Conservapedia - User contributions [en]

Deoxyribonucleic acid

2009-01-18T02:07:08Z

Mccusty93: /* Modern understanding */

[[Image:799.gif|right|thumb|300px]]
'''Deoxyribonucleic acid''' (DNA) is an [[organic compound|organic]] [[chemical compound]] made up of [[molecule]]s shaped like a [[double helix]] (like a twisted ladder). The individual building blocks of DNA (and other nucleic acids) are [[nucleotide]]s, which themselves consist of three principle parts: A nitrogenous base, a [[sugar]], and a [[phosphate]] group.

DNA contains [[gene]]s that help create [[protein]]s by first being transcribed into [[RNA]]. All plants and animals contain DNA, except for a few [[virus]]es. Offspring of sexually reproducing organisms contain DNA from both parents.

==History==
In the late 19th century [[Friedrich Miescher]], a Swiss [[biochemist]], discovered an unusual [[acid]] in the [[nuclei]] of cells. The acid was named deoxyribonucleic acid, or DNA. In 1944 the American [[biologist]]s, [[Alfred Hershey]], [[Thomas Gilmore]] and [[Martha Chase]] used experiments with [[bacteria]] and [[bacteriophage]]s to show that DNA passed [[gene]]s from one generation to the next.

At that time, it was unclear how this simple molecule could hold all the complex information controlling the development of humans, animals and plants. Scientists knew it was made of four chemical bases called [[adenine]] (A), [[thymine]] (T), [[guanine]] (G) and [[cytosine]] (C), plus [[phosphoric acid]] and a [[sugar]]. They also knew that the ratios of A and T as well as G and C were always the same, but they did not know the rules that controlled the arrangement.

British scientists [[Rosalind Franklin]] and [[Maurice Wilkins]] passed [[X-ray|X-rays]] through DNA to study the patterns made when the crystals diffracted them. From studying photographs of patterns, Rosalind Franklin concluded that DNA must be be a [[helix]]. [[James Watson]] and [[Francis Crick]], working in [[Cambridge]], used this information to help them solve the puzzle of DNA structure. They built a model showing that if A always paired with T and G paired with C, DNA must be like a ladder made of two strands twisted together in a double helix. The sugar and phosphoric acid were the sides of the ladder, and the rungs were the paired bases that were held together through hydrogen bonding.

Watson and Crick suggested that DNA could unzip itself into two separate strands, and each strand could act as a pattern to grow a new strand. Crick showed later that areas of the DNA known as genes worked in groups of three to code for amino acids, the building blocks of proteins. These groups are called [[codon|codons]]. They make about fifty thousand different types of [[protein]], which make all the different types of cell in the body. Indian biochemist [[Har Gobind Khorana]] made all the possible codons and worked out which codons controlled which [[amino acid]]. Most codons are redundant and code for the same amino acids, these mostly are different in only the third base pair. This means that differences in genotype can build up in the third position (thereby changing the genotype) without changing the protein (keeps the same phenotype).

If the DNA in one cell was stretched out, it would be about three feet long. Although DNA has a very simple structure, it can carry an enormous amount of [[information]]. Scientists do not yet understand the function of all DNA, but in 1991 a project called the [[Human Genome Project]] began to use computers to map the three billion base pairs which make up the 46 human [[chromosome|chromosomes]].

==Modern understanding==
[[Image:818.gif|right|thumb|Structure of DNA.]]
Small lengths of DNA called [[gene]]s serve as the instructions for the body to carry out its functions and give rise to the physical traits of the organism. <ref>"Eye-color genes, through the proteins they encode, direct the amount and placement of melanin in the iris." [http://www.hhmi.org/cgi-bin/askascientist/highlight.pl?kw=&file=answers%2Fgenetics%2Fans_044.html Ask A Scientist - Genes and eye color]</ref> DNA is packaged into [[chromosomes]]. Each individual human being has 23 pairs of [[chromosome]]s, where one set is inherited from his/her mother and the other set is inherited from his/her father. 22 of these chromosomes are referred to as [[autosome]]s, while the remaining chromosome is the sex chromosome that determines gender.

[[Prokaryotic DNA]] is circular (a closed loop), while [[eukaryotic DNA]] is linear (with ends) with the exception of [[Mitochondrial DNA]] and chloroplast DNA which is separate from that of the eukaryotic organism. Both mitochondria and chloroplasts were thought to once be prokayotic organisms that became symbiotes within eukaryotic organisms, this explains why they still retain their circular DNA. The ends of eukaryotic DNA is protected by [[telomere]]s, which are joined together in knots, except when the cell is undergoing [[mitosis]]. DNA in [[prokaryote]]s usually consists only of one closed loop chromosome.<ref>Campbell, Neil A, et. al. ''Biology''. 6th ed. San Francisco: Benjamin Cummings, 2002. 299, 530-31.</ref>

Some viral [[genome]]s are composed of DNA, such as that of the [[influenza]] virus.

