Another thing I was pondering and it's a bit over my head. This one might be over the heads of some the people here in fact. It has to do with the beginning of the universe. (Viking this isn't me showing my true colors as a creationist or something). I've heard numbers thrown around about the age of the universe. This is around a dozen billion years. Now my understanding is that time and space are the same thing and altering one alters the other. For instance if you warp space by piling up a bunch of matter it can change time for that area. Very fast movement through space can also change how time moves for moving object. So when the Universe began it was fairly small and has gotten larger over a period of time. Wouldn't the changing size of space itself also alter how time flows? Wouldn't the way time passes 10 billion years ago be different then how it passes now? And if so, how do you give a meaningful age of the universe?
Who gives a shit, the Russians got their uplink reestablished with the space geckos. So it appears they can't kill every animal they put into space.
Quote from: CountDeMoney on August 14, 2014, 07:58:45 PM
Who gives a shit, the Russians got their uplink reestablished with the space geckos. So it appears they can't kill every animal they put into space.
Okay... there's that. Not quite the answer I was expecting, but thanks for contributing.
r/askscience would probably give you a better answer.
Quote from: Grinning_Colossus on August 14, 2014, 08:16:27 PM
r/askscience would probably give you a better answer.
And then you would be on reddit which is an auto-fail condition.
The speed of light in a vacuum is constant. Age can be relevant relative to that.
The age of the universe is measured in a few different ways, and they generally agree on the result. Changes in time due to gravitation or velocity are always in relation to somewhere else. If you are at the bottom of a gravity well time won't seem any different to you. It will only be noticeable when you compare your clocks with someone outside the well (which is how it was experimentally confirmed (http://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment)). One of the methods of determining the minimum age of the universe is to look at the oldest stars and see how old they are. It's possible that there may have been all sorts of relativistic effects on the star, but since these effects only slow time relative to other frames the universe has to be at least as old as the oldest star. If you can get multiple old stars in different locations it further improves the estimate.
The main method used now analyzes the cosmic background radiation, remnants from the earliest observable period of the universe. This radiation is incredibly uniform in all directions, which indicates either that it is mostly free from relativistic effects or that any such effects were applied to all of it (presumably from the earliest moments of the universe). In fact the small variations in the background radiation can be used to determine gravitational influences.
What do you mean by 12 billion years?
Why are my posts waiting approval by a moderator?
Do you want me to wear a yellow star too?
I do know about time dilation with large bodies, but what I was thinking about was that since time is a function of space, if space was a different size wouldn't time also change? If the whole universe was functioning under some time dilation of the first billion years wouldn't that throw our understanding off?
Quote from: Siege on August 14, 2014, 09:31:55 PM
Why are my posts waiting approval by a moderator?
Because there are 7th grade Japanese schoolgirls that can handle their alcohol better than you can. I'm tired of having to clean up your vomit when you hit the Zimas. Fucking lightweight.
Quote from: Razgovory on August 14, 2014, 09:41:02 PM
I do know about time dilation with large bodies, but what I was thinking about was that since time is a function of space, if space was a different size wouldn't time also change? If the whole universe was functioning under some time dilation of the first billion years wouldn't that throw our understanding off?
I'm definitely not the expert on this stuff, but I think time dilation is a concept for measuring the difference in observed time between two bodies--it wouldn't be relevant for a single body (the universe).
I googled the definition of a unit of time: The official SI definition of the second is as follows:
The second is the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom.
So unless that has changed, there you have it.
Quote from: Razgovory on August 14, 2014, 09:41:02 PM
I do know about time dilation with large bodies, but what I was thinking about was that since time is a function of space, if space was a different size wouldn't time also change? If the whole universe was functioning under some time dilation of the first billion years wouldn't that throw our understanding off?
It would throw our understanding off how? The calculated age of the universe is based on several different types of measurements. Any time dilation would have to effect them all equally, in which case it probably isn't observable from within our universe. There is no "external to the universe" clock that we have access to, in order to see the extent of time dilation. All time measurements are based on being in the universe and are therefore based on "universe" time, all time dilation measurements are relative to a different frame that is not experiencing the dilation. If everything is experiencing the dilation there's nothing to compare it to.
Raz, the answer is "time appears to behave differently". Time isn't an absolute thing, it is a product of our observations about things changing. There isn't some big "T" time that is affected by a big "S" space, they are the same thing.
Quote from: frunk on August 14, 2014, 10:14:50 PM
Quote from: Razgovory on August 14, 2014, 09:41:02 PM
I do know about time dilation with large bodies, but what I was thinking about was that since time is a function of space, if space was a different size wouldn't time also change? If the whole universe was functioning under some time dilation of the first billion years wouldn't that throw our understanding off?
It would throw our understanding off how? The calculated age of the universe is based on several different types of measurements. Any time dilation would have to effect them all equally, in which case it probably isn't observable from within our universe. There is no "external to the universe" clock that we have access to, in order to see the extent of time dilation. All time measurements are based on being in the universe and are therefore based on "universe" time, all time dilation measurements are relative to a different frame that is not experiencing the dilation. If everything is experiencing the dilation there's nothing to compare it to.
Would it affect them equally? Let us say we that measure the half-life of some long lived radioactive isotope that was hanging around shortly after the big bang. Time dilation affects this isotope for the first billion years of the universe's history. Let's say we measure it in years (despite the fact there is no sun or earth). The years the isotope "experienced" are a different length then the ones that it experiences now. So it's age would be different then what we would expect then if the effect of time was constant over that period.
