Whitechapel - Chinese Physicists Prove Time Travel Impossible Sat, 25 May 2013 00:27:43 -0700 http://freakangels.com/whitechapel/ Lussumo Vanilla 1.1.4 & Feed Publisher Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303406#Comment_303406 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303406#Comment_303406 Tue, 26 Jul 2011 06:35:20 -0700 Finagle The hopes of going back in time and visiting the jurassic era escape a T-Rex and warping into the future to save the world from Skynet will never happen. Chinese physicists have just proved that time traveling is out of the realm of possibility (at least in this universe).

In a published study, Shengwang Du and his team of physicists at the Hong Kong University of Technology and Science stated that single photons can't travel faster than the speed of light.

By result, the possibilities of time traveling have been debunked in one fell swoop because it was previously believed that if a single photon could travel faster than the speed of light, it could "teleport" information to another time.


- http://dvice.com/archives/2011/07/chinese-physici.php ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303411#Comment_303411 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303411#Comment_303411 Tue, 26 Jul 2011 08:12:25 -0700 Slick Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303420#Comment_303420 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303420#Comment_303420 Tue, 26 Jul 2011 09:06:27 -0700 Beamish Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303427#Comment_303427 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303427#Comment_303427 Tue, 26 Jul 2011 10:37:33 -0700 Ben Johnson photons can't go faster than the speed of light. While it's true that we've never detected anything that moves faster than a photon, there is a theoretical particle familiar to anyone who has ever seen Star Trek, the tachyon, which is a particle that moves faster than the speed of light from its creation, and can never be slowed down to less than the speed of light.

Of course, there is no evidence that tachyons exist.

Another way to think of the speed of light is not as the "speed that photons move in a vacuum," since scientists recently were able to slow down a photon to the speed of sound, but as "the rate at which a theoretically detectable change can occur" (I say theoretically detectable because we don't have instruments accurate enough to get anywhere near the scales we're talking about). Photons, then, are just fast little buggers that change their position that quickly. So what's significant about their findings is actually that the speed of light might well be the "universal speed limit."

Anyway, yes, forget accelerating beyond light-speed. Focus on folding space instead. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303429#Comment_303429 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303429#Comment_303429 Tue, 26 Jul 2011 11:10:36 -0700 warrenellis Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303430#Comment_303430 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303430#Comment_303430 Tue, 26 Jul 2011 11:37:54 -0700 Alan Tyson Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303431#Comment_303431 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303431#Comment_303431 Tue, 26 Jul 2011 11:51:24 -0700 Oxbrow Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303434#Comment_303434 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303434#Comment_303434 Tue, 26 Jul 2011 12:59:00 -0700 Oddcult
Why is the Speed of Light the speed of light? ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303439#Comment_303439 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303439#Comment_303439 Tue, 26 Jul 2011 13:39:35 -0700 joe.distort Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303442#Comment_303442 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303442#Comment_303442 Tue, 26 Jul 2011 14:12:04 -0700 sellmeyoursoul
I don't remember my semester as a chemistry student well enough to break down e=mc^2 for you, but that's a big part. I'm sure someone will be more than happy to correct my sleep deprived, worked all day brain, but c is the universal constant, which is also the speed of light. If it wasn't that speed (in a vacuum) then the math behind pretty much all of Einsteinian physics wouldn't work. Which means that the laws of physics would literally be different. So the more sophisticated answer is "because that's how fast light goes." ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303446#Comment_303446 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303446#Comment_303446 Tue, 26 Jul 2011 14:37:53 -0700 Oddcult Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303449#Comment_303449 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303449#Comment_303449 Tue, 26 Jul 2011 14:54:39 -0700 warrenellis
Photons are massless. C, the speed of light, is the limit because a hair over C would require an infinite amount of energy to drive it. C is therefore the available energy in the universe working against the properties of vacuum. That's basically the best you can do with one massless photon.

"Why can't you just add a bit more energy and deal with a bit more mass?"

The curves involved are asymptotic. And you can't carve more mass off something classically massless.

Also consider: in a certain sense, C is also the velocity of time.

I am probably wrong about all of this. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303456#Comment_303456 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303456#Comment_303456 Tue, 26 Jul 2011 15:25:53 -0700 Oddcult
If photons didn't move, then you'd get a zero sum in the equation, sure, but as far as I'm aware they can't not move, and so therefore must have some kind of mass.

I am also probably wrong and going on a basic understanding of simple equations rather than advanced physics.

