand clear, as the wind shifted to the north-west and quickly developed into "one of the worst hurricanes any of us had ever experienced". For much of this time they were in danger of being driven on to the rocky South Georgia shore, or of being wrecked on the equally menacing Annenkov Island, five miles from the coast. On 10 May, when the storm had eased slightly, Shackleton was concerned that the weaker members of his crew would not last another day, and decided that whatever the hazard they must attempt a landing. They headed for Cave Cove near the entrance to King Haakon Bay, and finally, after several attempts, made their landing there. Shackleton was later to describe the boat journey as "one of supreme strife"; historian Caroline Alexander comments: "They could hardly have known—or cared—that in the carefully weighted judgement of authorities yet to come, the voyage of the James Caird would be ranked as one of the greatest boat journeys ever accomplished".

South Georgia

South Georgia. King Haakon Bay, where the James Caird landed, is the large indentation at the western (upper) end of the southerly side.

As the party recuperated, Shackleton realised that the boat was not capable of making a further voyage to reach the whaling stations, and that Vincent and McNish were unfit to travel further. He decided to move the boat to a safer location within King Haakon Bay, from which point he, Worsley and Crean would cross the island on foot, aiming for the station at Stromness.

On 15 May the James Caird made a run of about 6 nautical miles (11 km; 6.9 mi) to a shingle beach near the head of the bay. Here the boat was beached and up-turned to provide a shelter. The location was christened "Peggotty Camp" (after Peggotty's boat-home in Charles Dickens's David Copperfield). Early on 18 May Shackleton, Worsley and Crean began what would be the first confirmed land crossing of the South Georgia interior. Since they had no map, they had to improvise a route across mountain ranges and glaciers. They travelled continuously for 36 hours, before reaching Stromness. Shackleton's men were, in Worsley's words, "a terrible trio of scarecrows", dark with exposure, wind, frostbite and accumulated blubber soot. Later that evening, 19 May, a motor-vessel (the Norwegian whale catcher Samson) was despatched to King Haakon Bay to pick up McCarthy, McNish and Vincent, and the James Caird. Worsley wrote that the Norwegian seamen at Stromness all "claimed the honour of helping to haul her up to the wharf", a gesture which he found "quite affecting".

The advent of the southern winter and adverse ice conditions meant that it was more than three months before Shackleton was able to achieve the relief of the men at Elephant Island. His first attempt was with the British ship Southern Sky. Then the government of Uruguay loaned him a ship. While searching on the Falkland Islands he found the ship Emma for his third attempt, but the ship's engine blew. Then, finally, with the aid of the steam-tug Yelcho commanded by Luis Pardo, the entire party was brought to safety, reaching Punta Arenas in Chile on 3 September 1916.

Aftermath

The James Caird, preserved at Dulwich College in south London

The James Caird was returned to England in 1919. In 1921, Shackleton went back to Antarctica, leading the Shackleton–Rowett Expedition. On 5 January 1922, he died suddenly of a heart attack, while the expedition's ship Quest was moored at South Georgia.

Later that year John Quiller Rowett, who had financed this last expedition and was a former school friend of Shackleton's from Dulwich College, South London, decided to present the James Caird to the college. It remained there until 1967, although its display building was severely damaged by bombs in 1944.

In 1967, thanks to a pupil at Dulwich College, Howard Hope, who was dismayed at the state of the boat, it was given to the care of the National Maritime Museum, and underwent restoration. It was then displayed by the museum until 1985, when it was returned to Dulwich College and placed in a new location in the North Cloister, on a bed of stones gathered from South Georgia and Aberystwyth. This site has become the James Caird's permanent home, although the boat is sometimes lent to major exhibitions and has taken part in the London Boat Show and in events at Greenwich, Portsmouth, and Falmouth. It has travelled overseas to be exhibited in Washington, D.C., New York, Sydney, Australia, Wellington (Te Papa) New Zealand and Bonn, Germany.

The James Caird Society was established in 1994, to "preserve the memory, honor the remarkable feats of discovery in the Antarctic, and commend the outstanding qualities of leadership associated with the name of Sir Ernest Shackleton".