[[Mutation]]s in DNA accumulate over time and build up to create differences between organisms. Most mutations in DNA are harmless and don't affect the [[phenotype|observable traits]] of the organism. Others can have beneficial effects, but some can disrupt important functions. Many diseases such as Autism and Ellis-van Crevice syndrome have been shown to occur due to these harmful genetic mutations.

DNA is [[transcription|transcribed]] into [[mRNA]], which is in turn [[translation|translated]] into [[proteins]] built from [[amino acids]]. Additionally, DNA maybe transcribed into functional RNAs such as ribosomal (rRNA) or transfer (tRNA) that do not undergo translation. [[RNA]] can also be reverse-transcribed back into DNA, which is the called [[Complementary DNA]] or [[cDNA]].

However, DNA-containing cells are soon to go extinct, except for the heathens, who will soon die as it is. DNA is an acid, and as everyone knows, acids dissolve cells. Soon, God will change the cells of the faithful to not contain DNA so that they can live forever and do ministry work all over the world.

SERIOUSLY?!?!!?!?!? How can you POSSIBLY think that? Are you THAT blissfully unaware of the fact that your own BLOOD is acidic? Bigoted bitch. I doubt God wants you up on those damned ACIDIC clouds- he would hate to disturb the people up there in the non-existent heaven with your crackpot theories.

==DNA fingerprinting==

DNA can help police track down criminals if an attacker leaves something like hair or blood at a crime scene. Everybody’s DNA is unique unless they are identical twins, and the genetic ‘fingerprint’ of this material can be enough to confirm if a suspect was at the scene.
Genetic fingerprinting can also show if somebody is closely related to somebody else. Archaeologists used samples from living relatives to identify whether bodies found buried in a forest in [[Russia]] were the remains of the [[tsar]] and his family, killed during the 1919 [[Russian Revolution]].

As well as showing how different we all are, DNA shows how much we are all the same. Only one small part of one chromosome distinguishes a boy from a girl. Genes give us different colored [[eye]]s, [[hair]] and [[skin]], but 99.5% of any human's DNA is in the same order as everybody else’s.

Human DNA is made up of the same components as the DNA of other organisms, with most species even sharing the same genes which code for the same proteins. This is why even [[fruit fly|fruit flies]] and [[mouse|mice]] can be used as model organisms in order to help better understand human genetic diseases.

==External links==
*[http://www.learner.org/interactives/dna/index.html Interactive DNA] Learn about genetics, genetic engineering, the Human Genome Project and the ethical implications of these new technologies.
*[http://www.blackwellpublishing.com/trun/artwork/Animations/cloningexp/cloningexp.html Animated guide to DNA cloning]

== References ==
<references/>

[[Category:Genetics]]

Deoxyribonucleic acid

2009-01-18T02:06:49Z

Mccusty93: /* Modern understanding */

[[Image:799.gif|right|thumb|300px]]
'''Deoxyribonucleic acid''' (DNA) is an [[organic compound|organic]] [[chemical compound]] made up of [[molecule]]s shaped like a [[double helix]] (like a twisted ladder). The individual building blocks of DNA (and other nucleic acids) are [[nucleotide]]s, which themselves consist of three principle parts: A nitrogenous base, a [[sugar]], and a [[phosphate]] group.

DNA contains [[gene]]s that help create [[protein]]s by first being transcribed into [[RNA]]. All plants and animals contain DNA, except for a few [[virus]]es. Offspring of sexually reproducing organisms contain DNA from both parents.

==History==
In the late 19th century [[Friedrich Miescher]], a Swiss [[biochemist]], discovered an unusual [[acid]] in the [[nuclei]] of cells. The acid was named deoxyribonucleic acid, or DNA. In 1944 the American [[biologist]]s, [[Alfred Hershey]], [[Thomas Gilmore]] and [[Martha Chase]] used experiments with [[bacteria]] and [[bacteriophage]]s to show that DNA passed [[gene]]s from one generation to the next.

At that time, it was unclear how this simple molecule could hold all the complex information controlling the development of humans, animals and plants. Scientists knew it was made of four chemical bases called [[adenine]] (A), [[thymine]] (T), [[guanine]] (G) and [[cytosine]] (C), plus [[phosphoric acid]] and a [[sugar]]. They also knew that the ratios of A and T as well as G and C were always the same, but they did not know the rules that controlled the arrangement.

