World ending may 21 ?:S

[faysal]

woop woop! guess i'm heading to the party in hell too

well I figured that was obvious once we figured out that's where I was headed

 

[footballforlife]

http://en.wikipedia.org/wiki/Heat_death_of_the_universe

long live entropy

Its more likely this
http://en.wikipedia.org/wiki/Big_Rip

i think its a combination of both, entropy throughout the universe will increase up until the space time expansion of the universe begins to over come atomic strong, weak, and electromagnetic forces. you could say that universal expansion tearing apart everything on the atomic level is the final phase of entropic increase before the universe reaches some sort of dead steady state phase.

It is actually difficult to apply thermodynamics to the universe. In principle, one can model the universe with thermodynamics, but the accuracy of such a model is beyond poor since thermodynamic assumptions start breaking down at both the large scale (galactic scale) and the small scale (atomic scale). I mean much of this depends on the shape of the universe and if it is closed or open, but the current data supports an open universe, so I think the two most likely ends are a Big Rip or Big Freeze. But, this is rather fascinating stuff to think about..

 

[hardeep_singh]

http://en.wikipedia.org/wiki/Heat_death_of_the_universe

long live entropy

Its more likely this
http://en.wikipedia.org/wiki/Big_Rip

i think its a combination of both, entropy throughout the universe will increase up until the space time expansion of the universe begins to over come atomic strong, weak, and electromagnetic forces. you could say that universal expansion tearing apart everything on the atomic level is the final phase of entropic increase before the universe reaches some sort of dead steady state phase.

It is actually difficult to apply thermodynamics to the universe. In principle, one can model the universe with thermodynamics, but the accuracy of such a model is beyond poor since thermodynamic assumptions start breaking down at both the large scale (galactic scale) and the small scale (atomic scale). I mean much of this depends on the shape of the universe and if it is closed or open, but the current data supports an open universe, so I think the two most likely ends are a Big Rip or Big Freeze. But, this is rather fascinating stuff to think about..

shape, curvature, extradimensional composition are all important factors in the behavior of the universe and this behavior is an important factor when looking at how matter behaves within the universe. we might never know whether the universe is open or closed or whether it has positive or negative curvature or if there are more dimensions beyond the four we experience. all we have is the history of the universe, looking back at the 13.5 billion year lifetime of the universe so far the only conclusions we can make are that the universe has been expanding since it came into existance and that rate of expansion has increased and so far there's no evidence of the universe hitting any sort of barrier to this expansion. but i dont see why we cant consider the observable universe as a closed system when it comes to the behavior of matter and energy contained within it so unless there are forces outside the universe directly interacting with the matter and energy inside the universe i don't think there's any reason not to conclude that entropy will increase as long as space time keeps expanding.

 

[Kush]

woop woop! guess i'm heading to the party in hell too

well I figured that was obvious once we figured out that's where I was headed

touche.

 

[Navkarn]

3 min till we are doomed. goodbye btf i love you all

 

[footballforlife]

http://en.wikipedia.org/wiki/Heat_death_of_the_universe

long live entropy

Its more likely this
http://en.wikipedia.org/wiki/Big_Rip

i think its a combination of both, entropy throughout the universe will increase up until the space time expansion of the universe begins to over come atomic strong, weak, and electromagnetic forces. you could say that universal expansion tearing apart everything on the atomic level is the final phase of entropic increase before the universe reaches some sort of dead steady state phase.

It is actually difficult to apply thermodynamics to the universe. In principle, one can model the universe with thermodynamics, but the accuracy of such a model is beyond poor since thermodynamic assumptions start breaking down at both the large scale (galactic scale) and the small scale (atomic scale). I mean much of this depends on the shape of the universe and if it is closed or open, but the current data supports an open universe, so I think the two most likely ends are a Big Rip or Big Freeze. But, this is rather fascinating stuff to think about..

shape, curvature, extradimensional composition are all important factors in the behavior of the universe and this behavior is an important factor when looking at how matter behaves within the universe. we might never know whether the universe is open or closed or whether it has positive or negative curvature or if there are more dimensions beyond the four we experience. all we have is the history of the universe, looking back at the 13.5 billion year lifetime of the universe so far the only conclusions we can make are that the universe has been expanding since it came into existance and that rate of expansion has increased and so far there's no evidence of the universe hitting any sort of barrier to this expansion. but i dont see why we cant consider the observable universe as a closed system when it comes to the behavior of matter and energy contained within it so unless there are forces outside the universe directly interacting with the matter and energy inside the universe i don't think there's any reason not to conclude that entropy will increase as long as space time keeps expanding.

