Ronald Mallett - budding time-traveller

[Big Les]

Has anyone heard of this guy (http://en.wikipedia.org/wiki/Ronald_Mallett)? He appeared in a BBC Radio 4 interview this morning (listen here (http://www.bbc.co.uk/radio4/today/listenagain/)for 7 days) and claims to have a realistic hypothesis for backward (and presumably forward) time travel, or at least time-messaging. He says he got into black holes as a specialism as a "cover" for his time-travelling ambitions.

His University of Connecticut page is here (http://www.physics.uconn.edu/~mallett/main/main.htm).

Basically, is he talking sense, and is what he proposes a viable method for manipulating time? It sounded awfully like cobblers to me, but I'm no physicist.

ETA - should have posted a link to the criticisms on Wiki (http://en.wikipedia.org/wiki/Ronald_Mallett#Objections).

[Broes]

Well, I read a bit of "how it is supposed to work"...

The whole idea is founded on creating a gravity field with a lightbeam.
Energy (in the form of i.e. light) will bend space/time just like mass.

I see however a huge technical problem... You need a lot of mass to bend space/time significantly. The whole mass of the earth leaves a very tiny dent in the fabric of space/time. A mass as big as our sun already creates a larger curvature of space/time. The mass of a black whole will actually make space/time collapse upon itself.

Lets assume you want a noticable effect in space/time equal to that of the sun, then you need the mass of the sun but then in the form of energy!

Remember E=MC^2?... I bet thats a whole lot of zero's :)

[Big Les]

That seems to be one of the bigger problems, along with the size of the ring laser you'd need (bigger than the universe!) and the dependence upon a "CTC" phenomenon, which seem to exist only in theory (and not within the bounds of our universe).

From Olum and Everett's article (http://arxiv.org/PS_cache/gr-qc/pdf/0410/0410078v1.pdf):
there is no practical possibility of using an apparatus with a
circulating light beam to build a terrestrial time machine.

[andyandy]

Has anyone heard of this guy?

is he any relation to Timmy?