British scientists [[Rosalind Franklin]] and [[Maurice Wilkins]] passed [[X-ray|X-rays]] through DNA to study the patterns made when the crystals diffracted them. From studying photographs of patterns, Rosalind Franklin concluded that DNA must be be a [[helix]]. [[James Watson]] and [[Francis Crick]], working in [[Cambridge]], used this information to help them solve the puzzle of DNA structure. They built a model showing that if A always paired with T and G paired with C, DNA must be like a ladder made of two strands twisted together in a double helix. The sugar and phosphoric acid were the sides of the ladder, and the rungs were the paired bases that were held together through hydrogen bonding.

Watson and Crick suggested that DNA could unzip itself into two separate strands, and each strand could act as a pattern to grow a new strand. Crick showed later that areas of the DNA known as genes worked in groups of three to code for amino acids, the building blocks of proteins. These groups are called [[codon|codons]]. They make about fifty thousand different types of [[protein]], which make all the different types of cell in the body. Indian biochemist [[Har Gobind Khorana]] made all the possible codons and worked out which codons controlled which [[amino acid]]. Most codons are redundant and code for the same amino acids, these mostly are different in only the third base pair. This means that differences in genotype can build up in the third position (thereby changing the genotype) without changing the protein (keeps the same phenotype).

If the DNA in one cell was stretched out, it would be about three feet long. Although DNA has a very simple structure, it can carry an enormous amount of [[information]]. Scientists do not yet understand the function of all DNA, but in 1991 a project called the [[Human Genome Project]] began to use computers to map the three billion base pairs which make up the 46 human [[chromosome|chromosomes]].

==Modern understanding==
[[Image:818.gif|right|thumb|Structure of DNA.]]
Small lengths of DNA called [[gene]]s serve as the instructions for the body to carry out its functions and give rise to the physical traits of the organism. <ref>"Eye-color genes, through the proteins they encode, direct the amount and placement of melanin in the iris." [http://www.hhmi.org/cgi-bin/askascientist/highlight.pl?kw=&file=answers%2Fgenetics%2Fans_044.html Ask A Scientist - Genes and eye color]</ref> DNA is packaged into [[chromosomes]]. Each individual human being has 23 pairs of [[chromosome]]s, where one set is inherited from his/her mother and the other set is inherited from his/her father. 22 of these chromosomes are referred to as [[autosome]]s, while the remaining chromosome is the sex chromosome that determines gender.

[[Prokaryotic DNA]] is circular (a closed loop), while [[eukaryotic DNA]] is linear (with ends) with the exception of [[Mitochondrial DNA]] and chloroplast DNA which is separate from that of the eukaryotic organism. Both mitochondria and chloroplasts were thought to once be prokayotic organisms that became symbiotes within eukaryotic organisms, this explains why they still retain their circular DNA. The ends of eukaryotic DNA is protected by [[telomere]]s, which are joined together in knots, except when the cell is undergoing [[mitosis]]. DNA in [[prokaryote]]s usually consists only of one closed loop chromosome.<ref>Campbell, Neil A, et. al. ''Biology''. 6th ed. San Francisco: Benjamin Cummings, 2002. 299, 530-31.</ref>

Some viral [[genome]]s are composed of DNA, such as that of the [[influenza]] virus.

[[Mutation]]s in DNA accumulate over time and build up to create differences between organisms. Most mutations in DNA are harmless and don't affect the [[phenotype|observable traits]] of the organism. Others can have beneficial effects, but some can disrupt important functions. Many diseases such as Autism and Ellis-van Crevice syndrome have been shown to occur due to these harmful genetic mutations.

DNA is [[transcription|transcribed]] into [[mRNA]], which is in turn [[translation|translated]] into [[proteins]] built from [[amino acids]]. Additionally, DNA maybe transcribed into functional RNAs such as ribosomal (rRNA) or transfer (tRNA) that do not undergo translation. [[RNA]] can also be reverse-transcribed back into DNA, which is the called [[Complementary DNA]] or [[cDNA]].

However, DNA-containing cells are soon to go extinct, except for the heathens, who will soon die as it is. DNA is an acid, and as everyone knows, acids dissolve cells. Soon, God will change the cells of the faithful to not contain DNA so that they can live forever and do ministry work all over the world.

SERIOUSLY?!?!!?!?!? How can you POSSIBLY think that? Are you THAT blissfully unaware of the fact that your own BLOOD is acidic? Bigoted bitch. I doubt God wants you up on those damned ACIDIC clouds- he would hate to disturb the people up there in the non-existant heaven with your crackpot theories.

==DNA fingerprinting==

DNA can help police track down criminals if an attacker leaves something like hair or blood at a crime scene. Everybody’s DNA is unique unless they are identical twins, and the genetic ‘fingerprint’ of this material can be enough to confirm if a suspect was at the scene.
Genetic fingerprinting can also show if somebody is closely related to somebody else. Archaeologists used samples from living relatives to identify whether bodies found buried in a forest in [[Russia]] were the remains of the [[tsar]] and his family, killed during the 1919 [[Russian Revolution]].