In 2000, German polar explorer Arved Fuchs built a detailed copy of Shackleton's boat—named James Caird II—for his replication of the voyage of Shackleton and his crew from Elephant Island to South Georgia. The James Caird II was among the first exhibitions when the International Maritime Museum in Hamburg was opened. A further replica, James Caird III, was built and purchased by the South Georgia Heritage Trust, and since 2008 has been on display at the South Georgia Museum at Grytviken.

Endurance (1912 ship)

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Endurance_(1912_ship) 

 

Endurance trapped in pack ice (Hurley, 1915) during the Imperial Trans-Antarctic Expedition
History
Norway
Name:	Endurance
Builder:	Framnæs shipyards, Sandefjord, Norway
Launched:	1912
Out of service:	1915
Fate:	Sank in the Weddell Sea, November 1915
General characteristics
Type:	Barquentine
Tonnage:	348 GRT
Length:	144 ft (44 m)
Beam:	25 ft (7.6 m)
Propulsion:	350 hp (260 kW) Coal-fired steam and sail
Speed:	10.2 knots (18.9 km/h; 11.7 mph)
Complement:	28

Endurance was the three-masted barquentine in which Sir Ernest Shackleton and a crew of 27 men and one cat sailed for the Antarctic on the 1914–1917 Imperial Trans-Antarctic Expedition. She was launched in 1912 from Sandefjord in Norway; three years later, she was crushed by pack ice and sank in the Weddell Sea off Antarctica. All of her crew survived.

Design and construction

Designed by Ole Aanderud Larsen, Endurance was built at the Framnæs shipyard in Sandefjord, Norway, and fully completed on 17 December 1912. She was built under the supervision of master wood shipbuilder Christian Jacobsen, who was renowned for insisting that all men in his employment were not just skilled shipwrights but also be experienced in seafaring aboard whaling or sealing ships. Every detail of her construction had been scrupulously planned to ensure maximum durability: for example, every joint and fitting was cross-braced for maximum strength.

The ship was launched on 17 December 1912 and was initially christened Polaris (eponymous with Polaris, the North Star). She was 144 feet (44 m) long, with a 25 feet (7.6 m) beam, and measured 348 tons gross. Her original purpose to provide luxurious accommodation for small tourist and hunting parties in the Arctic as an ice-capable steam yacht. As launched she had 10 passenger cabins, a spacious dining saloon and galley (with accommodation for two cooks), a smoking room, a darkroom to allow passengers to develop photographs, electric lighting and even a small bathroom.

Though her hull looked from the outside like that of any other vessel of a comparable size, it was not. She was designed for polar conditions with a very sturdy construction. Her keel members were four pieces of solid oak, one above the other, adding up to a thickness of 85 inches (2,200 mm), while its sides were between 30 inches (760 mm) and 18 inches (460 mm) thick, with twice as many frames as normal and the frames being of double thickness. She was built of planks of oak and Norwegian fir up to 30 inches (760 mm) thick, sheathed in greenheart, an exceptionally strong and heavy wood. The bow, which would meet the ice head-on, had been given special attention. Each timber had been made from a single oak tree chosen for its shape so that its natural shape followed the curve of the ship's design. When put together, these pieces had a thickness of 52 inches (1,300 mm).

Shackleton looking overboard at Endurance being crushed by the ice

 

Endurance's final sinking, November 1915

Of her three masts, the forward one was square-rigged, while the after two carried fore and aft sails, like a schooner. As well as sails, Endurance had a 350 horsepower (260 kW) coal-fired steam engine capable of speeds up to 10.2 knots (18.9 km/h; 11.7 mph).

By the time of her launch in 1912, Endurance was perhaps the strongest wooden ship ever built, with the possible exception of Fram, the vessel used by Fridtjof Nansen and later by Roald Amundsen. There was one major difference between the ships. Fram was bowl-bottomed, which meant that if the ice closed in against her, the ship would be squeezed up and out and not be subject to the pressure of the ice compressing around her. Endurance, on the other hand, was designed with great inherent strength in her hull in order to resist collision with ice floes and to break through pack ice by ramming and crushing; she was therefore not intended to be frozen into heavy pack ice, and so was not designed to rise out of a crush. In such a situation she was dependent on the ultimate strength of her hull alone.

