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Saturday, December 28, 2013

Wht Do We Need the SPACE Launch System?

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Why is NASA using its precious, and shrinking, funding to construct a massive, Saturn V (which took Apollo astronauts to the moon) type rocket, the Space Launch System (SLS), when private companies, such as SpaceX and Orbital Sciences Corporation already or soon will have rockets that will accomplish all the functions sooner and cheaper?
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
SpaceX's Falcon 9 rocket is already delivering cargo regularly to the ISS (International Space System) and even to Geosynchronous orbit (22,000 miles high).  It is easily already man-rated in terms of safety, and will be carrying astronauts into orbit within a couple of years.  A more powerful version of the Falcon, the Falcon Heavy, is due for testing in 2014 and will also be ready for missions within the same time span.  While not as powerful as the SLS, the combination of a Falcon Heavy (to carry the needed equipment) and Falcon 9 (to carry a crew) will already have the capacity to send men to the moon or beyond -- even to Mars perhaps -- before the end of this decade, ahead of SLS' schedule.  SpaceX is also working on recoverable rocket stages and other advanced technologies.
 
 
Antares, known during early development as Taurus II, is an expendable launch system developed by Orbital Sciences Corporation. Designed to launch payloads of mass up to 5,000 kg (11,000 lb) into low-Earth orbit, it made its maiden flight on April 21, 2013. Designed to launch the Cygnus spacecraft to the International Space Station as part of NASA's COTS and CRS programs, Antares is the largest rocket operated by Orbital Sciences, and is scheduled to start supplying the ISS early 2014.

NASA awarded to Orbital a Commercial Orbital Transportation Services (COTS) Space Act Agreement (SAA) in 2008 to demonstrate delivery of cargo to the International Space Station. For these COTS missions Orbital intends to use Antares to launch its Cygnus spacecraft. In addition, Antares will compete for small-to-medium missions. On December 12, 2011 Orbital Sciences renamed the launch vehicle "Antares" from the previous designation of Taurus II, after the star of the same name.
 
I cannot see how, between SpaceX and COTS, the two companies and their rockets alone don't invalidate the need for the SLS.  If it were scrubbed (it is an Obama Administration project), large amounts of money could be freed up for more unmanned planetary missions, such as to Europa, Uranus, and Neptune, and to asteroids for mining possibilities.
 
 
Linus Torvalds

Linus Torvalds

On this date in 1969, Linus Torvalds was born in Helsinki, Finland. He started using computers when he was about 10 year old, and soon began designing simple computer programs. Torvalds earned his M.S. in computer science from the University of Helsinki in 1996, where he was introduced to the Unix operating system. In 1991, Torvalds began creating the innovative Linux, an operating system similar to Unix. Later in the year, he released Linux for free as an open source operating system, allowing anyone to edit its source code with Torvalds’ permission. Linux’s open source nature has contributed to its popularity and reliability, since it is regularly updated and improved by dedicated users. For his work with Linux, Torvalds received the 2008 Computer History Fellow Award and the 2005 Vollum Award for Distinguished Accomplishment in Science and Technology. The asteroid 9793 Torvalds was named after him.

After developing Linux, Torvalds worked for Transmeta Corporation from 1997 to 2003. He appeared in the 2001 documentary “Revolution OS,” and authored an autobiography titled Just for Fun: The Story of an Accidental Revolutionary (2001). He is married to Tove Torvalds, who also attended the University of Helsinki for Computer Science. They live in the U.S. and have three daughters, Patricia, born in 1996, Daniela, born in 1998, and Celeste, born in 2000.

In a Nov. 1, 1999 interview with Linux Journal, Torvalds described himself as “completely a-religious” and “atheist.” He explained his reasons for being an atheist: “I find it kind of distasteful having religions that tell you what you can do and what you can’t do.” He also believes in the separation of church and state, telling Linux Journal, “In practice, religion has absolutely nothing to do with everyday life.”
“I find that people seem to think religion brings morals and appreciation of nature. I actually think it detracts from both . . . I think we can have morals without getting religion into it, and a lot of bad things have come from organized religion in particular. I actually fear organized religion because it usually leads to misuses of power.”
—Linus Torvalds, Linux Journal, Nov. 1, 1999.
Compiled by Sabrina Gaylor
© Freedom From Religion Foundation. All rights reserved.

Why Consciousness Can't Keep Up with Fear

by Joseph LeDoux      
December 27, 2013, 6:00 AM
Brain_fear
 
Whenever you encounter some sudden danger out there in the world - let’s say it’s a snake on a path - the information from that stimulus goes into your brain through your visual system. It will then rise through the visual system through the standard pathways.  So every sensory system has this very well organized set of circuits that ultimately leads to a stop in the part of the brain called the thalamus on route to reaching the sensory cortex.  So each sensory system has an area in the cortex.  The cortex is that wrinkled part of the brain that you see whenever you see a picture of the brain.  And that’s where we have our perceptions and thoughts and all of that.  
 
In order to have a visual perception, information has to be transmitted from the eye, from the retina, through the optic nerve, into the visual thalamus, and from the visual thalamus to the visual cortex where the processing continues and you can ultimately have the perception.  So, the visual cortex connects directly with the amygdala, and so thats one route by which the information can get in: retina, thalamus, cortex, amygdala.  But one of the first things that I discovered when I started studying fear was that that pathway, the usual pathway that we think about for sensory processing was not the way that fear was elicited, or not the only way.  
 
What we found was that if the cortical pathway was blocked completely, rats could still form a memory about a sound.  We were studying sounds and shocks.  But we’ve also done it with a visual stimulus.  So, what we found was the sound had to go up to the level of the thalamus, but then it didn’t need to go to the auditory cortex or the visual cortex as if it happened to be a visual stimulus. 
Instead, it made an exit from the sensory system and went directly into the amygdala, below the level of the cortex.  That was really important because we generally think that the cortex is required for any kind of conscious experience.  So, this is a way that information was being sent through the brain and triggering emotions unconsciously.  So, the psychoanalysts love this because it vindicated the idea that you could have this unconscious fear that the cortex has no understanding of.  
 
This is important because a lot of people have fears and phobias and anxieties about things they don’t understand.  They don’t know why they’re afraid or anxious in a particular moment.  It may be through various kinds of experiences, the low road gets potentiated in a way that it’s activating fears and phobias outside of conscious awareness and that doesn’t make sense in terms of what the conscious brain is looking at in the world, or hearing in the world because they’ve been separately parsed out.  
 