The issue I'm curious about is that photons move at the speed of light without anything close to an infinite amount of energy, because there are lots of photons and there seems to be a vast difference between the energy that's required to power a simple torch, the filament of which gives of photons at the speed of light, and all of the energy in the universe ever. That's what I can't get my head around. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303460#Comment_303460 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303460#Comment_303460 Tue, 26 Jul 2011 15:32:45 -0700 warrenellis Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303461#Comment_303461 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303461#Comment_303461 Tue, 26 Jul 2011 15:50:06 -0700 Oddcult
Vaccum is by definition, frictionless and resistance-less though, so changing that can't be done, sure, but I can't help thinking along the lines of travelators or firing guns from aircraft, or all of the simple things that add velocity to movement. Why isn't a light shone from a spacecraft travelling faster than from one at rest, as you'd have added the energy then? The light is C from both, but one is (let's say) 1/2 C. So why don't the photons from the spacecraft at 1/2C travelling at C+1/2C when the energy requirements for this are present? If we're just talking about the properties of vacuum, then this means a resistance free state, so it comes back down to propellant, surely?

There probably is a simple answer to this and I'm missing something obvious, of course. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303467#Comment_303467 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303467#Comment_303467 Tue, 26 Jul 2011 16:23:36 -0700 SilentObjector Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303487#Comment_303487 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303487#Comment_303487 Tue, 26 Jul 2011 18:40:57 -0700 BrianMowrey
If it makes me feel better, that's sciencey enough ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303491#Comment_303491 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303491#Comment_303491 Tue, 26 Jul 2011 19:01:33 -0700 scs Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303497#Comment_303497 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303497#Comment_303497 Tue, 26 Jul 2011 19:41:27 -0700 Beamish Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303510#Comment_303510 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303510#Comment_303510 Tue, 26 Jul 2011 21:36:59 -0700 Sonny
I think. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303512#Comment_303512 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303512#Comment_303512 Tue, 26 Jul 2011 21:48:37 -0700 Jon Wake
So here's the deal: Nothing can go faster than the speed of light, not even light. Imagine you're in a car going a hundred km/hr, and you throw a baseball out of the car at 50 km/h. Relative to the car, the baseball is moving at 50 km/h. Relative to the Earth, the baseball is moving at 150 km/h. It's all good here.

Now lets say that you're in the same car, and you shine a laser at a distant object. (Lets also assume a perfect vacuum for the sake of simplicity.) The laser is moving at around 300,000 km/s relative to the car. However, to an observer on the ground, the laser is moving the exact same speed, completely ignoring the additive speed of the car.

Any honest physicist will tell you they have no idea why this is true. It's been tested and tested again, so it is, but the reasons for it are a mystery, just like what mass is, or why particles sometimes behave like waves. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303519#Comment_303519 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303519#Comment_303519 Tue, 26 Jul 2011 23:04:21 -0700 SilentObjector
Signed,
PlasteredObserver ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303529#Comment_303529 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303529#Comment_303529 Wed, 27 Jul 2011 01:40:25 -0700 Ariana
Point is (I mean, besides the obvious LIGHT SHARKS -- and, really, I won't be upset if that's your takeaway here): Light is moving, or it's not light. The cause of that moving is energy, and a side-effect of that moving is mass (physicists in the room will forgive this simplification because, if you can't tell from my LIGHT SHARKS metaphor, I'm using Fake Math. I do that. Stay with me.).

So. E=mc^2: Energy equals mass times 299,792,458 metres per second squared.

Your eyes may have just glazed over a bit there. That's totally fair. Because that 299,792,458 metres per second is actually totally recursive; a metre is based on how fast light travels in 1/299,792,458 of a second. OH YES. Because we made up all the numbers.

The truth is, you can call the speed of light "Bob, the fastest shark in the world!" and as long as "Bob" means "how fast light goes in a vacuum" you're good.

So. energy equals SHARKS times "Bob (how fast light goes)" squared.

If you're allergic to math, you can go ahead and toss out that squared. I mean, really, we'll just call whatever we're left with, "but MORE" right? And we've established that Bob is entirely ridiculous and arbitrary and only exists to give us a nice constant number, so let's toss him out, too.

And we're left with ENERGY and SHARKS.

These are the two most important things in the faster-than-light discussion. Energy is really straightforward. Even if you can't wrap your brain around the math, you can get that it takes some amount of energy for a shark to move through the water. But then you say "okay, well, sharks have a max speed that's a lot slower than, say, launching a shark out of a cannon -- why don't we just do that?"

And you know what? You can. You're going to have a dead shark at the end, but you absolutely can. There are also things that can move faster than Bob. No lie -- there's plenty of things that were (or could be, probably) in one spot and then they were in another spot and the time that passed was way shorter than our arbitrary 299,792,458 metres per second**. But no information moved that quickly. Essentially, we were tossing dead sharks. When we talk about faster-than-light travel, what we're really talking about is getting LIVE sharks from point A to point B.

And sharks can only move as fast as Bob. If we shove more energy into them or fuss about with that constant, we lose the ability to carry information (real sharks go brain dead, and light no longer has wave modulation).

