Slashdot Mirror
How to Build a Time Machine
frank249 writes "The September issue of Scientific American has an article discussing the possibility of time travel. They say that it wouldn't be easy, but it might be possible. It could be a while until we can expand worm holes and tow them to a neutron star but didn't someone say that if it is possible it will happen. If it is impossible it will just take a little longer."
Wouldn't the best way to speed up things for this be to leave a post-it note stuck in the files saying "when this is finally invented, please travel back to August 24, 2002AD and provide the HOW-TO."
--
Todd
Quick lesson in physics for those that don't want to read the article...
Time travel. Possible? Yes. It happens relativly speaking every day.
When you get onto an airplane you slow down in time. To say this simply. The faster you go, the slower time moves around you. This was confirmed back in the 1970's using atomic clocks. Although this isn't exactly time travel it's called time dilation which is a product of the general theory of relativity.
A quick little reference for those not familar with Relativity is a set of lecture notes from a basic astronomy class in U of Oregon.
For a little more in depth reading I'd look into buying The Large Scale Structure of Space-Time by Stephen W. Hawking. Or for those that are sadistic you can read Quantum Field Theory in Curved Spacetime and Black Hole Thermodynamics. That is a collection of lectures from the University of Chicago. Although good in a sense of understanding relativity it kinda takes a tagent into the debate about light being a particle or a wave argument.
Of course, this induces the potential for paradox, causing great cosmological and philosophical consternation. I don't know what will happen if/when someone goes backwards through time, but here's some ideas:
- The universe forks in two when a paradox is induced.
- The universe forks in two at the instant the traveller enters history (because at a micro-level, paradox is induced as soon as they appear).
- Paradox induces a cascading feedback loop of self-modifying universes (each inducing a time-traveller who goes back and causes another chage) until the sequence halts with a universe in which time travel is not developed. My bet is that if time-travel is possible, then this is what has happened, because there is no evidence of time travel.
Forward time travel is of course possible right now, requiring only some patienceCrispin
----
Crispin Cowan, Ph.D.
Chief Scientist, WireX Communications, Inc.
Immunix: Security Hardened Linux Distribution
Available for purchase
Wear weird clothes (not weird in the everyday weird people sense, but truly out of place). Walk up to someone (inventing an accent is fun) and ask them what year it is. When they say, puzzled, "2002", get a huge smile and dance a future dance away yelling "it worked, it worked!"
Fun to confuse people with.
Just as fun: Dress up like a hippie or something else interesting from the past and change everything accordingly to the past.
Crispin
----
Crispin Cowan, Ph.D.
Chief Scientist, WireX Communications, Inc. [wirex.com]
Immunix: [immunix.org] Security Hardened Linux Distribution
Available for purchase [wirex.com]
Oooo! Everyone check out the big brain on Crispin!
You're using her as bait, Master!
did i get first post?
no, but perhaps someday you can go back in time and get it.
I believe that travelling to the past would merely let us perform certain travelling at speeds faster than light.
...
.. quirks of worthy pursuit.
...
Or, put another way, the time required at maximum velocity to return to your point of origin is at least the amount of time you travelled back in time. I believe you must sacrifice time or sacrifice position.
Position may or may not be in the way we expect; I suspect it is based upon your "depth" in the gravitational field, and as such, you would travel towards or away from heavy celestial bodies, such as the sun. Travelling towards them requires velocity. By the same token, you can temporally return to the beginning of the universe if you travel far enough away from the centre of it (assuming that the gravitational "depth" continues to decrease with distance, and the exponential energy increase required to travel as such is not unreasonable)
Binary stars and other equilibrium comes to mind, but I conjecture that "free" time travel in perfect equilibrium would be impossible; your relationship with time can only be altered in respect to changes in the gravitational depth. However, they may have
So goes a theory
1. Build a time machine.
2. Go into the future to gather information about it.
3. Go back to your own time with your new knowledge.
4. ?????
