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Major Tom
2003-May-23, 07:53 PM
On another messageboard I have gotten involved in a debate about creationism. The tread has evolved into a discussion about the history of the universe. I am claiming that the universe has always existed in one form or another and that, as far as we have observed, nothing has ever ceased or begun to exist. The nature of things have changed but they havent dissapeard or come out of nowwhere. While the universe has and will continue to change, the stuff that it is made of will always exist in one form or another.

This is how I remember it from science class in what is the Norwegian equivalent of high-school in the US. If what I am claiming is wrong I would be thankful if anybody told me before I digg myself deeper into the mud.

Starjet
2003-May-23, 08:04 PM
Well, you are right, since the beginning of time the universe was here in one form or another and will always be here in one form or another. Remember the laws of conservations? Matter and energy canít be destroyed or created. They can switch between the two and changes forms but thatís all. The real question is though how did the universe get there in the first place? If you canít create matter where did it all come from in the beginning? Those are the questions that can be answered by creationism. Despite popular belief science and creationism can mesh very well. The thing is, is the bible is very vague on just about everything and can be interpreted many different ways. For example, it says god made the universe in six days. Well, how long is a day to god? Iím not trying to persuade you either way, but keep an open mind. Science can explain a lot of things but never can it explain everything.

Major Tom
2003-May-23, 08:13 PM
Well, you are right, since the beginning of time the universe was here in one form or another and will always be here in one form or another. Remember the laws of conservations? Matter and energy can’t be destroyed or created. They can switch between the two and changes forms but that’s all. The real question is though how did the universe get there in the first place? If you can’t create matter where did it all come from in the beginning? Those are the questions that can be answered by creationism. Despite popular belief science and creationism can mesh very well. The thing is, is the bible is very vague on just about everything and can be interpreted many different ways. For example, it says god made the universe in six days. Well, how long is a day to god? I’m not trying to persuade you either way, but keep an open mind. Science can explain a lot of things but never can it explain everything.

Thank you for answering. I agree that science and creationism doesnt exclude each other if one doesnt require the biblical version of events to be taken litteraly. My only beef is with those that categorically states that god created the world in six days and that this isnt just their interpretation of the bible.

pmcolt
2003-May-23, 08:21 PM
I'm not sure I'm completely clear on what you're asking. The universe has obviously always existed in one form or another since its beginning, which tends to be estimated at about 14 billion years ago. Google gave me this PBS timeline (http://www.pbs.org/deepspace/timeline/) on the basic history of the universe. It seems to agree with what I learned in high school, and shows several milestones in the history of the universe, as well as some future history. Though if you're debating creationists, I doubt they'll accept the model presented in the timeline.

Major Tom
2003-May-23, 08:36 PM
I'm not sure I'm completely clear on what you're asking. The universe has obviously always existed in one form or another since its beginning, which tends to be estimated at about 14 billion years ago. Google gave me this PBS timeline (http://www.pbs.org/deepspace/timeline/) on the basic history of the universe. It seems to agree with what I learned in high school, and shows several milestones in the history of the universe, as well as some future history. Though if you're debating creationists, I doubt they'll accept the model presented in the timeline.

The creationists seem to have backed out of the debate, but one guy started attacking my arguments agains them and saying that my assumption that the universe has always existed in one way or another, even prior to the big bang(In a different state) was just as dogmatic as the arguments the creationists used.

pmcolt
2003-May-23, 09:34 PM
Your position is only dogmatic if you're taking it as a matter of faith with no supporting evidence.

I remember reading about something called M-brane theory awhile back. It was supposed to be an alternative to inflation. IIRC the basic idea was that the universe was part of a larger, five-dimensional space, and the big bang was the result of a collision between two 'branes' in this space. The collision is what caused the expansion of the universe and created matter and energy. A google search on 'M-brane' or 'ekpyrotic universe' turns up a few things on it, including this article on space.com (http://www.space.com/scienceastronomy/astronomy/bigbang_alternative_010413-1.html). It makes predictions that are nearly the same as the inflationary model, but one key difference is that inflation predicts some visible effects of gravitational waves in the CMB, while the ekpyrotic model predicts none.

Ok, my point; the idea that something existed prior to the big bang is not necessarily dogmatic if it's part of a solid, falsifiable theory.

beskeptical
2003-May-23, 10:19 PM
.... The universe has obviously always existed in one form or another since its beginning, which tends to be estimated at about 14 billion years ago. .....

The Universe as we presently find it. Since energy and mass are conserved, just flexible as to whether they exist as one form or the other, the Universe would have been in another state prior to the BB. Most speculate (I think) it was all energy and no mass. So you can define the Universe as what exists today, and refer to whatever existed prior to the BB as another Universe.

The mass and energy in the Universe would have most likely existed into the infinite past and will exist into the infinite future. But I'm not sure we've got the evidence to conclude that for certain.

If one assumes the laws of physics are conserved then one could say the evidence supports infinity forward and backward in time. But I don't think it is agreed that the laws of physics are conserved before the BB.

informant
2003-May-24, 11:18 AM
Isn't the short answer that Major Tom's question cannot be answered by current physics?!
In other words, there is no scientific knowledge about what existed (or not) before the Big Bang. There's a lot of speculation, but no confirmation.

