Age of Universe v Expansion Rate
Discussion
So the age of the universe has been estimated by looking at it's size and rate of expansion, and interpolating backwards to the time when the universe was a point.
It has been discovered that the universe's rate of expansion is increasing.
Does this mean going back in time the rate of expansion was slower? If so the universe could be much older than we think.
It has been discovered that the universe's rate of expansion is increasing.
Does this mean going back in time the rate of expansion was slower? If so the universe could be much older than we think.
Interesting point, would this mean it could last a lot longer (as it's at an earlier stage in it's development)
Didn't it have an 'inclationary' period though, which would be analogous to the accelerating blast front? Analogies only go so far though.
Didn't it have an 'inclationary' period though, which would be analogous to the accelerating blast front? Analogies only go so far though.
Edited by Super Sonic on Monday 18th October 00:53
Sorry, what I meant was that originally the theory was that the universe was static (hence equations having a constant added to "fix" them). Then as you say, it was noted that the frequency lines in the stars light were shifted so we moved to the expansionary universe theory. But we still don't really have a coherent theory on why, by how much etc. Hard really, when it's not really testable either.
Big Bang theory is current paradigm. Have always wondered,as it asks as many Q's as it answers, which is part of the reason for the op. What if the size/ time graph wasn't a straight line but a curve? What if it's asymptomatic like Gabriel's horn? It would mean for one thing there wasn't a beginning in time. There is also the sea ov virtual particles in a vacuum thing as an origin of matter, or maybe a virtual matter/ virtual antimatter imbalance,which would provide matter and energy. Not claiming to the answers, just find it interesting.
My personal suspicion is that we don't know anywhere near as much as we think we do and there is a whole new branch of physics still waiting for us to find which will suddenly explain all the things such as dark matter/energy/inability to unify quantum and relativistic effects.
That's really always been the nature of scientific advance (or re-advance, given that sometimes earlier theories were proven correct).
e.g. The overly complicated models that attempted to retain the earth at the centre of the solar system (with ridiculously convoluted explanations for the motion of the planets). Switch to heliocentric and most of the crutches were no longer needed.
Or the progress from solid atoms to the "plum pudding" through "mini solar system" to "electron probability cloud" and other quantum effects.
Or attempts to explain relativistic effects with "luminiferous aether" and complicated equations for planets "dragging" the aether along etc.
Hence I feel that "dark matter" is a crutch to theories that are incomplete and if/when the "new stuff" is uncovered we'll be amazed at how simple the model and equations become.
That's really always been the nature of scientific advance (or re-advance, given that sometimes earlier theories were proven correct).
e.g. The overly complicated models that attempted to retain the earth at the centre of the solar system (with ridiculously convoluted explanations for the motion of the planets). Switch to heliocentric and most of the crutches were no longer needed.
Or the progress from solid atoms to the "plum pudding" through "mini solar system" to "electron probability cloud" and other quantum effects.
Or attempts to explain relativistic effects with "luminiferous aether" and complicated equations for planets "dragging" the aether along etc.
Hence I feel that "dark matter" is a crutch to theories that are incomplete and if/when the "new stuff" is uncovered we'll be amazed at how simple the model and equations become.
It is true that we have falsified things that were regarded as true, but in their falsification we have discovered new truths. It is highly likely that things regarded as true today will be falsified.
We don't know which, though, until we prove them false, we can't just speculate.
This is the nature of truth. A whole other topic.
ETA New Brian Cox series coming, on BBC "Universe". Should have some up to date ideas on here!
We don't know which, though, until we prove them false, we can't just speculate.
This is the nature of truth. A whole other topic.
ETA New Brian Cox series coming, on BBC "Universe". Should have some up to date ideas on here!
Edited by Super Sonic on Wednesday 20th October 21:45
'Everything created in the big bang'
'Guesstimate' is a pretty vague word, I think cosmologists have 'measured' it by looking at the CMB which is not a visible part of the electromagnetic spectrum.