Right, the universe has always been expanding, in fact it ran into the opposite of a barrier--inflation. Well, some say that you shouldn't look at the universe as a closed system (I'm not one of them), but I'll say this: the underpinnings of thermodynamics are the definition of temperature (Zeroth Law). However, at the small scale temperature is a meaningless quantity. The statement 'the temperature of a boron atom is.." is irrelevant. So, when you try to build thermodynamics for small stuff, it doesn't work out at all. So entropy is not well defined in this regime, and attempting to extend this to the universe actually is difficult to do. I've always viewed entropy as a construct that doesn't have too much of a physical meaning, but just to inform of the availability of energy in a system. And I'm not disagreeing necessarily; simply pointing out that entropy doesn't necessarily need to increase as the universe expands. Lastly, thermodynamics for the reason I outlined already (and many others) is supplanted by Statistical Mechanics to try to understand the behavior of (lots of) particles.

 

[hardeep_singh]

http://en.wikipedia.org/wiki/Heat_death_of_the_universe

long live entropy

Its more likely this
http://en.wikipedia.org/wiki/Big_Rip

i think its a combination of both, entropy throughout the universe will increase up until the space time expansion of the universe begins to over come atomic strong, weak, and electromagnetic forces. you could say that universal expansion tearing apart everything on the atomic level is the final phase of entropic increase before the universe reaches some sort of dead steady state phase.

It is actually difficult to apply thermodynamics to the universe. In principle, one can model the universe with thermodynamics, but the accuracy of such a model is beyond poor since thermodynamic assumptions start breaking down at both the large scale (galactic scale) and the small scale (atomic scale). I mean much of this depends on the shape of the universe and if it is closed or open, but the current data supports an open universe, so I think the two most likely ends are a Big Rip or Big Freeze. But, this is rather fascinating stuff to think about..

shape, curvature, extradimensional composition are all important factors in the behavior of the universe and this behavior is an important factor when looking at how matter behaves within the universe. we might never know whether the universe is open or closed or whether it has positive or negative curvature or if there are more dimensions beyond the four we experience. all we have is the history of the universe, looking back at the 13.5 billion year lifetime of the universe so far the only conclusions we can make are that the universe has been expanding since it came into existance and that rate of expansion has increased and so far there's no evidence of the universe hitting any sort of barrier to this expansion. but i dont see why we cant consider the observable universe as a closed system when it comes to the behavior of matter and energy contained within it so unless there are forces outside the universe directly interacting with the matter and energy inside the universe i don't think there's any reason not to conclude that entropy will increase as long as space time keeps expanding.

Right, the universe has always been expanding, in fact it ran into the opposite of a barrier--inflation. Well, some say that you shouldn't look at the universe as a closed system (I'm not one of them), but I'll say this: the underpinnings of thermodynamics are the definition of temperature (Zeroth Law). However, at the small scale temperature is a meaningless quantity. The statement 'the temperature of a boron atom is.." is irrelevant. So, when you try to build thermodynamics for small stuff, it doesn't work out at all. So entropy is not well defined in this regime, and attempting to extend this to the universe actually is difficult to do. I've always viewed entropy as a construct that doesn't have too much of a physical meaning, but just to inform of the availability of energy in a system. And I'm not disagreeing necessarily; simply pointing out that entropy doesn't necessarily need to increase as the universe expands. Lastly, thermodynamics for the reason I outlined already (and many others) is supplanted by Statistical Mechanics to try to understand the behavior of (lots of) particles.

i was referring more to energy levels when discussing entropy. my idea is that once space time expansion has over come all the nuclear forces and torn everything in the universe into subatomic particles all that will be left is will be these subatomic particles and photons and neutrinos floating around. what happens if the expansion of the universe reaches a point where every existing particle is wrapped within its own little event horizon, incapable of interacting with anything else, will its energy state/waveform asymptote to 0? what will happen to quantum space time fluctuations?

http://en.wikipedia.org/wiki/Entropy_%28energy_dispersal%29

 

[footballforlife]

http://en.wikipedia.org/wiki/Heat_death_of_the_universe

long live entropy

Its more likely this
http://en.wikipedia.org/wiki/Big_Rip

i think its a combination of both, entropy throughout the universe will increase up until the space time expansion of the universe begins to over come atomic strong, weak, and electromagnetic forces. you could say that universal expansion tearing apart everything on the atomic level is the final phase of entropic increase before the universe reaches some sort of dead steady state phase.

It is actually difficult to apply thermodynamics to the universe. In principle, one can model the universe with thermodynamics, but the accuracy of such a model is beyond poor since thermodynamic assumptions start breaking down at both the large scale (galactic scale) and the small scale (atomic scale). I mean much of this depends on the shape of the universe and if it is closed or open, but the current data supports an open universe, so I think the two most likely ends are a Big Rip or Big Freeze. But, this is rather fascinating stuff to think about..

shape, curvature, extradimensional composition are all important factors in the behavior of the universe and this behavior is an important factor when looking at how matter behaves within the universe. we might never know whether the universe is open or closed or whether it has positive or negative curvature or if there are more dimensions beyond the four we experience. all we have is the history of the universe, looking back at the 13.5 billion year lifetime of the universe so far the only conclusions we can make are that the universe has been expanding since it came into existance and that rate of expansion has increased and so far there's no evidence of the universe hitting any sort of barrier to this expansion. but i dont see why we cant consider the observable universe as a closed system when it comes to the behavior of matter and energy contained within it so unless there are forces outside the universe directly interacting with the matter and energy inside the universe i don't think there's any reason not to conclude that entropy will increase as long as space time keeps expanding.

