Welcome to MilkyWay@home

Is it posible that the universe are colapsing at this very moment?


Advanced search

Message boards : MilkyWay@home Science : Is it posible that the universe are colapsing at this very moment?
Message board moderation

To post messages, you must log in.

1 · 2 · 3 · 4 · Next

AuthorMessage
ProfileSimplex0
Avatar

Send message
Joined: 11 Nov 07
Posts: 232
Credit: 178,221,048
RAC: 0
100 million credit badge10 year member badge
Message 39359 - Posted: 2 May 2010, 7:14:15 UTC

Is it possible that the universe are collapsing at this very moment but wee are unable to se it?

If all the stars & galaxies emerged from an non rotating point in universe I expect that they would fly outwards but that the gravity will gradually slow
down the velocity of everything so they will eventually stop and than start to accelerate back to the origin of the staring point.

But what happens if the point rotating around 1, 2 or 3 axis?

Will the stars & galaxies in this case ever come to a complete stop in their path before the start to falling back to the point of origin?

Imagine that the galaxy that wee se traveling at the speed of light relative to us now traveling towards us then wee will only se the back light so to speak but the front light will wee not see until wee actually collide.

Or in other words wee will observe an expending universe right to the time when wee collide.

ID: 39359 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
ProfileJoses
Avatar

Send message
Joined: 8 Jul 09
Posts: 19
Credit: 799,954
RAC: 600
500 thousand credit badge9 year member badge
Message 39380 - Posted: 2 May 2010, 19:57:23 UTC - in response to Message 39359.  

Imagine that the galaxy that wee see travelling at the speed of light relative to us now travelling towards us then we will only see the back light so to speak but the front light will we not see until we actually collide.

Or in other words we will observe an expanding universe right to the time when we collide.


Have you ever noticed a train approaching sounds a bit louder, and the whistle sounds a bit higher in pitch, while a train leaving sounds a little quieter and the whistle sounds a bit lower in pitch. This is only at the speed of sound. If a plane is travelling faster than the speed of sound, you won't hear it until the sonic boom shock wave arrives.

If you put the same ideas towards light, if something was travelling towards us (very fast - closer to the speed of light), you would probably notice it is brighter, and activity would appear a bit faster too since light leaving the source would have less distance to travel compared to the "old light" which travelled from further back. If something was travelling faster than light, then it would catch-up on the light emitted and absorb that light, so to us, this would probably look like a black hole since whatever light tried to come this way wouldn't be fast enough to get ahead for us to see the light.

If everything was collapsing faster than the speed of light, then the entire sky would appear dark.

...but this is only a quick guess. If what you suggest is true, there isn't anything we could do about it, I don't think you need to worry about this, the shock wave would be spectacular, not even our Sun would have enough energy to stop the collision.

...but this is only a quick guess.
http://www.joescat.com/boinc/
ID: 39380 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
ProfileSimplex0
Avatar

Send message
Joined: 11 Nov 07
Posts: 232
Credit: 178,221,048
RAC: 0
100 million credit badge10 year member badge
Message 39381 - Posted: 2 May 2010, 20:52:21 UTC - in response to Message 39380.  

Imagine that the galaxy that wee see travelling at the speed of light relative to us now travelling towards us then we will only see the back light so to speak but the front light will we not see until we actually collide.

Or in other words we will observe an expanding universe right to the time when we collide.


Have you ever noticed a train approaching sounds a bit louder, and the whistle sounds a bit higher in pitch, while a train leaving sounds a little quieter and the whistle sounds a bit lower in pitch. This is only at the speed of sound. If a plane is travelling faster than the speed of sound, you won't hear it until the sonic boom shock wave arrives.

If you put the same ideas towards light, if something was travelling towards us (very fast - closer to the speed of light), you would probably notice it is brighter, and activity would appear a bit faster too since light leaving the source would have less distance to travel compared to the "old light" which travelled from further back. If something was travelling faster than light, then it would catch-up on the light emitted and absorb that light, so to us, this would probably look like a black hole since whatever light tried to come this way wouldn't be fast enough to get ahead for us to see the light.

If everything was collapsing faster than the speed of light, then the entire sky would appear dark.