5. Prophet!
Will work for bandwidth
Time travel isn't possible, except for the everyday kind that your wristwatch measures.
If time travel were possible, somebody (human, alien, whatever) from the future (perhaps billions of years into the future, or maybe just next week) would have traveled into the past already.
So, let's consider what can happen. Somebody will travel back in time to before the initial discovery in order to beat the ``original'' researcher to the punch. Now, we've got a cascade of ``inventions'' of the time machine racing backwards through time. Life and time-travel technology reach the earliest time after the Big Bang that the two are sustainable and both are prolifically spread throughout the infant universe. Clearly, that hasn't happened.
Don't think that some sort of morality would prevent this from happening, either. Time travel is an incredibly powerful weapon; consider what a knife to the throat of the infant Hitler would have done to history, and how many people would leap at the chance, consequences be damned. All it would take is one person to do so...at any time in the next many billion years.
The instant time travel becomes possible, the only possible method for self-preservation is to race to the beginning. After all, how do you know that some far-distant alien race with souls of pure evil won't do the same just out of spite?
There's a wonderful quote, and I wish I could remember who said it. ``Time is Nature's way of keeping everything from happening all at once.'' The obvious corollary is that, if you can break time, then everything will happen all at once.
Some people try to get around this in a few different ways. For one, there's the many-universes ilk: each act of time travel creates a whole new universe. In such a case, all of those universes would be on the same headlong rush to take time travel as early as possible. Besides, think of the incredible amount of energy and information needed to duplicate the universe--but I digress.
Others try to justify it by saying that it requires huge energy sources or otherwise make it hard. To this I say, ``so''? All you're talking about is a hard engineering project that'll take a lot of time. And--guess what? Even if it takes ten thousand years to build and the energy output of several stars, the payoff is worth it. Again, the alternative is to let somebody else do it...and invite certain disaster.
I take the mere fact that I'm typing this note as all the proof that I need that time travel is pure fantasy.
Cheers,
b&
All but God can prove this sentence true.
While real physics has always been about rigorous (and vigorous) lab work, the popular image of physics, and Science as a whole, has strayed from this considerably.
Gees. Not only do you insult theoretical physicists here but every other science that does not involve experimentation such as computer science and mathematics. Who are you to define what "real physics" and "real Science" is?
Witness, for example, the popular celebration of Einstein's thought experiments. The average layman is under the impression that Einstein reached his great intellectual climaxes by just sitting and thinking about things, maybe over a cup of hot chocolate. What people don't see is the hours of experimentation (real experimentation) as he tried to verify and correct the results of his thought experiments.
Einstein did some of his best work while employeed as a patent clerk [1] [2] [3]. As a patent clerk, he most likely did not have access to the laboratory equipment needed to perform experiments involving speeds close to that of light. In fact the first experimental verification of general relativity was done some years after his papers and by someone else.
So why is it like that? Are people just stupid?
Okay, you've called us all stupid. Now here's your chance to back up that claim by showing us proof of these supposed "hours of experimentation (real experimentation)" that Einstein needed to work out relativity.
Since the collapse of the Catholic Church in the times of Galileo Galilei, there has been a vacuum where religious fervor once stood. Science (or this fantastical mockery of Science) has filled that void, uncomfortably.
I don't know what country you live in, but here in the US, the Cathloic Church is a formidable force in people's lives and in public policies. It certainly has not collapsed.
Show the theorists some respect.
GMD
watch this
Here, since no one seems to be putting theories forward, here goes.
I think of time like a flashlight shining on a wall.
There is only one point shining at any one time. It may be possible to 'see' into the future, or travel there, but not backwards, namely because the Langoliers have eaten it.
It certainly is possible to travel faster than light, and will not result in time-travel. As time has shown again and again, there are no limits. Sound, Light, Warp 10, etc. So, this should tell you all one thing...
NEVER speak in infinitives. You will ALWAYS be proven wrong.
Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant