Age of Universe vs Furthest Object
Discussion
The Universe is approx 13.75bn years old (last time I looked!) and I keep reading about astomomers spotting another 'furthest object from the Earth' with a distance in the region of 13bn light years.
Now's when I get confused. Even if it travelled in the opposite direction from us after the big bang the relative speed between earth and the other object must be a significant proportion of the speed of light in order for the light to be 13bn years old before we first see it (I figure something more than (13.75/13.75+0.75) times the speed of light??). Problem is we're travelling nowhere near the speed of light so how does it work???
Now's when I get confused. Even if it travelled in the opposite direction from us after the big bang the relative speed between earth and the other object must be a significant proportion of the speed of light in order for the light to be 13bn years old before we first see it (I figure something more than (13.75/13.75+0.75) times the speed of light??). Problem is we're travelling nowhere near the speed of light so how does it work???
Look up "Inflation" in connection with the early universe. The idea is that there was a period of time when space-time expanded hugely (not things moving quickly in space-time but space-time itself expanding). So things are really far away but there has still been time for light to get back to us.
ewenm said:
Look up "Inflation" in connection with the early universe. The idea is that there was a period of time when space-time expanded hugely (not things moving quickly in space-time but space-time itself expanding). So things are really far away but there has still been time for light to get back to us.
See. That just confuses me. It sounds like someone couldn't to the maths so made something up to fit. Einstein et al have a lot to answer for.pointedstarman said:
ewenm said:
Look up "Inflation" in connection with the early universe. The idea is that there was a period of time when space-time expanded hugely (not things moving quickly in space-time but space-time itself expanding). So things are really far away but there has still been time for light to get back to us.
See. That just confuses me. It sounds like someone couldn't to the maths so made something up to fit. Einstein et al have a lot to answer for.If you have two points on the balloon that are moving away from each other and then you blow the balloon up they still move, relative to the surface of the balloon, at the same speed but the distance between the points grows more rapidly.
It's actually a crap analogy but it's about as close as one can easily visualise.
pointedstarman said:
See. That just confuses me. It sounds like someone couldn't to the maths so made something up to fit. Einstein et al have a lot to answer for.
So true!These days, it seems like a lot of science is just "filler". In other words, scientists are afraid to challenge the conventional wisdom. So they invent new theories that try to match observations with existing theories.
Galaxies appear to be spinning faster than we expect. Instead of thinking that our understanding of gravity may be incomplete, we invent the concept of "dark matter".
The expansion of the Universe seems to be accelerating. This contradicts our understanding of physics. The logical conclusion would be that our understanding of physics is wrong. Instead, our scientists have decided that there must be "dark energy".
We do not seem to be capable of accepting that we just do not know the answer to some questions.
Don
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don4l said:
So true!
These days, it seems like a lot of science is just "filler". In other words, scientists are afraid to challenge the conventional wisdom. So they invent new theories that try to match observations with existing theories.
Galaxies appear to be spinning faster than we expect. Instead of thinking that our understanding of gravity may be incomplete, we invent the concept of "dark matter".
The expansion of the Universe seems to be accelerating. This contradicts our understanding of physics. The logical conclusion would be that our understanding of physics is wrong. Instead, our scientists have decided that there must be "dark energy".
We do not seem to be capable of accepting that we just do not know the answer to some questions.
I think you need to read this,These days, it seems like a lot of science is just "filler". In other words, scientists are afraid to challenge the conventional wisdom. So they invent new theories that try to match observations with existing theories.
Galaxies appear to be spinning faster than we expect. Instead of thinking that our understanding of gravity may be incomplete, we invent the concept of "dark matter".
The expansion of the Universe seems to be accelerating. This contradicts our understanding of physics. The logical conclusion would be that our understanding of physics is wrong. Instead, our scientists have decided that there must be "dark energy".
We do not seem to be capable of accepting that we just do not know the answer to some questions.
http://en.wikipedia.org/wiki/Theory
pointedstarman said:
See. That just confuses me. It sounds like someone couldn't to the maths so made something up to fit. Einstein et al have a lot to answer for.
You mean to be thanked for, of course. Ever used GPS? Thank Einstein that it works.There's a very human arrogance/conceit that the Universe should be "undertandable" and "make sense" when there is no reason it should. Have a read of The Quantum Universe to gain an understanding of just how counter-intuitively the particles that make up our universe behave.
don4l said:
These days, it seems like a lot of science is just "filler". In other words, scientists are afraid to challenge the conventional wisdom. So they invent new theories that try to match observations with existing theories.
Galaxies appear to be spinning faster than we expect. Instead of thinking that our understanding of gravity may be incomplete, we invent the concept of "dark matter".
The expansion of the Universe seems to be accelerating. This contradicts our understanding of physics. The logical conclusion would be that our understanding of physics is wrong. Instead, our scientists have decided that there must be "dark energy".
How well do you understand gravitational theory? You keep saying "instead" rather than "the observations don't match the theory so the theory is adapted" - that's precisely how science works. If it proves impossible to adapt a theory to make accurate predictions that can then be observed then the whole theory will be replaced by something better. Dark matter and dark energy are precisely the scientists saying "our current understanding doesn't match observations, what happens if we postulate this?".Galaxies appear to be spinning faster than we expect. Instead of thinking that our understanding of gravity may be incomplete, we invent the concept of "dark matter".
