Science Questions

Could I see the end of the Universe?

Mon, 8th Aug 2016

Question

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?

We put this to astronomer Matt Middleton from the University of Cambridge...

Make a comment

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? chris, Sat, 28th May 2016

You might fall into another universe via its white hole? Alan McDougall, Sat, 28th May 2016

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, Sat, 28th May 2016

Chris, I agree it is highly speculative? Alan McDougall, Sat, 28th May 2016

If the black hole is sufficiently large then one could cross the event horizon without fear of spaghettification. chiralSPO, Sat, 28th May 2016

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. jeffreyH, Sat, 28th May 2016

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. evan_au, Sat, 28th May 2016