Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Mad Mark on 18/10/2009 01:27:36
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Would space time keep on expanding even when all the matter in the universe deconstructs?
Or would the universe made up of short lived virtual particle's keep it going to infinity?
Is our understanding of what's driving the acceleration flawed. If all the galaxies are just going along for the ride where is all the new energy coming from to drive an acceleration. Have scientist been able to determine if the expansion is equal everywhere (taking the effects of local gravity out of the equation) or has our universe grown more complex in time creating ever increasing probabilities and in doing so created extra space-time in the process.
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Would space time keep on expanding even when all the matter in the universe deconstructs?
Or would the universe made up of short lived virtual particle's keep it going to infinity?
Is our understanding of what's driving the acceleration flawed. If all the galaxies are just going along for the ride where is all the new energy coming from to drive an acceleration. Have scientist been able to determin if the expansion is equal everywhere(taking the effects of local gravity out of the equation) or has our universe grown more complex in time creating ever increasing probabilities and in doing so created extra spacetime in the process.
Chances are is that it will come to an end. Space and time simply could not extend forever because as galaxies receed, the physical signalling of the forces become strained. Eventually, this wil result in a big rip, where the fabric of spacetime cannot uphold the presence of galaxies at such long ranges, and so spacetime becomes so highly stretched, it will result in all matter being ripped apart - including spacetime... we would end catasprophically with a complete depletion of reality.
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All is well in the real universe. Consider that the forever expanding universe is a mental creation. It is a creation to help satisfy observations of really old light that has survived for billions of years. We can only observe the light. We must keep in mind that anyone explaining observations of that old light will try and show how it fits their own view of the construct of the universe.
Sometimes we form opinions about reality that is not real. I suspect that most of our opinions about reality are not real. The only thing we can know for certain is that reality is real, no matter what is our opinion of it.
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The acceleration of the expansion of the universe is a very curious thing.
If you were to plot the rate of expansion over time, from the Big Bang to the present, you end up with a complex curve that can't be described by a simple formula.
Basically, in the first models of expansion, the universe started expanding very quickly but from that point on, that rate of expansion was thought to decrease as it was slowed by gravity. This gives a nice simple curve.
Then it was found that there seemed to have been a discontinuity in the curve, just after the initial period of expansion, where the rate of expansion increased exponentially for a relatively short period of time, now called the inflationary epoch. However, a plausible reason for this was found, so the curve still made sense. That is to say, the factor that caused the discontinuity, and why it occurred when it did made sense.
Following the inflationary epoch, things seem to have settled down again. The universe was still expanding, but due to gravity, the rate of expansion was slowing, as you might expect. This put us back on an understandable and simple curve.
However, at another later point along the curve, the rate of expansion of the universe appears to have started accelerating again, introducing another change to the curve and meaning that another factor must have come into play at that point.
The current explanation for the accelerating rate of expansion is dark energy, but the problem with this is that not only do we not know what dark energy actually is, but we also don't know why it should have started acting when it did, and not before or after then. Of course, it's difficult to say why it started acting when it did when we don't really know what it is we're talking about.
To me, there seem to be two options here: either the accelerating expansion of the universe is real and there's a lot more to the nature of energy and matter than we're aware of, or that the accelerating expansion of the universe is actually incorrect and due to misinterpretation of the observations. Personally, and atm, I think there's still scope for either option.
Regarding the ultimate deconstruction of all matter: I just can't see this. As the universe expands, the matter within it does not expand, otherwise the relative distances between separating galaxies would remain the same i.e. the galaxies would expand along with the universe. They don't seem to do this though, and instead the galaxies seem to stay the same size but just move further apart. This being so, I see no reason to suggest that matter will tear itself apart as the universe expands. If the universe is expanding now, but matter is not already tearing itself apart, why should it start doing so at some point in the future? Once again, it would need an additional and as yet unidentified factor, and one that is not currently operating, to bring this about.