P.S. Also, the conservation of energy fails in General Relativity, IIRC.

kilopi
2003-May-24, 11:59 AM
The creationists seem to have backed out of the debate, but one guy started attacking my arguments agains them and saying that my assumption that the universe has always existed in one way or another, even prior to the big bang(In a different state) was just as dogmatic as the arguments the creationists used.

Your position is only dogmatic if you're taking it as a matter of faith with no supporting evidence.
I think it's pretty safe to say that there is no supporting evidence for existence of the universe before the big bang. (If there were a big bang.--disclaimer added to avoid dogmatism :) )

DStahl
2003-May-24, 07:50 PM
Nice answers, all. Here's my personal take on universal origins:

We can make some guesses about what the universe looked like at various times in the past, and we have pretty good observations to support our guesses back quite a long ways.

We're pretty sure that at one time the universe consisted of a gas of mostly hydrogen, helium, and a tiny bit of lithium and deuterium. This stuff was more or less evenly spread, and had not formed stars...but it was not perfectly homogenous and so it was gradually forming lumps and denser clouds which would, about 500,000 years after the beginning, become dense enough to ignite as the first stars.

We're pretty sure that before that the universe was composed of just the atomic nucleii of hydrogen, helium, and a bit of lithium and deuterium, and a bunch of free electrons; because the energy level of the universe was too high to let electrons stay bound to these atomic nucleii the universe consisted of an ionized gas--plasma.

We're pretty sure that, just before that, the universe was a hot mess of the stable subatomic particles--neutrons, protons, electrons--and electromagnetic radiation. None of these could stay bound to each other because the energy level was quite high and kept the particles bouncing around so violently that any bonds were quickly broken. But we know that the duration of this period must have been limited by the lifetime of free neutrons, which is between ten and twenty minutes.

We think that at an even earlier time the universe was so hot that subatomic particles of all sorts were constantly being created out of pure energy and annihilating with their anti-particle siblings, or decaying to other subatomic particles. At this time, Major Tom, the universe did not really look like what we see now. There were no atoms, no atomic nucleii, and even the population of protons, neutrons, electrons, and anti-protons, anti-neutrons, and positrons was in constant flux. What a mess.

We suspect that this hot particle soup was created by the collapse of a physical state called 'false vacuum'--using mathematical physics we can see how that might have happened. The physics of the false vacuum would also make the baby universe expand terrifically fast--doubling its size in less than a thousandth of a second, and putting the kinetic 'bang' in the Big Bang. During the time of the false vacuum the universe would not have looked anything like what we see today--if there was any matter at this time it would probably have been very sparse, and, oddly enough, quite cold (it was probably the collapse of the false vacuum which heated the early universe so terrifically); the false vacuum universe may have included oddities like magnetic monopoles.

In my opinion, the false vacuum era, often called the "inflationary era", when the universe grew from subatomic size to about the size of an orange, is just about the earliest thing for which we can connect observation with theory. We observe no magnetic monopoles today, and the false vacuum theory explains that; we observe an expanding universe with immense kinetic energy, and the false vacuum theory explains that too; we think that the universe is very nearly 'flat' and the false vacuum theory naturally forces the universe to be very nearly flat. So in my opinion we have some observational evidence for the false vacuum, inflationary era.

Prior to the inflationary false vacuum I personally think things get a bit dicey. Some speculate that a quantum fluctuation, perhaps one which required no net mass/energy creation at all, may have started the false vacuum; others speculate about extra-dimensional 'branes; Hawking and Hartle speculate that there is no 'beginning' at all because the universe is bounded in past time. I dunno. It's very exciting to speculate, but we need some kind of observational or experimental way to choose among the speculations--or at least give us some guidance.

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So, back to your topic: As far as I can say, matter has not always existed in the way we see it today; but atomic nucleii have existed since about 20 minutes after the Unknown Event, and fully-formed neutral atoms have existed as we know them since about 300,000 years after the Unknown Event (when electrons were able to be captured by the nucleii and not immediately knocked loose again by the energy of the background radiation). Stars have shone since maybe half a billion years after the UE, I think. And ever since the first stars exploded in supernovae heavier elements like carbon and oxygen have become increasingly common (though the universe is still overwhelmingly made up of hydrogen and helium).

DStahl
2003-May-24, 08:02 PM
Whoops, just a quick addendum: That's an outline of Big Bang theory, and most pro cosmologists think that some form of the BB is mostly likely correct. P.J.E. Peebles, most emphatically one of the pros, wrote that he really wished there were a good alternative to the Big Bang, but in his opinion the observations simply do not support any other theory nearly as strongly. Nevertheless, people are still looking at various steady-state models and it's conceivable that a good alternative to the Big Bang will be found.

Eta C
2003-May-25, 03:23 AM
Nevertheless, people are still looking at various steady-state models and it's conceivable that a good alternative to the Big Bang will be found.

And someday the Cubs will win the World Series. :P . It will take one heck of a theory to make observable predictions a BB based theory cannot. Remember, just because there are several BB-based theories out there (inflationary, non-inflationary, etc) doesn't reduce the acceptance of the big bang itself. This is similar to the various theories of evolution out there. Some are punctuated (that is, rapid changes) some are not (slow continuous changes). All, however, accept the realtiy of evolution. They differ in the mechanism.

tracer
2003-May-25, 05:43 AM
On another messageboard I have gotten involved in a debate about creationism. The tread has evolved
Ba-doom, kssssh!* He'll be here all week! Tip your waitstaff!




*) That's a rimshot sound effect, for those of you playing along at home.