Universe May Be Running Out of Time 343
RenHoek writes "With heat death, the big crunch and quite a few other nasty ways in which the universe could see its demise, we can now add "running out of time" to the list. A team of scientists came up with a new theory that would solve the problem of the elusive dark energy that seems to be accelerating the expansion of the universe. They figure that the universe is not speeding up but we are, in relation to the outer regions of space, slowing down. Tests with the upcoming Large Hadron Collider will give more insight if we're going to end up frozen in time."
Of course it could do anything (Score:5, Interesting)
Of course it could also flip us all upside down and turn everything a light salmon color!
Note to self: Patent method for garnering scientific celebrity. Come up with outlandish theory, then claim that LHC will move it to the mainstream.
Read the last line of the article first (Score:2, Interesting)
"If that happens, then these kind of theories will move out of the realm of speculation and into the mainstream."
There are a gazillion of these unsupported hunches out there, believe which ever one you want. Physics has become the domain of science fiction authors.
You'd never know (Score:2, Interesting)
A big stretch (Score:3, Interesting)
Then again I only took one entry level university class on the whole thing so I don't think that qualifies me. I just like to think of apposing theories
Failure of Context (Score:5, Interesting)
If time slows down, we slow down with it, and we don't notice because everything looks normal. This is precisely the gedankenexperiment of the moving train. If you can't handle the relativity, read some science fiction that uses it, such as Tau Zero (the ship can't stop accelerating and ends up crossing the entire universe and watching the big crunch and next big bang) or the Heechee stories (where the guy leaves the rest of his crew trapped around a black hole, and they're recovered decades later, havening spent weeks waiting).
To have an absolutely 0 tau would require a completely flat universe. As long as any matter and/or energy (dark or light) exists, this is impossible. The rate may approach 0 but cannot achieve it. Thus, there will always be duration, and we will experience it just as we do now.
Time could be speeding up and slowing down right now, like a lead foot motorist stuck in a traffic jam. We'd never notice because we're stuck in it, no matter what its rate is, like a passenger in said vehicle that can't see outside (minus the inertial effects, because we're talking the universe here, not a locally observable phenomenon).
The same argument applies to "the universe is expanding". We couldn't detect that either, because we're embedded in space time. We'd expand too. All we can see is the supposed effects of previous expansion, that of Hubble red shift. Try the dots-on-the-balloon experiment. The dots get farther apart. But the distance between them as measured by the size of a dot remains constant.
It's the same argument because time and space are integrated as space-time. It's essentially the inability to get outside a frame of reference known as "universe".
Whenever I see one of these goofy assertion articles, I hope for a summary of the math. These goofy results must be arrived at due to an error in assumption. Such an error, if considered to be a valid point, may be just the error that prevents us from integrating gravity with the other forces, and so illuminating and fixing that error could be a major step in theoretical physics.
Speed of light slowing down? (Score:4, Interesting)
Re:time? (Score:2, Interesting)
Re:er...define 'constant'... (Score:2, Interesting)
Spacetime = 3D space + time, always (Score:2, Interesting)
I hate lousy accounting. The fundamental coin of the Universe are events in spacetime. Talk about time separate from space, and garbage results. One needs to add, subtract, multiply, or divide events. The usual thing to do is to add. This is how we go forward in spacetime (mostly time, with a little bit of wandering in space to go from home to work to the grocery store and back).
There is no need for super symmetry either, a way of making spin 1/2 particles play nicely with spin 2 particles. Anyone who has watch diving at the summer olympics knows that one object can go around one axis at a different rate from another. It is easy enough to make a classical system where along one axis, it takes 2 pi to get around, and another axis 4 pi. I have the animations to prove it: http://picasaweb.google.com/dougsweetser/AnalyticAnimationsSpin12Spin1 [google.com]
doug
But there are more than four time zones (Score:3, Interesting)
RTFA, please (Score:3, Interesting)
Having actually read the linked article, it's funnier. What it seems to actually say is that the time of the whole universe runs slower now, than it ran some billion years ago. It's not "dt(here)/dt(there)", but "dt(now)/dt(back-then)". If that makes any sense.