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To me, there seem to be two options here: either the accelerating expansion of the universe is real and there's a lot more to the nature of energy and matter than we're aware of, or that the accelerating expansion of the universe is actually incorrect and due to misinterpretation of the observations. Personally, and atm, I think there's still scope for either option.
It is comforting to see that wisdom still exists in the main stream of physics. [:)]
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Could I, as a layman astrophysicist, propose an idea?
Please explain me why my idea would be wrong, as I'm almost certain it will be [;)]
Isn't it possible that the universe might still be expanding because there was an initial acceleration and a lack of 'spacetime friction' (?) because the universe is expanding in a 'spacetime void'
Or bizarre idea nr. 2: Maybe there's something we don't know yet outside our own spacetime, that pulls on the edges of our spacetime, instead of the general idea that expansion comes from a 'pushing' force within.
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Or bizarre idea No. 3: The amount of expansion of the universe is constant per unit (unoccupied) spatial volume, so as the volume increases due to expansion the total amount of expansion must also increase.
For example, if we say that expansion over a set period of time will increase the side of a one metre cube by one % then after that period of expansion the side of the cube will be 1.01 metre, an increase of 0.01 metre. However, the next period of expansion expansion will increase the side of our original cube by 0.0101 metre, so the rate of expansion has appeared to increase.
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Or bizarre idea No. 4; maybe it is the signals we use to detect the expansion that is expanding. [:)]
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No one knows what the hell will happen to the Universe. For almost my entire adult life the only arguement was whether expansion was fast enough to keep going, or would start colapsing back towards a big crunch. So, after 5 or 6 decades of this squabble, all of a sudden all the SOBs simply say "Never Mind"
Something similar to this took place before "inflation" of the early universe was found to be immune to the spead of light. They call it a Scalar Field. Who in the hell knows whether the current increasing speed of expansion is also subject to a Scalar Field that will suddenly come to an end.
You need to remind yourselves these people have very short timeframes in their lives, and do not generally think as big as they think they do. To this very day they can not account for something like 90 percent of matter in the universe. Black matter, black energy. Keep sending me your newsletters, but perhaps with a bit more humility.
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The early Michaelson Morley experiments on the speed of light unaccountable showed it to be the same in all directions. Once confirmed, that would make the equation E=mc2 inevitable. They were testing whether the 'either' that propogated light was similar to the 'either' that propogated the speed of sound.
It turns out you can travel fast enough to leave sound signal behind you. However, light did not seem subject to such contraints. Later, however, the big bang theory introduced the 'either' of expanding space. Specifically, the expansion of space over long distances can actually exceed the speed of light. In other words, at far enough distances, light will NEVER get to you because it has been propogated in an either that is expanding faster then that.
This is all very interesting and worthwhile work. However, it has convinced me there are so many dimensions in and about the universe that contemplation approaches theology. For instance, human self cognizance. We could build robots that acted like humans, and would tell us they are individuals. Could we believe them? In a deterministic universe all creatures great or small would act on the sum total of their accumulated experiences like insects.
Yet humans have a very odd idea they are separate from their fellows, and even if we act on the sum total of our accumulated experience, mine would be entirely destinct from yours.
After thinking about all this for a very long time I have become convinced each of us, perhaps supported by guantam mechanics and probability theory, has created an alternate universe from which we interact with all the other dimensions and universes that are NOT us. It might look like a seemless whole, but we inhabit our own space, created out of our own life experiences.
Just meandering thoughts...
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This is all very interesting and worthwhile work. However, it has convinced me there are so many dimensions in and about the universe that contemplation approaches theology. For instance, human self cognizance. We could build robots that acted like humans, and would tell us they are individuals. Could we believe them? In a deterministic universe all creatures great or small would act on the sum total of their accumulated experiences like insects.
Yes; it is very interesting. You have contemplated a scenario of human self cognizance. What about when the computers we develop progress to the point of self cognizance? Is this even possible? Will we ever see truly sentient non-life entities? Will they be friendly?
