There are more molecules of water in a cup then there are cups of water on the Earth.
So, statistically speaking, we've all eaten Jesus. Ironic that it doesn't take Christian magic to make that happen. Also makes you wonder about whether you need Catholic Priest for transubstantiation ("No thanks father, I brought my own Jesus to eat").
No one really suspects that life on Mars ever consisted of organisms with hard parts. Remember, on Earth, 4billion years passed with only soft parted organisms before hard parts burst on the scene at the beginning of the Cambrian 543 million years ago.
Soft parts can be "fossilized".
These fossilized soft parts, of single celled organisms, can be found on earth. To find them, scientists guess what rocks are likely to contain what they want in the field, take them back to the lab, and look. It's difficult work with a good bit of risk involved. Even if the same kind of fossils exist on Mars, they are likely to be in strata that have been buried and eroded for millions of years, with millions of years of new deposition on top of them. This is not going to be easy.
What do you mean by fossil? Life on earth was consisting of creatures equally complex to bacteria for approximately 4 billion years, and these organisms are tough to find and difficult to identity
That's sounds nice. However, finding fossils is not going to be easy. First, the relevant rocks on Mars are going to be rare, assuming that life was much more prevalent in the past. Geologic processes work at the surface to grind that surface into dust, meaning that we need to find a lucky outcrop.
Then, we need to identify something conclusively as a fossil. Single celled organisms don't preserve very well, and the odds of something being preserved is really bad. On the earth, it has taken a long time and a lot of work to find good evidence of early single cellular life. And there are still debates about whether certain morphologies are organic or mineralogic in source. A lot of these questions are solved by pointing to modern microbes that look the same. Of course, with no modern Martian microbes, this line of reasoning is shut down w/o the additional assumption that life on Mars would resemble life on Earth.
Also, remember that our tools for identifying anything on Mars are absolutely horrible. The rovers are great, but have you tried looking at some of the pictures that come out of them with the intention of identifying things? It's tough. Some recent work has been put into figuring out how good the information collecting of the rovers is by replicating them on the Earth. And uh, the results are not promising.
Getting a fossil back from mars would be super, duper, mega expensive. It would be dumb as hell to just spend the money. We need to continue looking for small signs that point us in the direction of that possibility, which is exactly what has been going on and exactly what will continue to go on.
This is indicative of what really is exciting in Science--- the debate over methods, that reveal the real history of the world.
One of the methods these scientists used--- which has been potentially thought to be reliable--- disagrees with another method that is more commonly considered reliable.
Aging the oldest rocks on Earth is important because it helps us understand when extraterrestrial impact slowed to the point that would allow solidification of the Earth's surface. This places important bound on the age of life on earth--- which has been pushed back more rapidly then the oldest rocks over the past decades. Life, it seems, is more resilient then may have been thought previously.
The important part of this research is the questions it raises--- and the future research it will spur!!
The actual plants being found are already scientifically known in great detail, but usually only in fragmentary form (think a leaf or two, maybe a cone in there).
The interesting part of this study is that the forest can be examined as a whole -- ecology level, instead of single plant level.
And yeah, most of the major lineages from the fossil forest are extinct- but hey, how different is one plant from another anyways?:)
At the time all this carbon was being stored, the earth gradually changed from a long-term period of warm temperatures (hot-house) to colder temperatures (ice-house).
http://www.scotese.com/climate.htm
Currently, we're in an ice-house period (this is a much longer term cycle then the glacial ones we are familiar with).
Makes you wonder what will happen when all that sequestered carbon is released...
Think about a peat bog forming--- thick layer of plant material that will later be turned to coal.
As the oceans begin to transgress (the 50-cent geologist term for sea level rise), the existing forest is quickly buried and you end up with a snapshot of the forest remaining. After removing all the coal, you end up with a cave where you look up to the interesting part. Well, interesting for me, since I'm a paleontologist.:)
Interestingly, this work is only done because the coal mining company is really, really, nice. They don't have any real incentive to let paleontologists in after they're done with operations. Kudos to them!
