| Pages:
1
2 |
Fulmen
International Hazard
Posts: 1716
Registered: 24-9-2005
Member Is Offline
Mood: Bored
|
|
That doesn't mean it's possible.
We already know that GR has limited range, and that there are significant lapses in our understanding of the makeup of reality. And we don't even
know what times really is. We cannot make any accurate predictions on this with our current understanding.
We're not banging rocks together here. We know how to put a man back together.
|
|
|
wg48
National Hazard
Posts: 821
Registered: 21-11-2015
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by Marvin  | wg48 is talking about a Tipler cylinder. When I went to university the first two papers I looked up first were "Possible High Tc in the La-Ba-Cu-O
system" and "Rotating cylinders and the possibility of global causality violation".
Travelling backwards in time is allowed by general relativity. This is not as weird as physics gets, the basic laws allow for negative mass, negative
energy and gravity that pushes. These solutions are routinely ignored by everyone from high school students to Nobel prize winners because they don't
correspond to anything anyone has ever observed.
|
Thanks for that. Now I have a name for it I have found lots of info on it even a wiki page https://en.m.wikipedia.org/wiki/Tipler_cylinder
In the approximately 40 years since Tipler proposed his time machine more analysis has been done. Originally the cylinder had to be infinitely long to
enable a solution to be found for the field equations. It was assumed or hoped a finite cylinder would work too.
However according to wiki Stephen Hawkings has proved that no smooth solutions exist for finite cylinders.
So sadly no Tipler time machine. But then that's only due to Hawkings a respected physicist who has got other things wrong LOL
[Edited on 5-6-2016 by wg48]
|
|
|
Marvin
National Hazard
Posts: 995
Registered: 13-10-2002
Member Is Offline
Mood: No Mood
|
|
Fulmen,
These things are allowed but they don't appear to match real observations. That was my point. However, so far all real observations about gravity
are predicted correctly by GR. It's not a T.O.E. and the accelerating universe doesn't seem to have a good explanation yet but GR just secured a
pretty major win with the direct detection of gravity waves.
I don't know what you mean by not knowing what time is. It's the fourth and final macroscopic dimension and we travel in 4D at a constant speed of c.
Warping of the four by mass/energy explains gravity. The direction we travel is of increasing entropy, non coincidentally a requirement for
computing devices like brains. Saying we don't understand time seems like not understanding width or length.
wg48,
Didn't occur to me to see if Wikipedia had anything, cool page.
This would probably produce better discussion on a physics forum, it's a bit out of place here. Perhaps it already has.
|
|
|
PHILOU Zrealone
International Hazard
Posts: 2893
Registered: 20-5-2002
Location: Brussel
Member Is Offline
Mood: Bis-diazo-dinitro-hydroquinonic
|
|
Michael Jackson with its famous "Moonwalking" was "traveling backwards/backsteps in time"   
An infine or finite long rotating axe of black hole matter spinning at speed of light would collapse on itself...because of its innerent gravity.
[Edited on 5-6-2016 by PHILOU Zrealone]
PH Z (PHILOU Zrealone)
"Physic is all what never works; Chemistry is all what stinks and explodes!"-"Life that deadly disease, sexually transmitted."(W.Allen)
|
|
|
| Pages:
1
2 |
![[*]](images/xpblue/default_icon.gif){kind=icon}