Let's say we look at the light of a star, some 5 billion light years away. The important thing there isn't the distance. It's that light also took 5 billion years to get here. So if time went faster 5 billion years ago, we'd see it red-shifted.
So, yes, the question isn't as confused as you seem to assume.
If we at least have "here" and "there" in the equation, we'd also have space in it, essentially. So they would have essentially linked dt to distance, which is palatable. But here we have time flow changing with... time.
Well, wtf? In relation to which time? It's like saying that the metre standard is bigger 1000 miles from here, measured with itself.
If it makes any sense, it's not as simple as "dt(here)/dt(there)". It may still make some, but I'd need a smarter explanation than yours (no offense.)
I can't even think of a way to express it in terms of "cost of money", because even money you can compare to something else. E.g., even in a closed economy you could say that a yen in 1800 was more valuable or less valuable than a yen in 1600, based, say, on how much rice you could buy with one yen. So we already have a comparison to _something_ else (kilos of rice), and with a whole other variable as the X of the graph, so to speak. You plot, say, yen vs year, which is two variable.
Now think plotting time, from 2000 BC to 2000 AD. You have, uh, time vs time. I'm not sure how you _can_ plot that without ending up with X = Y all along.
Even briefer, what they say, translated to scales laymen can intuitively understand, is like saying that time goes faster this year than in 1997. How would you measure that? In relation to _what_? One second is one second, by definition, and it was a second by definition in 1997 too. It may make sense to say that "time goes slower" in a metaphorical way, or maybe in a "perceived time" way, but in maths or physics it makes no sense whatsoever.
You have to introduce some other variable there, to compare time to that. Let's call that variable R, from the rice we compared yen to.
Linking it to galaxies and their redshift doesn't change much. "They're not accelerating, time is slowing." Well, blimey, then what do you use under the fraction line there? Because if you use time, they _are_ accelerating. dX/dt is a speed, but dX/dR is something entirely different, and saying that the latter didn't accelerate isn't exactly saying the same thing.
And how does that affect more mundane Newtonian mechanics? If you say that measured in dX/dR, you no longer need energy to accelerate them, then in effect you've re-linked the whole mechanics to dR instead of dt. With all that implies.
How would that affect our galaxy or our solar system, then? The solar system alone is some 5 billion years old, so dt/dR changed a lot in that time. If the mechanics -- thus, for example the planet orbits -- were linked to dR instead of dt, and the ratio between the two changed, then you should see some funky orbit changes in time. Oops, now you need some energy from outside just to keep Earth in the beginning from not being somewhere past Pluto's current orbit.
How would it affect some other stuff? Even quantum mechanics effects, end up depending on time, one way or another. E.g., no matter how you write Heissenberg's uncertainty, you'd notice some pretty nasty changes there in 5 billion years.
Expansion, and then contraction (Score:4, Interesting)
On the other side of the balance are the black holes, which suck in energy and condense it into a singularity, which has mass. More light falls into the hole, the more massive the hole gets, the more space it sucks in, the more it shrinks the universe. At our current point in the cycle there are more stars than there are black holes, so the universe expands at an accelerating rate. As stars burn out and become black holes the expansion will slow and eventually reverse as all the radiation eventually finds its way back into a black hole. Black holes coalesce and the larger ones can explode, creating material for star formation, thus continuing the cycle. See? No mysterious dark energy is needed; only basic physics.
Infinite universe after all? (Score:3, Interesting)
An astronaut falling toward a black hole (assuming for the sake of argument that he does not get torn apart by tidal forces) perceives that it actually takes forever to fall into the black hole. Externally we would seem him slow down and then stop at the even horizon, but this "stop" is merely the curve receding into infinity, so that further increments are so small we cannot see them. But the astronaut's subjective time becomes infinite.
So if time is slowing down locally, I guess that means in a few billion years we'll all be living in a static (albeit smaller) universe that goes on forever.
the Doctor said it all (Score:3, Interesting)
Re:We'll have to rethink everything (Score:3, Interesting)