Err. Two things: First, the cavern's aren't really caverns. They generally look for a layer of porous rock capped by non-porous rock. So they actually pump the air into the voidspace in the right sedimentary layer (usually a sandstone). Second, the 'caverns' are generally very deep. If there is significant leaking, it won't have much of an effect on the surface; too much dirt between there and here.
Epic movie received a total score of 17 (out of 100) from Metacritic. That is a dreadful score. Metacritic takes every critic review they can find and combine them into one metric. This means that your thesis is completely wrong, and that critics, on the whole, have the same opinion you do.
The irony is that while you're as good as the critics at reviewing movies, you're not good at reviewing critics.
1 & 2. Okay, sure. Quantifying the "certain percentage" that survived the plague due to having a specific allele would be very difficult. Except that, as stated in the article I sited,
"The smallpox virus also has more biological similarities to HIV-1 than does bubonic plague, the authors point out. Plague is a bacterial disease, and there is no evidence that the bacterium, Yersinia pestis, uses the CCR5 receptor in infection. The bacteria actually reproduce outside immune cells.
CCR5 is a coreceptor on our cell's surface that facilitates entry to our cells. This is obviously important to HIV, since HIV reproduces within our cells - deny it entry, it's in trouble. Smallpox also has this weakness. Bubonic plague, in comparison, is not linked to CCR5. Do you have a reference that refutes this?
3. Whaaa? Facilitate certain factors?
Proliferation of the delta 32 marker (by which I presume you mean the CCR5 delta 32 allele) is the same as saying evolution occurred. As far as I can tell, you're hypothesizing that differential survival by people with the marker resulted in the increased gene frequency. There's another scientific term for this: natural selection. Let's look at the sciencedaily article I linked above:
"Our population genetic model finds that genetic selection from plague wouldn't have been sufficient to drive the frequency of this genetic mutation to its current level," said Alison P. Galvani, a Miller Postdoctoral Fellow at UC Berkeley. "It was sufficient for smallpox."
Bubonic plague hasn't been a major source of death in Europe or elsewhere for the last 250 years, while smallpox was only eradicated in 1978, at the same time AIDS (acquired immune deficiency syndrome) appeared. The survival advantage this genetic mutation provided against smallpox has thus been transferred to AIDS, the authors noted.
Following a 1998 paper that linked the gene deletion with bubonic plague, "bubonic plague had been cited as a classical example of a historical selection pressure acting on a clinically important locus," she said. That classic example now changes, with smallpox replacing the plague. "
To sum up, the claim that bubonic plague has had an effect on CCR5 delta 32 frequency has been a popular story that's been bandied about for years; but there is no evidence for this, and smallpox is a more more plausible explanation.
Cheers,
Paltin
1. CCR5 delta 32 is not super common, with a gene frequency of about.1 across Europe as a whole and maxing at about.23 in Ashkenaz jews. Evidence indicates that the black plague ceased to be common because of human resistance to it; which means that a gene frequency of.1 would not protect a whole population, which means it can't be the sole cause of surviving black plague.
2. You need two copies of CCR5 delta 32 for it to truly protect someone,.1 x.1 =.01 , so about 1% of European are immune to HIV as a result of CCR5 delta 32. In the context of 'today', this is almost completely insignificant.
3. There is evidencethat bubonic plague could not produce the selective pressure necessary to spread CCR5 delta 32 widely, and smallpox is implicated instead.
There are already documented alleles in humans that give varying degrees of resistance to HIV. One of these is CCR5 delta 32; this specific allele is widespread in Europe, and while giving some resistance to HIV. This allele affects the CCR5 coreceptor on the cell walls, and helps mediate entry into cells. It is suspected that CCR5 delta 32 is widespread due to selective pressure caused by smallpox (or possibly black plaque)!
