Once light passes over the event horizon (where the spacial/temporal metric essentially stretches to infinity) it cannot leave (but this is because space has become stretched so much and not because light is changing its speed)...
. . . this is because space has become stretched so much and not because light is changing its speed.
I hope you don't mind me taking advantage of your willingness to answer questions, but I'd like to know your opinion on the other physical constants, other than c. It's my understanding that these are affected by mass of the universe and other factors. I hear that the cosmic constant, the one that Einstein threw out as his worst mistake, requires the greatest fine tuning of all for life to exist in the universe, although many other must be fine tuned beyond our imagination too. I guess speed of light must be one of the exceptions to dependence on parameter of the universe. I believe it's only recently that scientists have "rediscovered" the cosmic constant.
The so called cosmological constant doesn't matter to life...
I think there is a common misconception that if some constant was off by a bit that life wouldn't have formed -- there are two problems with this reasoning, one -- if life couldn't form no one would know, and two, in most cases (and even our universe) life is transient, our sun will eventually extinguish ending life in this solar system; in a broad sense, the universe will either expand into infinity reducing the likelihood of life coming about again or collapse into a point, likewise ending life.
I think it is reasonable to argue that the formation of life is likely (i suspect it happens far more often than we give it credit), and that even if our constants were slightly different life would still come about transiently...
I had to see whether you were so far beyond me that discussion would be impossible, but I see that I can add something constructive after all.
Quote:
Originally Posted by hardeeharhar
I think there is a common misconception that if some constant was off by a bit that life wouldn't have formed -- there are two problems with this reasoning, one -- if life couldn't form no one would know . . .
While this is true, it misses the point that we are capable of discovering whether the universe must be finely tuned for life. Take the strong and weak nuclear forces for example, which determine what atoms form in what quantities. These forces must be within about a 2 percent band for sufficient elements necessary for life. (Richard Swinburne, "Argument from the Fine Tuning of the Universe," Physical Cosmology and Philosophy, 1991) There are many such examples that appear to be very valid.
Quote:
I think it is reasonable to argue that the formation of life is likely (i suspect it happens far more often than we give it credit), and that even if our constants were slightly different life would still come about transiently. . .
Beside fine tuning of the universe, it appears that earth has been tuned for supporting life, and a planet like earth is much less likely to exist than most people believe. Simply obtaining the proper elements was quite amazing. (R. E. Davies and R. H. Koch, "All the Observed Universe Has Contributed to Life," Philosophical Transactions of the Royal Society of London, 1991)
Here are the the most extreme cases of fine tuning: cosmic mass density within one part in 10 to the 60th, and space energy density within one part in 10 to the 120th. According to Lawrence Krauss and other astrophysicists, these are by far the most extreme fine tunings yet discovered in physics.
I've received a thought a few seconds before it was officially due. This thread is going to go down the drainhole of creationist drivel.
It may have been Fred Hoyle who coined the term "anthropic principle," and I don't think anyone would accuse him of being a creationist. It is simply an amazing fact that most of the physical constants, I'll exclude speed of light, must be exactly right for life to exist. Whether you believe it is this way on purpose or by chance does not alter the evidence. For those who don't want to deal with these observation now, why not call it one of life's mysteries and let it go at that?
Discussing free will is closer to a religious discussion that discussing any phenomena observed in nature. I consider free will so obvious it is hardly worth discussing. What hard evidence shows that we don't have free will? I don't believe there is any. We can choose to sacrifice our will and do something for the good of another. It can make a good movie too. When you boil it down, it is still free will however.
I am not interested in a free will discussion, however, and I don't know what has been written on it, except that it keeps coming up in religious discussions. People use the Bible to try to prove we have no free will. God is in control and determines everything that happens. If so, why not just run a simulation? It wouldn't cost so much. Making the universe must have been expensive.
'The Anthropic Principle' refers to a human-centric view of how the universe came to be. It doesn't mean that the universe came into existence in order for us to be in it.
Free will, secondly, is a pretty controversial subject. There are philosophers like John Gray who say categorically that it doesn't exist, that there's nothing you can possibly do in reaction to anything that hasn't been decided by your genes and your environment and your experiences in your formative years.
