RIP Philo

I told myself this in 2050 -  You Can't Travel Back in Time, Scientists Say

Space-time, Liu explains, can be thought of as a piece of spandex with four dimensions. “When something that has mass—you and I, an object, a planet, or any star—sits in that piece of four-dimensional spandex, it causes it to create a dimple,” he said. “That dimple is a manifestation of space-time bending to accommodate this mass.”

The bending of space-time causes objects to move on a curved path and that curvature of space is what we know as gravity.

Mathematically one can go backwards or forwards in the three spatial dimensions. But time doesn’t share this multi-directional freedom.

“In this four-dimensional space-time, you’re only able to move forward in time,” Liu told LiveScience.

A little explanation would be nice.
Permalink son of parnas 
March 8th, 2007 10:29am
Subatomic particles move back through time, though. Yes, they have very little mass, but it's still some.
Permalink Send private email Flasher T 
March 8th, 2007 10:31am
Yes, but they don't have the brains to get all confused about it.
Permalink Practical Geezer 
March 8th, 2007 10:48am
particle == information
Permalink Send private email xampl 
March 8th, 2007 11:18am
This is just a restatement that there's a big -1 in the Minkowski matrix for the time slot.

s^2 = x^2 + y^2 + x^2 - c^2*t^2

Pythagoras would be so proud.
Permalink Send private email strawberry snowflake 
March 8th, 2007 11:24am
error ...

s^2 = x^2 + y^2 + z^2 - c^2*t^2
Permalink Send private email strawberry snowflake 
March 8th, 2007 11:24am
"Rotating cylinders and the possibility of global causality violation"

Frank J. Tipler
Department of Physics and Astronomy, University of Maryland, College Park, Maryland 20742

Phys. Rev. D 9, 2203 - 2206 (1974)
[Issue 8 – April 1974]

In 1936 van Stockum solved the Einstein equations Gμν=-8πTμν for the gravitational field of a rapidly rotating infinite cylinder. It is shown that such a field violates causality, in the sense that it allows a closed timelike line to connect any two events in spacetime. This suggests that a finite rotating cylinder would also act as a time machine.

a) build an infinitely long cylinder
b) spin it really fast
c) get in a spaceship and fly around it
d) depending on whether you go around in the direction the cylinder is spinning or against it, you go forward or back in time
e) profit!
Permalink Send private email Ward 
March 8th, 2007 12:16pm
Stuff like that is a good sign that the formulas are still incomplete.
Permalink Send private email xampl 
March 8th, 2007 1:16pm
So that's how Superman did it.
Permalink Send private email Aaron F Stanton 
March 8th, 2007 1:32pm
Superman had an infinitely long cylinder?
Permalink Send private email strawberry snowflake 
March 8th, 2007 1:41pm
Bow chicka wow wow.

So how come Superman never dumped that bitch Lois Lane for being so fucking shallow?  She was totally in love with Superman, who she didn't even know, but Clark Kent managed to escape her interest for years and years.

Lois was a cunt.
Permalink Send private email muppet 
March 8th, 2007 1:51pm
I think I can do it.

I just untarred some files and tar told me that the files were from the future.

Then I used ping and it told me that time was going backwards.