There have also been recent discoveries of Africans with no evidence of HIV infection despite high-risk behaviors (IE, prostitution). The logical conclusion is that the population will eventually evolve to be immune to HIV. This will take many generations. Before that happens, scientists may find a cure and stop evolution in its tracks.
There is a fairly standard definition of evolution, and it's not what you think it is.
Evolution is change over time.
The fact of biological evolution was well known before Darwin, and theories to explain it included Lamarkism as well as many seperate creations by God.
There is nothing in the definition of evolution that implies "getting better". The "getting better" is a consequence of selection.
In common parlance, people say evolution when they actually mean biologic evolution caused by natural selection.
This article, however, descrives memetic evolution caused by selection. Natural selection may or may not be the right term for what is causing the memetic evolution of boat design- but in this case, the basic tenets of natural selection do seem to accurately describe the system.
Ah, but you forget the possibility that life originating in one comet could spread to other comets. Imagine a large comet, where life formed, and completely filled with the little buggers---- and then the comet passes a little too closely to Jupiter, and the gravitational field tears that comet into tiny shreds that go shooting like a life shotgun into the solar system.
It might not be long before everything in the solar system that is compatible with that life form is infested. The authors of this paper are making the case that at 10e24 times more time and real estate, the rate of spread between
Put another way, we have numerous pieces of Mars here on Earth--- ejected from Mars' surface and out of it's gravitational pull following meteorite impact there. If there was life on Mars at some point, it traveled to Earth in this fashion. And vice-versa. And so too with every other major gravitational body in the solar system and most of the minor ones.
That's very untrue, we can place some reasonable constraints on life's origins based on what we see now.
A good starting point would be that the original replicators were subject to the three tenets of Darwinian selection: 1. Variability 2. Heretability 3. Differential fitness.
This excludes a great number of potential hypotheses, and suggests some avenues for research.
In any case, even if their number is "wrong" (they don't know the exact mass of comets, they had to guess) they do make a reasonable case based on time and real estate that life probably originating in space. The number is helpful in that others who might add a third or fourth variable to the equation have some idea of what kind of difference would be required to overturn their result- adding a 50% probability in a third variable doesn't change the conclusion.
I would recommend some Dawkins-- he goes through theories about origin of life in the beginning of Blind Watchmaker and Selfish Gene. Very easy to read, not very in depth, but a good starting place. Happy reading!
To sum it up, there are many, many theories and models for what could have preceded bacteria-like life and have been far simpler, yet could lead to bacteria-like life.
For example, if you put nucleotides, which have been observed to form in young-earth like conditions in a vat of water, they can slowly form a chain of RNA. Given enough time, these RNA chains will replicate without any of the machinery that today's life uses for the same task. The fact that these processes are slow is not an issue--- there was plenty of time back then, after all, for them to do their dirty work, and no other organic monsters lurking and waiting to eat them.
Given the limited supply of nucleotides, natural selection will kick in--- and variation will beget evolution.
CO2 levels are not the only control on global temperature. To assume such is asinine. However, in similar conditions, we might expect similar results.
Notice in your link that compares the Scotese global temperature scale to the Berner CO2 levels... that the last time that both were at minimal levels was during the Permian.
The Permian ended with a coincidental increase in both global temperature and CO2 levels, according to your data. These conditions have not repeated since.
The End-permian mass extinction resulted in the death of 95% of marine species. Marine species have better fossil records then land species, and beyond that, life in land during the permain isn't comprable to life on land today.
To repeat:
CO2 IS NOT THE ONLY CAUSE OF GLOBAL EUSTATIC TEMPERATURE CHANGE. THE LAST TIME THE EARTH HAD LOW TEMPERATURES AND LOW CO2, and CO2 LEVELS ROSE, ALMOST EVERYTHING DIED.