Maybe there's no hard evidence that it doesn't exist but it's impossible to prove either way, so there's no evidence it does either. Just because you think you perceive it is absolutely no proof that it exists, since studies in consciousness tell us that we attribute causes and explanations to our responses after the fact all the time. So it's a grey area, free will.
Oh, and while we're at it, there is absolutely zero evidence of the existence of the Christian God (or indeed any other god), so let's keep this on topic and keep all that religious nonsense out of this.
'The Anthropic Principle' refers to a human-centric view of how the universe came to be. It doesn't mean that the universe came into existence in order for us to be in it.
Thanks, but I already realized that distinction. The Anthropic Principle describes characteristics of our universe, but does not infer why these came to be.
Quote:
Free will, secondly, is a pretty controversial subject. There are philosophers like John Gray who say categorically that it doesn't exist, that there's nothing you can possibly do in reaction to anything that hasn't been decided by your genes and your environment and your experiences in your formative years.
Maybe there's no hard evidence that it doesn't exist but it's impossible to prove either way, so there's no evidence it does either. Just because you think you perceive it is absolutely no proof that it exists, since studies in consciousness tell us that we attribute causes and explanations to our responses after the fact all the time. So it's a grey area, free will.
I've noticed there are a lot of things that fall into this category, things we cannot prove or disprove. There are those who say the world and universe are just an illusion, and it is not real. Such topics make poor discussions, IMHO, since neither side can prove a thing. The theorist has an answer for every objection, but it is framed in acceptance of the theory in the first place. Maybe free will is a notch above the Matrix however.
I had to see whether you were so far beyond me that discussion would be impossible, but I see that I can add something constructive after all.
While this is true, it misses the point that we are capable of discovering whether the universe must be finely tuned for life. Take the strong and weak nuclear forces for example, which determine what atoms form in what quantities. These forces must be within about a 2 percent band for sufficient elements necessary for life. (Richard Swinburne, "Argument from the Fine Tuning of the Universe," Physical Cosmology and Philosophy, 1991) There are many such examples that appear to be very valid.
Beside fine tuning of the universe, it appears that earth has been tuned for supporting life, and a planet like earth is much less likely to exist than most people believe. Simply obtaining the proper elements was quite amazing. (R. E. Davies and R. H. Koch, "All the Observed Universe Has Contributed to Life," Philosophical Transactions of the Royal Society of London, 1991)
I disagree actually. How are these calculations done? We don't know how life came about in fine technical detail, and a crude back of the envelop calculation won't do.
Also, there is a presumption here that life can only exist on earth and not in a range of conditions.
I don't believe life is special. We are all just chemical reactions linked together.
I'd welcome comments, but I believe it is explained by Einstein's theory of general relativity. Constants in physics are the result of fields, such as gravity. The universe has a total mass and a density, which results in an overall gravitational field in the universe. Change it, and the speed of light will change. This explains why light slows down when it gets close to a heavy object, like a star. It explains why light cannot get out of a super heavy object like a black hole.
Fields like gravity and electromagnetism determine all the physical constants, not just the speed of light. This is how we have discovered that the universe is finely tuned so that life may exist somewhere, which happens to be earth. It has been debated whether such fine tuning is the results of an intelligent designer, or whether it is random chance. in some cases the fine tuning is to within one part in 10 to the 100th power. Although chance is easily ruled out for a single universe, some speculate that there are an infinite number of universes, and we are the lucky ones to be in the right universe. But that's another topic. Even the existence of other universes is unknowable according to one theory.
If as you suggest that C has a dependency upon 'an overall gravity field' in the universe, then should it change, according to the proximity of mass, in some relationship/correlation with the inverse square law? In deep 'intergalactic' space where the nearest star may be thousands of light years away and there is virtually zero gravitational influence, is the velocity of light any different, than in a region of space densely populated with stars? If so, is C really a true constant?.. and is there any way of measuring C in an relatively more "empty" part of space where the influence of gravitational fields is less than it is "locally"?
Quote:
Originally Posted by hardeehar
a better way to think about it is that the speed of light is a constant, period. Our units are arbitrary; it could be 530 barsdeit/umpta as long as it is 530 everywhere (in empty space).
My original question wasnt so much about units.. i realize they are arbitrary... it was about why that particular velocity, and what was the factor(s) about the structure of space that limits C to what it is. (which is such a snail's pace, when taking the size of the universe into consideration).