So, the subcortical pathway, we’ve been able to time all of this very precisely in the rat brain and it takes, in order for a sound to get to the amygdala from the sub cortical pathway takes about 10 or 12 milliseconds.  So, take a second and divide that into 1,000 parts, and after 12 of those little parts, the amygdala was already getting the sound.  For you to be consciously aware of the stimulus, it takes 250-300 milliseconds.  So, the amygdala is being triggered much, much faster than consciousness is processing.  
 
So, the brain ticks in milliseconds, the neurons process information on the level of milliseconds, but the mind is processing things on the order of seconds and half seconds here.  So, if you have a fear response that is being triggered very rapidly like that, consciously you’re going to be interpreting what’s going on, but it’s not going to necessarily match what’s really going on.  
 
In Their Own Words is recorded in Big Think's studio.
Image courtesy of Shutterstock

Lake Vostok: Life in one of the Inhospitable Places on Earth

Posted on December 28, 2013 at 9:00 am
By on Quarks to Quasars

Lake Vostok: Life in one of the most Inhospitable Places on Earth:     

800px-Lake_Vostok_drill_2011
Credit: Nicolle Rager-Fuller / NSF
Credit: Nicolle Rager-Fuller / NSF
 
Located on the seemingly inhospitable continent of Antarctica (a place with the lowest recorded temperature on the Earth at -89 degrees Celsius), lies a subglacial lake that is 160 miles wide and 30 miles across. This lake has been dubbed Lake Vostok. It is believed that the lake formed some 20 million years ago. Isolated from the rest of the world for at LEAST 100 000 years, Lake Vostok was one of the last untouched places on this globe.

The lake presents itself as an analog for the study of both extremophilic microbial life (and possibly larger organisms) and evolutionary isolation. This inhospitable environment parallels some environments that we think might exist elsewhere in the solar system – either in the subsurface of Mars or on icy moons like Enceladus or even Europa. Ultimately, the search for life on other planets could start here on Earth at Lake Vostok.
Drilling is restricted to 3590 meters (2.2 miles) below the surface ice (just a few hundred meters above the lake) as the lake itself is considered inaccessible due to fears of contamination. A number of scientists have examined ice cores taken from above the lake, focusing on the so-called “accretion ice” at the base of these cores. Accretion ice was once lake water that later froze and adhered to the overlying ice sheet—and what’s in that ice might therefore provide clues to what’s in the lake itself.

Radar satellite image of Lake Vostok (Credit: NASA)
Radar satellite image of Lake Vostok (Credit: NASA)

Lake Vostok has made news again because of its most recent published findings  shared recently in PLOS ONE. Scientists led by Yury Shtarkman, a postdoc at Bowling Green State University in Ohio, identified a startlingly diverse array of microbes in the accretion ice—the most diverse suggested yet.

By cultivating and sequencing nucleic acids found in the ice, they identified more than 3500 unique genetic sequences (mostly from bacteria, but there were some multicellular eukaryotes). And those were similar to those of creatures found in all sorts of habitats on the planet: lakes, marine environments, deep-sea sediments, thermal vents, and, of course, icy environments.

Overall, researchers have generally observed low concentrations of such microbes relative to most environments on Earth. But they found the POTENTIAL for a complex microbial ecosystem of bacteria and fungi, and genetic sequences from crustaceans, mollusks, sea anemones, and fish. Note that Lake Vostok was in contact with the atmosphere millions of years ago, so a complex network of organisms likely populated the lake during that time. The team also found bacteria sequences that are common symbionts (organisms that live in symbiosis of each other) of larger species. There could be the poFEussibility of distinct ecological zones. As they are just studying accretion ice, the idea of fish actually living in the lake remains unclear.

A scientist traversing above the ice miles above the ice of Lake Vostok (Credit: M. Studinger, 2001)
A scientist traversing above the ice miles above the ice of Lake Vostok (Credit: M. Studinger, 2001)

Either way, this lake is far from being devoid of life. This does not conclusively lead us to the conclusion that life exists on other planets and moons in our solar system. But if abiogenesis is correct (still repudiated, but evidence is starting to suggest it is), it makes the case that much stronger for those seeking life beyond our planet.

Fractals and Scale Invariance















 
Fractals are plots of non-linear equations (equations in the result is used as the next input) which can build up to astonishingly complex and beautiful designs.  Typical of fractals is their scale invariance, which means that no matter how you view them, zoom in or zoom out, you will find self-similar and repeating geometric patterns.  This distinguishes from most natural patterns (though some are fractal-like, such as mountains or the branches of a tree, stars in the sky), in which as you zoom in or out completely changes what you see -- e.g., galaxies to stars down to atoms and sub-atomic nuclei and so forth).  Nevertheless, what is most (to me) fascinating about fractals is that they allow us to simulate reality in so many ways.

The Mandelbrot set shown above is the most famous example of fractal design known. 
The Mandelbrot set is a mathematical set of points whose boundary is a distinctive and easily recognizable two-dimensional fractal shape. The set is closely related to Julia sets (which include similarly complex shapes), and is named after the mathematician Benoit Mandelbrot, who studied and popularized it.

Mandelbrot set images are made by sampling complex numbers and determining for each whether the result tends towards infinity when a particular mathematical operation is iterated on it. Treating the real and imaginary parts of each number as image coordinates, pixels are colored according to how rapidly the sequence diverges, if at all.

More precisely, the Mandelbrot set is the set of values of c in the complex plane for which the orbit of 0 under iteration of the complex quadratic polynomial
z n+1 =z n squared +c
remains bounded.[1] That is, a complex number c is part of the Mandelbrot set if, when starting with z0 = 0 and applying the iteration repeatedly, the absolute value of zn remains bounded however large n gets.

