Highly conductive ink-jet-printed silver films enable electronic
circuits without requiring high heat; lower-cost solar cells, RFID
chips, batteries, other devices now possible
Duke
University chemists have found that silver nanowire films like these
conduct electricity well enough to form functioning circuits without
applying high temperatures, enabling printable electronics on materials
like paper or plastic. (credit: Ian Stewart and Benjamin Wiley)
By suspending tiny metal nanoparticles in liquids, Duke University
scientists can use conductive ink-jet-printed conductive “inks” to
print inexpensive, customizable RFID and other electronic circuit
patterns on just about any surface — even on paper and plastics.
Printed electronics, which are already being used widely in devices
such as the anti-theft radio frequency identification (RFID) tags you
might find on the back of new DVDs, currently have one major drawback:
for the circuits to work, they first have to be heated to 200° C (392°F)
to melt all the nanoparticles together into a single conductive wire.
But Duke researchers have now found that electrons are conducted
through films made of silver nanowires much more easily than with films
made from other shapes (like nanospheres or microflakes). And the
nanowire films can now function in printed circuits without the need to
melt them first — heating at only 70° C (158°F) is required — and that
means the circuits can be printed on cheaper plastics or paper.
“The nanowires [in their research] had a 4,000 times higher
conductivity than the more commonly used silver nanoparticles that you
would find in printed antennas for RFID tags,” said Benjamin Wiley, assistant professor of chemistry at Duke.
The technology could also be used to make lower-cost solar cells,
printed displays, LEDs, touchscreens, amplifiers, batteries, and even
some implantable bio-electronic devices. The results appeared online
Dec. 16 in ACS Applied Materials and Interfaces.
The team is now experimenting with using aerosol jets to print silver
nanowire inks in usable circuits. Wiley says they also want to explore
whether silver-coated copper nanowires, which are significantly cheaper
to produce than pure silver nanowires, will give the same effect.
This research was supported by funding from the National Science
Foundation and a GAANN Fellowship through the Duke Chemistry Department.
Abstract of Effect of Morphology on the Electrical Resistivity of Silver Nanostructure Films
The relatively high temperatures (>200 °C) required to sinter
silver nanoparticle inks have limited the development of printed
electronic devices on low-cost, heat-sensitive paper and plastic
substrates. This article explores the change in morphology and
resistivity that occurs upon heating thick films of silver nanowires (of
two different lengths; Ag NWs), nanoparticles (Ag NPs), and microflakes
(Ag MFs) at temperatures between 70 and 400 °C. After heating at 70 °C,
films of long Ag NWs exhibited a resistivity of 1.8 × 10–5 Ω
cm, 4000 times more conductive than films made from Ag NPs. This result
indicates the resistivity of thick films of silver nanostructures is
dominated by the contact resistance between particles before sintering.
After sintering at 300 °C, the resistivity of short Ag NWs, long Ag NWs,
and Ag NPs converge to a value of (2–3) × 10–5 Ω cm, while films of Ag MFs remain ∼10× less conductive (4.06 × 10–4
Ω cm). Thus, films of long Ag NW films heated at 70 °C are more
conductive than Ag NP films sintered at 300 °C. Adding 10 wt % nanowires
to a film of nanoparticles results in a 400-fold improvement in
resistivity.
Nucleoproteins are any proteins that are structurally associated with nucleic acids, either DNA or RNA. Typical nucleoproteines include ribosomes, nucleosomes, and viral nucleocapsid proteins.
Structures
Cross-sectional drawing of the Ebola virus particle, with structures of the major proteins shown and labelled on the right.
A deoxyribonucleoprotein (DNP) is a complex of DNA and protein.[12] The prototypical examples are nucleosomes, complexes in which genomic DNA is wrapped around clusters of eight histone proteins in eukaryotic cell nuclei to form chromatin. Protamines replace histones during spermatogenesis.
In eukaryotic cells, DNA is associated with about an equal mass
of histone proteins in a highly condensed nucleoprotein complex called chromatin.[14]
Deoxyribonucleoproteins in this kind of complex interact to generate a
multiprotein regulatory complex in which the intervening DNA is looped
or wound. The deoxyribonucleoproteins participate in regulating DNA
replication and transcription.[15]
Deoxyribonucleoproteins are also involved in homologous recombination, a process for repairing DNA that appears to be nearly universal. A central intermediate step in this process is the interaction of multiple copies of a recombinase protein with single-stranded DNA to form a DNP filament. Recombinases employed in this process are produced by archaea (RadA recombinase),[16] by bacteria (RecA recombinase)[17] and by eukaryotes from yeast to humans (Rad51 and Dmc1 recombinases).[18]
A ribonucleoprotein (RNP) is a complex of ribonucleic acid and RNA-binding protein.