Right, the universe has always been expanding, in fact it ran into the opposite of a barrier--inflation. Well, some say that you shouldn't look at the universe as a closed system (I'm not one of them), but I'll say this: the underpinnings of thermodynamics are the definition of temperature (Zeroth Law). However, at the small scale temperature is a meaningless quantity. The statement 'the temperature of a boron atom is.." is irrelevant. So, when you try to build thermodynamics for small stuff, it doesn't work out at all. So entropy is not well defined in this regime, and attempting to extend this to the universe actually is difficult to do. I've always viewed entropy as a construct that doesn't have too much of a physical meaning, but just to inform of the availability of energy in a system. And I'm not disagreeing necessarily; simply pointing out that entropy doesn't necessarily need to increase as the universe expands. Lastly, thermodynamics for the reason I outlined already (and many others) is supplanted by Statistical Mechanics to try to understand the behavior of (lots of) particles.

i was referring more to energy levels when discussing entropy. my idea is that once space time expansion has over come all the nuclear forces and torn everything in the universe into subatomic particles all that will be left is will be these subatomic particles and photons and neutrinos floating around. what happens if the expansion of the universe reaches a point where every existing particle is wrapped within its own little event horizon, incapable of interacting with anything else, will its energy state/waveform asymptote to 0? what will happen to quantum space time fluctuations?

http://en.wikipedia.org/wiki/Entropy_%28energy_dispersal%29

Right so that's pretty much what the Big Rip is. The universe expands so much that everything is ripped apart, from clusters of galaxies, to solar systems, and then the very fabric of matter. So at the point where even protons have been ripped apart, if we assume ourselves to be say a photon, the observable universe will be a small sphere(like) shape, and this is the event horizon you talk about. Well, its wavefunction (energy state), I suppose would go to zero. Vacuum fluctuations would also go to zero I think, because the length scale of the universe would slowly go to zero as well. In other words, every point in the universe would be reduced to just that: a point of zero volume, zero length. Its also worth mentioning that we could run into the Planck Length, if it turns out to be the smallest possible length and the universe couldn't expand past that so to speak, there *might* still be some vanishingly small, yet nonzero, wavefunctions of particles.

http://en.wikipedia.org/wiki/Planck_length

 

[hardeep_singh]

http://en.wikipedia.org/wiki/Heat_death_of_the_universe

long live entropy

Its more likely this
http://en.wikipedia.org/wiki/Big_Rip

i think its a combination of both, entropy throughout the universe will increase up until the space time expansion of the universe begins to over come atomic strong, weak, and electromagnetic forces. you could say that universal expansion tearing apart everything on the atomic level is the final phase of entropic increase before the universe reaches some sort of dead steady state phase.

It is actually difficult to apply thermodynamics to the universe. In principle, one can model the universe with thermodynamics, but the accuracy of such a model is beyond poor since thermodynamic assumptions start breaking down at both the large scale (galactic scale) and the small scale (atomic scale). I mean much of this depends on the shape of the universe and if it is closed or open, but the current data supports an open universe, so I think the two most likely ends are a Big Rip or Big Freeze. But, this is rather fascinating stuff to think about..

shape, curvature, extradimensional composition are all important factors in the behavior of the universe and this behavior is an important factor when looking at how matter behaves within the universe. we might never know whether the universe is open or closed or whether it has positive or negative curvature or if there are more dimensions beyond the four we experience. all we have is the history of the universe, looking back at the 13.5 billion year lifetime of the universe so far the only conclusions we can make are that the universe has been expanding since it came into existance and that rate of expansion has increased and so far there's no evidence of the universe hitting any sort of barrier to this expansion. but i dont see why we cant consider the observable universe as a closed system when it comes to the behavior of matter and energy contained within it so unless there are forces outside the universe directly interacting with the matter and energy inside the universe i don't think there's any reason not to conclude that entropy will increase as long as space time keeps expanding.