In general, a fractal is a mathematical set that typically displays self-similar patterns, which means they are "the same from near as from far".[1] Often, they have an "irregular" and "fractured" appearance, but not always. Fractals may be exactly the same at every scale, or they may be nearly the same at different scales.[2][3][4][5] The definition of fractal goes beyond self-similarity per se to exclude trivial self-similarity and include the idea of a detailed pattern repeating itself.[2]:166; 18[3][6]

One feature of fractals that distinguishes them from "regular" shapes is the amount their spatial content scales, which is the concept of fractal dimension. If the edge lengths of a square are all doubled, the area is scaled by four because squares are two dimensional, similarly if the radius of a sphere is doubled, its volume scales by eight because spheres are three dimensional. In the case of fractals, if all one-dimensional lengths are doubled, the spatial content of the fractal scales by a number which is not an integer. A fractal has a fractal dimension that usually exceeds its topological dimension[7] and may fall between the integers.[2]

As mathematical equations, fractals are usually nowhere differentiable.[2][5][8] An infinite fractal curve can be perceived of as winding through space differently from an ordinary line, still being a 1-dimensional line yet having a fractal dimension indicating it also resembles a surface.[7]:48[2]:15

The mathematical roots of the idea of fractals have been traced through a formal path of published works, starting in the 17th century with notions of recursion, then moving through increasingly rigorous mathematical treatment of the concept to the study of continuous but not differentiable functions in the 19th century, and on to the coining of the word fractal in the 20th century with a subsequent burgeoning of interest in fractals and computer-based modelling in the 21st century.[9][10] The term "fractal" was first used by mathematician Benoît Mandelbrot in 1975. Mandelbrot based it on the Latin frāctus meaning "broken" or "fractured", and used it to extend the concept of theoretical fractional dimensions to geometric patterns in nature.[2]:405[6]

There is some disagreement amongst authorities about how the concept of a fractal should be formally defined. Mandelbrot himself summarized it as "beautiful, damn hard, increasingly useful. That's fractals."[11] The general consensus is that theoretical fractals are infinitely self-similar, iterated, and detailed mathematical constructs having fractal dimensions, of which many examples have been formulated and studied in great depth.[2][3][4] Fractals are not limited to geometric patterns, but can also describe processes in time.[1][5][12] Fractal patterns with various degrees of self-similarity have been rendered or studied in images, structures and sounds[13] and found in nature, technology, art, and law.

Much of this was taken from Wikipedia Mandelbrot Set and Fractal.

Green Technology Depends on Metals with Weird Names

Cover Image: January 2014 Scientific American Magazine
A supply of clean, affordable energy depends on little-known substances
Gold bar surronded by halo of hands
Image: Ross MacDonald
 
There's one problem with the silicon age: its magic depends on elements that are far scarcer than beach sand. Some aren't merely in limited supply: many people have never even heard of them. And yet those elements have become essential to the green economy. Alien-sounding elements such as yttrium, neodymium, europium, terbium and dysprosium are key components of energy-saving lights, powerful permanent magnets and other technologies. And then there are gallium, indium and tellurium, which create the thin-film photovoltaics needed in solar panels. The U.S. Department of Energy now counts those first five elements as “critical materials” crucial to new technology but whose supply is at risk of disruption. The department's experts are closely monitoring global production of the last three and likewise the lithium that provides batteries for pocket flashlights and hybrid cars.

Earlier this year the DoE took a major step by launching the Critical Materials Institute, a $120-million program to avert a supply shortage. Led by the Ames Laboratory in Iowa, with backing from 17 other government laboratories, universities and industry partners, the institute represents a welcome investment in new research. Unfortunately—like the original Manhattan Project—the program is driven more by the threat of international conflict than by ideals of scientific cooperation.
The appropriation made it through Congress almost certainly because of legislators' fear of China's dominance in many critical elements and Bolivia's ambition to become “the Saudi Arabia of lithium.”
The worries are probably inevitable. China—historically a prickly partner at best to the U.S.—effectively has much of the world's critical-materials market at its mercy. Take the rare earth elements neodymium, europium, terbium and dysprosium. Despite their name, rare earths are many times more common than gold or platinum and can be found in deposits around the world. In recent years, however, cheap labor and lax environmental regulation have enabled China to corner the global market, mining and refining well over 90 percent of rare earths.

At the same time, China has consistently fallen short of its own production quotas. In 2012 the U.S., the European Union and Japan, suspecting China was manipulating the market, filed a formal complaint with the World Trade Organization (WTO). China argues that production cutbacks were necessary for environmental cleanup. At press time, a preliminary ruling in October 2013 against China will likely be appealed. Meanwhile Japan has announced discovery of vast undersea deposits of rare earths, and the Americans, among others, are working to restart their own disused facilities. The shortages won't last.

Bolivia's lithium is a different story. The impoverished, landlocked country needs no artificial shortages to boost the market. As the lightest metal, lithium has unmatched ability to form compounds that can store electricity in a minimal weight and volume. At least half the world's known reserves are located in a relatively small stretch of the Andes Mountains, where Bolivia and Argentina share a border with Chile.

There's more at stake here than fancy gadgets for the rich. The point of critical materials is to use energy more efficiently. One fifth of the world still lives without access to clean, affordable electricity, a problem that unimpeded supplies of rare earths and lithium could eventually remedy. The hard part will be to prevent old international feuds from getting in the way of that goal. The U.S. can help by embracing the spirit of international development and cooperation. A start could be with the U.S. National Science Foundation, which already maintains an active office in Beijing. We need more such channels to encourage collaborative research on rare earths. Similarly, the strained relations between Washington and La Paz could benefit from signs of sincere U.S. willingness to assist Bolivia in developing the Uyuni salt flats, where a pilot processing plant began operating early in 2013.

Similar modest gestures could bring the world closer to a full-scale treaty on global mineral-supply security. A foundation of sorts has already been laid by efforts such as the Minamata Convention on Mercury, the recently adopted international pact to reduce emissions and use of the toxic metal.
Humanity's health and prosperity depend on the wise harnessing of natural resources. Narrow national interests and rivalries can only obstruct that process, ultimately leaving us all just that much poorer. The need for critical materials should catalyze international cooperation. After all, those materials can enlighten the world—literally.

Friday, December 27, 2013

The Benefits of Colonizing Space: Space Habitats and The O’Neill Cylinder


Posted on From Quarks to Quasars, December 27, 2013 at 5:00 am
By
                             
1280px-Spacecolony3edit
Image credit: Rick Guidice

Many argue that the world is in a state of crisis and that the human race is the cause. As a species, we are approaching an important turning point in our history, and if we make the wrong decisions we might be facing a future of deprivation, over population, hunger, and instability. Ultimately, many believe that we will eventually be forced to colonize space. Last year, the 100 Starship Symposium set on course a project to design and build an economical and practical spacecraft for interstellar travel.

But with the very immediate worries about over population, it might not be a good idea to wait for interstellar travel and the colonization of other worlds. Fortunately, there are also many suggestions in place for large space structures designed as places for people to live in their millions, much like a city is on Earth. Of course, building a space habitat comes with thousands of challenges, including: construction in space, recreating a livable atmosphere, recycling waste, producing artificial gravity, transporting food and materials to the habitat, and convincing people such a venture is worth it.