Faster-than-light is not an impossibility. We're pretty sure of that. If it were, then we'd call "light speed" INFINITE SPEED! Faster-than-light-with-a-payload-intact is what we're really talking about. And that remains questionable.

______________________________________________________________________________
* You know what? There's some small chance that someone is going to take this beautiful metaphor and try to ruin it by being that guy that says there are some sharks that can, in fact, hold still and get oxygen into their systems by opening and closing their mouths. You know what you are? No fun. And not invited to this party. And, anyway, even most of the mouth breathers still have to keep swimming because of their low blood pressure.

** Sort of. It's also accurate, in some cases, to say it's not moving at all, because it's in more than one place at once. Sort of. It gets ugly and math-y. We're just gonna go with what we've got. As an aside, shadows are my favorite example of this. Shadows are, in physics terms, the absence of something -- nothing. And they can move faster than light, no lie, even though you can't tell until the light catches up, moving at the slowpoke speed of Bob. But that's why I will nod but smile when folks intone "nothing can move faster than light." ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303534#Comment_303534 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303534#Comment_303534 Wed, 27 Jul 2011 02:31:29 -0700 Flabyo Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303554#Comment_303554 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303554#Comment_303554 Wed, 27 Jul 2011 05:41:42 -0700 roadscum
Roadscum's poor little head has just burst. Again. Someone get a mop and bucket please. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303588#Comment_303588 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303588#Comment_303588 Wed, 27 Jul 2011 09:45:08 -0700 Alan Tyson
Actually, could you (or anyone else who wants to pick up the torch [heh. get it? 'cuz we're talking about light?]) expand on what exactly "information" means, from a physics standpoint? ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303590#Comment_303590 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303590#Comment_303590 Wed, 27 Jul 2011 09:59:53 -0700 Ariana Ariana, where were you in high school science when I needed you?

Very likely talking my way out of homework with really good metaphors. And robots. And, one time, a robot metaphor. True story.

But, information: At the very, very, very simplest, "information" is ones and zeros. Those ones and zeros can be "A light turns on, a light turns off." They can be morse code, once it starts getting a little more complicated (duration is added in). They can be change in pitch or weight or temperature (add one, subtract one). Even transfer of mass and energy eventually can break down to those ones and zeros, when the zero is "static" and the one is "change".

The *very* fastest we can send information, right now, is turning a light on and off in a vacuum. At 299,792,458 metres per second we can flip a light on for yes, and off for no. If we can break that barrier -- if we can find something that we can observe that moves faster than that "speed of light" -- then we have the first building block for faster-than-light travel.

As it stands, the only things that can "move" faster than the speed of light can't be perceived until the light catches up. (Or are theoretical particles that we don't know how to look for, yet.) Like being blind in a thunderstorm: if you can't see the lightning flash, you need to rely on the sound of the thunder to get the information that lightning has occurred. At this point, in physics, we're theorizing that there's something like the lightning in that metaphor, something that can move faster than we are able to observe, but all we know for certain is the sound of the thunder. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303665#Comment_303665 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303665#Comment_303665 Thu, 28 Jul 2011 05:27:43 -0700 Oddcult Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303681#Comment_303681 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303681#Comment_303681 Thu, 28 Jul 2011 09:34:18 -0700 sellmeyoursoul Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303685#Comment_303685 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303685#Comment_303685 Thu, 28 Jul 2011 09:58:02 -0700 Artenshiur Short answer, no, you can't "send" classical information through quantum entanglement. I have no idea how that idea started floating around. You can "send" quantum information, but it can't be deciphered until some classical information has arrived by the conventional means. Your light cone remains your light cone.

Ariana and Warren have done an excellent job explaining why ftl is impossible as far as photons go.

But back to the original article, while the paper may be valid (I haven't read it), the conclusion that keeps being discussed is not. "Time travel is impossible" does not follow from "photons can't go ftl". Faster than light photons were a potential means. That means is gone, maybe. But the fact that I can't use a hammer to cook dinner does not mean I must eat it raw. We just need to discover fire. Or maybe not? ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303692#Comment_303692 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303692#Comment_303692 Thu, 28 Jul 2011 11:00:55 -0700 256
Why photons move at c:

Imagine a ball bearing rolling on a glass table. Because there's very little friction, if you give the ball bearing a push, it will roll for a very long time before it slows to a stop.

If there was NO friction, you could give the ball bearing a push and it would roll forever, without ever slowing down at all.

But, even without friction, the ball bearing needs a push before it will move. This is because it has mass, and mass doesn't accelerate without a force being applied to it.

Photons, however, do not have a mass. So, even without a force being applied to them, they race off at top speed.

Two really curious things:
1) That there actually IS a top speed in the universe - which we call c. Why this limit exists... we don't know yet. Call it a property of the universe.
2) That c, the constant with that value of the fastest speed possible, turns up all over the place in physics. Sometimes in things that have nothing to do with light or photons. c is really a property of the universe in general, rather than just light in particular.