I believe that is only true with respect of the light comming from the front end of the moving object. There are qasars with a redshift walue of Z>7 that
are moving away from us several times the speed of light but can still be obseved.


...but this is only a quick guess. If what you suggest is true, there isn't anything we could do about it, I don't think you need to worry about this, the shock wave would be spectacular, not even our Sun would have enough energy to stop the collision.

...but this is only a quick guess.


I'm not worry, just curious regarding what effect the curvature of space-time has on how the light traveling to us that are sent out from the back end compered with the light sent out from the front end :)
ID: 39381 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
JLConawayII

Send message
Joined: 27 Apr 10
Posts: 35
Credit: 90,782,487
RAC: 4,142
50 million credit badge8 year member badge
Message 39770 - Posted: 17 May 2010, 1:44:31 UTC

I believe our current view of how the universe is behaving is woefully inaccurate. To answer your question, in a limited way yes it is possible, just not quite the way you're describing it. That's really all I'm willing to say at this point in time, since I know how easy it is to be labeled a "lunatic" in the scientific community. I hope I can find a better answer for you sometime in the future.
ID: 39770 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Mike

Send message
Joined: 19 Jan 10
Posts: 7
Credit: 11,915,077
RAC: 0
10 million credit badge9 year member badge
Message 40317 - Posted: 10 Jun 2010, 15:05:13 UTC

Hi all, this is my first post in the forums but l have been crunching for some time now.

Interesting scenario there simplex0 and nice reply by Joses. Indeed if galaxies were moving closer to us then they should appear brighter.

Correct me if l am wrong and this might sound stupid to most of you, but how do we know where the galaxies should be moving towards to if we don't know in which space the big bang occurred? And technically that would be hard to pinpoint since space as we know it is a product of the big bang as well(as far as l remember).

It is very puzzling that galaxies move away from us at ever increasing speeds.

Again sorry if my post is stupid.
ID: 40317 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Matthew
Volunteer moderator
Project developer
Project scientist

Send message
Joined: 6 May 09
Posts: 217
Credit: 6,856,375
RAC: 0
5 million credit badge9 year member badge
Message 40410 - Posted: 15 Jun 2010, 18:58:00 UTC - in response to Message 40317.  

Good questions - the field of cosmology is fairly complicated, but I'll do my best to explain some things.

Indeed if galaxies were moving closer to us then they should appear brighter.


Depends on what you mean by 'brighter'. :) The hard physics definition of 'brighter' would be 'energy flux' from the source, or the amount of energy observed coming from the source. When an object, such as a galaxy, moves towards us, the light becomes Doppler shifted into appearing bluer - this is known as 'blue shift'. Bluer photons of light have more energy, [energy = (plank's constant)*(frequency of photon)] so the galaxy would appear 'brighter' in that it appears 'bluer', and we receive more energy than we would from the same galaxy if it were not moving. The number of photons that we observe, however, would be the same.
The same is true for receding galaxies: photon wavelengths are shifted to higher frequencies = lower energies = redder light. This is referred to as 'red shift'.

...we don't know in which space the big bang occurred?


Technically, the big bang occurred everywhere. Immediately after the big bang, the universe was only the size of a single atom, but expanded very quickly. As space expanded, the matter was able to cool down, and form galaxies, etc. It was thought that eventually, the gravity of the mass in the universe would overcome the initial expansion momentum from the big bang, and everything would contract in on itself and collapse back down. But Edwin Hubble discovered that everything in the universe is moving away from us, and the farther away something is, the faster it is moving away. (this has been repeatedly confirmed) This, and other observations, have led modern cosmology to the conclusion that space itself is still expanding, like raisins in a loaf of bread as the bread bakes and expands.

Is it possible that the universe are collapsing at this very moment but wee are unable to se it?