These complexes play an integral part in a number of important
biological functions that include DNA replication, regulating gene
expression[20] and regulating the metabolism of RNA.[21] A few examples of RNPs include the ribosome, the enzyme telomerase, vault ribonucleoproteins, RNase P, hnRNP and small nuclear RNPs (snRNPs), which have been implicated in pre-mRNAsplicing (spliceosome) and are among the main components of the nucleolus.[22]
Some viruses are simple ribonucleoproteins, containing only one
molecule of RNA and a number of identical protein molecules. Others are
ribonucleoprotein or deoxyribonucleoprotein complexes containing a
number of different proteins, and exceptionally more nucleic acid
molecules.Currently, over 2000 RNPs can be found in the RCSB Protein
Data Bank (PDB).[23]
Furthermore, the Protein-RNA Interface Data Base (PRIDB) possesses a
collection of information on RNA-protein interfaces based on data drawn
from the PDB.[24]
Some common features of protein-RNA interfaces were deduced based on
known structures. For example, RNP in snRNPs have an RNA-binding motif in its RNA-binding protein. Aromaticamino acid residues in this motif result in stacking interactions with RNA. Lysine residues in the helical
portion of RNA-binding proteins help to stabilize interactions with
nucleic acids. This nucleic acid binding is strengthened by electrostatic attraction between the positive lysine side chains and the negative nucleic acidphosphate backbones. Additionally, it is possible to model RNPs computationally.[25]
Although computational methods of deducing RNP structures are less
accurate than experimental methods, they provide a rough model of the
structure which allows for predictions of the identity of significant
amino acids and nucleotide residues. Such information helps in
understanding the overall function the RNP.
'RNP' can also refer to ribonucleoprotein particles. Ribonucleoprotein particles are distinct intracellular foci for post-transcriptional regulation. These particles play an important role in influenza A virusreplication.[27] The influenza viral genome is composed of eight ribonucleoprotein particles formed by a complex of negative-sense RNA bound to a viral nucleoprotein. Each RNP carries with it an RNA polymerase complex. When the nucleoprotein binds to the viralRNA, it is able to expose the nucleotide bases which allow the viral polymerase to transcribe RNA. At this point, once the virus enters a host cell it will be prepared to begin the process of replication.
The ribonucleoproteins play a role of protection. mRNAs
never occur as free RNA molecules in the cell. They always associate
with ribonucleoproteins and function as ribonucleoprotein complexes.[14]
In the same way, the genomes of negative-strand RNA viruses never
exist as free RNA molecule. The ribonucleoproteins protect their
genomes from RNase.[29] Nucleoproteins are often the major antigens for viruses because they have strain-specific and group-specific antigenic determinants.
Applications include a drug-delivery system to provide tailored
drug doses for precision medicine, catheters, stents, cardiac
pacemakers, and soft microbotics
Fabrication
and assembly of an iMEMS microdevice. Left: layer-by-layer fabrication
of support structures and assembly of gear components. Right: the
complete device after the layers have been sealed, with ferromagnetic
iron material (black) to enable external magnetic control. (credit:
SauYin Chin/Columbia Engineering)
Columbia Engineering
researchers have invented a technique for manufacturing complex
microdevices with three-dimensional, freely moving parts made from
biomaterials that can safely be implanted in the body. Potential
applications include a drug-delivery system to provide tailored drug
doses for precision medicine, catheters, stents, cardiac pacemakers, and
soft microbotics.
Most current implantable microdevices have static components rather
than moving parts and, because they require batteries or other toxic
electronics, they have limited biocompatibility.
The new technique stacks a soft biocompatible hydrogel material in
layers, using a fast manufacturing method the researchers call
“implantable microelectromechanical systems” (iMEMS).
iMEMS
drug-delivery system. The payload delivery system was tested in a bone
cancer mouse model, finding that the triggering of releases of
doxorubicin from the device over 10 days showed high treatment efficacy
and low toxicity, at 1/10th of the standard systemic chemotherapy dose.
The device contains iron nanoparticle–doped components, which respond to
external magnetic actuation. Actuation of the device triggers release
of payloads from reservoirs. (credit: Sau Yin Chin et al./Science
Robotics)
“Our iMEMS platform enables development of biocompatible implantable
microdevices with a wide range of intricate moving components that can
be wirelessly controlled on demand, and solves issues of device powering
and biocompatibility,” says Biomedical Engineering Professor Sam Sia, senior author of an open-access paper published online January 4, 2017, in Science Robotics).
The researchers were able to trigger the iMEMS device to release
payloads over days to weeks after implantation, with precise actuation
by using magnetic forces to induce gear movements that, in turn, bend
structural beams made of hydrogels with highly tunable properties.
(Magnetic iron particles are commonly used and are FDA-approved for
human use as contrast agents.)