Flight-of-fancy time, for a non-physicist: Heisenberg's uncertainty principle allows for the creation and spontaneous annihilation of "virtual particles", and the Casimir Effect is a practical demonstration of this property. Might this intrinsic property of space/vacuum have something to do with the limit of C? And if so, can technology be created to modify this characteristic of space/vacuum, and therefore allow FTL transmission of information, or even physical objects?
If as you suggest that C has a dependency upon 'an overall gravity field' in the universe, then should it change, according to the proximity of mass, in some relationship/correlation with the inverse square law? In deep 'intergalactic' space where the nearest star may be thousands of light years away and there is virtually zero gravitational influence, is the velocity of light any different, than in a region of space densely populated with stars?
I've put that thought aside for a while, but I think you miss one point. In deep space and on earth there is a gravitational influence from all the mass in the universe, as I understand it. It might be compared with the overall background radiation from the stars, in that it is everywhere. The mass of earth is too small to overshadow the effects of the total mass of the universe, which is enormous. However, near a good size star, its field does bend space somewhat. So it takes a lot of concentrated mass to change the effect of total mass of the universe even a little bit. It's pretty uniform, except at black holes.
I'm not an astrophysicist, so take it with a grain of salt.
I disagree actually. How are these calculations done? We don't know how life came about in fine technical detail, and a crude back of the envelop calculation won't do.
Also, there is a presumption here that life can only exist on earth and not in a range of conditions.
I don't believe life is special. We are all just chemical reactions linked together.
I believe life is very special. It can only be carbon based, which is the only stable source of the extremely long molecular chains needed for life and the codes in the DNA. Ideas of silicon based life is science fiction. Life is also very delicate. I think something like a 5 percent change in the sun's temperature would wipe out all life on earth. Our sun must be exceptionally stable, a second generation, medium size star.
Regarding the elements, there are certain ones that are essential for life. I'm not a biochemist, but this is what I've read. One of the essential elements on earth, for example, can only be produced in a white dwarf star. It had to be rotating in a binary star that exploded and scatter the element into space, to be a part of the matter that formed earth eventually. The literature is full of such examples.
The distribution of elements for life isn't so rare, and no it isn't essential to have very specific elements for very specific functions (I am a biophysicist/chemist).
You're still stuck on the idea that earth is the only place life can exist. If the sun were 5% warmer and Mars would look a hell of a lot more attractive.
It is also a mistake to believe that life is fragile. Some species are fragile, but life isn't.
The distribution of elements for life isn't so rare, and no it isn't essential to have very specific elements for very specific functions (I am a biophysicist/chemist).
You're still stuck on the idea that earth is the only place life can exist. If the sun were 5% warmer and Mars would look a hell of a lot more attractive.
It is also a mistake to believe that life is fragile. Some species are fragile, but life isn't.
Look at life here on Earth. It is everywhere. Life thrives in the vents of volcanoes, in the frigid wastes of Antarctica, the depths of the oceans, the hottest and driest deserts, in superheated underwater volcanic steam vents... in heavily acid or alkaline places... ie the most austere and unfriendly environments imaginable. Life is hardy.. (ask any gardener). Life is also composed of common elements that occur thoughout the universe. Even if life on Earth was triggered by some 'one in a billion event' (what might that have been, one wonders??), then the chances are that some form of life occurs somewhere in the universe, with so many quadrillions of stars and and presumably planetary systems. If 'life was triggered" by some random event... what was the material that "this event" affected, in order to start life in the first place.. and ...how does one define "life"?
The distribution of elements for life isn't so rare, and no it isn't essential to have very specific elements for very specific functions (I am a biophysicist/chemist).
With your knowledge of living organisms, how important is fluorine? It is the element that is produced on the surface of a white dwarf.
Quote:
You're still stuck on the idea that earth is the only place life can exist. If the sun were 5% warmer and Mars would look a hell of a lot more attractive.
Mars has other problems. It is not massive enough and has lost almost all its water to outer space. Planets a little heavier than Earth hang on to methane and ammonia. It's got to be just the right size. Those specific gravities are very close together.
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It is also a mistake to believe that life is fragile. Some species are fragile, but life isn't.