Right, the universe has always been expanding, in fact it ran into the opposite of a barrier--inflation. Well, some say that you shouldn't look at the universe as a closed system (I'm not one of them), but I'll say this: the underpinnings of thermodynamics are the definition of temperature (Zeroth Law). However, at the small scale temperature is a meaningless quantity. The statement 'the temperature of a boron atom is.." is irrelevant. So, when you try to build thermodynamics for small stuff, it doesn't work out at all. So entropy is not well defined in this regime, and attempting to extend this to the universe actually is difficult to do. I've always viewed entropy as a construct that doesn't have too much of a physical meaning, but just to inform of the availability of energy in a system. And I'm not disagreeing necessarily; simply pointing out that entropy doesn't necessarily need to increase as the universe expands. Lastly, thermodynamics for the reason I outlined already (and many others) is supplanted by Statistical Mechanics to try to understand the behavior of (lots of) particles.

i was referring more to energy levels when discussing entropy. my idea is that once space time expansion has over come all the nuclear forces and torn everything in the universe into subatomic particles all that will be left is will be these subatomic particles and photons and neutrinos floating around. what happens if the expansion of the universe reaches a point where every existing particle is wrapped within its own little event horizon, incapable of interacting with anything else, will its energy state/waveform asymptote to 0? what will happen to quantum space time fluctuations?

http://en.wikipedia.org/wiki/Entropy_%28energy_dispersal%29

Right so that's pretty much what the Big Rip is. The universe expands so much that everything is ripped apart, from clusters of galaxies, to solar systems, and then the very fabric of matter. So at the point where even protons have been ripped apart, if we assume ourselves to be say a photon, the observable universe will be a small sphere(like) shape, and this is the event horizon you talk about. Well, its wavefunction (energy state), I suppose would go to zero. Vacuum fluctuations would also go to zero I think, because the length scale of the universe would slowly go to zero as well. In other words, every point in the universe would be reduced to just that: a point of zero volume, zero length. Its also worth mentioning that we could run into the Planck Length, if it turns out to be the smallest possible length and the universe couldn't expand past that so to speak, there *might* still be some vanishingly small, yet nonzero, wavefunctions of particles.

http://en.wikipedia.org/wiki/Planck_length

ya planck length might be the smallest increment at which matter or energy and their interactions can be defined, but i don't believe that space time itself has any natural defining increments so i guess we shouldn't worry about space hitting any upper limit on its expansion. now for some abstract thinking, would it be possible for a universe to exist without containing any matter or energy?

this has to be the awesomest discussion ive ever had on btf

 

[footballforlife]

http://en.wikipedia.org/wiki/Heat_death_of_the_universe

long live entropy

Its more likely this
http://en.wikipedia.org/wiki/Big_Rip

i think its a combination of both, entropy throughout the universe will increase up until the space time expansion of the universe begins to over come atomic strong, weak, and electromagnetic forces. you could say that universal expansion tearing apart everything on the atomic level is the final phase of entropic increase before the universe reaches some sort of dead steady state phase.

It is actually difficult to apply thermodynamics to the universe. In principle, one can model the universe with thermodynamics, but the accuracy of such a model is beyond poor since thermodynamic assumptions start breaking down at both the large scale (galactic scale) and the small scale (atomic scale). I mean much of this depends on the shape of the universe and if it is closed or open, but the current data supports an open universe, so I think the two most likely ends are a Big Rip or Big Freeze. But, this is rather fascinating stuff to think about..

shape, curvature, extradimensional composition are all important factors in the behavior of the universe and this behavior is an important factor when looking at how matter behaves within the universe. we might never know whether the universe is open or closed or whether it has positive or negative curvature or if there are more dimensions beyond the four we experience. all we have is the history of the universe, looking back at the 13.5 billion year lifetime of the universe so far the only conclusions we can make are that the universe has been expanding since it came into existance and that rate of expansion has increased and so far there's no evidence of the universe hitting any sort of barrier to this expansion. but i dont see why we cant consider the observable universe as a closed system when it comes to the behavior of matter and energy contained within it so unless there are forces outside the universe directly interacting with the matter and energy inside the universe i don't think there's any reason not to conclude that entropy will increase as long as space time keeps expanding.

Right, the universe has always been expanding, in fact it ran into the opposite of a barrier--inflation. Well, some say that you shouldn't look at the universe as a closed system (I'm not one of them), but I'll say this: the underpinnings of thermodynamics are the definition of temperature (Zeroth Law). However, at the small scale temperature is a meaningless quantity. The statement 'the temperature of a boron atom is.." is irrelevant. So, when you try to build thermodynamics for small stuff, it doesn't work out at all. So entropy is not well defined in this regime, and attempting to extend this to the universe actually is difficult to do. I've always viewed entropy as a construct that doesn't have too much of a physical meaning, but just to inform of the availability of energy in a system. And I'm not disagreeing necessarily; simply pointing out that entropy doesn't necessarily need to increase as the universe expands. Lastly, thermodynamics for the reason I outlined already (and many others) is supplanted by Statistical Mechanics to try to understand the behavior of (lots of) particles.

i was referring more to energy levels when discussing entropy. my idea is that once space time expansion has over come all the nuclear forces and torn everything in the universe into subatomic particles all that will be left is will be these subatomic particles and photons and neutrinos floating around. what happens if the expansion of the universe reaches a point where every existing particle is wrapped within its own little event horizon, incapable of interacting with anything else, will its energy state/waveform asymptote to 0? what will happen to quantum space time fluctuations?

