[thedoc (OP)]

Vishal Mody  asked the Naked Scientists:



   Dear Dr. Chris,



I have been listening to the Naked Science podcast for the past few years and have become a fan.  Many thanks to you and all your guests for discussing science in such an interesting manner.  I am always looking forward to what your next episode brings.



My question for you is this:



We know that time slows down as an object gets closer to the speed of light.  So if I was falling into a black hole, and if I were to survive for long enough, would I be able to see the end of the universe approaching, however that may look?



Sincerely, Vishal







 



What do you think?

[chris]

I think you would have had to cross the event horizon at the margin of the black hole to distort time sufficiently in this way, meaning that you would be spaghetti-fied and unable to appreciate the phenomenon of the end of the Universe.

But what does everyone else think?

[Alan McDougall]

I think you would have had to cross the event horizon at the margin of the black hole to distort time sufficiently in this way, meaning that you would be spaghetti-fied and unable to appreciate the phenomenon of the end of the Universe.

But what does everyone else think?

You might fall into another universe via its white hole?

[chris]

Alan, we should caution that it's theoretical that what lies at the heart of a black hole is a white hole constituting a "big bang" giving birth to a new Universe... I think Michio Kaku elaborates on this in his book "Parallel Universes"...

[Alan McDougall]

Alan, we should caution that it's theoretical that what lies at the heart of a black hole is a white hole constituting a "big bang" giving birth to a new Universe... I think Michio Kaku elaborates on this in his book "Parallel Universes"...

Chris, I agree it is highly speculative?

[chiralSPO]

I think you would have had to cross the event horizon at the margin of the black hole to distort time sufficiently in this way, meaning that you would be spaghetti-fied and unable to appreciate the phenomenon of the end of the Universe.

But what does everyone else think?

If the black hole is sufficiently large then one could cross the event horizon without fear of spaghettification.

[jeffreyH]

Rather than falling in, if you had already attained a velocity close enough to the speed of light it could be possible to maintain an orbit just outside the photon sphere. If the time dilation was extreme enough it would be possible to see a significant proportion of the lifetime of the universe in one's own lifetime. However to get close enough to light speed to see to the end of the universe would require an exponential increase in energy.

[evan_au]

Rather than falling in (to a black hole)...

If you did fall straight into a black hole, you would attain a speed somewhere around 30% of the speed of light (as seen by a distant observer). Extrapolating the velocity of the infalling spaceship gives a finite (and very short) time to cross the event horizon.

From the viewpoint of the person falling in, the last part of the journey would last just an eyeblink - anything you saw would not register.

I agree with Jeffrey - a close orbit would be better.

[thedoc (OP)]

We discussed this question on our  show
We put this to astronomer Matt Middleton from the University of Cambridge...
Click to visit the show page for the podcast in which this question is answered. Alternatively, [chapter podcast=1001410 track=16.08.09/Naked_Scientists_Show_16.08.09_1005562.mp3] listen to the answer now[/chapter] or [download as MP3]