Succinctly, no. Nothing with mass in the universe can travel at the speed of light, and massless particles (such as photons) can only travel at the speed of light. (These are consequences of the Theory of Relativity, much of which has been experimentally verified) All of the evidence that we have points to a universe that is constantly expanding, and if it suddenly stopped expanding, we would be able to see this as the light from the 'stopped' objects reaches us. So if a galaxy 10 million light years away stopped moving away and is now moving towards us, we would notice it unless it turned around less than 10 million years ago. This is assuming that the turn-around is sudden, and that's not how the universe tends to work. :)

...how easy it is to be labeled a "lunatic" in the scientific community


lol - We are all lunatics, some of us just get more things right than others. :) Seriously, though, most people who get labelled 'lunatics' are the ones who start making wild theories and proclamations without doing their homework first. Our scientific knowledge is centuries-old, and very complicated - there is a reason that a PhD takes 10 years of schooling past High School. Most scientists appreciate questions, as long as the asker is not throwing around extreme presuppositions.

Just beware of the 'Dunning–Kruger effect' - it occurs when someone knows a little about something, and then they automatically assume that they know a lot. And they can get away with it until they meet someone who knows more. There are people who make entire careers out of knowing 'a little bit more' than most people, and then when they finally meet someone who knows more than they do, they accuse the more knowledgeable person of being part of a cover up or conspiracy.

We've all been victims of the Dunning-Kruger effect at some time or another, as it can be hard to tell where our actual knowledge stops.

Wow- this was longer than I thought. :) I hope I answered the major questions, but feel free to ask more. (I may take a few days to answer, though, because I will be travelling a lot very soon)

Cheers - Matthew
ID: 40410 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Fayvitt
Avatar

Send message
Joined: 11 Apr 10
Posts: 25
Credit: 375,893
RAC: 0
100 thousand credit badge8 year member badge
Message 40438 - Posted: 16 Jun 2010, 12:27:47 UTC
Last modified: 16 Jun 2010, 13:01:34 UTC

I'll be the lunatic/crackpot, James. I can bear it ;)

The field of Cosmology is NOT that complicated. Explaining theories that aren't valid or don't withstand scrutiny...is.

"It should be possible to explain the laws of physics to a barmaid." Al Einstein

Physics explain what's happening in Cosmology, but mathemeticians now use a host of wild, untestable theories. Mathematics does NOT explain observable events as we see them.

Technically, the big bang occurred everywhere. Immediately after the big bang, the universe was only the size of a single atom, but expanded very quickly. As space expanded, the matter was able to cool down, and form galaxies, etc.


Technically, the big bang had to occur in one place. A point...(loose term in quantam physics). Immediately after the big bang, the size of an atom? Immediately? Planck time disagrees with that. What is the universe expanding into? Big bang theory? No, big bang hypothesis. The mathematics does not explain how, or why.

Succinctly, no. Nothing with mass in the universe can travel at the speed of light, and massless particles (such as photons) can only travel at the speed of light. (These are consequences of the Theory of Relativity, much of which has been experimentally verified)


Is a photon a particle now, and not a wave? Or hell, is it both? Duality? Paradox? = 2 theories that are forced together that are not compatible. But made to exist and given a name. If it's a particle, it has to have mass, as you can say it is at x,y,z coordinates. If light takes 8 minutes to reach us from the sun, at 7 mins 26secs 100 ms etc etc you have to be able to say where that "photon" is. It HAS to be at a certain place at that exact time.
It can't be a wave, as that describes what an object does. Travels in a wave pattern.

And what parts of ToR have been experimientally verified? Not theorized or mathemeticized, what parts actually have experimental\tangible evidence of existence? Besides time speeding up as you travel faster, what else? Much means more than a few things.

And the one thing as a "scientist" you need to remember is, Relativity is not compatible with quantum theory. Gravity does not work at sub atomic level.
Graviton? PURELY hypothetical, and mathematical. Invented particle needed to explain a gap in knowledge. An invention needed to balanace a mathematical equation.
ID: 40438 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Matthew
Volunteer moderator
Project developer
Project scientist

Send message
Joined: 6 May 09
Posts: 217
Credit: 6,856,375
RAC: 0
5 million credit badge9 year member badge
Message 40446 - Posted: 16 Jun 2010, 20:53:32 UTC - in response to Message 40438.  