I was just looking out for my own hide, so I thought human life.
If as you suggest that C has a dependency upon 'an overall gravity field' in the universe...
The speed of light isn't dependent on gravity. What does slow light down is the density of the medium through which light is transmitted. Light travels slower through air than it travels through a vacuum, slower through water than through air, slower still through glass than water. The constant 'c' is more precisely defined as the speed of light in a vacuum.
Quote:
And if so, can technology be created to modify this characteristic of space/vacuum, and therefore allow FTL transmission of information, or even physical objects?
or should I go back and read relativity?
The speed of light is a very different kind of limit than, say, the speed of sound. It's not like you hit a barrier and have trouble moving past it. In fact, if you keep pushing harder and harder, you can travel to any place as arbitrarily quickly as you wish with no limit at all (apart from available energy and how much acceleration you can endure without turning into mush) from your own perspective on how long it takes to get there.
If you could survive the acceleration and had plenty of energy to burn, you could get from here to the other side of the galaxy in a year, or even a day. You could get back home just as quickly. Funny thing is, however, when you get back home something like 200,000 thousand years will have passed for everyone else on Earth. That's more jet lag than most people want to deal with.
What we'd ideally like is to take that same trip and have to same amount of time pass at home as we experienced while traveling, or at least not have the difference in the two rates of time be so vast. The problem is that anything (be it an actual physical object, or even nothing more the abstract concept of information) traveling from point A to point B faster than the speed of light will appear, from some frames of reference, to arrive at point B before it has left point A. That's not only just weird, but can lead to kill-your-own-grandfather paradoxes. One reason to suspect that faster-than-light travel or communication is impossible is because it seems reasonable to figure that those kinds of paradoxes simply can't happen.
There are a couple of ways to have faster-than-light communication and travel without these paradoxes arising, but you either end up with some fanciful system that can only be implemented at light speed (spend the next 100,000 years creating a grand Cross Galactic Highway, and when you're done, you can thereafter cross this galaxy FTL without those pesky paradoxes), or it could be true that one of the philosophical underpinnings of Relativity is false, that there is a "preferred frame of reference"... and I'm running out of time to make that all make sense right now, so I'll have to leave it at that.
Funny thing is, however, when you get back home something like 200,000 thousand years will have passed for everyone else on Earth.
It's nice to find someone who really understands special relativity. It is so weird. I keep wanting time to unwind on the trip back home, but it doesn't work that way. Back to the Future's time machine worked better IMHO.
Since relativity was confirmed by atomic clocks flying around Earth, I guess I have to believe it, even if I don't like it.
Comments
. . . this is because space has become stretched so much and not because light is changing its speed.
I hope you don't mind me taking advantage of your willingness to answer questions, but I'd like to know your opinion on the other physical constants, other than c. It's my understanding that these are affected by mass of the universe and other factors. I hear that the cosmic constant, the one that Einstein threw out as his worst mistake, requires the greatest fine tuning of all for life to exist in the universe, although many other must be fine tuned beyond our imagination too. I guess speed of light must be one of the exceptions to dependence on parameter of the universe. I believe it's only recently that scientists have "rediscovered" the cosmic constant.
I think there is a common misconception that if some constant was off by a bit that life wouldn't have formed -- there are two problems with this reasoning, one -- if life couldn't form no one would know, and two, in most cases (and even our universe) life is transient, our sun will eventually extinguish ending life in this solar system; in a broad sense, the universe will either expand into infinity reducing the likelihood of life coming about again or collapse into a point, likewise ending life.
I think it is reasonable to argue that the formation of life is likely (i suspect it happens far more often than we give it credit), and that even if our constants were slightly different life would still come about transiently...
I think there is a common misconception that if some constant was off by a bit that life wouldn't have formed -- there are two problems with this reasoning, one -- if life couldn't form no one would know . . .
While this is true, it misses the point that we are capable of discovering whether the universe must be finely tuned for life. Take the strong and weak nuclear forces for example, which determine what atoms form in what quantities. These forces must be within about a 2 percent band for sufficient elements necessary for life. (Richard Swinburne, "Argument from the Fine Tuning of the Universe," Physical Cosmology and Philosophy, 1991) There are many such examples that appear to be very valid.