Next up: Why nothing with mass can travel at c

(posting this bit now before I give up completely). ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303699#Comment_303699 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303699#Comment_303699 Thu, 28 Jul 2011 12:13:04 -0700 256 Why nothing with mass can travel at c:

The problem with accelerating a mass to c is that for objects moving at really, really high speeds, the universe works differently than it does for objects at everyday speeds.

Essentially, we find that there are a lot of things which seem linear and normal at everyday speeds, that stop being so at high speeds (when we get up to big fractions of c). This is because those equations include the Lorentz factor, gamma, the value of which depends on the speed of the mass:



Notice that gamma is very close to 1 for all the speeds you ever see in everyday life, which is why it has no effect there. But as the speed gets close to c, gamma shoots upwards. And, as speed tends to c, gamma tends to infinity.

This matters because the amount of energy you need to accelerate mass is multiplied by gamma. So to actually get to c, you would need an infinite amount of energy. Since you can't actually have an infinite amount of energy, speed = c is impossible.

Don't know if this makes any more sense than the previous shark-based explanations.

Note: If you're interested, the Lorentz factor is:
gamma = 1/ (sqrt(1-(v2/c2))). Physics is fun!

Edit: Apparently the greek character for gamma doesn't show up. Bastards. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303708#Comment_303708 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303708#Comment_303708 Thu, 28 Jul 2011 13:46:25 -0700 D.J.
I am perfectly alright with no time-travel. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303709#Comment_303709 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303709#Comment_303709 Thu, 28 Jul 2011 13:47:29 -0700 Alan Tyson
*head 'splodes* ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303769#Comment_303769 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303769#Comment_303769 Fri, 29 Jul 2011 03:48:53 -0700 Oddcult 1) That there actually IS a top speed in the universe - which we call c. Why this limit exists... we don't know yet. Call it a property of the universe.


So, okay, the answer to my first question is really 'mmmrrruummmidunno...shrug..'? Fair enough. I'll continue to find it amazing that a crappy AA battery can propel something to the speed of light, but anything more than that needs every star ever and then some and not worry about it too much then.

With regards to quantum entanglement, then if you link up lots of tangly things, and then they're either present in certain positions or not present, once they're unentangled, you've got the basis of a binary communications system? Instead of changing them, you destroy them in pattern? Is that feasible?

It would pretty much be complicated ticker tape, but workable in theory, if not yet in practice, maybe? ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303775#Comment_303775 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303775#Comment_303775 Fri, 29 Jul 2011 04:19:55 -0700 Purple Wyrm
E=mc^2. You plug the numbers into it, and get a result, BUT, depending on the units you use (km per hour vs cm per hour for instance), you'd get a different result out of it.

Now I can buy the fact that you use a standard set of units, and I can see how that works in that the units are defined in terms of each other. Units of Energy for instance are defined as the amount needed to move a standard Mass over a standard Distance. What I can't get my head around is where Time comes in. C is a speed, and I can see how the units for Energy and Mass are related, and how Distance plugs into them, but where does the Time necessary to define Speed come from? Or is it just there as a property of the universe?

Or am I just typing gibberish? :) ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303779#Comment_303779 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303779#Comment_303779 Fri, 29 Jul 2011 04:31:09 -0700 Slick Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303784#Comment_303784 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303784#Comment_303784 Fri, 29 Jul 2011 04:50:49 -0700 Purple Wyrm
And on actually doing some goddamn research I realise that a Joule can be based on Newtons and Metres (which I knew) or Amperes, Ohms and Seconds. Now I get it! :) ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303805#Comment_303805 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303805#Comment_303805 Fri, 29 Jul 2011 07:14:39 -0700 Ben Johnson China didn't actually ban time travel stories. That was a mistranslation. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303806#Comment_303806 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303806#Comment_303806 Fri, 29 Jul 2011 07:17:09 -0700 Finagle Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303829#Comment_303829 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303829#Comment_303829 Fri, 29 Jul 2011 09:57:16 -0700 256
I think you need to move away from the idea that photons are being "propelled" by their source, be it the Sun or a crappy torch. Moving at c is just a property that photons have, as soon as they're released. The amount of energy the photons carry doesn't have any relevance to their speed.

To the second point... Quantum stuff isn't my strong point, so I think I'm going to stay out of that one. Could probably do more harm than good. I will say, though, that quantum theory is really not a place to apply common sense reasoning, and I think trying to do so is where we run into a lot of trouble.