Ownership

Endurance was originally built for Adrien de Gerlache and Lars Christensen, who intended to use her for polar cruises for tourists to hunt polar bears. Financial problems led to Gerlache pulling out of their partnership, leaving Christensen unable to pay the Framnæs yard the final amounts to hand over and outfit the ship. For over a year Christensen attempted unsuccessfully to sell the ship, since her unique design as an ice-capable passenger-carrying ship, with relatively little space for stores and no cargo hold, made her useless to the whaling industry. Meanwhile, she was too big, slow and uncomfortable to be a private steam yacht. In the event, Christensen was happy to sell the ship to Ernest Shackleton for GB£11,600, which represented a significant loss to Christensen as it barely covered the outstanding payments to Framnæs, let alone the ship's total build costs. He is reported to have said he was happy to take the loss in order to further the plans of an explorer of Shackleton's stature. After Shackleton purchased the ship, she was rechristened Endurance after the Shackleton family motto, Fortitudine vincimus ("By endurance we conquer").

Shackleton had the ship relocated from Norway to London. She arrived at the Millwall Dock in the spring of 1914, where she was refitted and modified for expedition purposes. She was stripped of most of her luxurious accommodation and fittings. This included removing many of the passenger cabins to make room for space for stores and equipment, while the crew cabins on the lower deck were removed and converted into a cargo hold – the reduced crew of sailors that Shackleton would take on the expedition would make their quarters in the cramped forecastle. The darkroom remained in its original location ahead of the boiler. The refit also saw the ship repainted from her original white color to a more austere black, which was more visible amongst the ice, and features such as gilt scrollwork on the bow and stern were painted over. Despite her change of name, she retained a large badge in the shape of a five-pointed star on her stern, which originally symbolized her name after the pole star.

Her new equipment included four ship's boats. Two were 21-foot (6.4 m) transom-built rowing cutters purchased secondhand from the whaling industry. The third was a larger 22.5-foot (6.9 m) double-ended rowing whaleboat built for the expedition to specifications drawn up by Frank Worsley, Endurance's new captain. The fourth was a smaller motorboat. After her refit, Endurance made the short coastal journey to Plymouth.

In the previous 16 years, nearly two dozen wooden vessels had sailed to the icy seas of the far south. All had returned home but Aurora. Lloyd's of London and the Indemnity Marine Assurance Company had underwritten her hull, machinery and equipment for £15,000. Just before she sailed, The Times had reported that "Hitherto the insurance of vessels taking part in Antarctic exploration has ceased at the last port touched, and Endurance will be the first vessel to be insured in the ice zone." The Times praised Endurance as "built specially for work in Polar seas", adding that "in an ice-coated sea there can be no turbulent waves which are the causes of so many disasters in warmer zones."

Final voyage

Endurance sailed from Plymouth on 6 August 1914 and set course for Buenos Aires, Argentina, under Worsley's command. Shackleton remained in Britain, finalising the expedition's organization and attending to some last-minute fundraising. This was Endurance's first major voyage following its completion and amounted to a shakedown voyage. The trip across the Atlantic took more than two months. Built for the ice, her hull was considered by many of her crew too rounded for the open ocean. Shackleton took a steamer to Buenos Aires and caught up with his expedition a few days after Endurance's arrival.

On 26 October 1914, Endurance sailed from Buenos Aires to what would be her last port of call, the whaling station at Grytviken on the island of South Georgia, where she arrived on 5 November. She left Grytviken on 5 December 1914, heading for the southern regions of the Weddell Sea.

Two days after leaving South Georgia, Endurance encountered polar pack ice and progress slowed to a crawl. For weeks Endurance worked its way through the pack, averaging less than 30 miles (48 km) per day. By 15 January 1915, Endurance was within 200 miles (320 km) of her destination, Vahsel Bay. By the following morning, heavy pack ice was sighted and in the afternoon a gale developed. Under these conditions it was soon evident progress could not be made, and Endurance took shelter under the lee of a large grounded iceberg. During the next two days, Endurance moved back and forth under the sheltering protection of the berg.