http://en.wikipedia.org/wiki/Entropy_%28energy_dispersal%29

Right so that's pretty much what the Big Rip is. The universe expands so much that everything is ripped apart, from clusters of galaxies, to solar systems, and then the very fabric of matter. So at the point where even protons have been ripped apart, if we assume ourselves to be say a photon, the observable universe will be a small sphere(like) shape, and this is the event horizon you talk about. Well, its wavefunction (energy state), I suppose would go to zero. Vacuum fluctuations would also go to zero I think, because the length scale of the universe would slowly go to zero as well. In other words, every point in the universe would be reduced to just that: a point of zero volume, zero length. Its also worth mentioning that we could run into the Planck Length, if it turns out to be the smallest possible length and the universe couldn't expand past that so to speak, there *might* still be some vanishingly small, yet nonzero, wavefunctions of particles.

http://en.wikipedia.org/wiki/Planck_length

ya planck length might be the smallest increment at which matter or energy and their interactions can be defined, but i don't believe that space time itself has any natural defining increments so i guess we shouldn't worry about space hitting any upper limit on its expansion. now for some abstract thinking, would it be possible for a universe to exist without containing any matter or energy?

this has to be the awesomest discussion ive ever had on btf

So, if you agree if the Planck Length is the smallest possible measured scale, what difference does it make if space is truly continuous or not? If we cannot by definition even measure this length or past it, what meaning does it truly have for things smaller than that scale? It might as well live in world that cannot be measured by any other object in the universe. In addition all known (and accepted) physical theories break down at this scale as well. So that question is slightly more philosophical, what is the universe? My gut reaction is sure, why not.. if the equations can allow for it, then it is certainly possible, whether or not my understanding is correct though is questionable.

 

[faysal]

you guys really don't need to quote each other every time, seriously...it's quite clear you're replying to one another lol

 

[hardeep_singh]

http://en.wikipedia.org/wiki/Heat_death_of_the_universe

long live entropy

Its more likely this
http://en.wikipedia.org/wiki/Big_Rip

i think its a combination of both, entropy throughout the universe will increase up until the space time expansion of the universe begins to over come atomic strong, weak, and electromagnetic forces. you could say that universal expansion tearing apart everything on the atomic level is the final phase of entropic increase before the universe reaches some sort of dead steady state phase.

It is actually difficult to apply thermodynamics to the universe. In principle, one can model the universe with thermodynamics, but the accuracy of such a model is beyond poor since thermodynamic assumptions start breaking down at both the large scale (galactic scale) and the small scale (atomic scale). I mean much of this depends on the shape of the universe and if it is closed or open, but the current data supports an open universe, so I think the two most likely ends are a Big Rip or Big Freeze. But, this is rather fascinating stuff to think about..

shape, curvature, extradimensional composition are all important factors in the behavior of the universe and this behavior is an important factor when looking at how matter behaves within the universe. we might never know whether the universe is open or closed or whether it has positive or negative curvature or if there are more dimensions beyond the four we experience. all we have is the history of the universe, looking back at the 13.5 billion year lifetime of the universe so far the only conclusions we can make are that the universe has been expanding since it came into existance and that rate of expansion has increased and so far there's no evidence of the universe hitting any sort of barrier to this expansion. but i dont see why we cant consider the observable universe as a closed system when it comes to the behavior of matter and energy contained within it so unless there are forces outside the universe directly interacting with the matter and energy inside the universe i don't think there's any reason not to conclude that entropy will increase as long as space time keeps expanding.

Right, the universe has always been expanding, in fact it ran into the opposite of a barrier--inflation. Well, some say that you shouldn't look at the universe as a closed system (I'm not one of them), but I'll say this: the underpinnings of thermodynamics are the definition of temperature (Zeroth Law). However, at the small scale temperature is a meaningless quantity. The statement 'the temperature of a boron atom is.." is irrelevant. So, when you try to build thermodynamics for small stuff, it doesn't work out at all. So entropy is not well defined in this regime, and attempting to extend this to the universe actually is difficult to do. I've always viewed entropy as a construct that doesn't have too much of a physical meaning, but just to inform of the availability of energy in a system. And I'm not disagreeing necessarily; simply pointing out that entropy doesn't necessarily need to increase as the universe expands. Lastly, thermodynamics for the reason I outlined already (and many others) is supplanted by Statistical Mechanics to try to understand the behavior of (lots of) particles.

i was referring more to energy levels when discussing entropy. my idea is that once space time expansion has over come all the nuclear forces and torn everything in the universe into subatomic particles all that will be left is will be these subatomic particles and photons and neutrinos floating around. what happens if the expansion of the universe reaches a point where every existing particle is wrapped within its own little event horizon, incapable of interacting with anything else, will its energy state/waveform asymptote to 0? what will happen to quantum space time fluctuations?