Image credit: Mars One graphics

There’s no strict definition for a ‘space habitat’, but it’s generally agreed to be a permanent human living facility on a celestial body such as ‘Mars One’ (extra-terrestrial planets, moons, or in a spaceship orbiting the Earth). We may have no choice but to build one of these in the future, be it initiated as a matter of survival or an undeniable demand because of our desire to explore and gain new knowledge by expanding in space. Ultimately, there are a number of incentives to building such a habitat.

For governmental bodies and world leaders faced with a huge and unsustainable population, the concept of a space habitat would be attractive. Using the materials available in the Solar System, there is the potential to build enough surface area within space habitats to possibly house billions and even trillions of people. Populations would have the space to expand sustainably without destroying any current ecosystems, as well as relieving the pressure off Earth to provide resources. The planetary population could be stabilized and supported with the extra space to inhabit and develop agricultural plantations for food.

The expansion into space also offers up a wealth of privatized opportunities, such as access to energy and other interplanetary resources. On Earth, utilizing the Sun’s energy via solar cells is a disappointingly inefficient process with unavoidable problems associated with the atmosphere and night. In space, solar panels would have access to nearly continuous light from the Sun, and in Earth’s orbit this would give us 1400 watts of power per square meter (with 100% efficiency). This abundance of energy would mean that we could travel throughout much of the Solar System without a terribly significant drop in power.

Image credit: Ricky

Material resources would also be in abundance throughout the entire Solar System (especially if you include mining opportunities on Mars, Luna, and other moons). Asteroids contain almost all of the stable elements in the periodic table, and without gravity, extracting and transporting them for our uses could be done with ease. NASA is working on a project where one could manufacture fuel, building materials, water, and oxygen just from resources found the Moon. The shift from Earth based manufacturing and plantation to industries in space may not just become feasible, but incredibly economically beneficial.

So now that we’ve laid down some reasons as to why organisations may want to unite and build a space habitat, I want to introduce you to the O’Neill cylinder. My personal favourite suggestion is the O’Neill cylinder, a space settlement design proposed by Gerard K. O’Neill nearly 40 years ago, in 1976, when he published his book ‘The High Frontier: Human Colonies in Space’Gerard K. O’Neill was a lecturer at Princeton University, as well as a physicist and space activist. He designed and built the first mass driver prototype, and he developed new concepts to explore particle physics at higher energies than what had ever been possible (he was quite an awesome guy). But his lasting legacy was based in his work on space colonization. He founded the Space Studies Institute, an organisation devoted to research into this field.

Image credit: Rick Guidice

The design for his cylinder was spawned from a task that he set a group of physics and architectural students. The goal was to invent large structures that could be used for long term human habitation, and the results inspired the idea of the cylinder. The title is a little misleading, because it is actually two cylinders that rotate on bearings in opposing directions (to cancel gyroscopic effects). Each one would be 20 miles long and 8km in diameter, with 6 stripes along its length (3 windows and 3 habitable surfaces). Industrial processes and recreational facilities were envisaged to be on the central axis where it would effectively be a zero-gravity zone.

One difference between a planetary/moon-based space habitat and a man-made structure is the need for artificial gravity, and the O’Neill cylinder does this in a beautiful manipulation of basic Newtonian physics. As the two colossal cylinders rotate on their axis it utilizes the centripetal force on any object on the inner surface to create the appearance of gravity! Using the dimensions of the cylinder, the equation a=v²/r and the acceleration due to gravity on Earth (9.81m/s²), we can deduce that the cylinder will only need to rotate around 28 times every hour in order to simulate an equal force (though about 40 times is what the plans suggest).

Image credit: Donald Davis

The next box on the check list for a planetary habitat is maintaining an atmosphere with a composition and pressure that is similar to that of Earth’s. The cylinder is designed to have a carefully controlled ratio of gases much the same as Earth, but the pressure will be half of that at sea level. This will create a minor difference to how we breathe, but the advantages are the need for less gas and less of a requirement for thick walls. It also thought that the habitat will be able to generate its own micro-climate and weather systems that we could control using mirrors and by changing the ratios of gases in the cylinder.

Habitats also have to deal with a variety of problems that come as a consequence of living in space. With the colony situated in a vacuum the cylinder essentially turns into a giant thermos flask! O’Neill’s design to overcome this issue uses a series of mirrors hinged to each of the 3 windows. They are able to direct sunlight into the cylinder to simulate day time and warm the air, and turn away at ‘night’ so that the windows look out onto the blackness of space. This period of ‘night’ would allow heat in infrastructure, and that produced biologically, to radiate out just as the Earth’s atmosphere does (at night time too).

Another serious issue is that of small meteoroids or even man-made space debris. Radar systems based all around the outer skin of the cylinders will continuously map the region around the habitat to locate possible dangers. It was predicted that small scale collisions are inevitable; so to counteract the effect the windows would be built up of small panes built around a strong steel frame. The loss of gas would be so insignificant compared to the volume of the cylinder that repair jobs would not be an emergency. Though much larger pieces of rock would be a threat to the habitat, and methods of deflection or vaporization would be required.

Stephen Hawking said that he has predicted the extinction of the human race within the next thousand years, unless we build habitats in space or on other planets/moons in the next two hundred. That’s quite a statement, and with the current economic problems facing many developed countries around the world, it is highly unlikely that any big projects such as an O’Neill cylinder will be started soon. But with pioneers such as SpaceX and Mars One, what do you think the human race will do in the next 100 years?

Targeted synthesis of natural products with light

Targeted synthesis of natural products with light
Dec 17, 2013 
           Targeted synthesis of natural products with light       
The bulky Lewis acid (above) shields one side of the substrate (bottom) pushing the photoreaction in to the direction of the desired product. Furthermore the complex of Lewis acid and substrate requires a lower excitation energy than the substrate alone.
Radiating the complex with light of this wavelength favors the formation of the desired substance while it delivers not enough energy for the non-specific photoreaction of the uncomplexed substrate. Credit: Richard Brimioulle
 
Photoreactions are driven by light energy and are vital to the synthesis of many natural substances. Since many of these substances are also useful as active medical agents, chemists try to produce them synthetically. But in most cases only one of the possible products has the right spatial structure to make it effective. Researchers at the Technische Universitaet Muenchen (TUM) have now developed a methodology for one of these photoreactions that allows them to produce only the specific molecular variant desired.

For chemists, are compounds formed by organisms to fulfill the myriad biological functions. This biological activity makes them very interesting for industrial applications, for example as active agents in medication or as plant protection agents. However, since many natural substances are difficult to extract from nature, chemists are working on creating these substances in their laboratories.

