If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #89
Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145
There is a simple thought experiment that always bothered me - how much sense does it make to discuss 'passable wormholes', as they are usually imagined?
If an object is sent through a wormhole, and a laser beam at same time near the wormhole, the object arrives at destination before the beam.
What I can't understand is, why wouldn't this object, even if not locally surpassing c, travel into past for an external observer?
I'm trying to understand the ''spirit'' of relativity of simultaneity here.
I can't easily imagine how could a causality paradox arise here, since it's hard to use logic on this things.
I know there are paradoxes involving accelerated wormholes but I'd like to solve this first. :p
Registered Member #27
Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058
With stationary wormholes of this kind you only get "optical illusion" time travel. If you have two clocks and wormhole them around and then compare them side by they will still show the same time even if they appeared to show different times a moment ago.
If you take one wormhole and zip it around at realtivistic speeds (alternatively dangle it above a black hole) for some time it will age slower than the other wormhole and they will get out of sync timewise. Then you can pass a clock between them and make the clocks out of sync.
I would not call this theory but weak hypothesis. We are talking about oversimplified and incomplete equations that give certain solutions of very questionable validity.
Registered Member #89
Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145
With stationary wormholes of this kind you only get "optical illusion" time travel. If you have two clocks and wormhole them around and then compare them side by they will still show the same time even if they appeared to show different times a moment ago.
So there's nothing really preventing me from appearing at destination sooner than light beam sent off near the wormhole at same time...?
If you take one wormhole and zip it around at realtivistic speeds (alternatively dangle it above a black hole) for some time it will age slower than the other wormhole and they will get out of sync timewise. Then you can pass a clock between them and make the clocks out of sync.
Yes, but how does this break causality? If one throat is time dilated, I still can't see why would object exit before entering.
Registered Member #27
Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058
So there's nothing really preventing me from appearing at destination sooner than light beam sent off near the wormhole at same time...?
There are several theoretical ways according to general relativity to arrive at a destination before a light beam taking a straight line. There is nothing in the math that forbids it, but the implications makes everything quite messy and the math gives the impression of being incomplete.
If one throat is time dilated, I still can't see why would object exit before entering.
If we go to the extreme and move one wormhole around at the speed of light then it will not age and you can always travel back to the creation of the wormholes by passing from one to the other. I can't see how you can get back to the future you came from again because how would the wormhole know what time you came from? If lots of people jump in at different times and appear at the same time in the past, then back would be a different time for each person.
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
wormholes, causality.
