What is Time and Space

I have to do some more reading to proceed further. Man this has been great. I do have one question though. I went through several threads on this subject today. On one of them you reccommended "The Road to Reality" by Roger Penrose.I googled it and apparently it isn't an easy read. I'd like to learn some of the math but my last math high school course was back when the earth's crust was cooling and I'm wondering if you think the book would be worthwhile or not.It sounds to me like it would be more of a reference book than one that I would read right through.At any rate I'd appreciate your advice. In the meantime I'm going to re-read some more of Briam Greenes and thanks again.

Thanks. I'd like to try and learn some of the basic math involved. Is there a book that you know of that provides the concept, an explanation of the math and the formula?

I read up on the Schwarzschild metric. It is amazing that with the information and the technology they had in the early 1900's that he and Einstein could come up with what they did. As the black hole singularity has infinite density does it have a mass? Is the warped space time that you referred to created solely by the gravitational field of the black hole?One of the things that I am struggling with now is this. (Hopefully I'm still on topic. It seems to me this is would be considered what is space.)Greene says that planck length is the length of a string. First off what is the length of a string? I tend to think of a string as more like an elastic band in that it's a loop. Is its length measured as it was cut and strtched out or just the length as it is? This is no doubt a dumb question but I'd like to try and at least have a workable mental image. Also I understand that in string theory a string is the basic form of a particle. Are all particles and thus all strings considered to be the same size? (Planck length)

Thanks Justin
I read up on that and it sounds as if you don't know calculus you're toast. I have no calculus whatsoever so it might be well over my head. What do you think?Right now I'm re-reading Brian Greene's, "The Fabric of the Cosmos".This message has been edited by GDR, 08-02-2005 06:43 PM

The trouble is, I don't know what I don't know. I had algebra, and I even remember some basic Newtonian physics from high school, but I have no idea what is involved with learning some basic calculus.Also, I don't even know what learning some of the math behind the concepts will do for my overall comprehension.How is all that for a vague answer?

I read your posts this morning and I have been mulling over the idea the concept of superpositional. I had been able to get as far as the idea that light functions outside of distance and time but I hadn't made that additional step that a photon could be anywhere and everywhere at any time. Curiouser and curiouser!!I don't understand the concept of more than 4 dimensions. It seems to me that if light is outside of time and location then it isn't functioning in the 4 dimensions that we function in. Is light an additional dimension?

It seems to me that if static spacetime means that time flow is zero then it has become space. If distance, (which is really space) is zero it seems to put us right back where we started, which is something outside of our 4 dimensions. If there is no space and no time, how can it be static spacetime?In the same vain I got to thinking about gravity. Gravity acts instantly over time as it is a field. (I hope I got his right.) As gravity acts instantly over time and space is it possible again that this is another dimension, and what time is to space, light is to gravity?I realize that I have very little idea of what I'm talking about, as I only have a minimal grasp of very basic concepts, and no knowledge of the math behind it. I'm just trying to piece together the information that I'm gleaning from this forum and the books I'm reading. I apologise to those of you who do actually know what you're talking about, but this is a great way to learn. This message has been edited by GDR, 08-03-2005 04:26 PM

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Everybody is entitled to my opinion.

I was thinking of entanglement as well when I was reading about gravity affecting things instantly over space. In the case of gravity science has figured its a field but it doesn't seem to be suggest that entanglement involves a field.One thing I don't understand about the theories on gravity is this. Science says that in a magnetic field information passes at the speed of light. Why in a gravity field does information pass instantly?The thing that has me puzzled though is that although they haven't found them it is thought that there is a gravitational particle called gravitons. Wouldn't this mean then that a graviton would have to move at infinite speed?

In "The Fabric of the Cosmos" Greene says that if the moon were to disappear we would see the gravitational affects on the Earth immediately whereas we would have to wait for a second and a half to see the light disappear. (Pg 63) Is this wrong or am I misinterpretting it?

My problem is I know that both Greene and cavediver know what they're talking about, so I'm wondering what it is that I'm not getting as it looks to me as if their positions are contradictory.

No problem picturing that. From reading Greene I have been thinking of gravity as a field similar to a magnetic field. Would you say that is accurate and is that consistent with what you are saying?This message has been edited by GDR, 08-04-2005 03:47 PM

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Everybody is entitled to my opinion.

Is there, by any chance, a translator in the house?

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Everybody is entitled to my opinion.

I didn't mean to misrepresent what he said about the moon. He suggests what would happen if hostile aliens zapped the moon and beamed it clear across the galaxy.Now I have express apologies to all. What I missed is that Greene was talking Newtonian physics and if I had checked further on I would have realized that GR changed all of that and that gravity does function at the speed of light.Like so many other times in my life. All I had to do was say nothing.

Just so I can feel like one of the big boys for a couple of minutes could you tell me what the letters in that formula stand for. Also what is QFT.ThanksThis message has been edited by GDR, 08-04-2005 08:07 PMThis message has been edited by GDR, 08-04-2005 08:09 PM

Thanks cavediverIn the last part of Greene's book he contrasts string theory and loop quantum gravity. He says that ST grew out of the particle physics tradition and that LQG grew out of a tradition tightly grounded in GR. He says'"string theorists start with the small (quantum theory) and move to embrace the large (gravity), while adherents of LQG start with the large (gravity) and move to embrace the small (quantum theory)".After a lot of other detail he says the following. I find randman's comments of photons interesting as well. The idea of something that can be anywhere or everywhere at any time is intriguing. (Or at least it would be if I could properly comprehend it. )This message has been edited by GDR, 08-05-2005 06:03 AM

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Everybody is entitled to my opinion.