A key criterion in the manufacture of natural substances is that they can be produced with the desired spatial configuration. But photoreactions often create two mirror-image variants of the target molecule that can have very different properties. Since only one of theses molecules shows the desired effect, researchers would like to avoid producing the other.

A special catalyst
Thorsten Bach, professor for Organic Chemistry, and his doctoral student Richard Brimioulle have discovered a particularly elegant way of doing this. Their trick was to add a small amount of an electron-deficient compound, a so-called Lewis acid, as a catalyst. The bulky catalyst has a specific spatial structure and forms a complex with the starting substance.

What makes this reaction so special is that the complex of Lewis acid and substrate requires a lower excitation energy than the substrate alone. "Radiating the substance with light of this wavelength favors the formation of the desired substance," says Richard Brimioulle. "The energy is not sufficient for the non-specific reaction of the uncomplexed substrate." A further advantage of the synthesis: The Lewis acid is released upon formation of the product and can react with the next molecule of the starting substance. In addition, the reaction takes place in a single step – an important criterion for subsequent industrial deployment.

Elegant pathway to natural substances
Applying photoreactions to the production of natural substances has been a long aspired goal of the scientists headed by Professor Bach. Using this kind of reaction, even unusually complicated molecular frameworks can be produced quickly and efficiently from simple starting materials. One such molecule is grandisol, a pheromone of the cotton boll weevil. It is already being used as a plant protection agent. Many other agents that inhibit the growth of cancer cells or kill bacteria contain similar kinds of structures and could thus be suitable as medication.

Since other substrates also exhibit reduced excitation energies in the presence of Lewis acids, Bach and Brimioulle suspect that the new method can be used to synthesize many different substances selectively. In future work, the researchers plan to apply the catalysts to other types of photoreactions to give this type of reaction a fixed position among the synthesis methods of .
Explore further: New catalyst class uses halogen bridges for environmentally friendlier production

More information: R. Brimioulle and T. Bach: Enantioselective Lewis Acid Catalysis of Intramolecular Enone [2+2] Photocycloaddition Reactions, Science 2013, Vol. 342 no. 6160 pp. 840-843 - DOI: 10.1126/science.1244809
Journal reference: Science

Baisden

If you have hurt someone call them and tell them you're sorry. After that, move on!

Too often we torture ourselves over and over again for the same mistake. Suffering doesn't cleanse you it only makes you more dis-eased. You've suffered enough, it's time to move on to make new mistakes. ~ Michael Baisden

The Universe as we Don’t See It


I want to take you on a journey. For me it started quite young, but when at age twelve or thirteen my parents gave me a six-inch Newtonian reflector, it began in earnest. I am told that my largesse was the result of my sister getting (for a while) a pony, and their was fear I would be envious, but the two events were never connected in my mind and I never remember a trace of envy or resentment toward my sister. I was just so darn happy to have the telescope. .

Even in the rather light-polluted suburbia USA we lived in the telescope revealed a marvel of heavenly capital the naked eye never suspected. We all know there are craters on the moon, but with but 96X magnification I could see them, bright and clear. And the Galilean satellites of Jupiter. The rings of Saturn. And stars beyond stars, nebulae, galaxies – by any professional standards it was just a child’s toy, but what it brought into my backyard most of the greatest philosophers of history could not have dreamt about.

It took me … out there. Away from this secluded and narrow viewpoint of tiny spot on planet Earth where I stood, toward places hundreds or thousands of years of light speed travel that would have been needed to actually be there in the flesh (not that I would have survived long, but I never thought about that). It was a Asperger’s child’s vision of paradise, to this day probably the best thing my parents ever did for me. I was not to become an actual astronomer, but this gift opened that door to me better than anything else.

I’d like to repeat a figure from chapter one:


Figure I. (repeated)

Getting away from our ordinary, Earth-bound existence and planting ourselves somewhere in space – here, a position millions of miles beyond the sun-Earth system – we see already how much our perspective on things have changes. For one thing, the cause of the seasons, which had baffled us before, becomes obvious. We also see Earth (and the sun) as spherical objects in space, instead of as flat, infinite surfaces which or may not have boundaries. If the picture were to be fully fleshed out, we would see other planets too (specifically, the inner world of Mercury and Venus, and the fourth planet Mars; whether Jupiter and/or Saturn would show from here is not as clear).

Whether you realize it or not, I have done something profound to your senses; more precisely, to your brain’s interpretation of reality. But all I have really done is change your point of view, as my telescope changed mine. I call it profound, however, because the brilliant insights of Albert Einstein, in the beginnings of the twentieth century, demonstrated that it must be so.

* * *

If you have ever taken high school physics, or a general college physics course, you may have discovered that it is, in a very real sense, boring. It’s boring because you’re not learning anything you hadn’t already intuitively learned by about age two or so. If you don’t believe that, then watch next time a magic show is performed before a group of toddlers. They are just as dumb-founded and thrilled seeing the laws of ordinary physics seemingly violated as you or I. And even a small baby can tell when something is amiss; if you convince it something is in a certain place and then reveal that it isn’t, their eyes will open wide with surprise, and they may even become distressed.

But that’s just common sense,” you might be tempted to protest. Yet what is common sense? If it were as easy and as obvious as it seems, artificial intelligence would be a snap to accomplish, and would have been years ago.

The fact is, our brains evolved to perceive and “understand” reality in ways necessary for our stone-age ancestors and further back, and thus it is unsurprising that we should possess, even at a very young age, the common-sense concepts we collectively call reality. Recall what I said about magicians and how they do what they do; they use those “wired-in”, common-sense, laws of physics and manipulate our senses and points of view to cause us to see impossible things. Like bending a spoon with your fingers, if I may cite a rather common trick by “psychics” – magicians who pawn themselves off as special people with special powers.

What you learn in basic physics course are the details, the precise definitions, and the math behind the ordinary. And, despite what I said, it isn’t boring at all; I strongly recommend taking such a course (my mother did, and got a B, which somehow didn’t convey to her that she could grasp scientific thinking), perhaps even before reading what’s coming up.

* * *

The lesson of the last section, I hope, is that although we possess common-sense intuition about “ordinary” reality – the reality all of us spend all our lives in, a reality within a narrow range of space and time – at the same time evolution could not have bestowed us no gifts about reality outside those strict ranges, because our ancestors never encountered them. And indeed, it hasn’t. But until you understand that, it is only natural that you should think the Laws of Physics, as we somewhat pompously and arrogantly call them, will apply everywhere, all the time, across all scales of time and place.