On 18 January, the gale began to moderate and Endurance set the topsail with the engine at slow. The pack had blown away. Progress was made slowly until hours later Endurance encountered the pack once more. It was decided to move forward and work through the pack, and at 5:00 PM Endurance entered it. This ice was different from what had been encountered before, and the ship was soon amongst thick but soft brash ice, and became beset. The gale increased in intensity and kept blowing for another six days from a northerly direction towards land. By 24 January, the wind had completely compressed the ice in the Weddell Sea against the land, leaving Endurance icebound as far as the eye could see in every direction. All that could be done was to wait for a southerly gale to start pushing in the other direction, which would decompress and open the ice.

In the early morning of 24 January, a wide crack appeared in the ice 50 yards (46 m) ahead of the ship. Initially 15 feet (4.6 m) across, by mid-morning the break was over a quarter of a mile (0.4 km) wide, giving the men on the Endurance hope that the ice was breaking up. But the break never reached the ship itself, and despite three hours under full sail and full speed on the engine, the ship did not budge. Over the next days, the crew waited for the southerly gale to release the pressure on the ice, but while the wind backed to the hoped-for south/southwest direction, it remained light and erratic. Occasional breaks in the ice were spotted, but none reached the ship and all closed up within a few hours. Trials were made on January 27 with cutting and breaking the ice around the ship by manual labour but this proved futile.

On 14 February, an open channel of water opened up a quarter of a mile (0.4 km) ahead of the ship and dawn showed the Endurance was afloat in a pool of soft, young ice no more than 2 feet (0.61 m) thick, but the pool was surrounded by solid pack ice of 12–18 feet (3.7–5.5 m) in thickness, blocking the path to the open lead. A day's continual work by the crew saw them hack a clear channel 150 yards (140 m) long. This work continued through the following day (15 February) and, with steam raised, the Endurance was backed up within her pool as far as possible to allow the ship to ram her way through the channel. As the ship went astern for successive attempts, lines were attached from the bow to loosened blocks of ice, estimated to weigh 20 tons (18 tonnes), in order to clear the path. The pool proved too small for the ship to gain enough momentum to successfully ram her way clear and by the end of the day the ice began to freeze up again. By 3:00 PM, the Endurance had made 200 yards (180 m) of distance through the ice, with 400 yards (370 m) still to go to clear water. Shackleton decided that the consumption of coal and manpower, and the risk of damage to the ship, was too great and called a halt.

Drift

After this frustration, Endurance's boilers were extinguished, committing the ship to drift with the ice until released naturally. On 17 February, the sun dipped below the horizon at midnight, showing the end of the Antarctic summer. On 24 February, regular watches on the ship were cancelled, with the Endurance now functioning as a shore station. The ship had slowly drifted south and at this point was within 60 miles (97 km) of the intended landing point at Vahsel Bay. But the icy terrain between the ship and the shore was too arduous to travel while carrying the materials and supplies needed for the overland expedition.

By March, navigational observation showed that the ship (and the mass of pack ice that contained it) was still moving, but now swinging towards the west-northwest and increasing in the speed of its drift, moving 130 miles (210 km) between the start of March and May 2, when the sun disappeared below the horizon and the dark Antarctic winter began. Still, the men on the ship hoped for either a change in the weather which would break up the pack or that, by the spring, the warmer weather and the ship's northward drift would mean it was released.

On 14 July 1915, Endurance was swept by a southwest gale, with wind speeds of 112 km/h (31 m/s; 70 mph), a barometer reading of 28.88 inches of mercury (978 hPa) and temperatures falling to −33 °F (−36 °C). The blizzard continued until 16 July. This broke up the pack ice into smaller, individual floes, each of which began to move semi-independently under the force of the weather, while also clearing water in the north of the Weddell Sea. This provided a long fetch for the south-setting wind to blow over and then for the broken ice to pile up against itself while individual parts moved in different directions. This caused regions of intense localised pressure in the ice field. The ice began "working", with sounds of breaking and colliding ice audible to those on the ship through the next day. Breaks in the ice were spotted but none approached the ice holding the Endurance.