Batteryless implantable medical devices or sensors
Sia’s iMEMS technique addresses several issues in building
biocompatible microdevices, micromachines, and microrobots: how to power
small robotic devices without using toxic batteries; how to make small,
biocompatible, moveable components that are not silicon, which has
limited biocompatibility; and how to communicate wirelessly once
implanted (radio-frequency microelectronics require power, are
relatively large, and are not biocompatible).
The researchers developed a “locking mechanism” for precise actuation
and movement of freely moving parts, which can function as valves,
manifolds, rotors, pumps, and drug delivery systems. They were able to
tune the biomaterials within a wide range of mechanical and diffusive
properties and to control them after implantation without a sustained
power supply, such as a toxic battery.
“We can make small implantable devices, sensors, or robots that we
can talk to wirelessly. Our iMEMS system could bring the field a step
closer to developing soft miniaturized robots that can safely interact
with humans and other living systems,” said Sia.
The team developed a drug delivery system and tested it on mice with
bone cancer. The iMEMS system delivered chemotherapy adjacent to the
cancer, and limited tumor growth while showing less toxicity than with
chemotherapy administered throughout the body.
The study was supported by the National Science Foundation, NIH, and
the Agency for Science, Technology and Research (Singapore).
* The team used light to polymerize sheets of gel and
incorporated a stepper mechanization to control the z-axis and pattern
the sheets layer by layer, giving them three-dimensionality. Controlling
the z-axis enabled the researchers to create composite structures
within one layer of the hydrogel while managing the thickness of each
layer throughout the fabrication process. They were able to stack
multiple layers that are precisely aligned and, because they could
polymerize a layer at a time, one right after the other, the complex
structure was built in under 30 minutes.
“Hydrogels are difficult to work with, as they are soft and not
compatible with traditional machining techniques,” says Sau Yin Chin,
lead author of the study, who worked with Sia. “We have tuned the
mechanical properties and carefully matched the stiffness of structures
that come in contact with each other within the device. Gears that
interlock have to be stiff in order to allow for force transmission and
to withstand repeated actuation. Conversely, structures that form
locking mechanisms have to be soft and flexible to allow for the gears
to slip by them during actuation, while at the same time they have to be
stiff enough to hold the gears in place when the device is not
actuated. We also studied the diffusive properties of the hydrogels to
ensure that the loaded drugs do not easily diffuse through the hydrogel
layers.”
Abstract of Additive manufacturing of hydrogel-based materials for next-generation implantable medical devices
Implantable microdevices often have static components rather than
moving parts and exhibit limited biocompatibility. This paper
demonstrates a fast manufacturing method that can produce features in
biocompatible materials down to tens of micrometers in scale, with
intricate and composite patterns in each layer. By exploiting the unique
mechanical properties of hydrogels, we developed a “locking mechanism”
for precise actuation and movement of freely moving parts, which can
provide functions such as valves, manifolds, rotors, pumps, and delivery
of payloads. Hydrogel components could be tuned within a wide range of
mechanical and diffusive properties and can be controlled after
implantation without a sustained power supply. In a mouse model of
osteosarcoma, triggering of release of doxorubicin from the device over
10 days showed high treatment efficacy and low toxicity, at 1/10
of the standard systemic chemotherapy dose. Overall, this platform,
called implantable microelectromechanical systems (iMEMS), enables
development of biocompatible implantable microdevices with a wide range
of intricate moving components that can be wirelessly controlled on
demand, in a manner that solves issues of device powering and
biocompatibility.
Plato in the Theaetetus (200D-201C) defined knowledge as justifiedtrue belief. Justification was providing some reasons (λόγος or συλλογισμῶ), a rational explanation for the belief. True opinion accompanied by reason is knowledge. (δόξαν ἀληθῆ μετὰ λόγου ἐπιστήμην εἶναι) (202C)
Although "justified true belief" is the traditional philosophical
definition of knowledge, still in use in modern positions on
epistemology, the ancients were already skeptical of this Platonic idea.
Socratic dialogues normally did not reach any positive conclusions;
they were "negative dialectics."
Indeed, the Theaetetus ends with Socrates' utter rejection of
perception, true belief, or true belief combined with reasons or
explanations as justification. Socrates says:
And it is utterly silly, when we are looking for a definition of
knowledge, to say that it is right opinion with knowledge, whether of
difference or of anything else whatsoever. So neither perception,
Theaetetus, nor true opinion, nor reason or explanation combined with
true opinion could be knowledge (epistéme).
καὶ παντάπασί γε εὔηθες, ζητούντων ἡμῶν ἐπιστήμην, δόξαν φάναι ὀρθὴν
εἶναι μετ᾽ ἐπιστήμης εἴτε διαφορότητος εἴτε ὁτουοῦν. οὔτε ἄρα αἴσθησις, ὦ
Θεαίτητε, οὔτε δόξα ἀληθὴς οὔτε μετ᾽ ἀληθοῦς δόξης λόγος προσγιγνόμενος
ἐπιστήμη ἂν εἴη.
