It seems mathematically impossible for time to not have a beginning since you can't have infinity plus one. In other words, it would be impossible to ever get to this point in time if infinity is behind us.
2006-12-12 05:50:43 · 7 answers · asked by mikearion 4 in Science & Mathematics ➔ Physics
under the the currently most attractive cosmological models, time and space as we know them (or at least, as we model them mathematically in ways that stand up to empirical tests) have a beginning at the big bang. But the deeper question of what time fundamentally *is* doesn't really yet have a satisfying philosophical answer.
2006-12-12 06:02:23 · answer #1 · answered by Disembodied Heretic 2 · 1⤊ 0⤋
Is time finite or infinite? For example, did time have a beginning? By invoking the radical notion that God is "outside of time," St. Augustine claimed, "Time itself being part of God's creation, there was simply no before!" In the 20th century, scientists agreed with St. Augustine that the amount of past time is finite, but in the 21st century, cosmologists are tilting toward the opposite answer.
Steven Hawking said:
In this lecture, I would like to discuss whether time itself has a beginning, and whether it will have an end. All the evidence seems to indicate, that the universe has not existed forever, but that it had a beginning, about 15 billion years ago. The cosmologist, Sir Arthur Eddington, once said, 'Don't worry if your theory doesn't agree with the observations, because they are probably wrong.' But if your theory disagrees with the Second Law of Thermodynamics, it is in bad trouble. In fact, the theory that the universe has existed forever is in serious difficulty with the Second Law of Thermodynamics. The Second Law, states that disorder always increases with time. Like the argument about human progress, it indicates that there must have been a beginning.
At this time, the Big Bang, all the matter in the universe, would have been on top of itself. The density would have been infinite. It would have been what is called, a singularity. At a singularity, all the laws of physics would have broken down. This means that the state of the universe, after the Big Bang, will not depend on anything that may have happened before, because the deterministic laws that govern the universe will break down in the Big Bang. The universe will evolve from the Big Bang, completely independently of what it was like before. Even the amount of matter in the universe, can be different to what it was before the Big Bang, as the Law of Conservation of Matter, will break down at the Big Bang.
The focussing of our past light cone implied that time must have a beginning, if the General Theory of relativity is correct. But one might raise the question, of whether General Relativity really is correct. It certainly agrees with all the observational tests that have been carried out. However these test General Relativity, only over fairly large distances. We know that General Relativity can not be quite correct on very small distances, because it is a classical theory. This means, it doesn't take into account, the Uncertainty Principle of Quantum Mechanics, which says that an object can not have both a well defined position, and a well defined speed: the more accurately one measures the position, the less accurately one can measure the speed, and vice versa. Therefore, to understand the very high-density stage, when the universe was very small, one needs a quantum theory of gravity, which will combine General Relativity with the Uncertainty Principle.
The conclusion of this lecture is that the universe has not existed forever. Rather, the universe, and time itself, had a beginning in the Big Bang, about 15 billion years ago. The beginning of real time, would have been a singularity, at which the laws of physics would have broken down. Nevertheless, the way the universe began would have been determined by the laws of physics, if the universe satisfied the no boundary condition. This says that in the imaginary time direction, space-time is finite in extent, but doesn't have any boundary or edge. The predictions of the no boundary proposal seem to agree with observation. The no boundary hypothesis also predicts that the universe will eventually collapse again. However, the contracting phase, will not have the opposite arrow of time, to the expanding phase. So we will keep on getting older, and we won't return to our youth. Because time is not going to go backwards, I think I better stop now.
There is a probably apocryphal story, that when Laplace was asked by Napoleon, how God fitted into this system, he replied, 'Sire, I have not needed that hypothesis.' I don't think that Laplace was claiming that God didn't exist. It is just that He doesn't intervene, to break the laws of Science. That must be the position of every scientist. A scientific law, is not a scientific law, if it only holds when some supernatural being, decides to let things run, and not intervene.
2006-12-12 05:59:49 · answer #2 · answered by Anonymous · 1⤊ 0⤋
Time had no meaning before the creation of the known Universe. Time has a finite beginning at the Big Bang.
2006-12-12 05:55:52 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Why don't we ask Stephen Hawkins and Prof. Nash/A Beautiful Mind. By the way, Thank you Russell Crowe. How's the weather like in New Zealand? I heard a rumor... your Cabinet Minister says the Maoris are very welcoming. Thank you Madame la Ministre. Grateful for the info.
Iz, North Pole and True North (Blue)
2006-12-12 05:56:17 · answer #4 · answered by Anonymous · 0⤊ 1⤋
yes, i suppose you could always keep going farther back in time, but why bother? after a certain amount of time, there won't be anything to see, unless you're trying to figure out the big bang theory, or something...
2006-12-12 05:55:13 · answer #5 · answered by angel_firefaerie 2 · 0⤊ 1⤋
OK...
you asked if time have a beginning
Oh
a beginning ??
Begin!! then you are talking like we have a time on our time that our time started in... ha ha be aware Honey don't depend on your fundamentals that can't be changed...
2006-12-12 06:05:14 · answer #6 · answered by JwH 2 · 0⤊ 4⤋
Might I just say...
A long time ago, in a galaxy far far away...
2006-12-12 05:59:06 · answer #7 · answered by ? 2 · 0⤊ 1⤋