@Purple Wyrm: If you wanted the full rundown -

e = mc2

joule = kilogram x meter-per-second2

kg x m2 / s2 = kg x (m2 / s2)

... which all works out nicely. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303833#Comment_303833 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303833#Comment_303833 Fri, 29 Jul 2011 10:10:01 -0700 Artenshiur Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303837#Comment_303837 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303837#Comment_303837 Fri, 29 Jul 2011 10:40:47 -0700 ZJVavrek
256, thank you for the Lorentz graph. I'd always thought of it as "Well, it does take more force to change velocity from 10m/s to 20m/s than it does from 20m/s to 30m/s, just not much more", but hadn't seen the actual graph.

Ariana, thank you for sharks. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303883#Comment_303883 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=303883#Comment_303883 Fri, 29 Jul 2011 17:47:26 -0700 Purple Wyrm Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304231#Comment_304231 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304231#Comment_304231 Tue, 02 Aug 2011 05:13:56 -0700 Oddcult Quantum Ignorance rules. Heh. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304233#Comment_304233 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304233#Comment_304233 Tue, 02 Aug 2011 05:48:23 -0700 johnjones
2) That c, the constant with that value of the fastest speed possible, turns up all over the place in physics. Sometimes in things that have nothing to do with light or photons. c is really a property of the universe in general, rather than just light in particular.


What about the idea of tachyons or other "ftl" particles? I understand that nothing can accelerate to c, but are there potential particles who, by their very nature, start out going at c or beyond, that they don't start from a lower speed and go to ftl but begin already going ftl? ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304235#Comment_304235 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304235#Comment_304235 Tue, 02 Aug 2011 06:37:33 -0700 Oddcult does exist. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304282#Comment_304282 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304282#Comment_304282 Tue, 02 Aug 2011 14:37:01 -0700 taphead
(For reals!) ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304285#Comment_304285 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304285#Comment_304285 Tue, 02 Aug 2011 15:00:01 -0700 256
I suppose the idea is that there's some sort of symmetry to having a can't-go-slower-than-light particle to match our can't-go-faster-than-light particles. But it doesn't make much sense beyond that.

[And, for that matter, if normal particles can move at speeds from 0 up to c, then tachyons should be able to move at speeds from c, up to.. or down to ... ???]

It seems sort of possible that the whole idea formed out of a cloud of pot smoke sometime in the '70s.

Without wanting to muddy the waters, there are some effects that "travel" FTL. The classic example is shining a spotlight at a distant wall - by turning the spotlight quickly, you could make the projected spot move along the wall faster than the speed of light. The trick here is that no matter or energy is actually moving FTL. There are other examples, some complex and pretty exotic, but there's never been anything yet that demonstrates a violation of The Law. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304286#Comment_304286 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304286#Comment_304286 Tue, 02 Aug 2011 15:09:26 -0700 Ariana Just read Ariana's SCIENCE. I think she should have a weekly science thread.Alternatively: Bob, the Fastest Shark in the World, weekly. Week one in which Bob is threatened by his shadow, because it's always one step ahead of him. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304341#Comment_304341 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304341#Comment_304341 Tue, 02 Aug 2011 22:09:41 -0700 Alan Tyson
Also, is it just me, or has it become apparent that, between Sharkpony, Space Shark, Bob the Shark, and Shark Bukkake, that Sharks have become the unofficial Whitechapel mascot?

Also consider that Si Spurrier, not-so-secretly in love with the mysterious, predatory sea, will soon be taking over as Head Batman.

Coincidence? I think not.

Anyway, SCIENCE QUESTION: So, if c is the speed of light in a vacuum, presumably then there are other speeds of light in different environments - what, in non-vacuums, slows light down (besides brick walls, I mean)?

EDIT: For a second, I thought I'd figured out my own question, thinking the answer was "gravity." But, gravity only affects things with mass, and photons ain't got it... unless, for the purposes of gravity, they do...

Help. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304350#Comment_304350 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304350#Comment_304350 Wed, 03 Aug 2011 00:04:07 -0700 Ben Klumaster what, in non-vacuums, slows light down
Anything that light can pass through. Moving between substances of different density causes a change in speed, which is what causes refraction.
Gravity does bend light, but yeah, I don't properly get it. Spacetime curvature?

Edit: Internet says yes, you can express gravity as a curvature of spacetime with the light traveling in a straight line through it.
Edit2: I'm learning so much today. Apparently light changing speed is due to absorption and re-emission, rather than the photons moving at a different speed. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304379#Comment_304379 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304379#Comment_304379 Wed, 03 Aug 2011 06:21:53 -0700 Rick Griffin You know, I really don't know where the "tachyon" thing comes from.

It began as a thought experiment and is used just as a mathematical formalism to balance equations. Since relativity theory renders their existence impossible they are in the end done away with via tachyon condensation AKA you replace these parts of the equation with math that works in real life.

Reading the article posted by the op I can just say: Agh, sensationalist pop-science journalism at its best.