Plato's Theaetetus, (210A-B)
An infinite regress arises when we ask what are the justifications for the reasons themselves.
If the reasons count as knowledge, they must themselves be justified with reasons for the reasons, and so on, ad infinitum.
The problem of the infinite regress was a critical argument of the Skeptics in ancient philosophy.
Sextus Empiricus tells us there are two basic Pyrrhonian modes or tropes
that lead the skeptic to suspension of judgment (ἐποχῆ):
They [skeptics] hand down also two other modes leading to suspension of
judgement. Since every object of apprehension seems to be apprehended
either through itself or through another object, by showing that nothing
is apprehended either through itself or through another thing, they
introduce doubt, as they suppose, about everything. That nothing is
apprehended through itself is plain, they say, from the controversy
which exists amongst the physicists regarding, I imagine, all things,
both sensibles and intelligibles; which controversy admits of no
settlement because we can neither employ a sensible nor an intelligible
criterion, since every criterion we may adopt is controverted and
therefore discredited.
And the reason why they do not allow that anything is apprehended
through something else is this: If that through which an object is
apprehended must always itself be apprehended through some other thing,
one is involved in a process of circular reasoning or in regress ad infinitum.
And if, on the other hand, one should choose to assume that the thing
through which another object is apprehended is itself apprehended
through itself, this is refuted by the fact that, for the reasons
already stated, nothing is apprehended through itself. But as to how
what conflicts with itself can possibly be apprehended either through
itself or through some other thing we remain in doubt, so long as the
criterion of truth or of apprehension is not apparent, and signs, even
apart from demonstration, are rejected.
(Outlines of Pyrrhonism, Loeb Library, R.G.Bury tr., 1.178-79)
The skeptic can always ask a philosopher for justifying reasons. When
those reasons are given, he can demand their justification, and this in
turn leads to an infinite regress of justifications.
The endless controversy and disagreement of all philosophers cautions us
against accepting any of their arguments as knowledge. It is said by
some that philosophy has been two thousand years of failed attempts to
refute these skeptical arguments.
Second only to Kant 's
"scandal" that philosophers cannot logically prove the existence of the
external world, it is scandalous that professional philosophers to this
day are in such profound disagreement about what it means to know
something.
Epistemologists may not all be wrong, but with their conflicting theories of knowledge, how many of them are likely to be right?
This is especially dismaying for those epistemologists who still see a normative role for philosophy that could provide an a priorifoundation for scientific or empirical a posteriori knowledge. Kant called this the synthetic a priori.
In recent years, professional epistemologists have been reduced to quibbling over "Gettier problems" - clever sophistical examples and counterexamples that defeat the reasoned justifications for true beliefs.
Following some unpublished work of Gregory O'Hair, David Armstrong identifies and diagrams several possible ways to escape the Skeptic's infinite regress, including:
Skepticism - knowledge is impossible
The regress is infinite but virtuous
The regress is finite, but has no end (Coherence view)
The regress ends in self-evident truths, the axioms of geometry, for example (Foundationalist view)
Non-inferential credibility, such as direct sense perceptions
Externalist theories (O'Hair is the source of the term "externalist")
Tree of Life by Eli Content at the Joods Historisch Museum. The Tree of Life, or Etz haChayim (עץ החיים) in Hebrew, is a mystical symbol used in the Kabbalah of esoteric Judaism to describe the path to HaShem and the manner in which He created the world ex nihilo (out of nothing).
Look up ex nihilo in Wiktionary, the free dictionary.
Ex nihilo is a Latin phrase meaning "out of nothing". It often appears in conjunction with the concept of creation, as in creatio ex nihilo, meaning "creation out of nothing", chiefly in philosophical or theological contexts, but it also occurs in other fields.
In theology, the common phrase creatio ex nihilo (lit. "creation out of nothing"), contrasts with creatio ex materia (creation out of some pre-existent, eternal matter) and creatio ex deo (creation out of the being of God). Creatio continua is the ongoing divine creation.
The phrase ex nihilo also appears in the classical philosophical formulation ex nihilo nihil fit, which means "out of nothing comes nothing".
When used outside of religious or metaphysical contexts, ex nihilo also refers to something coming from nothing. For example, in a conversation, one might call a topic "ex nihilo" if it bears no relation to the previous topic of discussion.
History
Ancient Near Eastern mythologies and classical creation myths in Greek mythology
envisioned the creation of the world as resulting from the actions of a
god or gods upon already-existing primeval matter, known as chaos.[1]
An early conflation of Greek philosophy with the narratives in the Hebrew Bible came from Philo of Alexandria (d.AD50), writing in the context of Hellenistic Judaism. Philo equated the Hebrew creator-deity Yahweh with Aristotle's primum movens (First Cause)[2][3] in an attempt to prove that the Jews had held monotheistic views even before the Greeks.[citation needed]
However, this was still within the context of creation from
pre-existing materials (i.e., "moving" or "changing" a material
substratum.)