As well as showing how different we all are, DNA shows how much we are all the same. Only one small part of one chromosome distinguishes a boy from a girl. Genes give us different colored [[eye]]s, [[hair]] and [[skin]], but 99.5% of any human's DNA is in the same order as everybody else’s.

Human DNA is made up of the same components as the DNA of other organisms, with most species even sharing the same genes which code for the same proteins. This is why even [[fruit fly|fruit flies]] and [[mouse|mice]] can be used as model organisms in order to help better understand human genetic diseases.

==External links==
*[http://www.learner.org/interactives/dna/index.html Interactive DNA] Learn about genetics, genetic engineering, the Human Genome Project and the ethical implications of these new technologies.
*[http://www.blackwellpublishing.com/trun/artwork/Animations/cloningexp/cloningexp.html Animated guide to DNA cloning]

== References ==
<references/>

[[Category:Genetics]]

Deoxyribonucleic acid

2009-01-18T02:04:32Z

Mccusty93: /* Modern understanding */

[[Image:799.gif|right|thumb|300px]]
'''Deoxyribonucleic acid''' (DNA) is an [[organic compound|organic]] [[chemical compound]] made up of [[molecule]]s shaped like a [[double helix]] (like a twisted ladder). The individual building blocks of DNA (and other nucleic acids) are [[nucleotide]]s, which themselves consist of three principle parts: A nitrogenous base, a [[sugar]], and a [[phosphate]] group.

DNA contains [[gene]]s that help create [[protein]]s by first being transcribed into [[RNA]]. All plants and animals contain DNA, except for a few [[virus]]es. Offspring of sexually reproducing organisms contain DNA from both parents.

==History==
In the late 19th century [[Friedrich Miescher]], a Swiss [[biochemist]], discovered an unusual [[acid]] in the [[nuclei]] of cells. The acid was named deoxyribonucleic acid, or DNA. In 1944 the American [[biologist]]s, [[Alfred Hershey]], [[Thomas Gilmore]] and [[Martha Chase]] used experiments with [[bacteria]] and [[bacteriophage]]s to show that DNA passed [[gene]]s from one generation to the next.

At that time, it was unclear how this simple molecule could hold all the complex information controlling the development of humans, animals and plants. Scientists knew it was made of four chemical bases called [[adenine]] (A), [[thymine]] (T), [[guanine]] (G) and [[cytosine]] (C), plus [[phosphoric acid]] and a [[sugar]]. They also knew that the ratios of A and T as well as G and C were always the same, but they did not know the rules that controlled the arrangement.

British scientists [[Rosalind Franklin]] and [[Maurice Wilkins]] passed [[X-ray|X-rays]] through DNA to study the patterns made when the crystals diffracted them. From studying photographs of patterns, Rosalind Franklin concluded that DNA must be be a [[helix]]. [[James Watson]] and [[Francis Crick]], working in [[Cambridge]], used this information to help them solve the puzzle of DNA structure. They built a model showing that if A always paired with T and G paired with C, DNA must be like a ladder made of two strands twisted together in a double helix. The sugar and phosphoric acid were the sides of the ladder, and the rungs were the paired bases that were held together through hydrogen bonding.

Watson and Crick suggested that DNA could unzip itself into two separate strands, and each strand could act as a pattern to grow a new strand. Crick showed later that areas of the DNA known as genes worked in groups of three to code for amino acids, the building blocks of proteins. These groups are called [[codon|codons]]. They make about fifty thousand different types of [[protein]], which make all the different types of cell in the body. Indian biochemist [[Har Gobind Khorana]] made all the possible codons and worked out which codons controlled which [[amino acid]]. Most codons are redundant and code for the same amino acids, these mostly are different in only the third base pair. This means that differences in genotype can build up in the third position (thereby changing the genotype) without changing the protein (keeps the same phenotype).

If the DNA in one cell was stretched out, it would be about three feet long. Although DNA has a very simple structure, it can carry an enormous amount of [[information]]. Scientists do not yet understand the function of all DNA, but in 1991 a project called the [[Human Genome Project]] began to use computers to map the three billion base pairs which make up the 46 human [[chromosome|chromosomes]].

==Modern understanding==
[[Image:818.gif|right|thumb|Structure of DNA.]]
Small lengths of DNA called [[gene]]s serve as the instructions for the body to carry out its functions and give rise to the physical traits of the organism. <ref>"Eye-color genes, through the proteins they encode, direct the amount and placement of melanin in the iris." [http://www.hhmi.org/cgi-bin/askascientist/highlight.pl?kw=&file=answers%2Fgenetics%2Fans_044.html Ask A Scientist - Genes and eye color]</ref> DNA is packaged into [[chromosomes]]. Each individual human being has 23 pairs of [[chromosome]]s, where one set is inherited from his/her mother and the other set is inherited from his/her father. 22 of these chromosomes are referred to as [[autosome]]s, while the remaining chromosome is the sex chromosome that determines gender.