"It should be possible to explain the laws of physics to a barmaid." Al Einstein


True, the laws of physics are easy to explain, but the consequences of those laws are often quite complicated. The greatest success of a scientific theory is for it to predict observable phenomena mathematically, and then verify it experimentally. Physics represents a host of laws, while mathematics provides the hard logical extrapolations of those laws. When observation deviates from what the mathematics predict, there is something that we don't understand, and therefore need to discover.

"Crazy" hypothetical mathematical explorations are necessary for future work; most modern physical theories are based on complicated mathematical systems that were developed over a century ago, and were considered worthless in their time.


Immediately after the big bang, the size of an atom? Immediately?


You caught me using general terms here. :) It doesn't pay to be specific here, because there all multiple theories trying to merge quantum and relativistic (and other) theories, and we are not sure how to test them. But our universe today is consistent with a universe that was once smaller than an atom.

Big bang theory? No, big bang hypothesis


No, Big Bang Theory. :) A theory is a hypothesis with experimental evidence. While the Big Bang Theory was developed to explain the receding universe, it has since gained experimental evidence - one of the best examples is the discovery of the Cosmic Microwave Background, which was predicted by the theory before it was discovered. Observed galaxy correlation functions also match what the Big Bang Theory predicts. Mathematically, the Equations of General Relativity, when run backwards in time, also predict an infinitesimally small and infinitely dense beginning to the universe.

Is a photon a particle now, and not a wave? Or hell, is it both?


The photon is both a particle and a wave. Most particles, massless or massive, behave as both waves and particles - the theories are not incompatible, you just need a better understanding of quantum mechanics. ;) I suggest starting by reading up on the dual-slit experiment. Quantum theory (namely Heisenberg's uncertainty relation) says that you can't give anything a definite x,y,z position, or a definite time. This only becomes important at small scales, such as the scale that photons and other elementary particles operate at. All particles exist as statistical distributions in space and time, described by their quantum mechanical 'wavefunctions'.

And what parts of ToR have been experimientally verified?


Relativistic time dilation, as you mentioned, is one verification. Clocks on the space shuttle and longer lifetimes of relativistic decaying particles are concrete proofs of that. Gravitational time dilation, where time goes slower closer to a gravitational source, has also been verified by atomic clocks placed at different elevations. The perihelion precession of Mercury and orbital decay of tightly bound massive binaries are other experimentally verified predictions of GR (general relativity). The best evidence is light bending by massive sources, esp. galaxy clusters, also predicted before observed. This also has profound implications on the structure of our universe, but it is one of those conceptually and mathematically complicated subjects. (Which flows logically from the simple base postulates of GR)

If you are interested in Relativity, Hans Ohanian has a great book 'Gravitation and Spacetime' which is a fairly simple and rigorous introduction to GR. The later chapters are outdated, but he is working on a third edition now to correct this. The best feature of this book, in my opinion, is his constant references to experimental evidence.

Relativity is not compatible with quantum theory


True, although steps have been made to combine them. The Dirac Equation and subsequent equations of quantum field theory do an excellent job of describing relativistic, quantum mechanical systems. No one knows what gravity does on very small scales, as the other natural forces overwhelm the comparatively weak gravitational force, and experiments to detect it are very difficult. It is possible that gravity does not even exist at quantum mechanical distance scales.

We know that our current theory of gravitation is incorrect, but that does not mean that what we have is wrong. It simply means that we may need a small correction term to the math, or that some other physical process exists - the leading theory right now being Dark Matter.

Graviton? PURELY hypothetical, and mathematical.


I agree. :) The graviton was invented to help unify relativity and quantum theory. Although, Einstein's field equation, when viewed from the perspective of quantum field theory, looks exactly like a field equation that would describe a massless particle of quantum spin 2. My problem with the graviton is that it would 'know too much' because it would couple with the other forces - in order to produce light-bending, for example.

Scientific theories should be testable - I do not hold string theory to be true in any way. (yet) However, it pays in the long run to hypothesize, rigorously and mathematically, beyond what we can test now, so that we know what to look for when we achieve the necessary technology.

