I hate it when...

[G4YVM]

Kids ask better questions that I can

yesterday in the car my son asked me to tell him what a black hole is, so i did my best. Then we got to thee event horizon and I said light inside it falls into it, light outside it gets away but light ON the EH stays there, so if you my son fell in, whilst you would be destroyed your image would linger and I'd think you were forever on the edge of oblivion, just on the EH.

So he delivered the killer blow by saying: "then the event horizon must be a permanent record of everything that has ever fallen into the black hole".

Is that true?

david

[blinky]

I think so, at least thats my (very limited) understanding, but I may be wrong!

[barkis]

Not sure images would remain visible. Their light would become red shifted and disappear eventually I think. Although from the observers viewpoint, at an interminably slow rate.

Not a subject I know about. Too deep for me.

Ron.

[Beulah]

Woah....

That's all I can say....

[Talitha]

Brilliant question!! I haven't a clue regarding the answer, but wow.. what a bright boy you've got there.

[Tim]

That does it, if my kids ask what a black hole is, I'm gonna tell 'em that it's a movie from the 70's with a giant red robot in it.

The Black Hole - Wikipedia, the free encyclopedia

[kev 102 42]

it was on channel 5 yesterday i watched it.............kev

[Ant]

That is a great question. From my limited (very limited) knowlege I would think that the light would stay there untill the EH expanded due to the increased mass of the Black Hole.

My lad asked me at the weekend why people on the bottom of the Earth don't fall off.

I explained about gravity as best I could, he sat there listening (it was bed time and I was supposed to be reading Star Wars) for 20 minutes while I made a complete hash of explaining it.

Don't think he understood...

Maybe that's a project we could undertake - Science question? Answers for the under 10!

Ant

[acey]

David, your son's a smart kid!

The event horizon is a surface of infinite redshift so although there is theoretically a freeze-frame of everything that has arrived there, it's not visible light (it's radio waves of very long - theoretically infinite - wavelength).

There's an issue about the information that gets lost inside black holes, and whether it pops out again somewhere else (this is connected with something called "unitarity"). Stephen Hawking has said a lot about this, and I think his current position is that the information is preserved - but in another universe!