During July the ship drifted a further 160 miles (260 km) to the north. On the morning of 1 August, a pressure wave passed through the floe holding the ship, lifting the 400-ton Endurance bodily upwards and heeling the ship sharply to its port side before it dropped into a pool of water, afloat again for the first time in nearly six months. The broken sections of floe closed in around the ship on all sides, jarring the Endurance forward, backwards and sideways in violent fashion against the other slabs of ice. After over a quarter of an hour, a force from astern pushed the ship's bow up onto the floe, lifting the hull out of the pressure and with a list of five degrees to her port side. A gale overnight further disturbed the floe, driving it against the starboard side of the hull and forcing a sheet of ice upwards at a 45-degree angle until it reached the level of the scuppers. Despite the ordeal of the past few days, the ship remained undamaged.

Two pressure waves struck the ship on 29 August without incident. On the evening of 31 August, a slow-building pressure gripped the Endurance, causing her hull and timbers to creak and shudder continuously. The ice around the ship moved and broke throughout the night, battering the port side of the hull. All was quiet again until the afternoon of 30 September, by which time there were signs of spring with ten hours of sunlight per day and occasional temperature readings above freezing. A large floe was swept against the Endurance's port bow and then gripped that side of the ship against the built-up ice and snow on her starboard beam. The ship's structure groaned and wracked under the strain. Carpenter Harry McNish noted that the solid oak beams supporting the upper deck were being visibly bent "like a piece of cane". On deck the ship's masts were whipping back and forth as their stepping points on the keel were distorted. Despite these disconcerting signs, Captain Frank Worsley noted that the strength of the ship's structure was causing the ice itself to break up as it piled against the hull – "...just as it appears she can stand no more, the huge floe weighing possibly a million tons or more yields to our little ship by cracking across...and so relieves the pressure. The behaviour of our ship in the ice has been magnificent. Undoubtedly she is the finest little wooden vessel ever built...." Despite this, the ship's decks were permanently buckled following this ordeal.

Final destruction

By October, temperatures of nearly 42 °F (6 °C) were recorded and the ice showed further signs of opening up. The floe which had been jammed against the ship's starboard side since July broke up on 14 October, casting the Endurance afloat in a pool of open water for the first time in nine months.

On 16 October, Shackleton ordered steam to be raised so the ship could take advantage of any openings in the ice. It took nearly four hours for the boilers to be filled with freshwater melted from ice, and then a leak was discovered in one of the fittings and they had to be pumped out, repaired and then refilled. The following day a lead of open water was seen ahead of the ship. Only one boiler had been lit and there was insufficient steam to use the engine, so all the sails were set to try to force the ship into the loosening pack ice but without success.

In the late afternoon of 18 October, the ice closed in around the Endurance once again. In just five seconds the ship was canted over to port by 20 degrees, and the list continued until she rested at 30 degrees, with the port bulwark resting on the pack and the boats on that side nearly touching the ice as they hung in their davits. This put the ship in a seemingly safe position – instead of being pinched between two opposing masses of ice the Endurance had been pushed from starboard to port and further pressure from starboard would push her bodily upwards over the top of the port-side floe, which had actually collided with its counterpart under the ship's bilge. In any case, after four hours in this position, the ice drew apart and the ship returned to a level keel.

The ice was relatively still for the rest of the month. On 20 October, steam was raised again and the engines tested. On 22 October, the temperature dropped sharply from 42 °F (6 °C) to −14 °F (−26 °C) and the wind veered from southwest to northeast. This caused the loosening pack to compress against the Antarctic coast once again. On 23 October, pressure ridges could be seen forming in the ice and moving near the ship. The next day a series of pressure waves struck the Endurance, causing the ice around the ship to fracture into separate large pieces which were then tumbled and turned in all directions. The ship was shunted back and forth before being pinched against two floes on her starboard side, one at her bow and one at her stern, while on the port side a floe impacted amidships, setting up a huge bending force on the hull. Parts of the rigging were snapped under the strain.

A large mass of ice slammed into the stern, tearing the sternpost away from the hull planking. Around the same time, the bow planking was stove in, causing simultaneous flooding in the engine room and the forward hold. Despite using both the portable manual pumps and getting up steam to drive the main bilge pumps, the water level continued to rise. The main man-powered deck pumps did not work as their intakes had frozen and could only be restored by pouring buckets of boiling water onto the pump pipes from inside the coal bunkers and then playing a blowtorch over the intake valve. McNish constructed a cofferdam in the shaft tunnel to seal off the damaged stern area while the crew were arranged in spells of 15 minutes on, 15 minutes off on the main pump. After 28 hours of continuous work, the inflow of water had only been arrested – the ship was still badly flooded.