The other key point of science is that science is willing to admit when it is wrong - everything we know could be incorrect (not flat out wrong though, because modern science does a pretty good job describing most of what we perceive, so it must at least be on the right track), and could (and probably will) be replaced by better theories in the future.
ID: 40446 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Fayvitt
Avatar

Send message
Joined: 11 Apr 10
Posts: 25
Credit: 375,893
RAC: 0
100 thousand credit badge8 year member badge
Message 40454 - Posted: 17 Jun 2010, 4:55:02 UTC - in response to Message 40446.  
Last modified: 17 Jun 2010, 5:32:11 UTC

Nice to hear you don't subscribe to M/String Theory. There's hope for you yet!

The best evidence is light bending by massive sources, esp. galaxy clusters, also predicted before observed.


Gravitational lensing. But then....

This also has profound implications on the structure of our universe, but it is one of those conceptually and mathematically complicated subjects. (Which flows logically from the simple base postulates of GR)


If something 'logically' follows on from GR, why does it become complicated? It either is..or isn't. Something is either dead, or alive. Schrodinger's cat starts meowing. It could be half dead, and half alive. Or dead AND alive.

We know that our current theory of gravitation is incorrect, but that does not mean that what we have is wrong. It simply means that we may need a small correction term to the math, or that some other physical process exists - the leading theory right now being Dark Matter.


THAT'S what annoys me no end. If a theory is not testable, or is flawed, it is not a working theory. If the theory can be tested and does not work, it is incorrect i.e. WRONG.

How does making up non-existant particles, inserting their 'made up' properties into an equation/formula, make said equations/formulae correct?

What is Dark Matter? Well, it's a graviton. Something made up to explain a discrepency. Maybe gravity works differently on galactic scale just as it does at a subatomic level.
ID: 40454 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Cluster Physik

Send message
Joined: 26 Jul 08
Posts: 627
Credit: 94,940,203
RAC: 0
50 million credit badge10 year member badgeextraordinary contributions badge
Message 40455 - Posted: 17 Jun 2010, 5:42:37 UTC - in response to Message 40446.  

My problem with the graviton is that it would 'know too much' because it would couple with the other forces - in order to produce light-bending, for example.

Actually it doesn't really need to couple with the other forces as not the light is bent, but the space ;)
ID: 40455 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Fayvitt
Avatar

Send message
Joined: 11 Apr 10
Posts: 25
Credit: 375,893
RAC: 0
100 thousand credit badge8 year member badge
Message 40456 - Posted: 17 Jun 2010, 5:43:51 UTC

Got a little off track there. Photons. Light.

Duality..Paradox. Light as a wave and a particle.

Do you believe that light can be explained by a quantum vector field?
ID: 40456 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Cluster Physik

Send message
Joined: 26 Jul 08
Posts: 627
Credit: 94,940,203
RAC: 0
50 million credit badge10 year member badgeextraordinary contributions badge
Message 40457 - Posted: 17 Jun 2010, 5:52:16 UTC - in response to Message 40456.  
Last modified: 17 Jun 2010, 6:25:56 UTC

Do you believe that light can be explained by a quantum vector field?

Light is normally described by two (coupled) vector fields (which can be derived from a combination of one vector potential and a scalar potential). That doesn't change much if you look at it classically or in the frame of QM.
ID: 40457 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Cluster Physik

Send message
Joined: 26 Jul 08
Posts: 627
Credit: 94,940,203
RAC: 0
50 million credit badge10 year member badgeextraordinary contributions badge
Message 40458 - Posted: 17 Jun 2010, 6:43:54 UTC - in response to Message 39359.  

Going back to the original question of the thread.

Is it possible that the universe are collapsing at this very moment but wee are unable to se it?

We may see the full extent quite a bit later, but the relative velocities of nearby objects are so small that we would see it there first. It can't hide.

If all the stars & galaxies emerged from an non rotating point in universe I expect that they would fly outwards but that the gravity will gradually slow
down the velocity of everything so they will eventually stop and than start to accelerate back to the origin of the staring point.

If the universe will stop (or even reverse) its current expansion depends crucially on the density of the universe. If there isn't enough matter in here (exerting gravitational forces), the expension will never stop. The visible (known) matter in the universe accounts for less than 2% of the needed "critical density". Even when considering the dark matter evident from the measurement of the rotation of galaxies and their movements in the galaxy clusters, we have only about a fourth of the needed mass.

