ex-xian

Well, you're thinking of limits and convergence. Without going into all the gory details, the concept of a derivative is defined as a rate of change. If you have a particle, or anything that can be modelled as a particle, and it's position is given by some function of time, f(t), then the rate of change of postion over the rate of change in time is the velocity, one notation is f'(t) (read as "f prime of t"). The derivative of velocity (rate of change of velocity over the rate of change in time) is the acceleration.

By plugging in specific values of time, you can describe the motion of the object. A postive velocity and acceleration, means the object is moving to the right and speeding up. Positive velocity and negative acceleration means is moving to the right and slowing down, and vice versa.

But a zero value for velocity isn't a meaningless or useless result. A zero value means that there is no change in position, or the object is stationary. A zero accerlation means that the velocity is constant.

My point of this tangent post is that zero and negative integers are numbers that have legitimate uses and meanings, just at the natural numbers do. So it isn't fair to declare that t=0 is meaningless, or that time starts only at t=1. At t=0, nothing has happened yet, as soon as the big bang started, then time starts. Of course Hawking makes much of imaginary time, or t<0, in the articles referenced in the first page of this thread.

Einstien's theories of relativity describe the universe as 4-dimesional. I used to know the equation, but I'd have to go look it up now, but anyway, the three spatial dimensions are vector components of the equation and time is the scalar component. This implies that time and space cannot exist independently of one another. In fact, to introduce a dichotomy between time and space is a fallacious endeavor. Current cosmological theories hold that the earliest state of the universe was a point of infintite mass and zero volume. I would call this t=0. Immediately, the big bang occurred and time began to run, and the spatial dimensions as we know them began to expand.

It seems to me, that any attempt to speak of a coherent "time" before the big bang, would necessarily have to be some sort of metatime. But would that imply meta-spatial dimensions? Who knows?

Hawkingfan

Thanks ex-xian,

But even when we use 0 to track an object's motion, physical location, or to pinpoint a specific coordinate, etc., we are still just using it as a symbol that means a value doesn't exist, IMO. It's still a placeholder. X=0 means x has no value. You could say x=no value. or x= (blank) or x= 00 or 0000 or whatever. It's just to let us conceptualize a non-existent value. So theoretically you could easily write (6,0) as say (6, ) even though no one would do that, of course (you could lose your place). Or you could do any math problem by leaving out the written zeros (and keep your place by memory or some other means), but you would still come up with the same answer as if you left in the zeros.

River

[Chapter: 21, Verse: 30 Noble Quran]
Have not "those who disbelieve" known heavens and earth were of one piece,
We parted them and, We made every living thing of water
Will they not then believe?


The heavens we have built with power and We are expanding it. [Sura 51 verse 7 Noble Quran]

student738

River said:
The final "it" in the second excerpt refers either to "power" or "the heavens" or to something in a previous sentence which you have not included for us. Certainly it makes no sense to say, "...and we are expanding [this power]," so I will assume that this is not what is meant.

So, your reading seems to require us to accept both that "it" refers to "the heavens", and further either that "the heavens" are presently expanding, or that this passage represents a present tense account of some previous expanding of "the heavens".

However, consider again the statement:
The author or dictator of this passage is not representing him, her, or itself to be introducing the theory that, "...heavens and earth were of one piece..." Instead, noting the tense of "known", it is being claimed that there already existed at the time of the writing or dictation of this passage a contemporary theory among those who do not believe that the heavens and earth "were of one piece".

It is not implausible, and perhaps quite likely that this then contemporary theory also included the parting of the two.

This would explain why the passage reepresents itself to be a reason for belief, asking, "Will they not then believe?"

The dynamic of this passage seem to be that the author or dictator of the text is representing himself, herself, or itself to be the one who has done what it is that this then contemporary and preexisting cosmological theory, namely, parted the heavens and the earth.

The purpose of the text is not to introduce a new cosmological theory or provide additional clarification of a preexisting one, but rather is to identify the power which has caused the parting of the heaven and the earth, as being the author or dictator of the text, presumably, Allah.

Isn't this a common theme in other religious writings, perhaps most notably, the Torah?

Do we know of a preexisting or then contemporary cosmological theory which would probably have been known to "those who disbelieve" at the time of the writing or dictation of these passages?

I could make a guess as to a number of things theory might be, but perhaps that is better left to someone who has studied that time.

ex-xian

Is this the right forum for an exegesis of the koran?

Nowhere357

You can probably guess my take on this.

Time is what we call the fact that matter is changing. This is what clocks measure.

Until/unless some sort of change occurs, there is no time to measure.

What boggles my mind is a slightly different question: if the entire universe is compressed into a point, where exactly would the point be? What is the point in? What is it that contains reality?

Oh well, never mind.

Philosoft

No, it isn't. So let's drop the arguments from scripture, people. Thanks.

Virgil Tibbs

I have a few of questions I'd like to throw out, as clearly there are people here who have much better understanding of this subject than I do. I haven't read "A Brief History of Time" in a while, so please correct me if I get something wrong.

1) We still lack a theory that unifies quantum mechanics and general relativity (I believe Hawkings called this the "quantum theory of gravity"). This theory is needed to describe what happens during the initial moments of the universe when quantum forces would have been important.

Since our models currently break down shortly before the beginning of space-time is reached, wouldn't that make discussions about the Big Bang itself useless (at present)? In other words, wouldn't we need to find out how to model the Universe immediately after the Big Bang before going still further back in time to model the Big Bang itself?

2) I must admit I've never heard of this concept of "meta-time" before. I'd like a clarification:

How exactly is adding meta-time supposed to answer anything? If you speculate that the beginning of real time was an event in "meta-time," then you are forced to ask how did meta-time begin. It seems like you've added a needless level of complexity yet been left with the same problem (sort of like theism in that regard ). Unless meta-time is a blatant appeal to the supernatural, this seems like a fair question.



Although I'm admittedly getting over my head with this last, I'd just like to say that I don't see what is unreasonable about the universe beginning as a quantum fluctuation. Since the uncertainty principle leads us to zero point flucuations, it seems there could be some sort of fluctuation to cause "something to come from nothing" (since a zero point flucuation could perhaps be looked at as "some movement coming from no movement"). While this theory is obviously unfalsifiable at this juncture, it seems a great deal simpler than introducing meta-time so it has Occam's Razor going for it.

Tibbs

Nowhere357

Useless but fun (and a chance to wax pedantic!). I agree with you.

If you saw my position on this a couple of posts above, then you know that I definitely agree with this, also.

I find the cyclic universe easier to understand than the idea of "something from nothing".

Keith Russell

Yes, time is the measurement of differing rates of change.

If existence was compressed to a single 'point', and then exploded, something certainly changed.

For the point to be able to change, something caused the change.

Something (probably the 'point') had to exist before the Big Bang, in order for the Big Bang to occur.

K