You can do better than that. 
Time is related to energy, in that if you posit the existence of negative energy, it’s properties amount to antitime:[ul][]Negative energy is required in all (most?) known proposals for FTL travel, which invariably involves the potential for travel into the past.[]Given a limitless source of negative energy, you could unmake black holes, and reverse entropy.Negative energy =negative mass =negative gravity, which would warp spacetime in the opposite manner positive mass/energy does, which would yield a negative value for time in the spacetime equation.[/ul]
[QUOTE=Lumpy]
Time is related to energy, in that if you posit the existence of negative energy, it’s properties amount to antitime:[ul][li]Negative energy is required in all (most?) known proposals for FTL travel, which invariably involves the potential for travel into the past.[]Given a limitless source of negative energy, you could unmake black holes, and reverse entropy.[]Negative energy =negative mass =negative gravity, which would warp spacetime in the opposite manner positive mass/energy does, which would yield a negative value for time in the spacetime equation.[/ul][/li][/QUOTE]
[NO GOD EQUATES
SIMULTANEOUS
4 DAY CREATION,
in 1 Earth rotation.
Cubic Creation of 4 corner
separate simultaneous 24
hour Days within 1 Earth
rotation - transcends and
contradicts the 1 Day
rotation/1 God Creation
of Christianity - and all
ONEism / Singularity
religions - proving them
to constitute Evil on Earth
for the parallel Opposites.
Hey - got a death threat
from Temporal Phoenix
last night, saying that the
big ole boys that make the
world go round, are going
to wipe me off the Earth.
They can’t allow the Time
Cube Principle to continue.
Opposites Create, not God,
who equates queer creator
and masturbation creation
of Evil Oneness Educators.
Oneism equates to evil lie,
and Death for Opposites
of Hemispheres and Sexes.](http://www.timecube.com/)
Stranger
But seriously …
There is no way out of a black hole because all directions are leading in. On the other hand, you can’t get into a black hole becuase time stops when you get there.
Time and … er postion … er movement reverse roles at the maximim compactness of matter so that there is only one direction and time does … what? Give rise to more options?
I have seen this problem repeatedly lately and was left on the edge of my seat without an answer. The way the Hawking show put it was this: The guy falling into the black hole experiences time flowing as normal, but someone outside sees him die a gravity-spahgetti extrusion death as he is turned into a point starting with his feet and ending with his head.
Time and gravity have some serious 'splaining to do.
OK.
Time is 12:45PM, Central Daylight, 08/11/07 at posting.
Told ya.
WHAT the h…?!?
Silence, Neophyte!
If you are not one of the SDMB Enlightened Inner Circle, with access to the Secret Forums, you are not permitted to know!
The only context in which I’ve ever seen the term “anti-time” used, aside from a certain science fiction television series with little basis in reality, is on crackpot websites which also promote the notions of Hollow Earth and Little Grey Men Abducting Our Children and so forth. The rest of the business about “negative energy…unmak[ing]black holes, and revers[ing] entropy” and so forth is technobabble worthy of a Star Trek: Voyager staff writer. And assuming that by “spacetime equation” you are refering to the Einstein field equations, it doesn’t have a single value, positive or negative, but is instead expressed as a relationship between the curvature, metric, and stress-energy tensors.
Stranger
I am not a proponant of Cubic Time or any of the other crackpot cult science you mention. If I’d known the very phrase “antitime” would provoke such ridicule, I’d have said negative time or found another way to phrase it. The “technobabble” you scorn is directly from the February 2004 Scientific American article "Negative Energy, Wormholes and Warp Drive by Lawrence H. Ford and Thomas A. Roman ". Take it up with them.