The classical tradition of creation from chaos first came under question in Hellenistic philosophy (on a priori grounds), which developed the idea that the primum movens must have created the world out of nothing.[citation needed]
Theologians debate whether the Bible itself teaches creation ex nihilo. Traditional interpreters[4] argue on grammatical and syntactical grounds that this is the meaning of Genesis 1:1,
which is commonly rendered: "In the beginning God created the heavens
and the earth." They find further support for this view in New Testament
passages such as Hebrews
11:3—"By faith we understand that the universe was created by the word
of God, so that what is seen was not made out of things that are
visible" and Revelation 4:11, "For you [God] created all things, and by your will they existed and were created." However, other interpreters[5] understand creation ex nihilo as a second-century theological development. According to this view, church fathers opposed notions appearing in pre-Christian creation myths and in Gnosticism—notions of creation by a demiurge out of a primordial state of matter (known in religious studies as chaos after the Greek term used by Hesiod in his Theogony).[6] Jewish thinkers took up the idea,[7] which became important to Judaism, to ongoing strands in the Christian tradition, and—as a corollary—to Islam.
The first sentence of the Greek version of Genesis in the Septuagint starts with the words: ἐν ἀρχῇ ἐποίησεν, translatable as "in the beginning he made".[8]
A verse of 2 Maccabees (a book written in Koine Greek in the same sphere of Hellenized Judaism of Alexandria,
but predating Philo by about a century) expresses the following: "I
beseech thee, my son, look upon the heaven and the earth, and all that
is therein, and consider that God made them of things that were not; and
so was mankind made likewise." (2Maccabees 7:28, KJV). While those who believe in ex nihilo
point to God creating "things that were not", those who reject creation
out of nothing point out that the context mentions the creation of man,
who was "made from the dust" and not from absolutely "nothing". Many
ancient texts tend to have similar issues, and those on each side tend
to interpret the text according to their understanding.
Max Weber summarizes a sociological view of the overall development and corollaries of the theological idea:
[...] As otherworldly expectations become increasingly important, the
problem of the basic relationship of god to the world and the problem
of the world's imperfections press into the foreground of thought; this
happens the more life here on earth comes to be regarded as a merely
provisional form of existence when compared to that beyond, the more the
world comes to be viewed as something created by god ex nihilo,
and therefore subject to decline, the more god himself is conceived as a
subject to transcendental goals and values, and the more a person's
behavior in this world becomes oriented to his fate in the next. [...][9]
If the universe has a cause, then an uncaused, personal creator of
the universe exists, who without the universe is beginningless,
changeless, immaterial, timeless, spaceless, and infinitely powerful.
Therefore, an uncaused, personal creator of the universe exists, who
without the universe is beginningless, changeless, immaterial,
timeless, spaceless, and infinitely powerful.
Another argument for ex nihilo creation comes from Claude Nowell's Summum
philosophy that states before anything existed, nothing existed, and if
nothing existed, then it must have been possible for nothing to be. If
it is possible for nothing to be (the argument goes), then it must be
possible for everything to be.[10]
Ancient Greek
Some scholars[which?] have argued that Plethon viewed Plato as positing ex nihilo creation in his Timaeus.
In The Book of the Articles of Faith and Doctrines of Dogma (Kitāb al-Amānāt wa l-Iʿtiqādāt, Emunoth ve-Deoth, completed 933) written by Saadia Gaon
(c. 882−942) the metaphysical problems of the creation of the world and
the unity of the Creator are discussed. In this book, Saadia Gaon gives
four proofs for the doctrine of the creation of the world ex nihilo (yesh me-ayin).
To harmonize the biblical statement of the creation ex nihilo with the doctrine of the primordial elements, the Sefer Yetzirah assumes a double creation, one ideal and the other real.[13]
In introducing Sefer Yetzirah's theory of creation Saadia Gaon makes a distinction between the Biblical account of creation ex nihilo, in which no process of creation is described, and matter formed by speech as described in Sefer Yetzirah. The cosmogony of Sefer Yetzirah is even omitted from the discussion of creation in his magnum opus Emunoth ve-Deoth.
Islamic
Early Islamic philosophy,
as well as key Muslim schools of thought, have argued a wide array of
views, the basis always being that the creator was an eternal being who
was outside of the creation (i.e., any materially based entities within
all of creation), and was not a part of creation. Several schools of
thought stemming from the first cause argument, and a great deal of
philosophical works from Muslim scholars such as Al-Ghazali, came from the following verses in the Qur'an. The following quotations come from Muhammad Asad's translation, The Message of The Qur'an:
52:35: "Were they created by nothing? Or were they themselves the creators?"