As far as you waiting for someone to explain things to you... go read the literature. There has been a lot of hard work poured into understanding these things, and they're a lot more extensive then the websites you site and your blanket theory.
I just made it through single variable calculus and chemistry using an old TI-82 and a TI-86, which I had from high school ten years ago. Both were more then adequate for calc & chemistry, and you can get them for $10 / $30 respectively on ebay. They had most of the same functions as newer TI's, and served me well.
My only difficulty was an occasion scramble to find where some higher level functions were, as the rest of the class had newer calcs and they couldn't help me out.
Just do yourself a favor, get an older calc (with an instruction book), and spend the rest of the cash on ice cream.
This is relevant, because Seawolf class submarines have great windows so you can see everything outside them! Also, they are used for biological observation all the time!
A relevant submersible is the DSV Alvin, which is used consistently for science, has useful observation tools such as windows and lights, and can submerge to a depth in excess of 4500m.
First, the ice caps haven't existed for 5 billion years. They certainly didn't exist during the Hadean, when the surface of the Earth was molten. Clearly, the lack of ice caps at one point in history does not preclude their existence later on. And their existence today does not preclude their lack later on. Your argument is flawed.
Second, the known historical extent of the ice caps is far more then is an acceptable range for human civilization, as we see it today, to exist. Have you heard of the snowball earth hypothesis? Even though the Earth may not have been completely frozen, there is good evidence for massive worldwide glaciation.
And, what do you mean by run-away system? This research does not suggest that the melting would continue forever. It does suggest that ice caps may not remain during periods of global high temperature. Examine this page. The Earth's temperature has historically varied between two values, and there is no reason to think that we couldn't see a return to a temperature that precludes polar ice. It's happened before. It'll happen again. And the scientific consensus is that we're speeding it on it's way.
Slashdot Mirror
There are more molecules of water in a cup then there are cups of water on the Earth.
So, statistically speaking, we've all eaten Jesus. Ironic that it doesn't take Christian magic to make that happen. Also makes you wonder about whether you need Catholic Priest for transubstantiation ("No thanks father, I brought my own Jesus to eat").
Three things:
No one really suspects that life on Mars ever consisted of organisms with hard parts. Remember, on Earth, 4billion years passed with only soft parted organisms before hard parts burst on the scene at the beginning of the Cambrian 543 million years ago.
Soft parts can be "fossilized".
These fossilized soft parts, of single celled organisms, can be found on earth. To find them, scientists guess what rocks are likely to contain what they want in the field, take them back to the lab, and look. It's difficult work with a good bit of risk involved. Even if the same kind of fossils exist on Mars, they are likely to be in strata that have been buried and eroded for millions of years, with millions of years of new deposition on top of them. This is not going to be easy.
Fixed version:
What do you mean by fossil? Life on earth was consisting of creatures equally complex to bacteria for approximately 4 billion years, and these organisms are tough to find and difficult to identity
That's sounds nice. However, finding fossils is not going to be easy. First, the relevant rocks on Mars are going to be rare, assuming that life was much more prevalent in the past. Geologic processes work at the surface to grind that surface into dust, meaning that we need to find a lucky outcrop.
Then, we need to identify something conclusively as a fossil. Single celled organisms don't preserve very well, and the odds of something being preserved is really bad. On the earth, it has taken a long time and a lot of work to find good evidence of early single cellular life. And there are still debates about whether certain morphologies are organic or mineralogic in source. A lot of these questions are solved by pointing to modern microbes that look the same. Of course, with no modern Martian microbes, this line of reasoning is shut down w/o the additional assumption that life on Mars would resemble life on Earth.
Also, remember that our tools for identifying anything on Mars are absolutely horrible. The rovers are great, but have you tried looking at some of the pictures that come out of them with the intention of identifying things? It's tough. Some recent work has been put into figuring out how good the information collecting of the rovers is by replicating them on the Earth. And uh, the results are not promising.