[[Prokaryotic DNA]] is circular (a closed loop), while [[eukaryotic DNA]] is linear (with ends) with the exception of [[Mitochondrial DNA]] and chloroplast DNA which is separate from that of the eukaryotic organism. Both mitochondria and chloroplasts were thought to once be prokayotic organisms that became symbiotes within eukaryotic organisms, this explains why they still retain their circular DNA. The ends of eukaryotic DNA is protected by [[telomere]]s, which are joined together in knots, except when the cell is undergoing [[mitosis]]. DNA in [[prokaryote]]s usually consists only of one closed loop chromosome.<ref>Campbell, Neil A, et. al. ''Biology''. 6th ed. San Francisco: Benjamin Cummings, 2002. 299, 530-31.</ref>

Some viral [[genome]]s are composed of DNA, such as that of the [[influenza]] virus.

[[Mutation]]s in DNA accumulate over time and build up to create differences between organisms. Most mutations in DNA are harmless and don't affect the [[phenotype|observable traits]] of the organism. Others can have beneficial effects, but some can disrupt important functions. Many diseases such as Autism and Ellis-van Crevice syndrome have been shown to occur due to these harmful genetic mutations.

DNA is [[transcription|transcribed]] into [[mRNA]], which is in turn [[translation|translated]] into [[proteins]] built from [[amino acids]]. Additionally, DNA maybe transcribed into functional RNAs such as ribosomal (rRNA) or transfer (tRNA) that do not undergo translation. [[RNA]] can also be reverse-transcribed back into DNA, which is the called [[Complementary DNA]] or [[cDNA]].

However, DNA-containing cells are soon to go extinct, except for the heathens, who will soon die as it is. DNA is an acid, and as everyone knows, acids dissolve cells. Soon, God will change the cells of the faithful to not contain DNA so that they can live forever and do ministry work all over the world.

SERIOUSLY?!?!!?!?!? How can you POSSIBLE think that? Are you THAT blissfully unaware of the fact that your own BLOOD is acidic? Bigoted bitch. I doubt God wants you up on those ACIDIC clouds- he would hate to disturb the people up there in heaven with your crackpot theories.

==DNA fingerprinting==

DNA can help police track down criminals if an attacker leaves something like hair or blood at a crime scene. Everybody’s DNA is unique unless they are identical twins, and the genetic ‘fingerprint’ of this material can be enough to confirm if a suspect was at the scene.
Genetic fingerprinting can also show if somebody is closely related to somebody else. Archaeologists used samples from living relatives to identify whether bodies found buried in a forest in [[Russia]] were the remains of the [[tsar]] and his family, killed during the 1919 [[Russian Revolution]].

As well as showing how different we all are, DNA shows how much we are all the same. Only one small part of one chromosome distinguishes a boy from a girl. Genes give us different colored [[eye]]s, [[hair]] and [[skin]], but 99.5% of any human's DNA is in the same order as everybody else’s.

Human DNA is made up of the same components as the DNA of other organisms, with most species even sharing the same genes which code for the same proteins. This is why even [[fruit fly|fruit flies]] and [[mouse|mice]] can be used as model organisms in order to help better understand human genetic diseases.

==External links==
*[http://www.learner.org/interactives/dna/index.html Interactive DNA] Learn about genetics, genetic engineering, the Human Genome Project and the ethical implications of these new technologies.
*[http://www.blackwellpublishing.com/trun/artwork/Animations/cloningexp/cloningexp.html Animated guide to DNA cloning]

== References ==
<references/>

[[Category:Genetics]]

Universe

2009-01-18T01:56:36Z

Mccusty93: /* Age */

The '''universe''' is, in principle, all of material existence or natural things ([[matter]] and [[energy]]).
Therefore, everything outside of the universe is not natural or material, but supernatural (things going beyond nature).
However, in order to solve problems with naturalistic explanations of the the origin of the universe, some speculate that there are other universes.

There have been and continue to be a number of competing ideas about the universe, but most agree that the universe is expanding.
The size, shape, and age of the universe, as well as how it began, are, however, all points of contention.

== Shape ==

The common view among [[cosmology|cosmologists]] is that the universe is a four dimensional Riemannian [[manifold]] whose spatial part of the metric is increasing over time. This is interpreted as an expansion of the universe.