Of course photons don't travel faster than light, Einstein proved that with doing the math a century back. Later, other predictions of his theory were experimentally verified, verifying the rest by extension.

The reason the work of the Chinese scientists is noteworthy and thus appears in such a prestigious journal like the Physical Review Letters is because the measurement of individual photons is fiendishly difficult from a technical point of view.

They researched the nature of so called "optical precursors", i.e. photons that travel like the wind that moves ahead of a speeding train "before" other photons. This is called anomalous dispersion and causes the photons, which are both particle and wave, to exhibit a phase velocity (the rate at which the phase of the wave propagates in space) that exceeds the speed of light in a given medium. This doesn't mean there's any true FTL information or energy transfer happening, though.

Turns out, photons and optical precursor photons don't actually move faster than light, which was pretty much what everyone expected to happen.

Time travel via something that travels at superluminal speeds is impossible anyway, so no surprise here at all. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304387#Comment_304387 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304387#Comment_304387 Wed, 03 Aug 2011 07:59:24 -0700 TheEndsOfInvention
So how about photons? It being a particle and a wave sounds like uber-fudging on the scale of inventing tachyons.
Isn't it a third thing that hasn't been invented yet and is just called 'a particle and a wave' for now?

(Disclaimer: I have two B's in Science GCSE and no fucking idea what I'm talking about) ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304413#Comment_304413 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304413#Comment_304413 Wed, 03 Aug 2011 11:12:49 -0700 Oddcult Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304415#Comment_304415 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304415#Comment_304415 Wed, 03 Aug 2011 11:22:39 -0700 warrenellis Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304422#Comment_304422 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304422#Comment_304422 Wed, 03 Aug 2011 12:07:53 -0700 Oddcult
I remember the slits and torch experiment... ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304424#Comment_304424 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304424#Comment_304424 Wed, 03 Aug 2011 12:53:30 -0700 TheEndsOfInvention
Ohshit. It's "shark" isn't it? ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304494#Comment_304494 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304494#Comment_304494 Thu, 04 Aug 2011 01:12:08 -0700 sneak046 Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304533#Comment_304533 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=304533#Comment_304533 Thu, 04 Aug 2011 07:53:00 -0700 John Skylar
-There needs to be a foundation which explains what E=mc^2 means to EVERY CHILD. It has everything to do with converting matter to energy and very little to do with the speed of light.

-Ariana should be the President of this foundation.

-Connie Willis is still who I go to for sensible constructions of time travel.

-BAD Science press. NO. No.


And finally, I'm so sorry for doing this, but Artenshiur, doesn't that mean you could, say, force entanglement between two molecule-scale telegraphs, and then extrapolate information about telegraph one from telegraph two? "Pressing" the telegraph would place constraints on what its constituent particles could do (e.g., bound its wavefunction) and that would be "communicated" via entanglement to telegraph two, a receiving telegraph. Detectors could then read effects on the constraint and extrapolate the local conditions of telegraph one, communicating data via a nonclassical method. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305420#Comment_305420 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305420#Comment_305420 Tue, 09 Aug 2011 08:23:29 -0700 jonah
This would effectively let you time travel within your lifetime. Combined with life extension techniques you could theoretically experience all of the rest of time, until the heat death of the universe. I imagine a lot of people will choose to stay in that one perfect moment of their life forever, but with an infinite amount of time to think maybe someone will even come up with a way to survive that.

I have to say that hollywood style time travel seems completely irresponsible and I wouldn't trust anyone that was willing to do it. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305433#Comment_305433 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305433#Comment_305433 Tue, 09 Aug 2011 09:42:05 -0700 Oddcult Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305457#Comment_305457 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305457#Comment_305457 Tue, 09 Aug 2011 12:34:42 -0700 Flabyo Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305475#Comment_305475 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305475#Comment_305475 Tue, 09 Aug 2011 14:05:34 -0700 sellmeyoursoul Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305496#Comment_305496 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305496#Comment_305496 Tue, 09 Aug 2011 16:17:05 -0700 Artenshiur Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305533#Comment_305533 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305533#Comment_305533 Tue, 09 Aug 2011 22:51:18 -0700 John Skylar Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305559#Comment_305559 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305559#Comment_305559 Wed, 10 Aug 2011 04:54:48 -0700 256 Didn't Einstein theorize that time isn't linear, but that our perceptions shape it that way?
Not as far as I know. In fact, it's important to Einsteinian relativity that we see the universe as 4D spacetime, not just 3D space. Time being a dimension seems contrary to it being a perceptual artefact.