I think it is reasonable to argue that the formation of life is likely (i suspect it happens far more often than we give it credit), and that even if our constants were slightly different life would still come about transiently. . .
Beside fine tuning of the universe, it appears that earth has been tuned for supporting life, and a planet like earth is much less likely to exist than most people believe. Simply obtaining the proper elements was quite amazing. (R. E. Davies and R. H. Koch, "All the Observed Universe Has Contributed to Life," Philosophical Transactions of the Royal Society of London, 1991)
Here are the the most extreme cases of fine tuning: cosmic mass density within one part in 10 to the 60th, and space energy density within one part in 10 to the 120th. According to Lawrence Krauss and other astrophysicists, these are by far the most extreme fine tunings yet discovered in physics.
I've received a thought a few seconds before it was officially due. This thread is going to go down the drainhole of creationist drivel.
It may have been Fred Hoyle who coined the term "anthropic principle," and I don't think anyone would accuse him of being a creationist. It is simply an amazing fact that most of the physical constants, I'll exclude speed of light, must be exactly right for life to exist. Whether you believe it is this way on purpose or by chance does not alter the evidence. For those who don't want to deal with these observation now, why not call it one of life's mysteries and let it go at that?
Discussing free will is closer to a religious discussion that discussing any phenomena observed in nature. I consider free will so obvious it is hardly worth discussing. What hard evidence shows that we don't have free will? I don't believe there is any. We can choose to sacrifice our will and do something for the good of another. It can make a good movie too. When you boil it down, it is still free will however.
I am not interested in a free will discussion, however, and I don't know what has been written on it, except that it keeps coming up in religious discussions. People use the Bible to try to prove we have no free will. God is in control and determines everything that happens. If so, why not just run a simulation? It wouldn't cost so much. Making the universe must have been expensive.
Free will, secondly, is a pretty controversial subject. There are philosophers like John Gray who say categorically that it doesn't exist, that there's nothing you can possibly do in reaction to anything that hasn't been decided by your genes and your environment and your experiences in your formative years.
Maybe there's no hard evidence that it doesn't exist but it's impossible to prove either way, so there's no evidence it does either. Just because you think you perceive it is absolutely no proof that it exists, since studies in consciousness tell us that we attribute causes and explanations to our responses after the fact all the time. So it's a grey area, free will.
'The Anthropic Principle' refers to a human-centric view of how the universe came to be. It doesn't mean that the universe came into existence in order for us to be in it.
Thanks, but I already realized that distinction. The Anthropic Principle describes characteristics of our universe, but does not infer why these came to be.
Free will, secondly, is a pretty controversial subject. There are philosophers like John Gray who say categorically that it doesn't exist, that there's nothing you can possibly do in reaction to anything that hasn't been decided by your genes and your environment and your experiences in your formative years.
Maybe there's no hard evidence that it doesn't exist but it's impossible to prove either way, so there's no evidence it does either. Just because you think you perceive it is absolutely no proof that it exists, since studies in consciousness tell us that we attribute causes and explanations to our responses after the fact all the time. So it's a grey area, free will.
I've noticed there are a lot of things that fall into this category, things we cannot prove or disprove. There are those who say the world and universe are just an illusion, and it is not real. Such topics make poor discussions, IMHO, since neither side can prove a thing. The theorist has an answer for every objection, but it is framed in acceptance of the theory in the first place. Maybe free will is a notch above the Matrix however.
I had to see whether you were so far beyond me that discussion would be impossible, but I see that I can add something constructive after all.
While this is true, it misses the point that we are capable of discovering whether the universe must be finely tuned for life. Take the strong and weak nuclear forces for example, which determine what atoms form in what quantities. These forces must be within about a 2 percent band for sufficient elements necessary for life. (Richard Swinburne, "Argument from the Fine Tuning of the Universe," Physical Cosmology and Philosophy, 1991) There are many such examples that appear to be very valid.
Beside fine tuning of the universe, it appears that earth has been tuned for supporting life, and a planet like earth is much less likely to exist than most people believe. Simply obtaining the proper elements was quite amazing. (R. E. Davies and R. H. Koch, "All the Observed Universe Has Contributed to Life," Philosophical Transactions of the Royal Society of London, 1991)
I disagree actually. How are these calculations done? We don't know how life came about in fine technical detail, and a crude back of the envelop calculation won't do.