2:117: "The Originator is He of the heavens and the earth: and when
He wills a thing to be, He but says unto it, 'Be'—and it is."
19:67: "But does man not bear in mind that We have created him aforetime while at one point they were nothing?"
21:30: "ARE, THEN, they who are bent on denying the truth not aware
that the heavens and the earth were [once] one single entity, which We
(formal singular) then parted asunder? – and [that] We made out of water
every living thing? Will they not, then, [begin to] believe?"
21:56: "He answered: 'Nay, but your [true] Sustainer is the
Sustainer of the heavens and the earth—He who has brought them into
being: and I am one of those who bear witness to this [truth]!'"
35:1: "ALL PRAISE is due to God, Originator of the heavens and the
earth, who causes the angels to be (His) message-bearers, endowed with
wings, two, or three, or four. He adds to His creation whatever He
Wills: for, verily, God, is most competent over all things."
51:47: "It is We (formal singular) who have built the heaven with
(Our creative) power; and, verily, it is We who are steadily expanding
it."
Christian
Biblical scholars and theologians within the Christian tradition such as Augustine (354–430),[14]John Calvin (1509–1564),[15]John Wesley (1703–1791),[16] and Matthew Henry (1662–1714)[17] cite Genesis1:1 in support of the idea of Divine creation out of nothing.
Some of the early Christian Church Fathers with a Platonic
background argued that the act of creation itself involved pre-existent
matter, but made that matter in turn to have been created out of
nothing.[18]
Hindu
The RigVeda
quotes "If in the beginning there was neither Being nor Non-Being,
neither air nor sky, what was there? Who or what oversaw it? What was it
when there was no darkness, light, life, or death? We can only say that
there was the One, that which breathed of itself deep in the void, that
which was heat and became desire and the germ of spirit," which is
suggestive of the fact that Ex nihilo creator was always there and he is
not controlled by time or by any previous creation.[19]
Modern physical
A widely supported hypothesis in modern physics is the zero-energy universe
which states that the total amount of energy in the universe is exactly
zero. It has been argued that this is the only kind of universe that
could come from nothing.[20] Such a universe would have to be flat in shape, a state which does not contradict current observations that the universe is flat with a 0.5% margin of error.
The paper "Spontaneous creation of the Universe Ex Nihilo"
provides a model for a way the Universe could have been created from
pure 'nothing' in information terms.[23]
Opposing arguments
Logical
The
"first cause" argument was rooted in ancient Greek philosophy and based
on observation in physics. Originally, it was understood[by whom?]
in the context of creation from chaos. The observed phenomenon seen in
reality is that nothing moves by itself. In other words, motion is not
self-caused; thus, the Classic Greek thinkers argued that the cosmos
must have had a "prime mover" primum movens. However, this scientific observation of motion does not logically extend to the idea of existence, and therefore does not necessarily indicate creation from absolutely nothing.
In theology, ex nihilo creation states that there was a beginning to one's existence, and anything that exists has a beginning. This idea of a required beginning appears to contradict the proposed creator who existed without a beginning.
In other words, people are considered to be contingent beings, and
their existence depends upon a non-contingent being. However, if
non-contingency is possible, then there is no basis for arguing that
contingency is required for existence, nor can it be logically concluded
that the number of non-contingent beings or non-contingent things is
limited to one single substance or one single Being.
David Ray Griffin expressed his thoughts on this as follows:
"No
special philosophical problems are raised by this view: If it is
intelligible to hold that the existence of God requires no explanation,
since something must exist necessarily and "of itself," then it is not
unintelligible to hold that that which exists necessarily is God and a realm of non-divine actualities."[24]
Christian
Bruce
K. Waltke wrote an extensive Biblical study of creation theology in
which he argues for creation from chaos rather than from nothing - based
on the Hebrew Torah and the New Testament texts. The Western
Conservative Baptist Seminary published this work in 1974 and again in
1981.[25] On a historical basis, many[quantify] scholars agree that the doctrine of creatio ex nihilo was not the original intent of the Biblical authors, but instead a change in the interpretation of the texts that began to evolve in the mid-second century AD in the atmosphere of Hellenistic philosophy.[26][27] The idea solidified around 200AD in arguments and in response to the Gnostics, Stoics, and Middle Platonists.[28]
Thomas Jay Oord, a Christian philosopher and theologian, argues that Christians should abandon the doctrine of creation ex nihilo. Oord points to the work of biblical scholars such as Jon D. Levenson, who points out that the doctrine of creatio ex nihilo does not appear in Genesis.
Oord speculates that God created our particular universe billions of
years ago from primordial chaos. This chaos, however, did not predate
God, for God would have created the chaotic elements as well.[29][page needed] Oord suggests that God can create all things without creating from absolute nothingness.[30]
Oord offers nine objections to creatio ex nihilo:[31]
Theoretical problem: One cannot conceive absolute nothingness.
