Kurt Gurdal's time traveling scheme

[gib65]

I heard of a theory about how to travel back in time. My sources say it was proposed by Kurt Gurdal in 1948. You would need to spin a disc half the size of the solar system at near the speed of light, then take a spaceship and travel along its transverse axis. If you do this, supposedly you would travel back in time. Is this real science or pseudoscience?

[ecoli]

Who's Kurt Gurdal?

[gib65]

He's the guy who proposed this method to travel back in time in 1948.

[swansont]

Gödel, or Goedel, perhaps?

[gib65]

Yes, it's Godel (thank you). With the correct spelling, I was able to do a search and I found this quote:

 

"In the late 1940s he demonstrated the existence of paradoxical solutions to Albert Einstein's field equations in general relativity. These "rotating universes" would allow time travel and caused Einstein to have doubts about his own theory."

 

from this site (near the middle of the page).

 

So how exactly do his "rotating universes" entail time travel? Is it indeed time travel into the past? I understand the basic principles behind SR and GR, so is it explainable in these terms (please, no math, just concepts)?

[5614]

http://www.theage.com.au/news/science/time-tourists/2004/03/21/1079823223001.html?oneclick=true

Scientists are still arguing about time travel' date=' even if it was first given serious lab cred decades ago — in 1949 — by the great logician Kurt Godel while considering a rotating universe. Godel used the general theory of relativity (which tells you how to change the shape of a blend of space and time called spacetime and is the descendant of Einstein’s special theory) to create temporal loops: the river of time can contain whirlpools and eddy currents.

 

Several later theorists also used general relativity this way to make short cuts through spacetime that allow journeys into the past.

 

Even the great Einstein, while working with Nathan Rosen in Princeton in the 1930s, discovered that his equations could bridge time, without realising it. Such an "Einstein-Rosen bridge" — which we now call a wormhole — could lead to the possibility of movement through cosmic distances. But he did not seem to appreciate that by moving one end of the bridge, a wormhole might just as well link two different times as two different places.

 

However, the wormhole itself does not exist for long. In effect, gravity quickly slams this portal shut.[/quote']

 

I haven't heard of this and am interested, will look around for more info when I get more time.