And there is still the issue of the so called Dark Energy (pushing the universe apart). Current observations may hint to quite a bit of it (more than 70% of the total mass/energy in the universe is currently supposed to be dark energy), which leads to an accelarated expansion and not a slowdown. But frankly, I don't buy into that yet (but this is my personal opinion not based on anything I would call a sound reasoning, it's more a feeling, I simply don't like it ;).
ID: 40458 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Fayvitt
Avatar

Send message
Joined: 11 Apr 10
Posts: 25
Credit: 375,893
RAC: 0
100 thousand credit badge8 year member badge
Message 40459 - Posted: 17 Jun 2010, 7:04:29 UTC

It's also possible that what lies outside our universe may push back on the universe one day, condensing it. Or what encompasses our universe may actually be sucking it out.
ID: 40459 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Vid Vidmar*
Avatar

Send message
Joined: 29 Aug 07
Posts: 81
Credit: 60,360,858
RAC: 0
50 million credit badge10 year member badge
Message 40460 - Posted: 17 Jun 2010, 7:38:32 UTC - in response to Message 40458.  


ID: 40460 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Vid Vidmar*
Avatar

Send message
Joined: 29 Aug 07
Posts: 81
Credit: 60,360,858
RAC: 0
50 million credit badge10 year member badge
Message 40461 - Posted: 17 Jun 2010, 7:58:58 UTC - in response to Message 40459.  

It's also possible that what lies outside our universe may push back on the universe one day, condensing it. Or what encompasses our universe may actually be sucking it out.


To me a question of what is "outside" our universe is more philosophical than scientific. I strongly advocate idea, that "outside" our universe shouldn't even exist. Only that way all the "space" our universe needs is "provided". To explain this concept I usually use sets. I define our universe as universal set (convenient isn't it? :) ) then I ask what is "outside" of a set? A complement of a set of course, and a complement of universal set is an empty set. Voila!
Yet again, this is my personal belief and should not be treated as scientific fact until proven.
BR
ID: 40461 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Cluster Physik

Send message
Joined: 26 Jul 08
Posts: 627
Credit: 94,940,203
RAC: 0
50 million credit badge10 year member badgeextraordinary contributions badge
Message 40462 - Posted: 17 Jun 2010, 8:09:29 UTC - in response to Message 40461.  

It's also possible that what lies outside our universe may push back on the universe one day, condensing it. Or what encompasses our universe may actually be sucking it out.


To me a question of what is "outside" our universe is more philosophical than scientific. I strongly advocate idea, that "outside" our universe shouldn't even exist.

Correct. There is nothing "outside" by definition, there isn't even an "outside". Everything that can have an influence on our universe belongs to our universe.
ID: 40462 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Cluster Physik

Send message
Joined: 26 Jul 08
Posts: 627
Credit: 94,940,203
RAC: 0
50 million credit badge10 year member badgeextraordinary contributions badge
Message 40464 - Posted: 17 Jun 2010, 8:36:03 UTC - in response to Message 40460.  
Last modified: 17 Jun 2010, 8:42:31 UTC

I read somewhere, that by recent long-term CMB observations and measurements, it has been concluded that after all our universe seems to be flat instead of open. So it might be that your (and mine) feeling might not be far off.

Actually there is some reasoning that the universe should have a flat geometry and I like the idea a lot. Problem is we can't see that much of matter/energy. That's were the dark energy comes into the game. It is supposed to close the gap to the flat universe. But at the same time it needs to have repulsive properties leading to an accelerated expansion even with a flat universe. And that is what I don't like.

My reasoning in support of non-open universe goes somewhat along this line: the further out we look, we see further back in time. And we see redshift. To me that redshift means nothing more than a fact that things we observe moved at such speeds relative to us at THAT time, not NOW. And since doppler effect (blue/redshift) is a function of speed, is as such invariant to distance, so, if our universe was indeed accelerating in expansion, we should see a lot more redshift closer to us than further out.