Excuse me while I go add another layer of aluminum foil to my hat. :mad:
[January 2000 (PDF)](www.zamandayolculuk.com/ cetinbal/pdfdosya/wormholesjan.pdf), actually. The article does not use the term “anti-time”. It does throw out a lot of random business about time machines and disassembling black holes, to be sure, but puts none of it on a very solid footing. Scientific American isn’t intended to be a technical journal of course, but even from a pop-science standpoint this article is rather sloppy with terminology and obviously written to appeal to the Star Trek crowd rather than educate; a good illustration of why I rarely pick up a copy of Scientific American these days and am usually mostly regretful when I do (although one a couple of months ago did have an interesting article on the learning behavior of Corvus). In any case negative energy does not equate to negative time or anti-time or anysuch, and tossing it in there doesn’t really go toward answering the question of the o.p. any more than the Metaphysics/Philosophy crowd (who apparently from Frylock’s links, can’t be bothered to get even their basic facts right) does.
Stranger
my first thought was - It’s how we keep track of the increase in entropy.
I agree that there really isn’t any other definition. At least none that I ever heard.
After posting that link, I actually read it (a backwards procedure, I guess!) and was kind of disappointed to see it is kind of sketchy (in both senses of the term).
But out of curiosity, which incorrect basics did you spot in the article? I imagine you mean the stuff contained in the “Topology of Time” section?
-FrL-
[related hijack]Where can I get my monthly or weekly physics/math/evolution/AI buzz without having to go to the professional journals themselves? Is there anything above the level of SciAm and NewScientist etc.?
-FrL-
[/hijack]
OH FOR CRYING OUT LOUD. I asked this basic question although with guidelines last week, giving a calendar day as a perimeter. How long could a calendar day be extended if a person was to board an airplane at X and fly west.
Time is relevant only to humans.
Time is a human concept.
Time elevates man to a sense of self-importance and control.
Oh boy. I can re-open my questions from the end of this thread.
Which is, basically, if change in time is defined as change in entropy, then what do we make of the possibility, anomalous as it may be, of spontaneous entropy reduction? Is the Second Law of Thermodynamics meant to be a probabilistic law or a definitional tautology?
(Mathochist, if you’re reading this… forgive me, I haven’t done my assigned reading yet.)
Where?
What would it mean to extend a calendar day?
So the lion doesn’t need to time his pounce? He can just jump whenever he pleases, right?
Yes, but what is it a concept of? Or do you mean to say it is only a concept, and has no actual referent?
Time gives me a feeling of insignificance and lack of control.
-FrL-
Didn’t see it, CrisC2005. Is all this, more or less a rehash of your OP?
In any event, I apologize.
I like Nature and Science; however, these are peer-reviewed technical journals (albeit not discipline specific ones) and the papers are written with the assumption that the reader has a basic grounding in the topic area. You’ll have to subscribe to these, though, or have access to an academic library that does; you can’t just pick these up at the newsstand, and the subscriptions are pricey compared to mass market magazines. Physical Review Letters is a good summary of the goings-on in physics, without getting into too much dry detail; again, it’s subscription only. Proceedings of the National Academy of Sciences (please no PNAS=“penis” jokes) is available for free online, although it tends to skew toward the biological sciences.
To be fair, there’s nothing wrong with Scientific American, but it is either increasingly moving toward the Popular Science/Discover crowd, or I’ve just outgrown it. I used to enjoy it quite a bit, and some of the long articles are quite good, but much of the selection now really tends toward flashy, faddish pop-science articles with little substance, like the one cited, and it seems to have undergone a “Wiredization” toward short fluffly blurbs spaced in between ads for Swiss chronograph automatiques and premium vodka. Plus, it’s all downhill since Martin Gardner stopped writing his “Mathematical Games” column (though I only caught that on back issues).
I don’t read it regularly, but the science features in National Geographic Magazine are generally pretty good. I’ve picked up New Scientist a couple of times at the barber shop, and honestly never really formed an opinion about it one way or another, so it didn’t leave much of an impression.
Stranger
Oh, I forgot: Science News offers also a good, if very brief and summary, coverage of advancing topics in various fields of science.
Stranger