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Author Topic:   What is "the fabric" of space-time?
fallacycop
Member (Idle past 4748 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 6 of 327 (457745)
02-25-2008 5:24 AM
Reply to: Message 5 by Calypso
02-25-2008 2:54 AM


Is there a physical substance there being warped?

No.

Analogies can be dangerous. This analogy with a fabric can help you understand that space is warped by the presence of mass (Actually, it is more complicated then that, and things like momentum and pressure also contribute to the warping of space). But it can also give you the false impression that there must be some sort of physical substance that get warped. It mustn't. To better understand what meant by warping, think about the following questions.

Is the ratio between the circunference and the radius of a circle necessarily always equal to 2pi?

Is the sum of the three angles of a triangle always equal to 180 degrees?

Answer to both: Only if the space is flat!

For instance, we know that the surface of the Earth is not flat, even if we completely neglect mountains and other local features, because the Earth is a sphere.

Now make an equilateral triangle by starting ant the north pole, moving 10 000 kilometers southward all the way to the equator, then move another 10 000 kilometers eastward, and complete the triangle by moving 10 000 kilometers northward.

There you go, your triangle has three 90-degrees-angles for a total of 270 degrees!


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fallacycop
Member (Idle past 4748 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 15 of 327 (457815)
02-25-2008 5:20 PM
Reply to: Message 7 by johnfolton
02-25-2008 2:45 PM


If you only made sense...

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fallacycop
Member (Idle past 4748 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 24 of 327 (457854)
02-25-2008 8:49 PM
Reply to: Message 23 by Calypso
02-25-2008 7:50 PM


As far as I see it, mass is warping something is it not?

mass warps space


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fallacycop
Member (Idle past 4748 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 44 of 327 (457997)
02-26-2008 7:12 PM
Reply to: Message 43 by johnfolton
02-26-2008 3:37 PM


The ball was moving too fast for me to of had time to react, if the ball would of hit my head at that velocity I might of been seriously injured or killed, which is why I believe God caused time to stand down for an instant

I think the bat hit you on the head and you just don't remember it.
That would explain a lot...

PS: "would of" and "might of" ain't really english, but you know that, right?


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fallacycop
Member (Idle past 4748 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 65 of 327 (458723)
03-01-2008 6:53 PM
Reply to: Message 60 by Buzsaw
03-01-2008 4:53 PM


Re: Space Properties
What properties does space have capable of warping?

Distances and angles.

For instance. In flat space the ratio between the circunference and the radius of a circle is always 2pi, no matter how big the circle is.

I a warped space this ratio might be different. As an example, think of the surface f the Earth as a 2-dimensional space. Chose a point for the center of your circles (I will use the north pole, but any point would work as well). Start making circles around that point of ever increasing radius. At first, they seem to follow the 2pi ratio between circunference and radius. But what happens when the radius gets really large? Make that radius 10 000 kilometers, for instance and you will get to the equator which has a circunference of 40 000 kilometers (I'm assuming for sake of simplicity that the Earth is a perfec sphere). The ratio between the circunference and the radius is equal to 4<2pi. What happened? the surface of the Earth is curved (or warped).

In General Relativity, the space and the time form a 4-dimensional space-time. The presence of mass warps this space-time in a very specific way discribed by Einstein's field equations.

Edited by fallacycop, : fixing a trucated phrase


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fallacycop
Member (Idle past 4748 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 165 of 327 (459431)
03-07-2008 10:11 AM
Reply to: Message 146 by Silent H
03-05-2008 7:20 PM


Re: the gravity of general relativity
Looks like your post went unoticed (Most likely due to the barrage of non-sense produced by randman). I just want to point a couple of (commom) missconceptions.

Am I wrong in thinking that much of Feynman's work (or at least QED's explanatory power) would be undercut by the current direction of physics? He seemed to have a purely statistical concept driven by particle behavior (or theoretical behaviors) rather than fields.

Yes, you are wrong. Feynmann's work in QED is one of the greatest achievements of Quantum Field Theory (QFT). QFT is older then you think. Don't let Feynman Diagrams give you the false impression that QED is not a field theory. Feynman diagrams are merely mnemonics for expressions that can only be properly interpreted within QFT.

I did believe that mass and energy can be converted, and so where once you had no mass, suddenly you would have it. I did think that was happening in high energy collision experiments. Even if
mass is energy in a volume, isn't there a point where energy in an area moves from something that does not exert a gravitational force (aka warps space-time) to something that does? Perhaps an explanation of how mass -energy conversion occurs as it relates to "gravity" would be the best bet.

Wrong again. The Equation E=mc^2 is not an equation for converting mass into energy in the sense that one disapears when the other appears. It's a conversion factor between two different units for the same physical quantity, as when you convert inches into centimeters 1 in = 2.54 cm. c^2 is the conversion factor. Energy warps space-time. So does pressure, force, and stress. theese are all aspects of the same physical quantity.


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fallacycop
Member (Idle past 4748 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 183 of 327 (459845)
03-10-2008 8:57 AM
Reply to: Message 181 by Phalanx
03-10-2008 4:38 AM


Re: Energy from Nothing ???????
On an entirely different tangent - would it be possible for you to somehow edit your posts to make your thoughts more coherent. For the life of me, it seems that that post was just some stream of consciousness.

Only coherent minds can produce coherent thoughts.

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fallacycop
Member (Idle past 4748 days)
Posts: 692
From: Fortaleza-CE Brazil
Joined: 02-18-2006


Message 186 of 327 (459871)
03-10-2008 12:17 PM
Reply to: Message 184 by ICANT
03-10-2008 10:53 AM


Re: Space-time
If Space-time was not created, where did it come from?

Will you knock-it-out?

We already answered this question a thousand times in the other thread. We don't need you bogging that one too. Can't you come up with something new to ask?


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