Imagine you are at a random spot on a spotted balloon, when someone inflates the balloon you'll see the spots moving away from you, so it would seem you are at the center of the expansion.
Furthermore, the further away the spots are the faster they move away from you.
This is also true for the universe: the more distant a [[galaxy]] is, the faster it moves away from us.

Further imagine that you are a creature that only exists in two dimensions.
That is, you have width and depth, but no height.
So living on the surface of the balloon, you cannot see the shape of the balloon itself.
If you went for a walk in a straight line, you would actually go around the balloon and end up where you started, despite not being aware that you were travelling in a circle.

The theory goes that the three dimensions of our universe that we can see are like the two dimensions of the surface of the balloon, which wraps around on itself in another dimension, so that if we travelled through space in a straight line, we would eventually return to our starting point. The fourth dimension is [[time]] and [[String theory]] holds the universe exists right up to [[The Tenth Dimension|ten dimensions]].

One consequence of this idea is that the universe therefore has no edge (just like there is no edge to the surface of a balloon) and therefore no center.
Thus for any location in space, it would appear that that location is at the center of the expansion of the universe.

If we were really at the center of the universe, this would support the idea that the [[Earth]] occupies a "special place" in the universe, which would support the biblical idea of [[creation]], even though the [[Bible]] does not claim that the Earth is physically in the center of the universe.
So many scientists find the idea that it only ''looks like'' we are at the center of the universe an attractive one.

However, recent [[redshift]] data showing a series of concentric [[sphere]]s of redshift quantization supports the idea that our [[galaxy]] (the [[Milky Way Galaxy|Milky Way]]) really is at or close to the center of the universe.<ref>Humphreys, Russell, [http://www.creationontheweb.com/content/view/1570/ Our galaxy is the center of the universe, ‘quantized’ redshifts show], ''Journal of Creation'' 16(2):95–104, 2002.</ref>

== Age ==

According to one version of{{fact}} the [[big Bang theory|big bang theory]], the universe erupted into existence from nothing<ref>Discover magazine, in introducing the ideas of [[Alan Guth]], said, "The universe burst into something from absolutely nothing—zero, nada. And as it got bigger, it became filled with even more stuff that came from absolutely nowhere." Discover, April 2002.</ref> approximately 14 billion years ago, and has been expanding ever since.

<s>[[Young Earth Creationism|Young-Earth creationists]] have developed a number of models which explain the age of the universe as being affected by the time-warping effects of gravity as predicted by [[Einstein]]'s [[General Theory of Relativity]], so that the age of the universe as measured by a hypothetical observer at the edge of the universe might be 14 billion years, but as measured by an observer on Earth is only 6,000 years.<ref>Batten, Don, et. al., [http://www.creationontheweb.com/images/pdfs/cabook/chapter5.pdf How can we see distant stars in a young universe?], chapter 5 of ''The Creation Answers Book'', 2007.</ref></s>

Everything that was struck through is preposterous. The universe is 14 billion years all, and appears that to everyone everywhere. Not just at an edge of the universe that can never be reached, because it has expanded faster the speed of light, the absolute maximum speed of matter.

== Size ==

A recent calculation placed the visible universe at about 156 billion [[light year]]s across.<ref name="size">[http://www.space.com/scienceastronomy/mystery_monday_040524.html Universe Measured: We're 156 Billion Light-years Wide!] (Space.com)</ref>
This creates a dilemma of faster than light movement, but it is speculated that the expansion of space itself can exceed the [[speed of light]] even if the objects within it moving on their own can not.<ref name="size" />
As an analogy, imagine ants (galaxies), that can't walk faster than 20 centimetres per second, sitting on an elastic cord.
Normally two ants moving away from each other could not exceed a speed of 40cm/s relative to each other (speed of light).
However, if the cord is stretched while the ants are moving (expansion of space), the ants' speed relative to each other can be greater.

Current theories on the universe means that scientists are only able to account for 4% of the matter in the universe, so new theories of dark matter (unseen matter) have been developed to explain this.<ref>[http://www.msnbc.msn.com/id/20360059/ Where is the rest of the universe?]</ref>

==External Links==
*[http://www.relativitycalculator.com/models_universe.shtml Early Models of the Universe]
==References==
{{reflist|2}}

[[Category:Astronomy]]

Second Law of Thermodynamics

2009-01-18T01:52:34Z

Mccusty93: /* Interpretation */

The '''Second Law of Thermodynamics''' states that heat can never flow from a cold body to a warmer one. An equivalent definition is that the [[entropy]] of an isolated system tends to increase. <ref> “Another way of stating the second [[law]] then is: ‘The universe is constantly getting more disorderly!’ Viewed that way, we can see the second law all about us. We have to [[work]] hard to straighten a room, but left to itself it becomes a mess again very quickly and very easily. Even if we never enter it, it becomes dusty and musty. How difficult to maintain houses, and machinery, and our bodies in perfect working order: how easy to let them deteriorate. In fact, all we have to do is nothing, and everything deteriorates, collapses, breaks down, wears out, all by itself -- and that is what the second law is all about.” Isaac Asimov, Smithsonian Institute Journal, June 1970, p. 6 </ref>

According to this law, it is impossible to build a [[perpetual motion machine]], and [[entropy]] in a completely closed system must either increase or remain constant.