Mind boggling things, that.
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Or bizarre idea No. 4; maybe it is the signals we use to detect the expansion that is expanding. [:)]
Or bizarre idea #5:
Since I believe the universe to be infinite and not bounded like the Standard Model suggests, there is ample room for it to expand without limit. And I agree with Vern that the expansion we are observing is do to the expanding signal of tired light.
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Or bizarre idea No. 4; maybe it is the signals we use to detect the expansion that is expanding. [:)]
Or bizarre idea #5:
Since I believe the universe to be infinite and not bounded like the Standard Model suggests, there is ample room for it to expand without limit. And I agree with Vern that the expansion we are observing is do to the expanding signal of tired light.
Since everyone is wildly speculating:
Bizzare idea 6: Tired light is caused by quanta moving through a smear of virtual particles; the ether. As it ploughs through the ether, it will gradually loose energy and momentum, over large periods of time due to its sufficiently high velocity due to the vacuum energy density.
p.s. I don't support tired light :)
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I wonder if anyone has thought to look for spectral lines in lower frequencies; that might give a clue as to how long the universe has been expanding. There's already a Quasar with a spectral shift that places it about 28 billion light years away.
Some of the radio telescopes might be capable of doing it.
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ethos:
You raise an interesting paradox. If the universe is already infinite, how can it expand? By deffinition infinity can neither be added to or subtracted from! Personally, I do not believe actual infinities of any sort exist in our four dimensional universe.
For instance, if there are an infinite number of suns, we would need Sunscreen with an infinite SPF. On the other hand, if the universe is expanding space at an increasing rate, it is entirely feasible that it could exceed the speed of light, as was apparently the case during 'inflation'.
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Vern,
Yeah. I think some new Eintein should begin work on human consciousness. Here is a human analog to the smart robot. Thank Gene Rodenbery. I enter the transporter, get disasembled and reasembled elswhere. I feer to do so would kill me, but create my clone at the other end. No one, not even the clone would know that, however.
I quess the metaphysical part of this is whether human consciousness is created independently of the matterial brain, and can be transmitted along with the dissasembled me.
I reall love this kind of stuff!
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Mr S.
Interesting. A photon that does not encounter anything in its travels, will none the less lose energy as space expands and reduces its energy through red shift. [From the perspective of someone looking at it from a long distance.] So, where would that energy go? Perhaps the very expansion of the 'space ether' draws its expansion from the photon. If that is the case, then energy is moved from electromagnetic, to physical creation and maintenance of space itself.
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ethos:
You raise an interesting paradox. If the universe is already infinite, how can it expand?
Exactly why I don't ascribe to an expanding universe. BTW, infinities can be of different sizes. Google the term infinity and it will explain...............
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Ethos
I googled Infinity and was subsequently invited to test drive the latest FX. The idea infinities can be of different sizes intriques me. Could you take the time to provide a link?
Thanks
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Ethos
I googled Infinity and was subsequently invited to test drive the latest FX. The idea infinities can be of different sizes intriques me. Could you take the time to provide a link?
Thanks
There is a book; 'One, two, three, infinity.'
One example I can think of would be the simple exercise:
Let's say we have a set of infinite numbers. Now let's divide the odd from the even into two different sets. Both are infinite but are only half as large as the original set.
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For instance, if there are an infinite number of suns, we would need Sunscreen with an infinite SPF. On the other hand, if the universe is expanding space at an increasing rate, it is entirely feasible that it could exceed the speed of light, as was apparently the case during 'inflation'.
This assumes that light forever remains intact; in its travels light encounters space debris. Given enough time all of the light may be absorbed.
I have thought of the same scenario about "beam me up". My first thought was whether the same mental essence, I hesitate to say soul, materializes at the destination. Yep; the beamed up person could never know. [:)]
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Ethos! One Two Three Infinity!