Getting a fossil back from mars would be super, duper, mega expensive. It would be dumb as hell to just spend the money. We need to continue looking for small signs that point us in the direction of that possibility, which is exactly what has been going on and exactly what will continue to go on.
This is indicative of what really is exciting in Science--- the debate over methods, that reveal the real history of the world.
One of the methods these scientists used--- which has been potentially thought to be reliable--- disagrees with another method that is more commonly considered reliable.
Aging the oldest rocks on Earth is important because it helps us understand when extraterrestrial impact slowed to the point that would allow solidification of the Earth's surface. This places important bound on the age of life on earth--- which has been pushed back more rapidly then the oldest rocks over the past decades. Life, it seems, is more resilient then may have been thought previously.
The important part of this research is the questions it raises--- and the future research it will spur!!
The actual plants being found are already scientifically known in great detail, but usually only in fragmentary form (think a leaf or two, maybe a cone in there).
:)
The interesting part of this study is that the forest can be examined as a whole -- ecology level, instead of single plant level.
And yeah, most of the major lineages from the fossil forest are extinct- but hey, how different is one plant from another anyways?
At the time all this carbon was being stored, the earth gradually changed from a long-term period of warm temperatures (hot-house) to colder temperatures (ice-house).
http://www.scotese.com/climate.htm
Currently, we're in an ice-house period (this is a much longer term cycle then the glacial ones we are familiar with).
Makes you wonder what will happen when all that sequestered carbon is released...
Think about a peat bog forming--- thick layer of plant material that will later be turned to coal.
:)
As the oceans begin to transgress (the 50-cent geologist term for sea level rise), the existing forest is quickly buried and you end up with a snapshot of the forest remaining. After removing all the coal, you end up with a cave where you look up to the interesting part. Well, interesting for me, since I'm a paleontologist.
Interestingly, this work is only done because the coal mining company is really, really, nice. They don't have any real incentive to let paleontologists in after they're done with operations. Kudos to them!
http://geology.geoscienceworld.org/cgi/content/abstract/35/5/415 There's the link to the abstract from their work last year.
Err. Two things: First, the cavern's aren't really caverns. They generally look for a layer of porous rock capped by non-porous rock. So they actually pump the air into the voidspace in the right sedimentary layer (usually a sandstone). Second, the 'caverns' are generally very deep. If there is significant leaking, it won't have much of an effect on the surface; too much dirt between there and here.
You are, unfortunately, completely wrong.
Epic movie received a total score of 17 (out of 100) from Metacritic. That is a dreadful score. Metacritic takes every critic review they can find and combine them into one metric. This means that your thesis is completely wrong, and that critics, on the whole, have the same opinion you do.
The irony is that while you're as good as the critics at reviewing movies, you're not good at reviewing critics.
When do we get a wireless protocol droid to go with it?
What does this have to do with the price of tea on Trantor?
1 & 2. Okay, sure. Quantifying the "certain percentage" that survived the plague due to having a specific allele would be very difficult. Except that, as stated in the article I sited,
"The smallpox virus also has more biological similarities to HIV-1 than does bubonic plague, the authors point out. Plague is a bacterial disease, and there is no evidence that the bacterium, Yersinia pestis, uses the CCR5 receptor in infection. The bacteria actually reproduce outside immune cells.
CCR5 is a coreceptor on our cell's surface that facilitates entry to our cells. This is obviously important to HIV, since HIV reproduces within our cells - deny it entry, it's in trouble. Smallpox also has this weakness. Bubonic plague, in comparison, is not linked to CCR5. Do you have a reference that refutes this?
3. Whaaa? Facilitate certain factors?
Proliferation of the delta 32 marker (by which I presume you mean the CCR5 delta 32 allele) is the same as saying evolution occurred. As far as I can tell, you're hypothesizing that differential survival by people with the marker resulted in the increased gene frequency. There's another scientific term for this: natural selection. Let's look at the sciencedaily article I linked above:
"Our population genetic model finds that genetic selection from plague wouldn't have been sufficient to drive the frequency of this genetic mutation to its current level," said Alison P. Galvani, a Miller Postdoctoral Fellow at UC Berkeley. "It was sufficient for smallpox."