And that is exactly how the accelerated expansion was measured. They took a certain type of supernovae known to have always the same absolute brightness (so the apparent brightness we see on earth gives us the distance at some time in the past) and compared it with the redshift.
But as those measurements aren't particularly easy (and some assumptions need to be fullfilled for the method to be working), I'm still not completely convinced (even as there is some solid evidence).

And not wanting to become a victim of Dunningļæ½Kruger effect, I am fully aware that my knowledge in this area is far from perfect, I just wanted to present my line thinking about this question.

Hey, I'm also not an expert in this field (even as I'm a physicist, but I'm doing something completely different). So a lot of my "knowledge" qualifies more as hearsay and handwaving as I heard the lectures about some of the topics years ago and forgot almost everything in the meantime ;)
ID: 40464 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Fayvitt
Avatar

Send message
Joined: 11 Apr 10
Posts: 25
Credit: 375,893
RAC: 0
100 thousand credit badge8 year member badge
Message 40465 - Posted: 17 Jun 2010, 8:42:24 UTC - in response to Message 40462.  
Last modified: 17 Jun 2010, 8:52:49 UTC

Ok, i define our universe as the "bubble universe" theory. Convenient, isn't it? Nice theory also.

What's the bubble forming in?

Want to not discuss it as it doesn't fit your theory? Easier to ignore than put a hypothesis forward?

It's just as philisophical as dark energy. 'We think something is accelerating the universe, so it must be inside'. That's kind of ignoring any other opinion, as it doesn't fit yours.

I believe the fate of the universe depends solely upon the medium into which it was born, big-banged. Blow up a balloon real fast, a huge influx of energy. What happens to it depends upon the pressures outside it.
ID: 40465 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
Cluster Physik

Send message
Joined: 26 Jul 08
Posts: 627
Credit: 94,940,203
RAC: 0
50 million credit badge10 year member badgeextraordinary contributions badge
Message 40466 - Posted: 17 Jun 2010, 8:54:11 UTC - in response to Message 40465.  
Last modified: 17 Jun 2010, 9:18:34 UTC

Ok, i define our universe as the "bubble universe" theory. Convenient, isn't it? Nice theory also.

What's the bubble forming in?

Want to not discuss it as it doesn't fit your theory? Easier to ignore than put a hypothesis forward?

It's just as philisophical as dark energy. 'We think something is accelerating the universe, so it must be inside'. That's kind of ignoring any other opinion, as it doesn't fit yours.

Not at all!

But first, the whole "bubble universe theory" is currently nothing more than a game with some advanced mathematics, it is not substantiated by any experimental/observation data (opposed to the dark energy stuff, there is some evidence for that).

And the second point comes straight from Wikipedia:

The bubble universe model proposes that different regions of this inflationary universe (termed a multiverse) decayed to a true vacuum state at different times, with decaying regions corresponding to ā€œsubā€- universes not in causal contact with each other

The bold part simply says that it is impossible to detect, if there is anything. Occams Razor tells me that there is nothing (at it is the simpler alternative and you can't tell the difference). Actually it fits very well with my definition that everything that can have an influence on our universe belongs to our universe. Or in more physical terms: a universe is not only a closed system, it is an isolated system.

Edit:
I believe the fate of the universe depends solely upon the medium into which it was born, big-banged. Blow up a balloon real fast, a huge influx of energy. What happens to it depends upon the pressures outside it.

Important difference is that our universe didn't pop up in some place or in some environment. The whole big bang happens inside our universe.

If there is anything outside (Caution! Heavy unfounded speculation which doesn't matter anyway because it does not influence our universe follows.) it may very well be that our universe is just a vacuum fluctuation in another universe where a tiny black hole with Planck mass und Planck radius was formed just by chance and disappeared again from this other universe within the Planck time (<10^-43 seconds) to conserve energy. And within this randomly created and immediately destroyed tiny thing our own universe develops completely disconnected from its origin with its own spacetime and billions of galaxies. Isn't that a beautiful thought?
ID: 40466 · Rating: 0 · rate: Rate + / Rate - Report as offensive     Reply Quote
1 · 2 · 3 · 4 · Next

Message boards : MilkyWay@home Science : Is it posible that the universe are colapsing at this very moment?

©2019 Astroinformatics Group