Man, does that bring back memories. I read it in probably 1964, and have been hooked on the stuff ever since. Right now I am not up to the technical issues of infinity variations, however, after all these years I finally figured out the special theory of relativity!
Specifically, if we send an travelor toward point A and back at near the speed of light, he will have aged less then us. Howevever, how old was he when he GOT there. After all, for the entire duration we have been communicating with each other. It suddenly became christal clear, HE observes his SPEED as much greater then do we.
His time is running more slowly, and so when he does solar navigation he reports his progress much faster then we do. Theoretically, he could travel faster then the speed of light, according to his clock.
My problem was always this. As we await his round trip return, I am perplexed at WHEN he got to Point A, from his point of view.
The obvious answer is he observes,
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Vern,
You are spot on. Space is not empty of matter and photons will hit stuff. When this happens they will inevitably lose energy, but only in the form of wave lenght. They will not, however, be reduced in velocity in the vacuum of space.
One of the quandries I have thought about is the speed of light in the vacuum of space that is itself expanding. The best I can come up with is the speed of light I see passing me will be 186,000 miles per second. However, as space expands, that light has further to go and will loose energy by method of red shift that I will observe when it passes by.
I see no other way to accomodate this crap then to infer other spacial dimensions the likes of which could include something that could reasonably be construed as a diety. I will even go further. The arguement against a diety is that it never seems to interfere with the universe, and thus the universe is of its own thing.
I am convinced this is not the case. On the one hand, I do not believe a diety will interveine on behalf of individuals simply because they or others pray for it. I don'd discount the possibility of possitive 'karmic' energy, but the 'diety' of the old testament is described as an insecure power hungry maniac.
However, the more I study history, the more I begin to believe in some sort of provinance. The number of close call incidents in both cosmic and human development seem statistically insurmountable. I do not want go elaborate on the Drake equation very much. It established some basic parameters by which we could estimate the number of other technological civilation in the universe. He had almost no data, and came up with a SWAG of 19 in the Milkyway.
In recent years we have begun to fill in the equation with actual data. In ALL cases the actual data reduces the probablitilty. Often by very large orders of magnitude. The formation of our own moon is a near miraculous and necessary event.
But in earth history itself, mathematically capable life forms have had 4 BILLION years to evolve, but during that time, none did. Further, our very own species, genetically speaking, seems to have been reduced at one point or another to no more the a few thousand individuals. [There is more genetic diversity in a single Chimpanzee troop then the entirety of homo sapiense.}
The modern history of climate, empire, and scientific advance coincidences beggars belief. But thats for another day.
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I suspect the probability that life exists in other systems is more probable than we suspect. We always assume our own circumstance for life. Maybe all that is needed is something that can self replicate and evolve. Maybe something like that could exist in the gasses of gas giant planets.
But I doubt that we'll ever meet up with any extra terrestrial sentient beings. Distances are too great, unless there is some as yet unknown means of communication.
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Maybe all that is needed is something that can self replicate and evolve. Maybe something like that could exist in the gasses of gas giant planets.
Absolutely, consider the deep ocean life we have already encountered. Unbelievable diversity of life surrounding hydrothermo vents along moving techtonic plates. I believe in Murphy's Law;
"If it can happen, it will"
And because it happened here on earth, it will also happen where ever the slightest chance exists! And that would encompass areas well beyond our obsurdest imaginations....................
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You are spot on. Space is not empty of matter and photons will hit stuff. When this happens they will inevitably lose energy, but only in the form of wave lenght.
When a photon hits something, it is absorbed, not reduced in energy and not transformed in wavelength. We can actually see the results of this in astronomical observations.
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Pys - You are right, I was thinking of something else.
Assuming a photon is completly annihalated, all of its energy will have been transformed into something else. Examples are electricity and chemical energy (photsynthesis) and heat. And even a photon of radiant heat is probably a whole new one.