==The three forms of the Second Law of Thermodynamics==
There are three different types of systems that the Second Law of Thermodynamics can apply to:

* Isolated system - Does not exchange matter or energy with its surroundings
* Closed system - Exchanges energy, but not matter, with its surroundings
* Open system - Exchanges both matter and energy with its surroundings

==Interpretation==
A simplification caused by misinterpretation says: disorder will increase within a closed system.

Actually entropy is a little more abstract and the second law of thermodynamics means something like this: the universe will always become increasingly uniform, that is: heat will spread until the entire universe has the temperature and energy level (in a closed system heat will always spread from a place where there is a lot of heat to a place where there is less until balance is achieved), forces will continue to work until a universal balance has been achieved. Scientific estimates place this in occurring in 10100 years as a conservative estimate, which is 1090 longer than the currently scientifically accepted 13.7 billion years of the age of the universe, which can be verified by long accepted properties of light and its behavior, even if creationist quasi-science rejects it because of an absurdly strict adherence to not changing incongruous beliefs that were known to be wrong in the Middle Ages.

In this final state the universe is one uniform space where nothing happens and no work (moving something) can be done since there are no above average concentrations of energy left.
This state is called maximum entropy and is said to be in perfect disorder (although intuitively its uniformity would seem to be a state of perfect order) because it has become impossible to determine what happened in the past. ''i.e.'' There are an infinite number of ways (histories of the universe) maximum entropy could have been reached.

==Entropy and disorder for dummies==

In this context "increasing disorder" means "that which happens if you let nature take its course".
Imagine your old room at your parent's house. Remember how easy it was to let the room turn into a uniform mess (disorder) and remember how hard it was to clean it up until it fit a specific, non-uniform design (order). Not cleaning up would always result in an increase of entropy in your room!

Now, in nature there is no one to clean up the universe, only chances. The chance of something becoming orderly is a lot smaller than the chance of something becoming disorderly (since there are far more possible disorderly states to choose from).

Alternatively one could think of how difficult it is to construct a house of cards, while almost everything that happens in nature will result in its collapse.

On a universal scale a tidy room would be a universe which has pockets of above average concentrations of energy (remember that E=mc^2 so this includes matter as well.)
A messy room would be a universe in which all energy is equally spread out.

The flow of energy (by heat exchange) to places with lower concentrations is called the "heat flow".

The often heard argument that this law disproves an eternal universe is true, since in that case maximum entropy would have been reached already.

==References==
<references/>

[[Category:Physics]]

Syphilis

2009-01-18T01:41:46Z

Mccusty93: /* Prevention */

[[Image:Hitlerspeech.jpg‎|thumb|300px|right|In his work ''Mein Kampf'', [[Adolf Hitler]] wrote that the "fight against syphilis demands a fight against prostitution, against prejudices, old habits, against previous conceptions, general views among them not least the false prudery of certain circles."<ref>http://www.mondopolitico.com/library/meinkampf/v1c10.htm</ref>]]
Syphilis is a [[sexually transmitted disease]] caused by the [[bacteria]] [[Treponema pallidum|Treponema pallidum]]. Syphilis originated in the [[New World]] and was introduced to [[Europe]] in the late 15th century by [[Roman Catholic|Catholic]] explorers returning from the New World<ref>[http://www.archaeology.org/9701/newsbriefs/syphilis.html Origins of Syphilis]</ref>. The first European record of a syphilis epidemic was in 1493, a year after the Catholic explorer [[Columbus]] discovered [[America]].

==Causes, incidence, and risk factors==
[[Image:Ro0304F8Treponema.jpg|thumbnail|175px|right|Syphilis is an easily spread infection caused by the [[bacteria]] [[Treponema pallidum|Treponema pallidum]]]]

Syphilis is an infectious disease. The bacteria that causes it spreads through broken skin or mucous membranes. It is most often spread by sexual contact.

Pregnant mothers infected with the disease can pass it to the baby developing in their womb. This is called congenital syphilis.

Syphilis infection in the United States mainly occurs between sexually active adults aged from 20 to 29, with around 20,000 to 30,000 cases reported per year. 