You're " pretty sure " this has been factored in- you guessing or you know?
I've never seen any mention of a cosmological constant since Einstein said it's probably not true.
'Guesstimate' is a pretty vague word, I think cosmologists have 'measured' it by looking at the CMB which is not a visible part of the electromagnetic spectrum.
You're " pretty sure " this has been factored in- you guessing or you know?
I've never seen any mention of a cosmological constant since Einstein said it's probably not true.
Time is just a metric of the rate of change. There was no time before things started happening as…things weren’t happening (yes, saying ‘before time’ is a tautology).
Also, it’s not helpful to think of the Big Bang (often regarded as the worst moniker in science) as an explosion. An explosion expands out into a space, whereas the Big Bang is space. We are the Big Bang, it’s still happening, all of the vast extended spatial dimensions now and everything within them was once much much more condensed and ordered.
We are losing density and order (entropy). Time is one way to express this. 13,772,000,000 years is as good a calculation as any other. It’s derived from many different measurements, known as the Lambda-CDM (cold dark matter) concordance model.
https://en.m.wikipedia.org/wiki/Lambda-CDM_model
Also, it’s not helpful to think of the Big Bang (often regarded as the worst moniker in science) as an explosion. An explosion expands out into a space, whereas the Big Bang is space. We are the Big Bang, it’s still happening, all of the vast extended spatial dimensions now and everything within them was once much much more condensed and ordered.
We are losing density and order (entropy). Time is one way to express this. 13,772,000,000 years is as good a calculation as any other. It’s derived from many different measurements, known as the Lambda-CDM (cold dark matter) concordance model.
https://en.m.wikipedia.org/wiki/Lambda-CDM_model
Flooble said:
My personal suspicion is that we don't know anywhere near as much as we think we do and there is a whole new branch of physics still waiting for us to find which will suddenly explain all the things such as dark matter/energy/inability to unify quantum and relativistic effects.
That's really always been the nature of scientific advance (or re-advance, given that sometimes earlier theories were proven correct).
e.g. The overly complicated models that attempted to retain the earth at the centre of the solar system (with ridiculously convoluted explanations for the motion of the planets). Switch to heliocentric and most of the crutches were no longer needed.
Or the progress from solid atoms to the "plum pudding" through "mini solar system" to "electron probability cloud" and other quantum effects.
Or attempts to explain relativistic effects with "luminiferous aether" and complicated equations for planets "dragging" the aether along etc.
Hence I feel that "dark matter" is a crutch to theories that are incomplete and if/when the "new stuff" is uncovered we'll be amazed at how simple the model and equations become.
I think it's fair to say physicists don't think they know that much, that's why they work in the field. If it was known they'd be looking at other stuff.That's really always been the nature of scientific advance (or re-advance, given that sometimes earlier theories were proven correct).
e.g. The overly complicated models that attempted to retain the earth at the centre of the solar system (with ridiculously convoluted explanations for the motion of the planets). Switch to heliocentric and most of the crutches were no longer needed.
Or the progress from solid atoms to the "plum pudding" through "mini solar system" to "electron probability cloud" and other quantum effects.
Or attempts to explain relativistic effects with "luminiferous aether" and complicated equations for planets "dragging" the aether along etc.
Hence I feel that "dark matter" is a crutch to theories that are incomplete and if/when the "new stuff" is uncovered we'll be amazed at how simple the model and equations become.
I did my physics degree in the 1980s (81-84), and what they're talking about now, bears very little relation to what they were talking about then
MiseryStreak said:
Time is just a metric of the rate of change. There was no time before things started happening as…things weren’t happening (yes, saying ‘before time’ is a tautology).
Also, it’s not helpful to think of the Big Bang (often regarded as the worst moniker in science) as an explosion. An explosion expands out into a space, whereas the Big Bang is space. We are the Big Bang, it’s still happening, all of the vast extended spatial dimensions now and everything within them was once much much more condensed and ordered.
