Author Topic: Wormhole Physics  (Read 15614 times)

Offline Celebrimbor

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Re: Wormhole Physics
« Reply #20 on: 01/07/2011 01:00 PM »
Sincere there seem to be a lot of bright guys around, I'm going to ask it here. I hope this doesn't qualify as "Oogie Boogie Science" (wormholes are consistent with known physics).


It might ;) But considering this is a term a lot of public have heard about - mainly via movies - it's interesting :)

Perhaps not Oogie Boogie Science, but certainly Madcap Dreamstate Engineering!

Quote from: MP99

[Plot spoiler] Stephen Baxter (IIRC) wrote a story where someone attempts to transit the wormhole whilst the distant end is still undergoing it's relativistic journey. This destroys the wormhole, although I've no idea if that is based on any actual wormhole theory.

I know you stopped short of doing it yourself, but lets stay away from reading sci-fi books like they were physics text books...

Quote from: DLP

b) a wormhole will have massive mass to it consistent with the huge amount of negative energy needed to keep it open. A puny thruster wouldn't do anything to move it significantly.
c) the atmosphere would evacuate through it into space at the other end.


Not just the atmosphere would evacuate but large quantities of the Earth... how is such a thing to be held on the ground???

Quote from: johnfornarno
Quote
...a black hole at 1.5 Schwarzchild radius...
Not to be confused with the Schwarzenegger radius....

There are around 17.645 Schwarzenegger radii per Schwarzchild, but the latter is the SI unit.

Offline Celebrimbor

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Re: Wormhole Physics
« Reply #21 on: 01/07/2011 01:17 PM »

Anyway, is there a way to calculate the mass and energy requirements to open a wormhole of a given size, say 10m in diameter?

How massive would the wormhole be?

From what perspective? We're talking relativity here so questions like this don't make sense.

Offline DLR

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Re: Wormhole Physics
« Reply #22 on: 01/07/2011 02:02 PM »
From the perspective of an outside observer.

Let's say I find a tiny wormhole bubbling up in the quantum foam around me and want to increase its size, make it traversable and permanent. How much energy (or exotic matter) do you have to expend in order to make this happen? How massive will the wormhole throat be?

I read that everytime you enter a wormhole on one side, you add mass to that end, and when you exit from the other this one loses mass. If it loses all of its mass, the wormhole collapses and turns into a black hole, is that correct?

Offline scienceguy

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Re: Wormhole Physics
« Reply #23 on: 01/07/2011 03:16 PM »
This paper

http://prl.aps.org/abstract/PRL/v90/i20/e201102

has an interesting result. If you can get the full paper, you will see that you just need a tiny amount of negative mass or exotic matter to stabilize a wormhole. However, the amount of mass you can get through it will also be tiny.
e^(pi*i) = -1

Offline DLR

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Re: Wormhole Physics
« Reply #24 on: 01/07/2011 03:25 PM »
Can't access the paper ...

... what about "inflation" to macroscopic size, say 10m or so? Do the energy requirements scale linearly?

Offline scienceguy

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Re: Wormhole Physics
« Reply #25 on: 01/08/2011 12:57 AM »
The paper didn't say if the energy requirements scale linearly. It only said that a macroscopic application would require a macroscopic scaling (at the end).
e^(pi*i) = -1

Offline DLR

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Re: Wormhole Physics
« Reply #26 on: 01/08/2011 07:20 AM »
Which means specifically? Don't they give you numbers?

Offline SiriusGrey

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Re: Wormhole Physics
« Reply #27 on: 01/08/2011 10:35 AM »
"Exotic matter" is hypothetical stuff that has negative energy density. I've read some accounts that it could in principle exist from a gravitational perspective, distributing itself as a thin mist instead of clumping, but I have not repeated the calculations.

Unfortunately no exotic matter has been found to date, either in astronomy or in particle physics. I personally think while it would be very nice to have, it is probably not part of our universe.

However, on the subject of quantity I remind you that even a wormhole that "only" allows single photons to pass would be incredibly valuable snd useful, since you could send messages through it.

Another quick note: You still have to overcome a gravity gradient "in" your wormhole if the two openings are at different places in gravity wells. So my answer is that if you have a wormhole from here to orbit, the atmosphere would definitely not get sucked into space! However, if you throw the other end into the sun...

Regards,
Sirius

Offline scienceguy

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Re: Wormhole Physics
« Reply #28 on: 01/08/2011 04:08 PM »
Which means specifically? Don't they give you numbers?

No, no numbers. I'm guessing the author didn't know how to scale it up. You can contact the author, here's his web page:

http://homepages.mcs.vuw.ac.nz/~visser/

e^(pi*i) = -1

Offline mboeller

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Re: Wormhole Physics
« Reply #29 on: 01/08/2011 05:47 PM »

Offline Suzy

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Re: Wormhole Physics
« Reply #30 on: 01/12/2011 03:59 AM »
I have a couple of questions:

Assuming you construct a wormhole, how do you determine where it exits?

Galactic co-ordinates? Which could be programmed into the wormhole-creator gadget.  :) Also (I don't know if it's relevant) pulsars can be used as a galactic GPS.

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