We're finally ready to deal with the topic you've all been waiting for: Schwarzschild swirlers, Chandrasekhar crushers, ol' matter manglers, sucking singularities... ...

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ooooooo im sooo excited, been waitin 18 episodes for this

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Feeling all warm inside

Frasier and Pamela,

Thanks for another great podcast. My wife and I really enjoy your weekly show. Keep up the good work.

Now for a question about the show. It was mentioned that smaller black holes can vaporize. The analogy was that a glass of water, if left for a time, will vaporize and the water will disappear. However, the water really just changes form from a liquid to a gas. If I understand correctly the laws of physics require the vaporized black hole to not "disappear", but to also change into something else. Just what does it change in to?

John Switzer
Centerpoint, IN

First let me just say that I love your podcasts and look forward to sync'ing up my IPod every Monday so that I can listen to your podcasts at work.

Now to my questions...

I'm still not clear on the whole black hole evaporation process. If you have these particle pairs that are randomly being generated where one goes into the black hole and the other isn't, how does it evaporate if it is still consuming particles?

Thank you,
Phil M.

sooooooo..... if a blackhole 'evaperates' does it push out all the matter is sucked in?????

also is does anyone know any links to the pictures that Pamela and Fasier mentioned???

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Feeling all warm inside

So, first off, we know that energy and matter are the same thing (E=mc2). So, when a particle-antiparticle pair gets created, they take some of the energy from local space. When they collide and destroy each other, they give back the energy they took.

At the event horizon of a black hole, energy (and therefore mass) gets taken from the black hole to create a particle-antiparticle pair. One of the particles gets freed into space and, thus, the black hole doesn't get back the energy that got taken from it. This causes it to be less massive. (It gets back half the energy that it gave to create the particle-antipartcle pair in the form of the single particle that it consumes)

So, when matter gets sucked into a black hole, it gets converted into energy. When Hawking radiation occurs, the energy gets transformed into matter again and gets spat out. Make sense?

Dr. Pamela suggested googling Plate ways a black hole will hurt you.

Didn't work for me. Did I spell "Plate" incorrectly? Anybody have the link she was talking about?
Thanks.

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Feraldoc

So the black hole is actually eating "negative calories'? It keeps eating but gets lighter by doing so.

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Black holes are where God devided by zero

Hi Feraldoc,
The doctor was talking about dr.Philip Plait. The slideshow she was talking about is called: Seven ways a black hole can kill you!

http://glast.sonoma.edu/presentation...003/index.html

Cheers

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Black holes are where God devided by zero

Hi Feraldoc,
The doctor was talking about Philip Plait, founding father of Bad Astronomy. The slideshow she was talking about is called: Seven ways a black hole can kill you!

http://glast.sonoma.edu/presentation...003/index.html

Cheers

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Black holes are where God devided by zero

That would be 'Plait,' as in Dr. Phil Plait, Bad Astronomer Extraordinaire. Here's your link:

Seven Ways Black Holes Can Kill You!

In this episode Pamela described the Earth as a “people hole” I was wondering how big a lump of rock would have to be to have enough gravity to prevent Pamela jumping off it….

Well, if you look at matter and energy as being the same thing (which they are), the black hole isn't realy eating negative calories is it? It's just spewing them out.

Hi Fraser! I would like to thank you and Dr. Pamela very much for the great show on “Black Holes Big and Small”. I got to learn a whole lot of new stuff from the show.

Dr. Pamela said that the rate at which materials fall into the black hole is choked by the law of conservation of angular momentum. Materials cannot fall directly straight in until they have a perfectly magical trajectory which never happens to be in the real universe.

Why do not the materials fall straight into the black hole?
Why do they have to go round the massive object before falling into it instead of going straight into it?
How does the law of the conservation of angular momentum apply?

Please explain the physics behind this.

I just ran the numbers and, assuming that she can jump up 1 foot on earth and that the asteroid is spherical with a density of 1500 kg/m^3 (making it a C-Type), it would have to have a mass greater than 1.4 x 10^14 kg to prevent her from jumping off it.

Equations look truely terrible in text format. I wrote them out as a MS Word file, but, understandably, the site won't let me attach a doc to a thread post. If anyone is interested in checking my numbers, e-mail me, and I'll be happy to send it to you.

My $0.02.

If a black hole is spinning, then according to general relativity, space itself near the event horizon will also spin which causes any object approaching the black hole to circle it a bit first before falling in. This would be similar to a piece of styrofoam floating in the bathtub. Once you pull out the stopper, the water starts to spin as goes down the drain, which drags the piece of foam along with it. You would have to flick the foam with a precise amount of force at a precise angle in order to get it to go directly down the drain with no angular velocity. Highly unlikely.

So, do black holes spin?

Short answer, to the best of my knowledge, everything in space rotates around an axis.

-Chas

If I might recommend, Kip Thorn's book Black Holes & Time Warps, is an excellent introduction to the topic.

What is quarksoup?
And please let us in on some more details about the bet Hawking and Thorne made!

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Black holes are where God devided by zero

Is there a limit as to how much matter can be consumed by a black hole or will it devour any and all comers across the event horizon? If there is a limit, how is it quantified?

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"Sometimes you have to dream deep to find your real life..."

I was disappointed with Dr. Pamela’s not mentioning several aspects about time transformation with a black hole. She never spoke a word about point of view, but it would radically change what you believe happens. Time slows for a person approaching the event horizon, and stops when he gets there, but only from the point of view of the outside observer. From the point of view of the inbound traveler, his time is completely normal. Instead of stopping, he squirts right on through. If the black hole is massive enough, he might not even be aware that he had passed the event horizon.

On the other hand, his perceives the outside observer’s time as going faster. When the traveler reaches the event horizon, he would see the outside observer experience all the time through the end of infinity.

What I had hoped to see Dr. Pamela explain was the meaning of time from the point of view of the inbound traveler inside the event horizon in explaining the outside observer. This time must be greater than infinity, which I have difficulty understanding.

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http://members.elirion.net/~maddad
There are ten kinds of people. Those that understand binary, and those that do not.

That's covered in our question show.

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Fraser Cain
Publisher
Universe Today - Free space news delivered by email every weekday.

Where could I find the question show?

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http://members.elirion.net/~maddad
There are ten kinds of people. Those that understand binary, and those that do not.