http://en.wikipedia.org/wiki/Entropy_%28energy_dispersal%29

Right so that's pretty much what the Big Rip is. The universe expands so much that everything is ripped apart, from clusters of galaxies, to solar systems, and then the very fabric of matter. So at the point where even protons have been ripped apart, if we assume ourselves to be say a photon, the observable universe will be a small sphere(like) shape, and this is the event horizon you talk about. Well, its wavefunction (energy state), I suppose would go to zero. Vacuum fluctuations would also go to zero I think, because the length scale of the universe would slowly go to zero as well. In other words, every point in the universe would be reduced to just that: a point of zero volume, zero length. Its also worth mentioning that we could run into the Planck Length, if it turns out to be the smallest possible length and the universe couldn't expand past that so to speak, there *might* still be some vanishingly small, yet nonzero, wavefunctions of particles.

http://en.wikipedia.org/wiki/Planck_length

ya planck length might be the smallest increment at which matter or energy and their interactions can be defined, but i don't believe that space time itself has any natural defining increments so i guess we shouldn't worry about space hitting any upper limit on its expansion. now for some abstract thinking, would it be possible for a universe to exist without containing any matter or energy?

this has to be the awesomest discussion ive ever had on btf

So, if you agree if the Planck Length is the smallest possible measured scale, what difference does it make if space is truly continuous or not? If we cannot by definition even measure this length or past it, what meaning does it truly have for things smaller than that scale? It might as well live in world that cannot be measured by any other object in the universe. In addition all known (and accepted) physical theories break down at this scale as well. So that question is slightly more philosophical, what is the universe? My gut reaction is sure, why not.. if the equations can allow for it, then it is certainly possible, whether or not my understanding is correct though is questionable.

on the subject of continuity of space, if you assume that there is a limit to the smallest increment that the universe can be divided into and that this limit is a property of the universe itself aren't you implying that there is also an upper limit to the size of universe? the part that confuses the hell out of me is the interaction between matter/energy and space-time, we now know definitively that matter/energy affects space-time at least gravitationally (warping, frame dragging, "dark energy" causing universe to expand faster) we know that the "structure" (size, shape, dimensional composition) of the universe affect the properties of matter/energy both on atomic scale and on the galactic scale, so does that mean space-time can be defined as a medium that matter/energy exist in, instead of the assumption that it is just emptiness/void that matter/energy reside in. so is it impossible for matter/energy to exist outside of space-time and inversely is it impossible for space-time to "exist" if there is no matter/energy contained within it?

 

[footballforlife]

on the subject of continuity of space, if you assume that there is a limit to the smallest increment that the universe can be divided into and that this limit is a property of the universe itself aren't you implying that there is also an upper limit to the size of universe? the part that confuses the hell out of me is the interaction between matter/energy and space-time, we now know definitively that matter/energy affects space-time at least gravitationally (warping, frame dragging, "dark energy" causing universe to expand faster) we know that the "structure" (size, shape, dimensional composition) of the universe affect the properties of matter/energy both on atomic scale and on the galactic scale, so does that mean space-time can be defined as a medium that matter/energy exist in, instead of the assumption that it is just emptiness/void that matter/energy reside in. so is it impossible for matter/energy to exist outside of space-time and inversely is it impossible for space-time to "exist" if there is no matter/energy contained within it?

What exactly do you mean by the size of the universe? It seems as if the universe will expand forever, so the limit is no limit at all. And I think I will retract my previous statement; space itself should have energy. The actual fabric of space is some minimal energy, and so the universe must have some amount of it be definition. Going by that then, by definition space exists with energy, so if space exists so does energy. However, the existence of energy doesn't automatically guarantee space because again according to big bang theory, there was something and then space started expanding from some infinitely small point (we think), and so that point had all of the energy of the universe inside it. But there was no space as we know it, so I guess in that sense, energy is everything. Its very difficult to talk about the true beginning of the universe since that is also when time started and trying to think of something 'before' that is utterly meaningless.

 

[gursikhpreet1]

clearly the world hasn't ended. although if btf somehow got shut-down, a part of my world would end

 

[sonehdataweet]

you guys really don't need to quote each other every time, seriously...it's quite clear you're replying to one another lol

LMAO Faysal you're too funny!

 

[disharma1317]

http://en.wikipedia.org/wiki/Heat_death_of_the_universe

long live entropy

Its more likely this
http://en.wikipedia.org/wiki/Big_Rip

i think its a combination of both, entropy throughout the universe will increase up until the space time expansion of the universe begins to over come atomic strong, weak, and electromagnetic forces. you could say that universal expansion tearing apart everything on the atomic level is the final phase of entropic increase before the universe reaches some sort of dead steady state phase.

