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# Tag Archives: black hole

## Big Bang singularity

Does a singularity contain mass?? if yes then according to big bang , our universe sprang into existence as “singularity” around 13.7 billion years ago. it means there was already a mass centered in zero volume.

and only a black-hole has singularity it means at the time of big bang there was a black hole in which explosion occurred.
please guide me and give me ans.

The word singularity means

“the state, fact, quality, or condition of being singular.”

“a point at which a function takes an infinite value, especially in space–time when matter is infinitely dense, such as at the centre of a black hole.”

” a point at which the derivative of a given function of a complex variable does not exist but every neighborhood of which contains points for which the derivative does exist”

Evidently, singularity refers to a unique situation, in big bang whatever state of affairs triggered contributes to the singularity.

Refer to

https://en.wikipedia.org/wiki/Initial_singularity

http://www.hawking.org.uk/the-beginning-of-time.html

Did The Universe Really Begin With a Singularity?

http://www.big-bang-theory.com/

## Space Time Curvature and the TRampoline analogy

In the trampoline demonstration representing space-time and gravity, it is obviously the friction between the trampoline and the ball that determines the path of the ball. Friction is a physical interaction, so space-time has to physically interact with matter for this demonstration to be a plausible description of what is happening actually. My question is, what is or what causes that physical interaction or “friction” between space-time and matter when space-time is curved?? Thank you

The trampoline is just an analogy to understand the phenomenon. Gravity is like the depression of the trampoline causing a curvature in the space time continuum.

## Speed of Light

How can the speed of light be a constant, when time is not?
If the rate of time can change depending of speed of matter or extreme gravity, the speed of light is 186,000 miles per second, but a second could flow at different rates.
If light from a star passes close to a black hole where time flows slower, this changes the speed of light we perceive?

## Entropy

The latest thinking about black holes is that they may not collapse into a singularity at all, but may actually explode back with  a “big bounce” once the diameter of the black hole reaches the Planck Scale or maximally compact state and once the “big bounce” diameter expands to that of the event horizon, it would release all of the information that till then had been trapped inside the black hole, back into the universe.

My question is this, if in fact the “big bang” that led to the creation of our current universe was the result of the “big bounce” associated with the collapse of a prior universe, is there any measure of entropy that could detect this. In other words would any measure of entropy differ between the universe caused by “big bounce” n and the universe caused by “big bounce” n+k?

The question is left for the visitors to answer

## Is the universe expanding or are we getting smaller?

Is the universe expanding or are we getting smaller?

## Speed of Light and Protons

If the definition of the speed of light is for massless particles, then how is a proton, having mass, accelerated to the speed of light?  This sounds like a conumdrum.

Posted Thierence

No massive particle has not so far crossed the speed of light. Even the extremely light particles – the neutrinos – couldnot cross the speed of light. Protons have not crossed the speed of light. When it nears the speed of light, the relativistic mechanics will become prominent and the it is to be treated is different from the classical mechanics.

## Can the process of Pair Production be used as a source for energy generation in space?

Can the process of Pair Production

be used as a source for energy generation in space?  Can Gamma Rays in space become the source for generating  energy using Pair Production process?  EM radiation >1.02 MeV enery, Pair Production is the dominant absorption process.

(Posted By Chintan Shah)

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