But what I have been pondering lately is the proposal to use solar sails for long distance travel at high speed. The sail would be propelled by massive objects emited by the sun. However, the scenario I heard include reflecting sun light. That scenario seemed to imply photons have momentum, and when reflected will transfer that to the sail. If that is true, the only way it could be done is if the photon is reduced in frequency.
Just babbling....
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Vern - You wrote: "I suspect the probability that life exists in other systems is more probable than we suspect..."
Two things. First, am skeptical there are very many mathematically capable creatures in the universe, judging from my own experiences with mathematics. However, I have been following the Drake equation for a very long time now. At the time Drake had very little data to plug into his formula. I think he predicted 19 advanced civilization in our galaxy right now. Then came nothing but a series of bummers.
As far as I can recall, the actual data we have gathered since was unfavorable in each and every case. Further, we found variables he did not include that are spectacularly negative. The REALLY big one is the moon. Not only do we need a goldie locks orbit, but we need a goldie locks moon as well. And the chances to produce the moon we have are WAY bad. I mean orders of magnitude bad.
Then it turns out our gas giants are more important then he figured. Specifically, they are in the outer system, and act as giant hoovers protecting us from otherwise marauding stuff like comet Schumaker Levie
In addition, we have now found about 300 planets, mostly gas giants. It is one thing to say we just do not yet have the technology to detect earth like planets. It is entirely another thing to note the hundreds of gas giants found just about preclude any earthling type creatures in those systems. It turns out that all or almost all of the gas giants orbit close, even VERY close to their respective suns.
In otherwords, they would hoover up anything in the goldie locks zone anyway!
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Yes; the chances are slim earth like systems. I suspected the probabilities would be greater if the only requirement for life was a self replicating entity. Something like that might even be in the innards of a star. [:)]
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Vern - You also wrote: "... I doubt that we'll ever meet up with any extra terrestrial sentient beings. Distances are too great, unless there is some as yet unknown means of communication."
In this respect I have better news. I speculate entangled particles can be used for instanious communications once we detect them being sent out. Specifically, as an advanced and curious civilization I send out alternating strings of entangled and non entangled particles.
The advanced receiving civilization recognizes the difference, and manipulates the entangled sets thus sending instantaneous communications to the sender. Of course, the particles might have been sent millions of years ago. But if this works, it would instantaneously connect us to any network of such communications already established.
Further, it is entirely possible for sentient creatures to travel way beyond the speed of light. [See my thread on time dialation]. Of course, it is something of a one way trip, and by our observations it would have taken them WAY WAY longer to get here then they experinced.
Still, if the human race lasts long enough to where it really really needs to get out of town, even intergalactic trips are possible. Just add enough energy to the space vehicle, and you can slow time down to near zero while the ship itself is traveling near the speed of light. Of course space is not empty, and traveling at such speeds might require actual Startrek type force fields to keep it from burning up.
But what the hell, its all speculation anyway!
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Vern
I am once again running out of beer and will shortly retire for the day. However, I believe organic life of lower orders is entirely possible in extreme environments. It is the mathematically capable life that will be in short supply.
Even earth, with its magical orbit and magical moon never produced a mathematically capable dynosaur even after tens of millions of years. Further, our own mathematically capable people [not me] almost didn't make it. Recent genetic research suggests our species was climatically reduced to no more then a couple of thousand individuals not that long ago.
Specifically, there is more genetic diversity in a single Chimpanzie troop then all of human kind.
Cheers!
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The advanced receiving civilization recognizes the difference, and manipulates the entangled sets thus sending instantaneous communications to the sender. Of course, the particles might have been sent millions of years ago. But if this works, it would instantaneously connect us to any network of such communications already established.
Well; we can hope; but so far we have been unable to communicate anything via entangled particles. Each experiment so far has not given enough evidence to determine whether the observed entangled particle assumed its observed state at the time of entanglement or at the time of manipulation --- observation. I've been paying attention to that, so far no cigar. [:)]