The expansion of the Universe seems to be accelerating. This contradicts our understanding of physics. The logical conclusion would be that our understanding of physics is wrong. Instead, our scientists have decided that there must be "dark energy".
The problem with gravity is that the current theory works extremely well in nearly all cases (as evidenced by the use of it to plan accurate space missions and predict astronomical events), so it is not unreasonable for theoreticians to use it as a starting point.
don4l said:
We do not seem to be capable of accepting that we just do not know the answer to some questions.
So we should stop trying to find out? 
Down that road is the answer "God did it". You missed the word "yet" off the end of the sentence. We may never know but we may discover some other useful stuff while trying to find out.an entirely incorrect but good analogy is this.
get a massive rubber sheet and pour on a load of ants, excite them to run in various directions.
Pull the massive sheet in all direction at once. The ants will keep moving at the same pace (ie their legs dont' start moving faster), but they move apart much much faster.
edited for spelling and being a retard.
get a massive rubber sheet and pour on a load of ants, excite them to run in various directions.
Pull the massive sheet in all direction at once. The ants will keep moving at the same pace (ie their legs dont' start moving faster), but they move apart much much faster.
edited for spelling and being a retard.
Edited by PugwasHDJ80 on Monday 12th March 13:16
pointedstarman said:
The Universe is approx 13.75bn years old (last time I looked!) and I keep reading about astomomers spotting another 'furthest object from the Earth' with a distance in the region of 13bn light years.
Now's when I get confused. Even if it travelled in the opposite direction from us after the big bang the relative speed between earth and the other object must be a significant proportion of the speed of light in order for the light to be 13bn years old before we first see it (I figure something more than (13.75/13.75+0.75) times the speed of light??). Problem is we're travelling nowhere near the speed of light so how does it work???
Slight correction, we can trace back what we 'know' to around the figure you mention, but that does not mean that the age of the Universe is necessarily that figure, it is 'at least' that amount, but it could well be a billion times older still.Now's when I get confused. Even if it travelled in the opposite direction from us after the big bang the relative speed between earth and the other object must be a significant proportion of the speed of light in order for the light to be 13bn years old before we first see it (I figure something more than (13.75/13.75+0.75) times the speed of light??). Problem is we're travelling nowhere near the speed of light so how does it work???
The reason is simple, we do not understand what a 'singularity' is in this respect.
Relativity tells us that whether you are here or on a distant planet, the track-back is going to be the same figure you mention.
ewenm said:
So we should stop trying to find out? Down that road is the answer "God did it". You missed the word "yet" off the end of the sentence. We may never know but we may discover some other useful stuff while trying to find out.
I don't think that we should stop trying to find out. Quite the opposite. Down that road is the answer "God did it". You missed the word "yet" off the end of the sentence. We may never know but we may discover some other useful stuff while trying to find out.I think that we would be able to make more progress if we were a bit quicker to accept that some theories are wrong. Invariably, scientists are ridiculed if they go against the conventional wisdom.
"Nullius in Verba" sums up my view quite nicely.
Don
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Simpo Two said:
PugwasHDJ80 said:
an entirely incorrect but good analogy is this... get a massive rubber sheet
Demonstrates gravity nicely too. Place a heavy object on the sheet, then roll a marble past it and watch the 'orbit'.PugwasHDJ80 said:
Simpo Two said:
PugwasHDJ80 said:
an entirely incorrect but good analogy is this... get a massive rubber sheet
Demonstrates gravity nicely too. Place a heavy object on the sheet, then roll a marble past it and watch the 'orbit'.Actually, thinking about the distortion in a 2D sheet (from a gravity source) they are all 'downward' in the plane of the sheet so they would never touch...
Simpo Two said:
The rubber sheet is actually 3D , the third dimension (down) representing gravity 
It leads me to infer that 'up' would be anti-gravity.
I may be onto something...
Indeed - doesn't help with the wormhole theory though!It leads me to infer that 'up' would be anti-gravity.
I may be onto something...
You may well be onto something, not sure what though.
I once read that a fool can ask more questions than a wise man can answer and something tells me that there's a lot of truth in that expression.
The analogies used in the video, or that of the stretching rubber sheets with the ever more isolated ants, suggests space time is either being constantly stretched and/or created. A cynic may think this was put forward as a solution to get around the problem of the universe expanding more rapidly than 'common sense' would allow.
I think my problem stems from what seems to be absolute certainty with which solutions to such problems are put forward. Only last month I read in The Sky at Night mag that some stars are substantially further away than previously thought, something that seems fairly fundamental in the scheme of things, and it does set me thinking about how much we really know and how much we just make up to fit what we see.
The analogies used in the video, or that of the stretching rubber sheets with the ever more isolated ants, suggests space time is either being constantly stretched and/or created. A cynic may think this was put forward as a solution to get around the problem of the universe expanding more rapidly than 'common sense' would allow.
I think my problem stems from what seems to be absolute certainty with which solutions to such problems are put forward. Only last month I read in The Sky at Night mag that some stars are substantially further away than previously thought, something that seems fairly fundamental in the scheme of things, and it does set me thinking about how much we really know and how much we just make up to fit what we see.
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