We are losing density and order (entropy). Time is one way to express this. 13,772,000,000 years is as good a calculation as any other. It’s derived from many different measurements, known as the Lambda-CDM (cold dark matter) concordance model.
https://en.m.wikipedia.org/wiki/Lambda-CDM_model
This assumes time and space had a beginning.Also, it’s not helpful to think of the Big Bang (often regarded as the worst moniker in science) as an explosion. An explosion expands out into a space, whereas the Big Bang is space. We are the Big Bang, it’s still happening, all of the vast extended spatial dimensions now and everything within them was once much much more condensed and ordered.
We are losing density and order (entropy). Time is one way to express this. 13,772,000,000 years is as good a calculation as any other. It’s derived from many different measurements, known as the Lambda-CDM (cold dark matter) concordance model.
https://en.m.wikipedia.org/wiki/Lambda-CDM_model
The big bang is a model that leaves a lot unanswered even unanswerable as 'physics didn't apply then'
The Lambda CDM postulates CDM to account for the accelerated expansion. CDM has not been found. I'm hoping the upcoming Brian Cox program proves enlightening :-)
Super Sonic said:
'Everything created in the big bang'
'Guesstimate' is a pretty vague word, I think cosmologists have 'measured' it by looking at the CMB which is not a visible part of the electromagnetic spectrum.
You're " pretty sure " this has been factored in- you guessing or you know?
I've never seen any mention of a cosmological constant since Einstein said it's probably not true.
At least you cleared up the definition.'Guesstimate' is a pretty vague word, I think cosmologists have 'measured' it by looking at the CMB which is not a visible part of the electromagnetic spectrum.
You're " pretty sure " this has been factored in- you guessing or you know?
I've never seen any mention of a cosmological constant since Einstein said it's probably not true.
Yes, it is a "guesstimate" as Cosmologists still don't have any idea what happened before a certain Plank time. So yes, the expansion of the "Universe" could have been very, very slow before that point. No-one knows.
Yes they've looked at the CMB but the "Universe" existed before that "time" it was too hot to be visible to us.
I'm "pretty sure" as Cosmologists are hardly not going to factor in a known expansion rate into their best calculations for the age of the "Universe", are they...
ridds said:
At least you cleared up the definition.
Yes, it is a "guesstimate" as Cosmologists still don't have any idea what happened before a certain Plank time. So yes, the expansion of the "Universe" could have been very, very slow before that point. No-one knows.
Yes they've looked at the CMB but the "Universe" existed before that "time" it was too hot to be visible to us.
I'm "pretty sure" as Cosmologists are hardly not going to factor in a known expansion rate into their best calculations for the age of the "Universe", are they...
So your second and third para seem to be saying the universe could be older than we thought, which was my original post.Yes, it is a "guesstimate" as Cosmologists still don't have any idea what happened before a certain Plank time. So yes, the expansion of the "Universe" could have been very, very slow before that point. No-one knows.
Yes they've looked at the CMB but the "Universe" existed before that "time" it was too hot to be visible to us.
I'm "pretty sure" as Cosmologists are hardly not going to factor in a known expansion rate into their best calculations for the age of the "Universe", are they...
The last one seems to be implying scientists had an age for the universe, and added a constant to make the maths agree w the observations.
Just seen an article on 'The Big Think' about this. "Surprise! The Big Bang Isn't the Beginning of The Universe Anymore"
Can't wait for the new BC series!
ETA the gist of the article appears to be there was a big bang AFTER the inflationary phase,and it was not necessarily the beginning of time. It even has a graph showing the asymptote I mentioned in my op. ETA graph from 'Big Think+'
Can't wait for the new BC series!
ETA the gist of the article appears to be there was a big bang AFTER the inflationary phase,and it was not necessarily the beginning of time. It even has a graph showing the asymptote I mentioned in my op. ETA graph from 'Big Think+'
Edited by Super Sonic on Friday 22 October 00:35
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