Quote from: Viking on August 15, 2014, 02:23:32 AM
Raz, the answer is "time appears to behave differently". Time isn't an absolute thing, it is a product of our observations about things changing. There isn't some big "T" time that is affected by a big "S" space, they are the same thing.
Astronomers don't use any kind of standard for time?
Quote from: Razgovory on August 15, 2014, 03:00:32 AM
Quote from: Viking on August 15, 2014, 02:23:32 AM
Raz, the answer is "time appears to behave differently". Time isn't an absolute thing, it is a product of our observations about things changing. There isn't some big "T" time that is affected by a big "S" space, they are the same thing.
Astronomers don't use any kind of standard for time?
No, they just use the normal definition, this is why time dilation appears to happen. The standard "thought experiment" is the traveller with clock travelling at near light speed returning to his origin point. Both have travelled the identical distance in space time, but have done so in different observed time.
Time isn't really a thing, it's just a really really convenient way to explain stuff. Time as we know it was invented by newton in calculus to explain the motion of planets (and in the process resolving xeno's paradox).
Like everything newton did it perfectly explain's what dawkins calls "middle world" (the stuff that is larger than electrons and smaller than stars moving at non-relativistic speeds), it just doesn't explain the world outside that. Stop thinking of time as a thing, start thinking of it as the observers perception of change. Outside "middle world" time isn't really a thing. This is why scientists talk about space-time, its the thing that what we in "middle world" call space and what we call time, it's the same thing.
Are you sure that "time" isn't a thing? That's sort of an odd statement. I mean it can be altered by movement through space that seems to suggest that it is in fact something (even if it is just the same thing as space). The existence of time seems somewhat important for cause and effect. Otherwise everything would be happening at once. Now I understand that time for one person is not the same for another and that there is no preferential frame of reference for time.
I'm trying to remember something, maybe you remember it. I think it had to do with natural fission reactors in Africa. The evidence of the reactors was quite old (a couple of billion years), and scientists had found that isotopes were decaying at an unexpected rate in the distant past suggesting that scientific constants may have been different in the past. Unfortunately it's 4 in the morning here, and I don't think I'm remembering the story right.
I'd like to appreciate you guys not looking down your nose at me on this. I suppose you guys have noticed that I wonder about many odd scientific things and sadly do not understand them very well.
Quote from: Razgovory on August 15, 2014, 02:56:15 AM
Would it affect them equally? Let us say we that measure the half-life of some long lived radioactive isotope that was hanging around shortly after the big bang. Time dilation affects this isotope for the first billion years of the universe's history. Let's say we measure it in years (despite the fact there is no sun or earth). The years the isotope "experienced" are a different length then the ones that it experiences now. So it's age would be different then what we would expect then if the effect of time was constant over that period.
Time isn't constant anywhere. There's always small fluctuations due to gravity and velocity. Aggregate time in the past likely was slower due to the higher density of the universe. If we could compare time to some outside reference point this would matter (and for some calculations I'm sure it does matter), but since all points of reference for time are inside the universe it doesn't make much of a difference. If there were strong local time dilation effects for a significant part of the universe not experienced by the rest in the distant past it would show up in the background radiation. Its uniformity points to that not happening.
Look at it this way. What if all of a sudden the rate of time slowed in the whole universe by some constant factor, one that wouldn't change the results of any relativistic comparisons, but everything was just slower. Nobody would notice, there wouldn't be perceptible difference anywhere, and it wouldn't make a single change to anything except to a theoretical observer outside the universe.
Quote from: Razgovory on August 15, 2014, 04:15:10 AM
Are you sure that "time" isn't a thing? That's sort of an odd statement. I mean it can be altered by movement through space that seems to suggest that it is in fact something (even if it is just the same thing as space). The existence of time seems somewhat important for cause and effect. Otherwise everything would be happening at once. Now I understand that time for one person is not the same for another and that there is no preferential frame of reference for time.
I'm trying to remember something, maybe you remember it. I think it had to do with natural fission reactors in Africa. The evidence of the reactors was quite old (a couple of billion years), and scientists had found that isotopes were decaying at an unexpected rate in the distant past suggesting that scientific constants may have been different in the past. Unfortunately it's 4 in the morning here, and I don't think I'm remembering the story right.
I'd like to appreciate you guys not looking down your nose at me on this. I suppose you guys have noticed that I wonder about many odd scientific things and sadly do not understand them very well.
Raz, I'm not the expert on this, but as I and others have mentioned in so many words, I don't think you can reference relativistic concepts like time dilation if your reference point is the whole universe.
Man, where's Hamilcar when you need him? He might have been a twat, but this would have been right up his alley.
I used to think time was the enemy, but I realize now is not.
Time is a measure of technological development.
The more time you have the less technologically developed your environment is.
The less time you have the more technology, until you pass the knee of the curve of technological exponential growth, and then time is infinite.
(https://languish.org/forums/proxy.php?request=http%3A%2F%2Fhvelleca.files.wordpress.com%2F2012%2F09%2Fexponentialcurve.jpg&hash=325610ddf82c516d728b60c0b71378300570345a)
Quote from: Siege on August 22, 2014, 03:19:17 AM
I used to think time was the enemy, but I realize now is not.
When you decide it's Miller Time, it is for us.