On 24 October, the damaged ship was wracked by further pressure waves. The port-side floe was pressed more heavily against the side, warping the keel along its length and causing near-continual creaks, groans, cracks and "screams" from the ship's timbers. The footplates in the engine room were pushed up and would no longer sit in place as the compartment was compressed. The planking of the ship's port side was bowing inwards by up to 6 inches (15 cm). At 10 PM, Shackleton ordered the ship's boats, stores and essential equipment to be moved onto the surrounding ice.

In the afternoon of 25 October, the pressure of the ice increased further. The main deck of the Endurance buckled upwards amidships and the beams sheared. As the ice moved against her stern, the aft part of the ship was lifted up and the damaged sternpost and the rudder were torn away. This angle caused all the water in the ship to run forward, collecting in the bow where it then began to freeze. The action of the ice in the stern and the excessive weight in the bow caused the ship to sink into the ice bow-first. Under its own pressure, the ice then broke over the forecastle and piled up onto the deck in the forward part of the ship, further weighing this end of the ship down. Through all of this, the pumping operations had continued, but by the end of the day Shackleton ordered this to stop and for the men to take to the ice.

During the course of the next day, parties were sent back to the ship to recover more supplies and stores. They found that the entire port side of the Endurance had been driven inwards and compressed, and the ice had entirely filled the bow and stern sections. The ship's Blue Ensign was hoisted up her mizzen mast so that she would, in Shackleton's word's, "go down with colours flying."

After a failed attempt to man-haul the boats and stores overland on sledges, Shackleton realised the effort was much too intense and that the party would have to camp on the ice until it carried them to the north and broke up. More parties were sent back to the Endurance, still with her masts and rigging intact and all but her bow above the ice, to salvage any remaining items. A large portion of provisions had been left on the submerged lower deck. The only way to retrieve them was to cut through the main deck, which was more than a foot thick in places and itself under three feet of water. Some crates and boxes floated up once a hole had been cut, while others were retrieved with a grapple. In total, nearly 3.5 tons of stores were recovered from the wrecked ship.

The party was still camped under 2 miles (3.2 km) from the remains of the Endurance on 8 November when Shackleton returned to the ship to consider further salvage. By now the ship had sunk a further 18 inches (46 cm) into the ice and the upper deck was now almost level with the ice. The interior of the ship was almost full of compacted ice and snow, making further work impossible. The damage to the bow and stern, and the force of the ice against the port side, had caused a large portion of the hull on that side of the ship to break free of the rest of the ship and, under the force of the ice, be moved bodily inwards in a telescoping effect. In some places, the outer hull planks were now in line with the keel. A stash of empty fuel oil cans placed against the port side wall of the deckhouse had been pushed through the wall and then the cans and the wall had come to rest against its counterpart on the starboard side of the deckhouse. The row of five cabins that had been on the port side of the main deck above the engine room and their contents had been compressed into the space of a single cabin.

On 13 November, a new pressure wave swept through the pack ice. The forward topgallant mast and topmasts collapsed as the bow was finally crushed. These moments were recorded on film by expedition photographer Frank Hurley. The mainmast was split near its base and shortly afterwards the mainmast and the mizzen mast broke and collapsed together, with this also filmed by Hurley. The ensign was re-rigged on the tip of one of the foremast yardarms which, constrained by the rigging, was now hanging vertically from the remains of the foremast and was the highest point of the wreck.

In the late afternoon of 21 November, movement of the remaining wreckage was noticed as another pressure wave hit. Within the space of a minute, the stern of the Endurance was lifted clear of the ice as the floes moved together and then, as the pressure passed and they moved apart, the entire wreck fell into the ocean. By daylight the following day, the ice surrounding the spot where the Endurance had sunk had moved together again, obliterating any trace of the wreck. Worsley fixed the position as 68° 38.5'S 52° 58'W.

