Saw this on Mark Vernon’s blog today.

It’s part of a short essay about a book he’s reading by Yourgrau entitled “A World Without Time: The Forgotten Legacy of Gödel and Einstein”. The subject of the book deals particularly with a set of solutions to Einstein’s equations by Gödel that would point to a form of “time” that is more subjective than we tend to think of it.

From his blog entry:

“If I’ve understood it right, Gödel demonstrated that the existence of intuitive time – time that we experience as flowing minute by minute – is inconsistent with the time ‘t’ of special relativity, since the latter is really spatial, a fourth dimension on top of the usual three. In short, if you have ‘t’ you can’t have the time of day, as it were.

He then generalised his find to embrace general relativity, where time is tantamount to the movement of mass in spacetime. This appeared to make for a kind of return of intuitive time, or ‘cosmic time’, associated with the mean distribution of mass and motion. However, Gödel went on to find some solutions of the equations of general relativity, representing fast rotating universes, in which time travel is possible, or at least ‘t’-time travel. Again, though, this possibility is bought at the cost of cosmic or intuitive time. In other words, if time travel is possible, intuitive time – time as we experience it – is not. Gödel then took a further step which persuaded him that time is actually ideal – perhaps in agreement with Augustine, who wrote: ‘In the Eternal nothing passeth away, but that the whole is present.’ (Not that Augustine thought he had it sussed, for he also said, ‘What then is time? If no one asks me, I know what it is. If I wish to explain it to him who asks, I do not know.’

Now, apart from being a fascinating reflection on time, this is interesting since it is quite fashionable in physics books these days to speculate on the possibility of time travel, not least on the basis of Gödel’s rotating universes. Michio Kaku does it here. However, what Kaku appears to forget is that Gödel’s time travel is bought at the cost of intuitive time, this side of eternity at least.”

Read the full article here.

Which is an interesting point to make. Interesting especially in terms of the theological connections. I’ll probably have to add this to me reading list for the summer…