# What is space made of?

1. Nov 30, 2006

### nannoh

I know, probably a stupid question, but if there's a simple answer or a thread that already answers it, I'd like to know it. I realize there are trace elements of practically everything in space but when I say "in space" this means its "in" what?

2. Nov 30, 2006

### waht

Nothing at normal scales. But if you zoom in to planck's length, you should see random and chaotic ripples in space, and virtual particles popping in and out of existance.

3. Nov 30, 2006

### PhanthomJay

Good question, and you're probably never going to get a good answer. Try this one: You can't talk about space without talking about time, ; your question should therefore read "What is Space-time"? My answer, which may not be worth much, is that spacetime is the 11 dimensional gravitational field of graviton particles permeated by the Higgs Boson of the Higgs Field, none of which has yet been proven to exist, (but many are working on it), and through which all energy and matter is created. Developing M-Theory (formerly string theory) and the Quantum Theory of Gravity MAY provide a clue. Otherwise, spacetime might just be a figment of our own imagination.

4. Nov 30, 2006

### PhanthomJay

Yes, good point. The secrets of spacetime may lie not in the macro scales of its infinities, but in the quantum micro scales of its infinitesimals, and what is exactly happening in the unknowns of Planck scale spacetime.

5. Nov 30, 2006

### nannoh

I think this is a great start - thank you. Does dark matter hold a place as part of space? Does anti matter for that matter?!

I suppose you can't measure space without using a concept like time. Are the two really inseparable?

If energy cannot be created or destroyed, what are you talking about PhanthomJay?

6. Nov 30, 2006

### PhanthomJay

Energy and matter cannot be created or destroyed, but it can be converted to one form or the other..energy into matter or matter into energy, per E=mc^2. But your question relates as to how matter and energy can be created from empty space-time. The answer more or less in non Hawking terms is that 'empty' spacetime consists of equal amounts of both positive and negative energy....that adds up to nothing....but for some inexplicable reason the positive energy has won the battle over the negative energy and converted itself to matter, antimatter, and photons....which is exactly balanced by the remaining negative gravitational energy of spacetime...such that the entire energy in the Universe, when you convert the matter back to its energy equilavent, remains at ...NOTHING. No energy at all!

And yes, time and space are inseparable, at least beyond Planck limits, and outside of the region of the black hole singularity (if it exists), where spacetime and all the laws of Physics break down; and, at the speed of light in a vacuum, where time and space is nought.

And finally, on Dark Matter, while there are many theories, the most promising seems to stem from M-Theory....where Dark matter is actually gravitational energy seeping into our 11 dimensional Universe from matter in ANOTHER universe , via way of black holes!
BTW, some say the separation between the universes is only a few millimeters. I don't know the mathematics behind this, but I would venture to guess that they are much closer than that: 1.6(10^-33)cm, the Planck Length of the unknown. No other distance makes sense.

Last edited: Dec 1, 2006
7. Dec 1, 2006

### nannoh

Amazing!

Do you have a general link to these sorts of explainations that will talk to someone like myself with very little background in this type of physics? I had no idea you could measure the unknown. I suppose its an approximation?

8. Dec 1, 2006

### PhanthomJay

I don't have any links; I would refer you to the great one, Stephen Hawking, and his 2 masterpiece books, "A Brief History of Time", and "The Universe in a Nutshell". Both are 'must' reads, and can be generally understood without a great knowledge of Physics.

I didn't mean to imply you can measure the tiny scales of the planck length. Nothing is known within the "Planck Time" first 10^-43 seconds after the "Big Bang" (Note: Planck time is the time it takes the speed of light to travel the Planck length of 10^-33 cm). And nothing may ever be known as to what happened in that ever so brief split second following the creation of the Universe. The Heisenberg Uncertainty principle forbids it. The extra 7 space dimensions of spacetime may be curled up in a size on the order of the Planck length, or slightly higher. The size is so small that not even light or high frequency, short wave gamma rays can penetrate through it. But, according to Hawking, perhaps the mysterious yet undetected gravity wave can, and escape the spacetime of our universe and enter into another universe. Since light cannot, we will never be able to get a glimpse of what's going on out there in those other worlds. Such a shame, isn't it?

9. Dec 1, 2006

### Repetit

How does the Heisenberg uncertainty principle prevent us from knowing anything about what happend at the first few split seconds after Big Bang? I mean, the uncertainty principle is:

$$\Delta E \Delta t \geq \frac{\hbar}{2}$$

So if the time scale is very short, the uncertainty in energy must be very large. How is this to be interpreted in relation to the creation of the universe?

10. Dec 1, 2006

### waht

We don't know what existed before the big bang, if time did not exist, then the uncertainty in energy would be close to infinity. If you tried measuring energy, your readings would be fluctuation from a few joules to a quadzillion of joules in the next consecutive reading.

But then some kind of flip happened, or an uncertainty oscillation that released all that energy in bigbang. Now you can take accurate readings of energy, but are uncertain in what time with respect to the universe, becaseu time is going to infinity.

11. Dec 1, 2006

### nannoh

I have Hawking's books and I'll do my best to gleen what you have pointed out. I did see some of the text and illustrations about multiple universes. Rather perplexing in that while on one hand they're flat yet in the illustrations they're funneling to various degrees. Its probably a graph-like representation to show amount of time/space - I need a refresher look at it!

12. Dec 1, 2006

### PhanthomJay

"Thus it seems that even God is bound by the Uncertainty Principle, and can not know both the position, and the speed, of a particle." -Hawking