That’s why I started out talking about my childhood telescope, and showing Figure I again. Even this is not too far a deviation from our hum-drum down on this planet’s lives, but there are some noteworthy differences. The biggest one may be that the light from the sun or that reflected from Earth will take several minutes to reach our new vantagepoint. We certainly aren’t used to significant (or any) delays between the time something happens and when we observe it, for light travels – well, it travels faster than anything known in the universe, a full 186,282 miles per second. That being the case, when a bank of lights at a stadium are turned on, the stadium is full alit “at once” , though it actually takes around a fraction of a millisecond or one thousandth of a second fir this miracle to happen. Since our brains can’t measure time intervals that short (we’re a tad slow, to tell the truth), this is instantaneously as far as we are concerned. Indeed, by all common-sense measurements the speed of light is for all practical purposes infinite.

Yet it is in fact not infinite, as our hovering over Figure I. shows. That light – electromagnetic radiation I should call it, including radio, microwaves, infrared (heat) rays, ultraviolet (black) light, x-rays, and gamma rays – journeys at a specifically defined speed came out of work on electricity and magnetism in the 1800’s, already dents our common sense view of things. But what comes next tramples it into unrecognizable shards.

I have to backtrack some to explain why. I’ll ask you to close your eyes (but don’t stop reading!) and imagine the following: someone else and I are on a rail car, travelling at fifty mph down the track. We both have baseball mitts (not actually necessary), and one baseball, and we are playing a game of catch between us. Some kindly passenger (you, as it turns out) on the train is timing how fast we throw, and reports us both hurling the ball at 50 miles per hour, or 73 feet per second. You can easily calculate this because the rail car is 73 feet long and it takes exactly one second from throw to catch.

Open your eyes again. That was probably easy to picture before your mind’s eye, I’m certain; we do things like this all the time, if never exactly this.

Okay, close ‘em again, and this time picture yourself on a train platform at a station, watching the train whizz by at fifty mph (it’s an express, and doesn’t stop there). You can easily look through the car’s windows and watch the game of throw and catch.

Question: what do you see now?

You are probably already uncertain as to whether you will see the same thing, but if you haven’t quite figured out what you do see, I’ll hand you the answer and then explain it. Using the same clock, you now see the thrower at the rear of the car throwing, like a top flight major league pitcher, the ball at 73 + 73 = 146 feet in the one second that ticks off your clock, or one hundred mph; while the thrower at the front can accomplish a mere 73 – 73 = 0 feet in that second, or zero mph.

The explanation is that speeds add. The train is travelling fifty mph forward, and this speed must be added to the rear of car thrower speed and subtracted from the front of car’s thrower’s velocity. If all the window shades are drawn, however, the passengers have no way of knowing their speed with respect to the station, because we can’t sense constant speed, only acceleration (speeding up, slowing down, or changing direction). Everything here, keep in your mind, is at constant speeds and directions. And I’ll wager it doesn’t gall you too much. You’ve actually witnessed it first hand many times in your life; you know you can’t really say an object is travelling at such and such a speed without specifying the reference point that speed is being measured from. Ever sat in a motionless train and, while watching another train moving slowly by you, actually sense yourself moving in the opposite direction? This is why. Like magic. it confuses your brain again.

Let’s get back to light. Nineteenth century physicists showed that visible light was in fact an electromagnetic wave, or possibly some kind of particle like a baseball only infinitely tinier, and the speed of that wave was a well-measured 186,282 mps. The natural question now? With respect to what point of reference? The answer is either: either none, because all the laws of physics up to that point demonstrated that there are no privileged or special points of reference in the universe, that they are all equal; or, despite those laws (and, to their defense, a law of physics is so only because we humans to our meager abilities have been able to estimate it well enough to call it a law, so we can at least bend if not outright break it when needed) their was something called the universal aether, a fluid having no density, no color, no resistance to movement through it (viscosity), indeed no observable properties at all, which permeated all space and actually was stationary in some absolute sense.

A note of personal preference before I go on here. Lots of books on relativity have lots of pictures of trains and trolleys and clocks and other pertinent things – only natural, as this is what got Einstein thinking about the issues raised here – but I won’t, because if I haven’t presented my concepts in a simple, straightforward enough manner, then I’ve already failed in the main aim of this book. I assure you, it has nothing to do with my incompetence in drawing pictures (OK, well it does some).

I’ve given you the two possibilities and, if I have been successful, you are probably up a creek paddleless trying to choose. How can there be no point of reference for light’s speed; or, alternatively, there is a point, the aether, that has no physical properties that can be observed and measured? You should be reeling a bit by this point, because by the late 19’th century almost all scientists were reeling trying to answer this seemingly impossible conundrum. So you are in good company.

I’ve suggested that there are only two solutions to this problem, but, and in fair warning this is where things get strange (but still logical!), a third solution does present itself. Oh, how I wish I could say I thought of it myself. No, it took the genius of an Einstein to see what was so unobvious to the rest us. The third solution is that light is in fact it’s own reference point, and all other speeds must pay homage to it. It is light, electromagnetic radiation, to which we must bow to and follow it’s rules, however absurd they may seem to us.

Again, an aside before I move on. The speed of light is so enormous that, compared to it, the differences between the ordinary speeds we encounter (and the 50,000+ mph of space probes and objects, as fast as they seem to us, are still way below light’s 670,000,000 mph, by a factor of ten thousand and more) are so insignificant to render the light speed problem moot. This is why we never notice it in our lives, or ever imagine it in our minds. It is certainly not part of our intuitive understanding of physics for it never had to be in our evolutionary history.

* * *

I apologize here, for I must lay down some equations for your edification. They are not really complicated, not unless you’re going to go into full-fledged physics mode, which there is no need to do. The first equation involves a quantity that you’ve probably heard of, momentum. It is simply the mass of an object multiplied by its velocity (speed + direction, remember). Prior to Einstein, and as still presented in all general physics courses today it is:



momentum( or p) = mass(or m) × velocity(or v)

p = mv

Equation I.


This is the equation Newton derived for what, essentially, he called inertia, and so derived the now famous Law of Conservation of Linear Momentum (quite similar to the one for Angular Momentum we’ve already encountered). Newton derived it assuming that all velocities were relative to some point of reference, even light, although he had little idea what light was or how/how fast it travelled. Science wasn’t developed well enough in his day, through no fault of his.

In Einstein’s new formulation, the equation of momentum must be modified from p = mv to:

p = m0v

Equation II.

Where or gamma (mathematics is all symbolized, even X + Y = Z, so don’t let this throw you), stands for:


Equation III.
The naught (0) on m indicates rest mass, which we’ll come to in a tick, and c means the speed of light.