Crew

The crew of Endurance on her final voyage was made up of the 28 men listed below:

• Sir Ernest Shackleton, Expedition Leader
• Frank Wild, Second-in-Command
• Frank Worsley, Captain and Navigator
• Lionel Greenstreet, First Officer
• Tom Crean, Second Officer
• Alfred Cheetham, Third Officer
• Hubert Hudson, Navigator
• Lewis Rickinson, Engineer
• Alexander Kerr, Engineer
• Alexander Macklin, Surgeon
• James McIlroy, Surgeon
• Sir James Wordie, Geologist
• Leonard Hussey, Meteorologist
• Reginald James, Physicist
• Robert Clark, Biologist
• Frank Hurley, Photographer
• George Marston, Artist
• Thomas Orde-Lees, Motor Expert and Storekeeper
• Harry "Chippy" McNish, Carpenter
• Charles Green, Cook
• Walter How, Able Seaman
• William Bakewell, Able Seaman
• Timothy McCarthy, Able Seaman
• Thomas McLeod, Able Seaman
• John Vincent, Boatswain
• Ernest Holness, Stoker
• William Stephenson, Stoker
• Perce Blackborow, Steward
• Mrs Chippy, Ship's Cat

Supposed advertisement

To find crew for the Endurance, Shackleton reportedly placed an advertisement in the London Times, reading:

Men wanted for hazardous journey. Small wages, bitter cold, long months of complete darkness, constant danger, safe return doubtful. Honour and recognition in case of success.

When discussing the advertisement in the 1944 book Quit You like Men, Carl Hopkins Elmore quoted Shackleton as saying that "so overwhelming was the response to his appeal that it seemed as though all the men of Great Britain were determined to accompany him." Although the advertisement was listed in Julian Watkins' The 100 Greatest Advertisements: 1852-1958, no trace has been found to date. Many sources have concluded that the story of Shackleton's advertisement is likely apocryphal. The crew did receive the recognition the advertisement promised; Time Magazine has deemed their voyage "the most storied epic of survival".

Legacy

American journalist Alfred Lansing's 1959 book Endurance: Shackleton's Incredible Voyage described the ordeal that Shackleton and his men endured aboard the ship, and quickly became a bestseller.

Two Antarctic patrol ships of the British Royal Navy have been named Endurance in honour of Shackleton's ship. The first HMS Endurance, launched in May 1956 and awarded pennant number A171 sometime later, acted as an ice patrol and hydrographic survey ship until 1986. The second HMS Endurance was bought from Norway in 1992 where she was named MV Polar Circle. She suffered severe flooding in 2008 due to procedural errors during maintenance and, despite being returned to the UK, was not repaired prior to being scrapped in 2016.

Wreck of the Endurance

In 1998, wreckage found at Stinker Point on the southwestern side of Elephant Island was incorrectly identified as flotsam from the ship. It instead was from the 1877 wreck of the Connecticut sealing ship Charles Shearer. In 2001, wreck hunter David Mearns unsuccessfully planned an expedition to find the wreck of Endurance. By 2003, two rival groups were making plans for an expedition to find the wreck, but no expedition was actually mounted.

In 2010, Mearns announced a new plan to search for the wreck. The plan is sponsored by the National Geographic Society but is subject to finding sponsorship for the balance of the US$10 million estimated cost. A 2013 study by Dr. Adrian Glover of the Natural History Museum, London suggests the Antarctic Circumpolar Current could preserve the wreck on the seabed by keeping wood-boring "ship worms" away. A Weddell Sea Expedition to locate and possibly photograph the wreck using long-range Autonomous Underwater Vehicles (AUV) was underway in the Antarctic summer of 2018–2019. This expedition failed when the researchers' AUV was lost to the ice as well. The wreck itself is speculated to rest on flat terrain at around 3,000 metres, undisturbed by massive sediment disposition and little to no erosion. According to Professor Julian Dowdeswell of the Scott Polar Research Institute, that due to the aforementioned conditions on the sea bed, there is speculation that the Endurance shouldn't be harmed and that it would be in the same state as it was when it sank in the pack ice in 1915. He also noted that any future attempts at finding the Endurance would be "add-ons" to other main scientific expeditions to the area such as the one in 2019, which was launched with the intention to study the melting and retreat of the Larsen ice shelves.