Don't know where this idea of time being subjective comes from, but people (outside the sciences) seem to bring it up quite a lot. I guess there is the fact that sometimes it feels as if time is moving faster or slower, but there's a really big leap to saying that time itself is imaginary. When I discover that something was bigger than I thought it seems reasonable that my perception was wrong and not that, I dunno, width is imaginary. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305562#Comment_305562 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305562#Comment_305562 Wed, 10 Aug 2011 05:01:18 -0700 Flabyo
Sensory perception as a whole is a fun one to experiement with, it's very easy to proove for example that everyone has a unique pattern of audio frequencies that they can't hear. Which means that what I sound like to myself isn't what I sound like to anyone else at all. This extrapolates out through sight (colour blindness, for example) and across all the other human senses (phantom limb syndrome, synaesthesia and so on...)

Our ability to perceive anything at all is very personal and unique, and changes during the course of our lives.

In terms of raw science, a second is a second and pretty much immutable. It's just that what feels like a second can vary to us. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305563#Comment_305563 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305563#Comment_305563 Wed, 10 Aug 2011 05:07:51 -0700 256
You can verify this experimentally on Earth, if you happen to have two atomic clocks. Synchronise them at sea level, then take one to the top of a mountain (further away from the mass of the Earth's core). Leave it there for a few weeks, then bring it down. The clock that stayed at home will be a teeny tiny bit behind the clock that went on holiday.

Of course, you can't perceive that time runs slower closer to huge masses because everything runs slower including your brain and your perceptions.

And, interestingly, the two places (that I can think of) where we see time being distorted, we also see spatial dimensions being distorted: Lorentz contraction when moving at relativistic speeds, and gravity - the effect of mass on space. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305594#Comment_305594 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305594#Comment_305594 Wed, 10 Aug 2011 08:41:19 -0700 Artenshiur found it (and felt stupid, because it is the no-communication theorem) and it doesn't fully disallow communication. But I find it unlikely because superluminal communication necessarily leads to causality paradox. It remains an open question. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305599#Comment_305599 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305599#Comment_305599 Wed, 10 Aug 2011 09:22:05 -0700 BrianMowrey Didn't Einstein theorize that time isn't linear, but that our perceptions shape it that way?
Were you maybe thinking of Kurt Vonnegut.. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305603#Comment_305603 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305603#Comment_305603 Wed, 10 Aug 2011 09:29:40 -0700 Alan Tyson Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305634#Comment_305634 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305634#Comment_305634 Wed, 10 Aug 2011 13:48:05 -0700 Ariana during a crisis" when they talk about being able to see things moving in crystal-clear slow motion -- but that's not how our brains work. All we ever know is how well we can remember what happened in a crisis.

Small distinction: all the difference.

At any normal time, our brains are processing a shedload of information. Right this very second, you are taking in sounds you're not even bothering to listen to, you're aware of the light in the room, but another part of your brain is actually measuring the levels of light and calculating approximate time. There's an entire server-room full of brain power monitoring biological functions. A part of your brain is reading the words I've typed here, while another part matches the individual words to previous memories. You're smelling things, feeling *everything* including the clothes (or lack of) on your body. If I draw attention to it, you'll notice yourself breathing, or blinking.

At any normal time, you process every little bit of that and *so* much more... and promptly forget it from one second to the next. I mean, come on -- try to imagine remembering every breath you've ever taken in your entire life. Right. Most moments in your life get a twitter status update: "Stuff happened, time passed."

In times of crisis, you process (very likely) the *exact same things*. It's not like your brain swells (except, I suppose, in situations where the crisis *is* your brain swelling) to give you more processing room. What *happens* is that, after the fact, you *remember* more of it because instead of filing everything that happened as "natural as breathing: easily forgotten" your brain assigns emotional impact to the events. Just like you can remember falling in love, or happy childhood events, or the scene of a movie when you got something in your eye, you can remember more of the events during a crisis because your brain files it as "this mattered more than breathing: we were *feeling* so more than usual." Those *big* moments in your life: fear, love, pain, focus -- they get an extended liveblog update. When you look *back* you can remember more than you usually do -- so you think you were seeing more, or time was slower.

In reality, everything was pretty much exactly the same, your heart just flagged the moment as more memorable. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305635#Comment_305635 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305635#Comment_305635 Wed, 10 Aug 2011 14:13:51 -0700 BrianMowrey
I always ride my bike on the street, because sidewalks get you in trouble. But as I had crossed a street earlier than I meant to, I was heading two blocks on the sidewalk right next to the incoming traffic of Burnet Rd this one time. My bike is a road bike. I was going fast because there was good sidewalk ahead. When I was crossing a side street and saw that the next sidewalk was curbed with no ramp, I was in a shit ton of trouble. Braking takes ten seconds, I had one.

Point being, it's not just that I came to the decision to hop-and-bale on the grass by the sidewalk instantly, sparing my precious wheels, but that I remember waiting for the curb to come after I made that decision, and thinking how weird it is that I'm waiting, because again, this is only a one second window between when I saw the curb and would have hit it.

It's only anecdotal, and we all have false memories, but given how much people tend to be capable of in instant crises, it seems to point to something.