Again, don’t let any of this get too heavy on you; you should have had all the symbolisms in high school, or can reference them easily. Anyway, this factoring in of the square root (what ¯ means) of 1 – (v/c)2 to the momentum equation, which remember, applies to all objects, takes into account c (speed of light) being this supreme reference point in the universe we must all be subservient to. Note something critical here: if v << c, as is the case with all velocities we normally encounter, then (v/c)2 goes to essentially zero, and just as essentially goes to 1, meaning that gamma is just 1/1 or 1 and drops out of the equation, leaving us with our Newtonian original, except for that lingering naught on m which we’ve let to explain beyond calling it the rest mass. Is there such a thing as a different not at rest mass?

Yes there is, and a little examination of Equation III. should show why. Imagine we make v very close to c, or even make it equal to c. Then (v/c)2 becomes just 1, and as 1 - 1 = 0 the bottom half of becomes infinite, meaning that p becomes infinite too!

Even as v gets closer and closer to c, p grows rapidly. It is as though all the energy we are throwing into our object to make it go faster and faster end up only increasing its mass as the speed of light is approached. If we could get to c the mass would be infinite in fact.

The only possible physical interpretation of this is that energy and mass are somehow equivalent, and dumping more of the former onto an object means it also has more of the latter. The math for that is just hairy enough to excuse us from examining it but the bottom line is the equation we all know and love: E = m0c2. The naught after m is, as said, the object’s rest mass; multiplying it by the speed of light squared gives its equivalent in energy, and since c2 is a very large number you will see (as scientists in the 1930’s were beginning to see, the results being Hiroshima and Nagasaki), if you can make the conversation you will release a very large amount of energy indeed.

Other, equally strange phenomena crop up when we move close to the light speed. Because all observers must find the same value for the this speed, regardless of their reference points, time and space become, well, malleable; it can be different with different observers.

Let’s go back to our baseball throwers in the rail car. The big difference, instead of throwing baseballs back and forth and each other, each one now has a laser pointer. As soon as the light from one pointer reaches the corresponding “catcher”, he in turn flashes his collaborator with his own pointer.

This experiment, as described, may sound absurd. The laser light travels so fast that it takes only 7.422×10-8 seconds, or 74 billionths of a second, for the light to exit the pointer and reach the other player, still fifty feet away. Very well then; let’s makes this easier to visualize by making the rail car 186,282 miles long, so that it now takes our full second for the traverse time. Never mind that this makes the experiment physically impossible (the rail car would stretch around our world over seven times!). Experiments can, in many cases are, done in our minds; as long as we get the math right and imagine things correctly, this is a perfectly valid approach to the subject. (Such experiments are called gedanken, a German word meaning literally ”done in thought”).

Do you have the picture in your head, though admittedly it is a bit tougher this time? Good. Next: imagine yourself, as before, the measurer in the rail car, timing how long it takes the laser light to get from pointer to receiver, and back. Naturally you find this number to be 186,282 mps, just the speed of light. No surprises there.

Now place yourself on the station again. You time the laser pulses again, just as you timed the baseball throw before from the platform. Now, one, crucial, last part of the experiment to stitch into your mind’s eyes: the rail car is also travelling 186,282 mps pass the station, in the same way as it was travelling 50 mph before. So: what do you expect to see?

With the baseballs, we obtained the answer that the speeds were either 50 + 50 = 100 mph for the back of car thrower, or 50 – 50 = 0 mph for the front of car, for now our reference point is the platform at the train station. Speeds, velocities more precisely, are additive because they depend on the point of reference you are measuring them from.

Amazingly, the result is completely different for the laser pointers and the car travelling at the speed of light! Recall my statement that the speed of light is its own reference. This means that its speed is always the same, regardless of any other point of reference. The platform observer, pocket watch in hand, finds that the laser pointers still fire their light beams at each other at c, just as the car observer does. Indeed, every observer, wherever he is in space and time, obtains the same values. There is no adding of speeds, at least not the way it was with baseballs.

If you are trying to make sense of this, and failing, I can tell you why. You are making the common-sense assumption that space and time are the same for all viewers. But that is incorrect. It feels right only because all your experience comes from speeds much below c, and evolution by natural selection has been geared to that. But our, rather simple, gedanken experiment has shown that both time and space are malleable, and depend on the observer’s state of motion.

Space and time are not flat and absolute. Special relativity shows this beyond a doubt. But if they are not flat and absolute, then – what are they? It was to take Einstein ten more years to work that out, and so much of modern cosmology depends on what he discovered. It is time to turn to there, the next state: the general theory of relativity, published in 1916.

* * *

Einstein was a person gifted with deep imagination and insight into nature. He knew that if he tried to work out his ideas about light and space and time not only with static motion but with accelerated motion as well, he would probably never have succeeded at either. So he started with static, meaning straight line, constant speed, motion, and in 1905 arrived at his special theory. It’s special because it specifically excludes all motions which involve changes in speed or direction (collectively known as accelerations), and concentrates purely on static motion. It was a maneuver which rewarded him with pure gold. It showed that mass and energy were equivalent, that the speed of light was the ultimate speed in the universe, and perhaps most importantly, that time and space were not flat, abstract constructs, the same for everyone everywhere, but ebbed and flowed depending on different circumstances. An enormous triumph, which earned him little notice at the time (he was still working at the same Swiss patent office well after publication), and which decidedly did not impress those who bequeathed Nobel Awards (though he did earn one some years later for a different line of work, which we’ll discuss in the next chapter).

Getting back to the theme of this section, special relativity was just that; a special case of relativity at work. Einstein’s main goal was a general theory of relativity, one which included accelerated motion as well as static. It was to take him another ten years to grind out the final, so-called field equations for relativity, equations I will not present here, fully confessing I don’t know enough math to do so.

We don’t need to understand that math (few do) to get a decent sense of what general relativity is about. One of the things Einstein noticed when dealing with accelerated motion was the results were virtually indistinguishable from being in a gravitational field. Here on Earth, as we would on all mass bodies in the universe, we feel ourselves being pulled downward by some unknown, almost magical force, which we call gravity. And indeed, if the ground beneath our feet were to give way, we would fall, ever faster and faster, into the resulting abyss, until we were smashed to our deaths by whatever we finally landed on (if the opening goes deep enough, however, we will be incinerated by the heat of Earth’s depths and crushed by the overwhelming pressures first – this all assumes the fall is far enough, of course).