Biblical problem: Scripture – in Genesis, 2 Peter, and elsewhere –
suggests creation from something (water, deep, chaos, etc.), not
creation from absolutely nothing.
Historical problem: The GnosticsBasilides and Valentinus first proposed creatio ex nihilo
on the basis of assuming the inherently evil nature of creation, and in
the belief that God does not act in history. Early Christian
theologians adopted the idea to affirm the kind of absolute divine power
that many Christians now reject.
Empirical problem: We have no evidence that our universe originally came into being from absolutely nothing.
Creation-at-an-instant problem: We have no evidence in the history of the Universe after the big bang
that entities can emerge instantaneously from absolute nothingness. As
the earliest philosophers noted, out of nothing comes nothing (ex nihilo, nihil fit).
Solitary power problem: Creatio ex nihilo assumes that a powerful God once acted alone. But power, as a social concept, only becomes meaningful in relation to others.
Errant revelation problem: The God with the capacity to create
something from absolutely nothing would apparently have the power to
guarantee an unambiguous and inerrant message of salvation (for example:
inerrant Bible). An unambiguously clear and inerrant divine revelation does not exist.
Problem of Evil:
If God once had the power to create from absolutely nothing, God
essentially retains that power. But a God of love with this capacity
appears culpable for failing to prevent evil.
Empire Problem: The kind of divine power implied in creatio ex nihilo supports a theology of empire, based upon unilateral force and control of others.
Process theologians argue that humans have always related a God to some "world" or another. They[32] also claim that rejecting creatio ex nihilo
provides the opportunity to affirm that God has everlastingly created
and related with some realm of non-divine actualities or another
(compare continuous creation).
According to this alternative God-world theory, no non-divine thing
exists without the creative activity of God, and nothing can terminate
God's necessary existence.
Some non-trinitarian Christian churches do not teach the ex nihilo doctrine:
The Church of Jesus Christ of Latter-day Saints (LDS) teaches that Jehovah (whom they identify as the heavenly form of Jesus Christ), under the direction of God the Father, organized this world and others like it out of eternal, pre-existing materials.[33][34]
The first modern (non-biblical) prophet of the religion, Joseph Smith,
explained the LDS view as follows: "Now, the word create does not mean
to create out of nothing; it means to organize... God had materials to
organize the world out of chaos... The pure principles of element are
principles which can never be destroyed; they may be organized and
reorganized, but not destroyed. They had no beginning and can have no
end"[35]
Debate continues on the issue of creation Ex Nihilo versus creation Ex
Materia between evangelical authors Paul Copan and William Lane Craig[36] and LDS/Mormon apologist Blake Ostler.[37]
Jehovah's Witnesses teach that God used the energy he possesses to create the Universe based on their interpretation of Isaiah40:26.[38]
They believe this harmonizes with the scientific idea of the
relationship between matter and energy. They distinguish Jehovah from
Jesus Christ, teaching that before he created the physical universe,
Jehovah created Jesus and that Michael is the heavenly form of Jesus.
Hindu
The Vedanta schools of Hinduism reject the concept of creation ex nihilo for several reasons, for example:
both types of revelatory texts (śruti[39] and smṛti) designate matter as eternal although completely dependent on God—the Absolute Truth (param satyam)
believers then have to attribute all the evil ingrained in material life to God, making Him partial and arbitrary,[40] which does not logically accord with His nature
The Bhagavad Gita
(BG) states the eternality of matter and its transformability clearly
and succinctly: "Material nature and the living entities should be
understood to be beginningless. Their transformations and the modes of
matter are products of material nature."[41] The opening words of Krishna in BG2.12-13 also imply this, as do the doctrines referred to in BG16.8 as explained by the commentator Vadiraja Tirtha.[42]
Most philosophical schools in Hinduism maintain that material
creation started with some minute particle (or seed) which had to be
co-eternal or a part of ultimate reality (Brahman). This minute starting
point is also the point into which all creation contracts at the end of
each cycle. This concept varies between various traditions, such as the
Vishishtadvaita tradition (which asserts that the Universe forms a part
of God, created from some aspect of His divinity) and Tamil Shaiva
Siddhanta traditions (which state that the minute initial particle
(shuddha Maya) has always existed and was never created).
Linguistic and textual
Scholars have suggested alternative translations from the Biblical Hebrew for the concept often rendered as "created" in English-language
versions of Genesis 1. Van Volde, for example, suggests that the
Genesis account tells of the "separation" of existing material rather
than of creation ex nihilo.[43]
Note that ordinary language may lack a concise definitive native expression for "creation ex nihilo" - hence the need for the technical Latinate phrase itself. The English-language word "create" itself comes from the Latin creare (to make, bring forth, produce, beget), with a root cognate with crescere (to arise, to grow) and allied to the English word crescent (originally meaning "growing").