Bubonic plague hasn't been a major source of death in Europe or elsewhere for the last 250 years, while smallpox was only eradicated in 1978, at the same time AIDS (acquired immune deficiency syndrome) appeared. The survival advantage this genetic mutation provided against smallpox has thus been transferred to AIDS, the authors noted.
Following a 1998 paper that linked the gene deletion with bubonic plague, "bubonic plague had been cited as a classical example of a historical selection pressure acting on a clinically important locus," she said. That classic example now changes, with smallpox replacing the plague. "
To sum up, the claim that bubonic plague has had an effect on CCR5 delta 32 frequency has been a popular story that's been bandied about for years; but there is no evidence for this, and smallpox is a more more plausible explanation. Cheers, Paltin
1. CCR5 delta 32 is not super common, with a gene frequency of about .1 across Europe as a whole and maxing at about .23 in Ashkenaz jews. Evidence indicates that the black plague ceased to be common because of human resistance to it; which means that a gene frequency of .1 would not protect a whole population, which means it can't be the sole cause of surviving black plague.
.1 x .1 = .01 , so about 1% of European are immune to HIV as a result of CCR5 delta 32. In the context of 'today', this is almost completely insignificant.
2. You need two copies of CCR5 delta 32 for it to truly protect someone,
3. There is evidencethat bubonic plague could not produce the selective pressure necessary to spread CCR5 delta 32 widely, and smallpox is implicated instead.
There are already documented alleles in humans that give varying degrees of resistance to HIV. One of these is CCR5 delta 32; this specific allele is widespread in Europe, and while giving some resistance to HIV. This allele affects the CCR5 coreceptor on the cell walls, and helps mediate entry into cells. It is suspected that CCR5 delta 32 is widespread due to selective pressure caused by smallpox (or possibly black plaque)! There have also been recent discoveries of Africans with no evidence of HIV infection despite high-risk behaviors (IE, prostitution). The logical conclusion is that the population will eventually evolve to be immune to HIV. This will take many generations. Before that happens, scientists may find a cure and stop evolution in its tracks.
There is a fairly standard definition of evolution, and it's not what you think it is.
Evolution is change over time.
The fact of biological evolution was well known before Darwin, and theories to explain it included Lamarkism as well as many seperate creations by God.
There is nothing in the definition of evolution that implies "getting better". The "getting better" is a consequence of selection.
In common parlance, people say evolution when they actually mean biologic evolution caused by natural selection.
This article, however, descrives memetic evolution caused by selection. Natural selection may or may not be the right term for what is causing the memetic evolution of boat design- but in this case, the basic tenets of natural selection do seem to accurately describe the system.
Thanks,
Paltin
Ah, but you forget the possibility that life originating in one comet could spread to other comets. Imagine a large comet, where life formed, and completely filled with the little buggers---- and then the comet passes a little too closely to Jupiter, and the gravitational field tears that comet into tiny shreds that go shooting like a life shotgun into the solar system. It might not be long before everything in the solar system that is compatible with that life form is infested. The authors of this paper are making the case that at 10e24 times more time and real estate, the rate of spread between Put another way, we have numerous pieces of Mars here on Earth--- ejected from Mars' surface and out of it's gravitational pull following meteorite impact there. If there was life on Mars at some point, it traveled to Earth in this fashion. And vice-versa. And so too with every other major gravitational body in the solar system and most of the minor ones.
