Slashdot Log In
No Time Travel, Sorry
Posted by
CmdrTaco
on Thu Feb 09, 2006 03:37 PM
from the time-to-make-new-vacation-plans dept.
from the time-to-make-new-vacation-plans dept.
MOBE2001 writes "The bad news is that time does not change. Spatial velocity is given as dx/dt. Velocity in time(dt/dt) is nonsensical. As simple as that. In other words, no time travel to the past or the future, no motion in space-time, no wormholes and no hanky-panky with your great, great grandmother. There is only the changing present, aka the NOW. The good news is that distance is an illusion and we'll be able to travel instantly from anywhere to anywhere."
This discussion has been archived.
No new comments can be posted.
The Fine Print: The following comments are owned by whoever posted them. We are not responsible for them in any way.
Of course time travel is possible! (Score:5, Funny)
Re:Of course time travel is possible! (Score:5, Funny)
Read that in Mad Magazine about 20 years ago.
Only change: Alfred E. Neuman has been elected. Twice.
Parent
Re:Of course time travel is possible! (Score:5, Funny)
Parent
Drinking to much funny-juice (Score:5, Insightful)
That's weird because I could have sworn when I went to bed last night it was yesterday and now its today.
Nevertheless...this is fun. Looking at the equation from which all his arguments flow, it seems he is only demonstrating that it doesn't make sense to talk about one's velocity through time. I would agree. If I hop in my time machine and zip off to tomorrow, it doesn't make much sense for you to ask how long it took to get there. Or if you and I both have time machines and we decided to race to 1:00 pm tomorrow it would be always be a tie. But this is a far stretch from demonstrating that it is impossible. By this same logic we could define slope as the change in x over y or s = dx/dy. Does this definition make it impossible to move along the y axis because then the slope of our movement would be dy/dy? No. but it does say that if you move along the y axis your slope will be a constant.
Re:Drinking to much funny-juice (Score:5, Insightful)
Not really. Now it's now, and that's all that is. You remember yesterday, but that is a memory occuring now. The past doesn't physically exist. Nor does the future. The only real (i.e. existing physically) part of our time perception is now.
Parent
Re:Drinking to much funny-juice (Score:5, Funny)
Dark Helmet: What the hell am I looking at? When does this happen in the movie?
Colonel Sandurz: Now. You're looking at now sir. Everything that happens now, is happening now.
Dark Helmet: What happened to then?
Colonel Sandurz: We passed then.
Dark Helmet: When?
Colonel Sandurz: Just now. We're at now, now.
Dark Helmet: Go back to then!
Colonel Sandurz: When?
Dark Helmet: Now.
Colonel Sandurz: Now?
Dark Helmet: Now!
Colonel Sandurz: I can't.
Dark Helmet: Why?
Colonel Sandurz: We missed it.
Dark Helmet: When?
Colonel Sandurz: Just now.
Dark Helmet: When will then be now?
Colonel Sandurz: Soon.
Parent
Re:Drinking to much funny-juice (Score:5, Funny)
Parent
Idiotic (Score:5, Informative)
Everyone agrees that practical time travel is at the very least exceptionally unlikely. But whether our model of the universe excludes the posibility of time travel is another matter entirely.
Note that even if our model of the universe allows for time travel it does not mean that time travel is possible. Not least because we know that our model of the universe cannot possibly be completely right. Quantum physics provides an excelent model of the universe at a large scale, relativity provides a good model at the cosmological scale. The problem is that the two models are incompatible. At leas one of our models must be wrong. Most likely they are both approximations.
The other issue that the writer does not seem to grasp is that the ability for matter to travel through time and the ability of information to travel through time are very different issues. For meaningful time travel it has to be possible for information to move backwards in time and not just matter. Otherwise what would come out the other end would be a random soup of quantum particles, not the time traveller. This is the problem with black hole time travel, the most that can come out the other side is a random soup.
The 'proof' provided by the author only demonstrates that he does not have the slightest understanding of the subject he is pontificating on. dt/dt = 0??? No, all that shows is that the dimensions of the two quantities are the same. Besides x/x = 1 in most algebras.
Parent
I'm no physicist (Score:5, Insightful)
But I time travel every day! (Score:5, Funny)
--dave
The e-mail I sent to the editor was ignored. (Score:5, Informative)
This guy is a pseudo-scientific moonbat. Please don't waste your time with the not-so-FA.
Re:The e-mail I sent to the editor was ignored. (Score:5, Informative)
http://www.rebelscience.org/Crackpots/notorious.ht
http://www.rebelscience.org/Crackpots/nasty.htm#Sp
(emphasis mine.) That alone should make it pretty clear that this isn't meant to be taken seriously. Oh yeah, and the story got the "foot" icon, too, so even Taco got it.
Parent
Or, as Ford Prefect put it... (Score:5, Funny)
Let's play: spot the Loony (Score:5, Insightful)
I'm sorry, but if you're going to put up a web page in which you call all the foremost theoretical physicsts in the world frauds, then you'd better have more evidence than some undergraduate-level pseudo-calculus and verbal smoke screens.
The t-axis or time-axis velocity component is 1, a dimensionless number. Now there are relativists who will insist that it is perfectly acceptable to express velocity in time with a dimensionless number but the rest of us with our head on our shoulders, know that it is not true. We know that a dimensionless number such as 1 has absolutely no meaning in as far as expressing velocity.
Not true. Normalized velocities are perfectly reasonable things to express. Mach 1.25 is a perfectly well-defined speed that does not violate any laws of physics, and what do you know--it's a dimensionless number.
I'm sorry, but this page is really quite embarassing for the author's parents and any physics teacher's they've ever had. This sort of reminds me of people that read things like A Brief History of Time, a perfectly excellent book, and then try to tell me that the physics is really great and it would be so much better unencumbered by the mathematics.
I don't think real time travel, a-la Dr. Who is physically possible. But the "arguments" on this web page don't really make sense, much less prove all those physics wrong.
Craig Steffen
Ph.D. Physics, Indiana Unversity, 2001
Ha! (Score:5, Funny)
HA! Take this from a person who has been in a long distance relationship... The distance is a reality, the relationship is the illusion.
We really outa get these theoretical scientist types out of a lab for a beer.
I must complain (Score:5, Funny)
All you need for time travel is... (Score:5, Funny)
Re:All you need for time travel is... (Score:5, Funny)
Parent
I desperately want to mod the story... (Score:5, Funny)
Actually, ... (Score:5, Funny)
Dan Church is Wicked Ill [danchurch.tk]
Re:Actually, ... (Score:5, Funny)
Parent
Textbook strawman arguments. (Score:5, Insightful)
That would be a lovely argument if changes in position were measured in velocity.
You describe spacial travel as the dx, not the dx/dt. It stands to reason that you would describe time travel with the dt, not as some rate of travel we haven't come up with yet.
Closet time travel (Score:5, Funny)
Now wait...and eat sometimes.
5 years later, exit the closet.
You will find that time of the world has advanced from when last remembered by 5 years.
PS. don't forget to setup an auto-pay for your residential rent/payment. Otherwise your travel may be interrupted, and you will not be able to travel the full 5 years.
Not nearly as cool as timecube... (Score:5, Interesting)
Re:Method of Travel? (Score:5, Funny)
That works well when aliens try to talk to whales.
Parent