Structural
proteins that bind DNA are well-understood examples of non-specific
DNA-protein interactions. Within chromosomes, DNA is held in complexes
with structural proteins. These proteins organize the DNA into a compact
structure called chromatin. In eukaryotes, this structure involves DNA binding to a complex of small basic proteins called histones. In prokaryotes, multiple types of proteins are involved.[8][9] The histones form a disk-shaped complex called a nucleosome,
which contains two complete turns of double-stranded DNA wrapped around
its surface. These non-specific interactions are formed through basic
residues in the histones making ionic bonds to the acidic sugar-phosphate backbone of the DNA, and are therefore largely independent of the base sequence.[10]Chemical modifications of these basic amino acid residues include methylation, phosphorylation and acetylation.[11]
These chemical changes alter the strength of the interaction between
the DNA and the histones, making the DNA more or less accessible to transcription factors and changing the rate of transcription.[12]
Other non-specific DNA-binding proteins in chromatin include the
high-mobility group (HMG) proteins, which bind to bent or distorted DNA.[13] Biophysical studies show that these architectural HMG proteins bind, bend and loop DNA to perform its biological functions.[14][15] These proteins are important in bending arrays of nucleosomes and
arranging them into the larger structures that form chromosomes.[16]
Proteins that specifically bind single-stranded DNA
A distinct group of DNA-binding proteins are the DNA-binding proteins that specifically bind single-stranded DNA. In humans, replication protein A
is the best-understood member of this family and is used in processes
where the double helix is separated, including DNA replication,
recombination and DNA repair.[17] These binding proteins seem to stabilize single-stranded DNA and protect it from forming stem-loops or being degraded by nucleases.
Binding to specific DNA sequences
In
contrast, other proteins have evolved to bind to specific DNA
sequences. The most intensively studied of these are the various transcription factors,
which are proteins that regulate transcription. Each transcription
factor binds to one specific set of DNA sequences and activates or
inhibits the transcription of genes that have these sequences near their
promoters. The transcription factors do this in two ways. Firstly, they
can bind the RNA polymerase responsible for transcription, either
directly or through other mediator proteins; this locates the polymerase
at the promoter and allows it to begin transcription.[18] Alternatively, transcription factors can bind enzymes that modify the histones at the promoter. This alters the accessibility of the DNA template to the polymerase.[19]
These DNA targets can occur throughout an organism's genome.
Thus, changes in the activity of one type of transcription factor can
affect thousands of genes.[20] Thus, these proteins are often the targets of the signal transduction processes that control responses to environmental changes or cellular differentiation
and development. The specificity of these transcription factors'
interactions with DNA come from the proteins making multiple contacts to
the edges of the DNA bases, allowing them to read the DNA sequence. Most of these base-interactions are made in the major groove, where the bases are most accessible.[21]
Mathematical descriptions of protein-DNA binding taking into account
sequence-specificity, and competitive and cooperative binding of
proteins of different types are usually performed with the help of the lattice models.[22]
Computational methods to identify the DNA binding sequence specificity
have been proposed to make a good use of the abundant sequence data in
the post-genomic era.[23]
Protein–DNA interactions
Protein–DNA interactions occur when a protein binds a molecule of DNA, often to regulate the biological function of DNA, usually the expression of a gene. Among the proteins that bind to DNA are transcription factors that activate or repress gene expression by binding to DNA motifs and histones that form part of the structure of DNA and bind to it less specifically. Also proteins that repair DNA such as uracil-DNA glycosylase interact closely with it.
In general, proteins bind to DNA in the major groove; however, there are exceptions.[24]
Protein–DNA interaction are of mainly two types, either specific
interaction, or non-specific interaction. Recent single-molecule
experiments showed that DNA binding proteins undergo of rapid rebinding
in order to bind in correct orientation for recognizing the target site.[25]
There are many in vitro and in vivo techniques which are useful in detecting DNA-Protein Interactions. The following lists some methods currently in use:[27]
DNase footprinting assay can be used to identify the specific site of binding of a protein to DNA.
Chromatin immunoprecipitation
is used to identify the sequence of the DNA fragments which bind to a
known transcription factor. This technique when combined with high
throughput sequencing is known as ChIP-Seq and when combined with microarrays it is known as ChIP-chip.
Yeast One-hybrid System (Y1H) is used to identify which protein binds to a particular DNA fragment.
Structure determination using X-ray crystallography has been used to give a highly detailed atomic view of protein–DNA interactions.
Manipulating the interactions
The protein–DNA interactions can be modulated using stimuli like ionic strength of the buffer, macromolecular crowding,[28] temperature, pH and electric field. This can lead to reversible dissociation/association of the protein–DNA complex.
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