===Syphilis and Homosexuality===
In respect to [[Syphilis and Homosexuality|syphilis and homosexuality]], an early publication to propose the link between homosexuality contributing to the spread of the [[sexually transmitted disease]] syphilis was the [[England|English]] publication '' Proceedings of the Royal Society of Medicine'' in 1962.<ref>[http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1896863 A.J. King, The Complications of Homosexuality, Proceedings of the Royal Society of Medicine, Volume 55 October 1962]</ref> The '' Proceedings of the Royal Society of Medicine'' made the following statement: "The importance of homosexual practices in the spread of [[venereal disease]]s has attracted particular attention recently. It almost seems that these practices are keeping syphilis alive in this country." <ref>[http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1896863 A.J. King, The Complications of Homosexuality, Proceedings of the Royal Society of Medicine, Volume 55 October 1962]</ref>

The [[Centers for Disease Control and Prevention]] (CDC) stated the following regarding homosexuality and syphilis:
{{cquote|"While surveillance data are not available by risk behavior, a separate CDC analysis suggests that approximately 64 percent of all adult P&S syphilis cases in 2004 were among men who have sex with men, up from an estimated 5 percent in 1999....Syphilis increases, especially among men who have sex with men, demonstrate the need to continually adapt our strategies to eliminate syphilis in the [[United States]],” said Dr. Ronald O. Valdiserri, acting director of CDC’s [[HIV]], [[STD]] and [[Tuberculosis|TB]] prevention programs."<ref>http://www.cdc.gov/od/oc/media/pressrel/r051108.htm</ref>}}

Syphilis is one of the maladies of [[Gay Bowel Syndrome|gay bowel syndrome]] which is a condition which has been linked to [[HIV]] Infection.<ref>[http://www.ncbi.nlm.nih.gov/sites/entrez?Db=PubMed&Cmd=ShowDetailView&TermToSearch=946385&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstractPlus The gay bowel syndrome: clinico-pathologic correlation in 260 cases.]</ref><ref>[http://www.hopkins-hivguide.org/literature_review/02-2004/new_look_at_gay_bowel_syndrome.html Johns Hopkins HIV Guide - duplicate of Medscape's New Look at Gay Bowel Syndrome]</ref>

==Symptoms==

The symptoms of syphilis depend on the stage of the disease. Many people do not have symptoms.

In general, painless sores and swollen lymph nodes are symptoms of primary syphilis. Those with secondary syphilis may also have fever, fatigue, aches and pains, and loss of appetite, among other symptoms. Tertiary syphilis causes heart, brain, and nervous system problems.

Syphilis has several stages.

Primary syphilis is the first stage. Painless sores ( chancres ) form about 2-3 weeks after you are first infected. You may not notice the sores or any symptoms, particularly if the sores are inside the rectum or cervix. The sores disappear in about 4-6 weeks.

Secondary syphilis occurs about 2-8 weeks after the first sores form. About 33% of those who do not have primary syphilis treated will develop this second stage.

Tertiary syphilis is the final stage of syphilis. The infection spreads to the brain, nervous system, heart, skin, and bones.

==Signs and tests==

Blood tests can be done to detect substances produced by the bacteria that causes syphilis. The older test is the VDRL test. Other blood tests may include RPR and FTA-ABS.

==Prevention==

Syphillis is most effectively prevented by practicing [[abstinence]]. However, syphilis can also be transmitted through mucous membranes, open sores, and cut skin.

==Treatment==

Antibiotics are used to treat syphilis. The antibiotic of choice is penicillin, yet doxycycline may be used as an alternative in individuals with a penicillin allergy.

The penicillin is either injected into a muscle or vein, depending on what stage syphilis the person has.

Several hours after treatment of early stages of syphilis, there may be a reaction called Jarish-Herxheimer reaction. Symptoms of this reaction include:

:*Fever
:*Chills
:*Headache
:*Nausea
:*General feeling of being ill
:*General joint aches
:*Genera muscle aches

These symptoms usually disappear within 24 hours.

A person undergoing Syphilis treatment must have follow-up blood tests at 3, 6, 12, and 24 months to make sure the infection is gone. They should avoid sexual conduct until two follow-up tests show that the infection has been cured. Syphilis is extremely contagious in the primary and secondary stages.

Syphilis is a reportable infection -- that means that doctors must reported any cases of syphilis to public health authorities, so that potentially infected sexual partners may be identified and treated.

==Expectations (prognosis)==

With prompt treatment and follow-up care, syphilis can be cured.

Late-stage syphilis can lead to long-term health problems, despite therapy.

==Complications==

Complications of untreated syphilis include:

Neurosyphilis 
[[Heart]] and blood vessel problems, including aneurysms and inflammation of the aorta 
Damage to the skin and bones

==See also==

[[Category:Syphilis]]
[[Sexually transmitted disease]]
[[Category:Sexually Transmitted Disease]]
[[Category:Diseases]]
==References==
{{reflist|2}}