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Q & A: Event horizon of black holes

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Relativity
Most recent answer: 05/16/2013
Q:
If black holes exist at the center of all spiral galaxies such as our Milky Way, is it not true that our solar system has already crossed the event horizon of that black hole and that, as far as our solar system itself is concerned, we have passed the point of no return? And if the above proposition is true, might this account for our perception of Time due to the effects of spagettification? Might it not also account for our occassional perceptions of deja vu as we spin around the cosmic wheel like wet laundry in a dryer, with Time splayed, stretched and plastered, yet contained within the event horizon of the drum? Cheers, Clay
- Clay Adams (age 52)
Jacksonville, FL
A:
The theory of General Relativity produces a formula for the radius of the event horizon of a black hole,  R = 2*G*M/c2. Here, G is Newton\'s gravitational constant, M is the mass of the object and c, as always, is the velocity of light.  For a black hole with a mass of our sun this radius turns out to be about 3 kilometers.   Of course our sun is not a black hole so the calculation is not relevant. Even for a real, super-massive black hole of a million solar masses, the radius is only a few million kilometers, a puny distance on the scale of our galaxy.   
It is believed by most astronomers that the star Sagittarius A near the middle of our galaxy is a black hole.  Take a look at http://en.wikipedia.org/wiki/Sagittarius_A*   for some more information.

LeeH

(published on 05/16/2013)

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