It is actually difficult to apply thermodynamics to the universe. In principle, one can model the universe with thermodynamics, but the accuracy of such a model is beyond poor since thermodynamic assumptions start breaking down at both the large scale (galactic scale) and the small scale (atomic scale). I mean much of this depends on the shape of the universe and if it is closed or open, but the current data supports an open universe, so I think the two most likely ends are a Big Rip or Big Freeze. But, this is rather fascinating stuff to think about..

shape, curvature, extradimensional composition are all important factors in the behavior of the universe and this behavior is an important factor when looking at how matter behaves within the universe. we might never know whether the universe is open or closed or whether it has positive or negative curvature or if there are more dimensions beyond the four we experience. all we have is the history of the universe, looking back at the 13.5 billion year lifetime of the universe so far the only conclusions we can make are that the universe has been expanding since it came into existance and that rate of expansion has increased and so far there's no evidence of the universe hitting any sort of barrier to this expansion. but i dont see why we cant consider the observable universe as a closed system when it comes to the behavior of matter and energy contained within it so unless there are forces outside the universe directly interacting with the matter and energy inside the universe i don't think there's any reason not to conclude that entropy will increase as long as space time keeps expanding.

Right, the universe has always been expanding, in fact it ran into the opposite of a barrier--inflation. Well, some say that you shouldn't look at the universe as a closed system (I'm not one of them), but I'll say this: the underpinnings of thermodynamics are the definition of temperature (Zeroth Law). However, at the small scale temperature is a meaningless quantity. The statement 'the temperature of a boron atom is.." is irrelevant. So, when you try to build thermodynamics for small stuff, it doesn't work out at all. So entropy is not well defined in this regime, and attempting to extend this to the universe actually is difficult to do. I've always viewed entropy as a construct that doesn't have too much of a physical meaning, but just to inform of the availability of energy in a system. And I'm not disagreeing necessarily; simply pointing out that entropy doesn't necessarily need to increase as the universe expands. Lastly, thermodynamics for the reason I outlined already (and many others) is supplanted by Statistical Mechanics to try to understand the behavior of (lots of) particles.

i was referring more to energy levels when discussing entropy. my idea is that once space time expansion has over come all the nuclear forces and torn everything in the universe into subatomic particles all that will be left is will be these subatomic particles and photons and neutrinos floating around. what happens if the expansion of the universe reaches a point where every existing particle is wrapped within its own little event horizon, incapable of interacting with anything else, will its energy state/waveform asymptote to 0? what will happen to quantum space time fluctuations?

http://en.wikipedia.org/wiki/Entropy_%28energy_dispersal%29

Right so that's pretty much what the Big Rip is. The universe expands so much that everything is ripped apart, from clusters of galaxies, to solar systems, and then the very fabric of matter. So at the point where even protons have been ripped apart, if we assume ourselves to be say a photon, the observable universe will be a small sphere(like) shape, and this is the event horizon you talk about. Well, its wavefunction (energy state), I suppose would go to zero. Vacuum fluctuations would also go to zero I think, because the length scale of the universe would slowly go to zero as well. In other words, every point in the universe would be reduced to just that: a point of zero volume, zero length. Its also worth mentioning that we could run into the Planck Length, if it turns out to be the smallest possible length and the universe couldn't expand past that so to speak, there *might* still be some vanishingly small, yet nonzero, wavefunctions of particles.

http://en.wikipedia.org/wiki/Planck_length

ya planck length might be the smallest increment at which matter or energy and their interactions can be defined, but i don't believe that space time itself has any natural defining increments so i guess we shouldn't worry about space hitting any upper limit on its expansion. now for some abstract thinking, would it be possible for a universe to exist without containing any matter or energy?

this has to be the awesomest discussion ive ever had on btf

So, if you agree if the Planck Length is the smallest possible measured scale, what difference does it make if space is truly continuous or not? If we cannot by definition even measure this length or past it, what meaning does it truly have for things smaller than that scale? It might as well live in world that cannot be measured by any other object in the universe. In addition all known (and accepted) physical theories break down at this scale as well. So that question is slightly more philosophical, what is the universe? My gut reaction is sure, why not.. if the equations can allow for it, then it is certainly possible, whether or not my understanding is correct though is questionable.

on the subject of continuity of space, if you assume that there is a limit to the smallest increment that the universe can be divided into and that this limit is a property of the universe itself aren't you implying that there is also an upper limit to the size of universe? the part that confuses the hell out of me is the interaction between matter/energy and space-time, we now know definitively that matter/energy affects space-time at least gravitationally (warping, frame dragging, "dark energy" causing universe to expand faster) we know that the "structure" (size, shape, dimensional composition) of the universe affect the properties of matter/energy both on atomic scale and on the galactic scale, so does that mean space-time can be defined as a medium that matter/energy exist in, instead of the assumption that it is just emptiness/void that matter/energy reside in. so is it impossible for matter/energy to exist outside of space-time and inversely is it impossible for space-time to "exist" if there is no matter/energy contained within it?