That's very untrue, we can place some reasonable constraints on life's origins based on what we see now. A good starting point would be that the original replicators were subject to the three tenets of Darwinian selection: 1. Variability 2. Heretability 3. Differential fitness. This excludes a great number of potential hypotheses, and suggests some avenues for research. In any case, even if their number is "wrong" (they don't know the exact mass of comets, they had to guess) they do make a reasonable case based on time and real estate that life probably originating in space. The number is helpful in that others who might add a third or fourth variable to the equation have some idea of what kind of difference would be required to overturn their result- adding a 50% probability in a third variable doesn't change the conclusion.
You are ignorant on this topic.
I would recommend some Dawkins-- he goes through theories about origin of life in the beginning of Blind Watchmaker and Selfish Gene. Very easy to read, not very in depth, but a good starting place. Happy reading!
To sum it up, there are many, many theories and models for what could have preceded bacteria-like life and have been far simpler, yet could lead to bacteria-like life.
For example, if you put nucleotides, which have been observed to form in young-earth like conditions in a vat of water, they can slowly form a chain of RNA. Given enough time, these RNA chains will replicate without any of the machinery that today's life uses for the same task. The fact that these processes are slow is not an issue--- there was plenty of time back then, after all, for them to do their dirty work, and no other organic monsters lurking and waiting to eat them.
Given the limited supply of nucleotides, natural selection will kick in--- and variation will beget evolution.
Cheers.
CO2 levels are not the only control on global temperature. To assume such is asinine. However, in similar conditions, we might expect similar results.
Notice in your link that compares the Scotese global temperature scale to the Berner CO2 levels... that the last time that both were at minimal levels was during the Permian.
The Permian ended with a coincidental increase in both global temperature and CO2 levels, according to your data. These conditions have not repeated since.
The End-permian mass extinction resulted in the death of 95% of marine species. Marine species have better fossil records then land species, and beyond that, life in land during the permain isn't comprable to life on land today.
To repeat:
CO2 IS NOT THE ONLY CAUSE OF GLOBAL EUSTATIC TEMPERATURE CHANGE. THE LAST TIME THE EARTH HAD LOW TEMPERATURES AND LOW CO2, and CO2 LEVELS ROSE, ALMOST EVERYTHING DIED.
As far as you waiting for someone to explain things to you... go read the literature. There has been a lot of hard work poured into understanding these things, and they're a lot more extensive then the websites you site and your blanket theory.
Ouch.
For 10 tickets, though, an -82 is much more forgivable for not having statistical functions these days then it would have been at full price.
I just made it through single variable calculus and chemistry using an old TI-82 and a TI-86, which I had from high school ten years ago. Both were more then adequate for calc & chemistry, and you can get them for $10 / $30 respectively on ebay. They had most of the same functions as newer TI's, and served me well.
My only difficulty was an occasion scramble to find where some higher level functions were, as the rest of the class had newer calcs and they couldn't help me out.
Just do yourself a favor, get an older calc (with an instruction book), and spend the rest of the cash on ice cream.
This is relevant, because Seawolf class submarines have great windows so you can see everything outside them! Also, they are used for biological observation all the time!
A relevant submersible is the DSV Alvin, which is used consistently for science, has useful observation tools such as windows and lights, and can submerge to a depth in excess of 4500m.
First, the ice caps haven't existed for 5 billion years. They certainly didn't exist during the Hadean, when the surface of the Earth was molten. Clearly, the lack of ice caps at one point in history does not preclude their existence later on. And their existence today does not preclude their lack later on. Your argument is flawed.
Second, the known historical extent of the ice caps is far more then is an acceptable range for human civilization, as we see it today, to exist. Have you heard of the snowball earth hypothesis? Even though the Earth may not have been completely frozen, there is good evidence for massive worldwide glaciation.
And, what do you mean by run-away system? This research does not suggest that the melting would continue forever. It does suggest that ice caps may not remain during periods of global high temperature. Examine this page. The Earth's temperature has historically varied between two values, and there is no reason to think that we couldn't see a return to a temperature that precludes polar ice. It's happened before. It'll happen again. And the scientific consensus is that we're speeding it on it's way.