Recent content by bcrelling

Surely something must be changing to measure time. The clock must increment or the observer must accumulate memories of the past- these processes would involve entropy?

Would the increased temperature as measured by an observer at the horizon be definable? Is this where the idea of the black hole fire wall comes from?

Black holes are claimed to radiate at a temperature corresponding to the hawking radiation. But who is measuring the temperature? If the radiation is measured from far away the red shift will indicate a lower temperature won't it? Is the temperature given by the formula as measured from a...

We have a large mass, and we increase it slowly- dropping in one atom at a time. Will a black hole form suddenly, or will it gradually become blacker with the addition if each atom? I assume that a mass marginally below the threshold must at least partially have the properties of a black hole...

I see that the formula for hawking radiation is related the the formula for unruh radiation. The accelleration experienced by a body yields an unruh temperature equivalent to a black holes hawking temperature with an equivalent value of g. The unruh effect happens at all accelerations, therefore...

To be exact: The planet is not rotating. Both riders start at the same time and same place. Time is compared by the twins carrying clocks which are compared after driver B completes a circuit of the globe and both drivers meet at the starting point. But I think you've already answered my...

If we have two twins driving cars. They remain at the same height above sea level so gravitational time dilation is equal. Both cars travel at the same speed so time dilation due to speed is equal for both. However... Car A drives around a small circular race track and experiences centripetal...

Ok thanks for that guys.

I used the formula: With m (of universe)= 10^53 kg This gives 15.6 light years as the swartzchild radius. Which is pretty close to the age of the universe. I was also thinking that the matter escaping our cosmological event horizon might be analogous to a black hole losing mass via Hawking...

If a large mass of matter and anti-matter collided to form a black hole, I assume they would anihilate and you would have a black hole made of photons. Now considering the black hole as a container of photon, there must be a net pressure pushing against the confines of the gravity. The force of...

A substance of arbitrarily low density can form a black hole if there is enough of it. So I took the mean density of the universe and calculated how big it would have to be to form a black hole. It's a surprising coincidence that the swartzchild radius in light years is the exact age of the...

Hi all I gather a normal black hole has maximum angular velocity at the point that the event horizon is moving at The speed of light. However what would be the maximum rotational velocity for a maximally charged black hole- for example one made purely of electrons? Thanks

Experiment: Imagine the dalayed time quantum eraser experiment, except the pair of "idler" photons(which would normally pass onto the detectors d1,d2,d3,d4) instead fall into a black hole. Would d0 detect interference or not? It seems commonly accepted that the information of...

Could the "hidden variables" be encoded in the observer? The hidden variables that have been proposed to dictate the action of quantum outcomes, Could they be in observer dependent as opposed to encoded in the particle? We know the observer is an integral part of the process. Has this...

I only saw the options under the physics heading- this forum is bigger than I thought!