get a room guys

 

[hardeep_singh]

on the subject of continuity of space, if you assume that there is a limit to the smallest increment that the universe can be divided into and that this limit is a property of the universe itself aren't you implying that there is also an upper limit to the size of universe? the part that confuses the hell out of me is the interaction between matter/energy and space-time, we now know definitively that matter/energy affects space-time at least gravitationally (warping, frame dragging, "dark energy" causing universe to expand faster) we know that the "structure" (size, shape, dimensional composition) of the universe affect the properties of matter/energy both on atomic scale and on the galactic scale, so does that mean space-time can be defined as a medium that matter/energy exist in, instead of the assumption that it is just emptiness/void that matter/energy reside in. so is it impossible for matter/energy to exist outside of space-time and inversely is it impossible for space-time to "exist" if there is no matter/energy contained within it?

What exactly do you mean by the size of the universe? It seems as if the universe will expand forever, so the limit is no limit at all. And I think I will retract my previous statement; space itself should have energy. The actual fabric of space is some minimal energy, and so the universe must have some amount of it be definition. Going by that then, by definition space exists with energy, so if space exists so does energy. However, the existence of energy doesn't automatically guarantee space because again according to big bang theory, there was something and then space started expanding from some infinitely small point (we think), and so that point had all of the energy of the universe inside it. But there was no space as we know it, so I guess in that sense, energy is everything. Its very difficult to talk about the true beginning of the universe since that is also when time started and trying to think of something 'before' that is utterly meaningless.

http://en.wikipedia.org/wiki/Vacuum_energy
just read through that, so your assumption of the relationship between space and energy makes sense. the "fabric" doesn't itself have energy, theoretically the "emptiness" itself contains quantum fluctuations which can be defined as energy.
"The theory considers vacuum to implicitly have the same properties as a particle, such as spin or polarization in the case of light, energy, and so on. According to the theory, most of these properties cancel out on average leaving the vacuum empty in the literal sense of the word."
so if this theory is correct then vacuum energy is a property of space and will always occur naturally for as long as the universe exists. what i'm wondering at this point is whether the properties of vacuum energy have changed over time, i know there are theories out there that present the idea that certain properties such as the speed of light or the charges of certain particles might have been slightly different earlier in the universe's lifetime. it would be crazy if this sort of "evolution" could be related to the behavior we see currently, mainly the increased rate of expansion.

 

[campy614]

One man wasted 140k on ads for the rapture. Must have sucked to wake up the next morning.

People have always misinterpreted the Bible. Many of these cases are from people thinking too deeply into stories, numbers, and details without getting the actual message behind each passage.

Some day everything will make sense. But that day was not 5/21/11.

I do think we should learn a lesson from this. We never know when it will be our time to go, so we should live every day like it is our last and love like there's no tomorrow.

 

[footballforlife]

http://en.wikipedia.org/wiki/Vacuum_energy
just read through that, so your assumption of the relationship between space and energy makes sense. the "fabric" doesn't itself have energy, theoretically the "emptiness" itself contains quantum fluctuations which can be defined as energy.
"The theory considers vacuum to implicitly have the same properties as a particle, such as spin or polarization in the case of light, energy, and so on. According to the theory, most of these properties cancel out on average leaving the vacuum empty in the literal sense of the word."
so if this theory is correct then vacuum energy is a property of space and will always occur naturally for as long as the universe exists. what i'm wondering at this point is whether the properties of vacuum energy have changed over time, i know there are theories out there that present the idea that certain properties such as the speed of light or the charges of certain particles might have been slightly different earlier in the universe's lifetime. it would be crazy if this sort of "evolution" could be related to the behavior we see currently, mainly the increased rate of expansion.

Right, so there is no such thing as a true vacuum, there is always something there. In that sense, I view that as space and don't really differentiate between it and the fabric. That is a very good fundamental question--no one knows. Vacuum energy seems to have a relation to the initial conditions of the universe, and it is certainly possible for what we consider constants to not actually be constant at all. Perhaps they seem constant to us at our small human timescales, but aren't over large times. Or, these constants could slowly be converging to their 'final' value after being something different in the early universe. There is certainly a precedence in this area. The fundamental forces, EM, strong, weak, and gravity, all have what is termed a coupling constant associated with it determining their strengths. If we ignore gravity (its coupling constant is about 10^-36 smaller than weak, which is weaker than the other two), then it is possible to unite the three forces, EM, strong, weak, IF we assume that at very high energy these constants unify to a single value. These high energies only existed at the beginning of the universe. There is some evidence that this holds some promise as a viable avenue of research.

If you're still interested in this type of stuff and don't mind technical detail, shoot me a PM. I think we've thread jacked this enough, haha.

 

[gursikhpreet1]

I do think we should learn a lesson from this. We never know when it will be our time to go, so we should live every day like it is our last and love like there's no tomorrow.

+1 well said!