Also, there is a presumption here that life can only exist on earth and not in a range of conditions.
I don't believe life is special. We are all just chemical reactions linked together.
I'd welcome comments, but I believe it is explained by Einstein's theory of general relativity. Constants in physics are the result of fields, such as gravity. The universe has a total mass and a density, which results in an overall gravitational field in the universe. Change it, and the speed of light will change. This explains why light slows down when it gets close to a heavy object, like a star. It explains why light cannot get out of a super heavy object like a black hole.
Fields like gravity and electromagnetism determine all the physical constants, not just the speed of light. This is how we have discovered that the universe is finely tuned so that life may exist somewhere, which happens to be earth. It has been debated whether such fine tuning is the results of an intelligent designer, or whether it is random chance. in some cases the fine tuning is to within one part in 10 to the 100th power. Although chance is easily ruled out for a single universe, some speculate that there are an infinite number of universes, and we are the lucky ones to be in the right universe. But that's another topic. Even the existence of other universes is unknowable according to one theory.
If as you suggest that C has a dependency upon 'an overall gravity field' in the universe, then should it change, according to the proximity of mass, in some relationship/correlation with the inverse square law? In deep 'intergalactic' space where the nearest star may be thousands of light years away and there is virtually zero gravitational influence, is the velocity of light any different, than in a region of space densely populated with stars? If so, is C really a true constant?.. and is there any way of measuring C in an relatively more "empty" part of space where the influence of gravitational fields is less than it is "locally"?
a better way to think about it is that the speed of light is a constant, period. Our units are arbitrary; it could be 530 barsdeit/umpta as long as it is 530 everywhere (in empty space).
My original question wasnt so much about units.. i realize they are arbitrary... it was about why that particular velocity, and what was the factor(s) about the structure of space that limits C to what it is. (which is such a snail's pace, when taking the size of the universe into consideration).
Flight-of-fancy time, for a non-physicist: Heisenberg's uncertainty principle allows for the creation and spontaneous annihilation of "virtual particles", and the Casimir Effect is a practical demonstration of this property. Might this intrinsic property of space/vacuum have something to do with the limit of C? And if so, can technology be created to modify this characteristic of space/vacuum, and therefore allow FTL transmission of information, or even physical objects?
or should I go back and read relativity?
If as you suggest that C has a dependency upon 'an overall gravity field' in the universe, then should it change, according to the proximity of mass, in some relationship/correlation with the inverse square law? In deep 'intergalactic' space where the nearest star may be thousands of light years away and there is virtually zero gravitational influence, is the velocity of light any different, than in a region of space densely populated with stars?
I've put that thought aside for a while, but I think you miss one point. In deep space and on earth there is a gravitational influence from all the mass in the universe, as I understand it. It might be compared with the overall background radiation from the stars, in that it is everywhere. The mass of earth is too small to overshadow the effects of the total mass of the universe, which is enormous. However, near a good size star, its field does bend space somewhat. So it takes a lot of concentrated mass to change the effect of total mass of the universe even a little bit. It's pretty uniform, except at black holes.
I'm not an astrophysicist, so take it with a grain of salt.
I disagree actually. How are these calculations done? We don't know how life came about in fine technical detail, and a crude back of the envelop calculation won't do.
Also, there is a presumption here that life can only exist on earth and not in a range of conditions.
I don't believe life is special. We are all just chemical reactions linked together.
I believe life is very special. It can only be carbon based, which is the only stable source of the extremely long molecular chains needed for life and the codes in the DNA. Ideas of silicon based life is science fiction. Life is also very delicate. I think something like a 5 percent change in the sun's temperature would wipe out all life on earth. Our sun must be exceptionally stable, a second generation, medium size star.
Regarding the elements, there are certain ones that are essential for life. I'm not a biochemist, but this is what I've read. One of the essential elements on earth, for example, can only be produced in a white dwarf star. It had to be rotating in a binary star that exploded and scatter the element into space, to be a part of the matter that formed earth eventually. The literature is full of such examples.
You're still stuck on the idea that earth is the only place life can exist. If the sun were 5% warmer and Mars would look a hell of a lot more attractive.
It is also a mistake to believe that life is fragile. Some species are fragile, but life isn't.