An aside to describe accelerated motion. Our falling would occur under a force of one g (the gravitational force at Earth’s surface), meaning that we would plunge ever faster downward, at a rate of 32 feet per second per second, or 32fps2. All this means is that, after the first second, we are travelling at 32 fps, after the second second 64 fps, after the third 96fps, and so on. (All this ignores air friction, which counteracts the acceleration and limits us to 200-300 fps final speed, depending on our orientation.) Acceleration means a change in velocity, faster or slower (or in a different direction) over time.

All sorts of phenomena call cause accelerated motion. Take, as I believe Einstein did, an elevator. If you were sealed inside a windowless elevator somewhere out in deep interstellar space, you would be weightless and float freely all about the car. Now imagine that some unknown being of prodigious powers attaches a rope to the top of the elevator car, and starts pulling it upward with a force of one g (32fps2, remember). I think you intuitively sense that you would be slammed onto the floor of the car, and you would be right – though be careful about intuitions! I ask you a question: now that you are standing on a floor with a 32fps2 acceleration force trying to pull you downward, what is the difference between this situation and being in an elevator on Earth, at a stopped floor level? Remember there are no windows, nothing to tell you what is going on outside the elevator except this force pulling you down.

If I tell you basically nothing, you are probably not surprised. After all, we have all been in elevators, and felt the lurch in our stomachs, and the temporary lightness or heaviness in our bodies as we moved up or down in the car (try this at the Empire State Building or another monster skyscraper with express elevators if you really want to feel this effect). The sensation of falling if an elevator plunges down rapidly can be quite unnerving, rather like being on a roller coaster. I still have dreams about it, once in a while.

So our super being accelerating us at 32fps2 “upwards” (there is no such thing as direction in deep space, remember) feels exactly the same as being on an elevator on Earth, stopped at a specific floor. The being could even lurch us “upward” at more or less than one g if it really wanted to mimic the effects of the ground-based car. The point being, you simply could not tell the difference.

Here’s where an Einstein mind works on a different plane than our own. He made the deduction that, the scenario described above being true, there was no difference, according to the laws of physics, between them. They are in essence one and the same phenomena. Like me, I suspect you’ll have to put this book down at this point and chew on this idea. If there is no difference in the perception of two or more experiences, than physics tells us they are intimately linked by some thread; essentially, they are the same thing. This most certainly does violate our intuitions, which accounts for the warning I gave before.

* * *

But what is the thread connecting the two? Einstein finally realized that space and time, and their malleability, had to be brought into the situation to make that thread. But another, hopefully short, aside on another needed prerequisite is needed here to show how. You have probably heard of the concept called entropy, though you might (and should be) puzzled as to its exact meaning. We won’t get into that here, except to say that one meaning is that physical systems are inexorably (actually, probabilistically) drawn to their lowest energy states. An example is the falling we’ve been talking about; think about the energy, derived from its load of jet fuel, it takes to keep an airliner miles above the ground, or the far greater amount of rocket fuel it takes to put an astronaut on the moon or a robot about the planet Saturn. Falling things lose energy, which, according to the laws of entropy, is exactly what they should and must do, unless something stops them, like the floor of an elevator car.

The elevator, whether on Earth or in deep space, is providing energy to keep its occupants out of a state of free fall, i.e., what they’d be doing without the forces acting on them, floating about in a zero gravity (g) field. In both cases we are dealing with acceleration, even for an elevator stationary on Earth’s surface. What could account for such a curious conundrum?

Space and time. Spacetime. Special relativity had indicated that the two were indivisibly connected, and the fertile mind of the Swiss patent clerk finally become modest physics professor worked instinctively along these lines. If spacetime were a flexible, or curvable, concept that changed as an observer’s reference point changed, then maybe it was more that that: if was a real thing, and not only real but highly variable depending on perhaps many conditions. One of those conditions, he realized, was the presence of mass. He realized that mass objects somehow distorted spacetime, in a way that caused other objects to be attracted toward them. Using this insight, he finally solved the problem of the cause of gravity, which Newton knew better than to destroy his reputation on solving two hundred years earlier.

To explain how spacetime operates under general relativity I could reproduce a fairly standard picture, chances are you’ve seen, which appears to illustrate it:

Figure IV.

The grid represents the “curvature” of spacetime about the massive body of the planet Earth. Although it gives a good feeling for what is going on – you can easily picture objects approaching Earth being drawn in by the curvature of spacetime (the white grid), but the picture works only because Earth is at the bottom of a deep well and we intuitively know that objects near a well will be drawn into it. What I am objecting to in this picture as that it assumes what it is supposed to be explaining. It’s not a bad start but it must not be an end to the explanation. The reader wants to know what is really happening.

If instead of falling downwards the gridlines (representing spacetime, remember) get closer together as they approach Earth, then I believe we have a better picture of why objects fall toward other objects. Objects cause spacetime to compress, rather than to indent; a very small compression for objects the size of Earth, larger for the size of the sun, and quite large for nasty things like neutron stars and black holes, which compress them into singularities, a place which we won’t cover here.

Recall entropy. Objects “prefer” to be at the most compressed regions of spacetime because they can lose energy that way and obtain entropy by this particular meaning. That’s why they’re attracted toward each other, and will either fall into each other or orbit each other, the latter until loss of energy results in an eventual (trillions of years and more for the Earth-sun system, so don’t worry) collision.

If spacetime can curve in one way, it can – at least in theory – curve many ways – and many of the solutions to Einstein’s field equations describe the entire universe as being “closed” (spherically even) or “open”, or “saddle-backed” or plain old flat. New solutions crop up once every few years or decades, describing how the universe must be or how it will evolve in time, or what phenomena (like black holes) it might reveal. There is also a “standard” solution, which itself gets itself upgraded once in a while, as the result of new astronomical observations (e.g., that the universe is not only expanding but expanding more and more so, due to something called “dark energy”) and other considerations. .

* * *

I am going to stop here, because if you have been following me reasonably well, then I’ve succeeded in what I set out to do in this chapter. I wanted to describe for you a field of physics which, although it violates all our common-sense notions about how things behave and why, was within your grasp to at least get a good feel for. Don’t worry about all the sundry details I’ve left out (though if this has left you hungering for a deeper understanding of relativity, all power to you!); I just wanted to give you a taste for how strange and wonderful reality can be when we drag ourselves away from our evolutionary-derived intuitions. Again, if I’ve succeeded, than we are ready to talk about what I’ve been setting forth to cover, some chemistry and biology that should be within your understanding as well. This is where we start on a very new road from the physics of Einstein, to the physics (and chemistry) of the quantum, a field many great minds have contributed to and to which, I think, no one can be designated the creator of. On to quantum cats.