The production of a black hole using television sets

[marcus]

The Dutch physicist Gerard 't Hooft
has just posted an article which
investigates a way in which
trillions of television sets could be
utilized to form a black hole

http://arxiv.org./gr-qc/0401027

Despite its great seriousness , the article is a mere 15 pages. In case you wish to download the pdf directly:

http://arxiv.org./PS_cache/gr-qc/pdf/0401/0401027.pdf

 

[MathematicalPhysicist]

from what you have read marcus what can you tell us about this particular new idea?

from the abstract there is no mention of tv creating black holes so i guess you read the article.

 

[wolram]

this article, like so many refers to HAWKINGS RADIATION as
if it has been found, sadly this is not true, as this
hypothosised radiation is extreemly weak it may never be
detected with any certanty, so any theory that uses it
should be open to critisism.

 

[marcus]

Originally posted by loop quantum gravity
from what you have read marcus what can you tell us about this particular new idea?

from the abstract there is no mention of tv creating black holes so i guess you read the article.

loop, after reading your post I realized mine wasn't clearly written enough, so I edited it by adding a smilie

't Hooft did world-class work in 1971 that got him and his co-worker the Nobel, yes, but what about this paper that he is posting today in 2004?

well what I enjoyed most about it was the idea of trillions of television sets collapsing to form a black hole

he specifies that they are all battery powered and all turned on, and they continue to function as they all fall inwards past the event horizon----how this can happen I am not too sure, since I didnt check his numbers, but it is a funny image don't you think?

when I say "trillions" of TV sets, that is a gross understatement. He does not say how many but it is a huge number.
I think maybe he does not like television, or maybe he thinks people should not spend so much time watching it, but he does not explain so one cannot be sure. Perhaps on the contrary he loves television and imagines all of the sets tuned to receive his favorite program.

 

[ranyart]

Originally posted by marcus
The Dutch physicist Gerard 't Hooft
has just posted an article which
investigates a way in which
trillions of television sets could be
utilized to form a black hole

http://arxiv.org./gr-qc/0401027

Despite its great seriousness , the article is a mere 15 pages. In case you wish to download the pdf directly:

http://arxiv.org./PS_cache/gr-qc/pdf/0401/0401027.pdf

Posted in a relevant thread yesterday?:https://www.physicsforums.com/showthread.php?s=&threadid=11478

Its a great paper, I have read it three time allready, and its not alone, Hooft posted another great paper a number of days ago.

 

[marcus]

ranyart, I see you have already picked up on this paper and posted an enthusiastic comment in "astrophysics" forum! consider this as supplemental :)

out of respect for 't Hooft, since he is such a great physicist and a man of vivid imagination, I have worked out the numbers for all these television sets.

it is mathematically straightforward and even approximately Newtonian

there is a natural constant which gives the event horizon mass loading
which goes as the reciprocal of the mass of the hole
and this constant is
3.6E52 kg^2/m^2

this means if the mass of material is 3.6E52 kilograms then the mass loading----mass per area---of the event horizon is 1 kilogram per square meter.

Or if you want the loading to be 1000 kilograms per sq. meter then you can make the mass 3.6E49 kilograms.

In that case the area of the event horizon is 3.6E46 sq. meter and the
Schwar radius is 5.4E22 meters
a lightyear is 9.5E15 meter
so this is roughly on the order of a million lightyears.

't Hooft's picture is robust in the sense that it does not depend on getting the numbers in some narrow range. It will work with any numbers over a broad range. To get one out of many possible realizations, we can start out by imagining the television sets arrayed in a spherical shell where
the sphere is a few kilometers thick and a few million lightyears in radius
the sets are dispersed with plenty of room between them so they don't bump each other
the total mass of sets is, say, 3.6E49 kilograms

we let all these sets go at the same moment and they begin falling towards the center of the sphere. The sphere will contract under its own gravitation at first until it is the size of the event horizon, and then still further.

as they pass the event horizon, the TVs are still spread out enough so they don't bump each other and break. they continue to operate as they fall thru the horizon.

the concentration of mass at this point of passing the EH is only some 1000 kg per sq. meter and the sphere is on the order of a kilometer thick---it has not yet contracted by a big percentage, only by a factor of perhaps two or three.

 

[drag]

Hey, some TV shows just need one of'em darn things
to produce a black hole in your brain...
Oh and... some can even cause supernovas and spiral
collisions when the shows are really bad...
Sometimes even a single TV can look just like a nasty pulsar...
Well, got'ta go, I got Spock building a sub-space transmitter
out of toothpeaks and a couple of forks in my kitchen...