The distribution of elements for life isn't so rare, and no it isn't essential to have very specific elements for very specific functions (I am a biophysicist/chemist).
You're still stuck on the idea that earth is the only place life can exist. If the sun were 5% warmer and Mars would look a hell of a lot more attractive.
It is also a mistake to believe that life is fragile. Some species are fragile, but life isn't.
Look at life here on Earth. It is everywhere. Life thrives in the vents of volcanoes, in the frigid wastes of Antarctica, the depths of the oceans, the hottest and driest deserts, in superheated underwater volcanic steam vents... in heavily acid or alkaline places... ie the most austere and unfriendly environments imaginable. Life is hardy.. (ask any gardener). Life is also composed of common elements that occur thoughout the universe. Even if life on Earth was triggered by some 'one in a billion event' (what might that have been, one wonders??), then the chances are that some form of life occurs somewhere in the universe, with so many quadrillions of stars and and presumably planetary systems. If 'life was triggered" by some random event... what was the material that "this event" affected, in order to start life in the first place.. and ...how does one define "life"?
The distribution of elements for life isn't so rare, and no it isn't essential to have very specific elements for very specific functions (I am a biophysicist/chemist).
With your knowledge of living organisms, how important is fluorine? It is the element that is produced on the surface of a white dwarf.
You're still stuck on the idea that earth is the only place life can exist. If the sun were 5% warmer and Mars would look a hell of a lot more attractive.
Mars has other problems. It is not massive enough and has lost almost all its water to outer space. Planets a little heavier than Earth hang on to methane and ammonia. It's got to be just the right size. Those specific gravities are very close together.
It is also a mistake to believe that life is fragile. Some species are fragile, but life isn't.
I was just looking out for my own hide, so I thought human life.
If as you suggest that C has a dependency upon 'an overall gravity field' in the universe...
The speed of light isn't dependent on gravity. What does slow light down is the density of the medium through which light is transmitted. Light travels slower through air than it travels through a vacuum, slower through water than through air, slower still through glass than water. The constant 'c' is more precisely defined as the speed of light in a vacuum.
And if so, can technology be created to modify this characteristic of space/vacuum, and therefore allow FTL transmission of information, or even physical objects?
or should I go back and read relativity?
The speed of light is a very different kind of limit than, say, the speed of sound. It's not like you hit a barrier and have trouble moving past it. In fact, if you keep pushing harder and harder, you can travel to any place as arbitrarily quickly as you wish with no limit at all (apart from available energy and how much acceleration you can endure without turning into mush) from your own perspective on how long it takes to get there.
If you could survive the acceleration and had plenty of energy to burn, you could get from here to the other side of the galaxy in a year, or even a day. You could get back home just as quickly. Funny thing is, however, when you get back home something like 200,000 thousand years will have passed for everyone else on Earth. That's more jet lag than most people want to deal with.
What we'd ideally like is to take that same trip and have to same amount of time pass at home as we experienced while traveling, or at least not have the difference in the two rates of time be so vast. The problem is that anything (be it an actual physical object, or even nothing more the abstract concept of information) traveling from point A to point B faster than the speed of light will appear, from some frames of reference, to arrive at point B before it has left point A. That's not only just weird, but can lead to kill-your-own-grandfather paradoxes. One reason to suspect that faster-than-light travel or communication is impossible is because it seems reasonable to figure that those kinds of paradoxes simply can't happen.
There are a couple of ways to have faster-than-light communication and travel without these paradoxes arising, but you either end up with some fanciful system that can only be implemented at light speed (spend the next 100,000 years creating a grand Cross Galactic Highway, and when you're done, you can thereafter cross this galaxy FTL without those pesky paradoxes), or it could be true that one of the philosophical underpinnings of Relativity is false, that there is a "preferred frame of reference"... and I'm running out of time to make that all make sense right now, so I'll have to leave it at that.
Funny thing is, however, when you get back home something like 200,000 thousand years will have passed for everyone else on Earth.
It's nice to find someone who really understands special relativity. It is so weird. I keep wanting time to unwind on the trip back home, but it doesn't work that way. Back to the Future's time machine worked better IMHO.
Since relativity was confirmed by atomic clocks flying around Earth, I guess I have to believe it, even if I don't like it.