Bill

Well, nothing in "String Theory" has been discovered in actual reality. What they have is mathmatical models that demonstrate that what we see (and which is currently unexplained) in particle physics can have a cause that arises from some theme and variation of String Theory. Its sort of an "if this is true, then that can be proven" sort of an observation. But it can't be called a "discovery" yet because the predicate truth is itself mere speculation......

== Bill

Oolon Colluphid

Ugh! My brane (sic) hurts!

Answerer

Okay guys, there is something that I don't understand about the imaginary time theory. On what basics or evidences did Hawkings use when he said that imaginary time has no boundary?

Oolon Colluphid

I'm no expert, but I think it's the universe that has no boundary when you measure time using imaginary numbers...

Oolon

Steven S

Although I think Hawking does dabble in string theory this path integral approach to quantum gravity as described in the article is entirely different from string theory. It is much less ambitious then ST aiming only to quantize gravity itself.

Answerer

Well Oolon, my question is how does the imaginary numbers show that time or universe (in your case) has no boundary.

Oolon Colluphid

I’m not sure about the universe being “in my case”. As I understand it, it is in Hawking’s case. But anyway, I wouldn’t like to try to explain stuff on the outer edges of my knowledge (now, if you fancy a trip over to Evolution/creation... ), at least without ABHoT to hand (IOW, can’t remember, cos I didn’t follow it all that well when I read it, years ago ). If this helps, here’s a bit of it I have used before for my pet creationist:

“When we apply Feynman’s sum over histories to Einstein’s view of gravity...” [using imaginary numbers to allow the calculations, and taking the curved space-times to be Euclidean] “...time is imaginary and indistinguishable from directions in space”. This means that his proposed “quantum theory of gravity has opened up a new possibility, in which there would be no boundary to space-time and so there would be no need to specify the behavior [sic] at the boundary”. (Pages 135-6)

I suggest you get hold of a copy of Hawking’s book and find out for yourself! A search at the wonderful <a href="http://www.abebooks.com" target="_blank">www.abebooks.com</a> shows that you can pick up a secondhand copy for US $2 or less (50c was the lowest), but the postage to Singapore might be a bit steep

Alternatively, try a browse through <a href="http://www.hawking.org.uk/text/public/bot.html" target="_blank">these public lectures of his</a>.

Hope that helps.

Oolon

Answerer

Well thanks Oolon, anyway, just curious have you meet Hawkings before since you are from England?

Oolon Colluphid

Sorry, nope! There are 56 million people here you know...

Also, I haven’t gone out of my way to see him, even if there have been opportunities. Cosmology goes a little too over my head, cos it’s a bit too, well, weird. I can parrot that imaginary time is sort of at right angles to real time, but how, without the maths, does anyone understand it? I have however met and corresponded with Richard Dawkins...

Cheers, Oolon

Francois Tremblay

You lucky bastard.