Typed on mobile ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305636#Comment_305636 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305636#Comment_305636 Wed, 10 Aug 2011 14:38:28 -0700 Ariana
If you're not dead at this point, having run into the road and in front of an oncoming car, you should have a better idea of the repetitive tasks you've done enough times that your brain can run them without *telling* you about them. At incredible speeds. Supercomputer speeds. All the time.

Jumping on the grass in a second is, really, not that big a deal on top of every other thing you process ever millisecond you're on a bike. What you remember, very likely is that it took a moment for you to consciously, actively think about what you were doing. Just like breathing, pedaling, balancing, seeing cars, all the other things you do all the time and your brain doesn't mark as memorable. The only reason you *do* remember is because of the emotional impact of the moment -- slightly higher than the calm moments beforehand.

How do we (pretty sure) know this? We stuck digital timers on people's wrists, going *just* faster than they could perceive even when they were focusing. The numbers were speeding by at a blur, just like the blades of a ceiling fan, even a little faster so they couldn't catch the numbers even by blinking or shaking their heads. And then we dropped those people from a very high place to make them panic. And while they swear that time went so much slower than usual, they *swear* they had more time to make decisions about how to relax or tense their bodies, they *swear* they could see every second of the ground rushing up to meet them -- they still couldn't see the numbers on those timers. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305653#Comment_305653 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305653#Comment_305653 Wed, 10 Aug 2011 16:57:32 -0700 Flabyo
I'm a computer programmer, never been taught proper touch typing in my life, but I can type a post like this 6 pints down because the connection between what I want to say, and typing it out, is at a level where I can do it faster than I can actually speak.

I enjoy freaking out my folks by 'air typing' stuff, because I'm past the point where I have to think about where to place my fingers.

But I can't drive. Never taken a lesson. And sitting in a car being driven somewhere by friends scares the shit out of me because there are so many things going on there that they simply don't even need to think about anymore. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305660#Comment_305660 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305660#Comment_305660 Wed, 10 Aug 2011 17:43:53 -0700 BrianMowrey Jumping on the grass in a second is, really, not that big a deal on top of every other thing you process ever millisecond you're on a bike.
Oh.

No, I don't do stunts or bale on my bike very often. Usually if I fall it'll be more of a horrible helpless bumbling slide. The curb-bale was a pretty elaborately novel, in that I had to pull up, turn sideways so body goes left, but keep bike moving with me instead of kicking it right, off the sidewalk and under some SUV's tires, meanwhile keep the left arm from getting broken under the sideways me and bike when landing.

I just don't think everything is down to memory. If you look at time perception as an issue of memory, then it looks like memory is behind all of time perception, but it seems that there are at least one or two other things that lead to real quicker thinking going on. Also, the points just made about idle brain activity seem to be blending conscious and unconscious processes a lot. Unconscious processes don't usually add load to our mid or fore-brains, of course -- so I think it's not something that can be portrayed as like passing through the same processor and being forgotten. The hind-brain is handling breathing and heartbeat for us (pons (brainstem)) and probably does the work of typing-without-aiming (cerebellum (guy in the back)) -- that's not really a memory awareness issue I think.

Speaking of the good old cerebellum, that guy is a lot heavier by cell-count (almost 3/4 of our brain's neurons are crammed in there) and obviously a lot faster than our conscious brain (the cerebellum is the supercomputer that keeps me balanced on my bike in habitual scenarios). For unhabitual scenarios, the moment where the car is heading straight for us and we say "that's not right", in that one second of crisis maybe our brain's decision center becomes more blended. When we come up with instinctual physical responses and execute them in time, we are letting our muscle memory give the green light, rather than our verbal "i should do this movement" memory. Maybe that's where the big perceptive difference in thinking speed comes from. We are living for a small second in the faster part of our brain.

On the other hand, that watch test was pretty devious, and convincing.

(PS Flabyo, learning to drive doesn't take as much practice as learning to type without aiming. Required muscle-learning for driving is like 0, you're just sitting and pushing your arms around. The learning curve is all just visual memory, which the brain is very good at as I understand it: it soaks in all the situations and the relevance of every smallest detail when you are starting out, and within three months you can tell at a glance what is going on, really.) ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305663#Comment_305663 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305663#Comment_305663 Wed, 10 Aug 2011 18:11:41 -0700 Ariana If you look at time perception as an issue of memory, then it looks like memory is behind all of time perception. This is precisely several theories of time perception. To get *incredibly* pedantic, there's not a thing you've ever seen in your entire life that wasn't over a microsecond before the image got from your eye to your brain. To get a little less, but still fairly, pedantic, you need to remember the words at the beginning of this sentence to understand what it said by the time you get to the period. To point: a second is an *awful* lot of time -- 60 bpm is slooooow -- but in order to realize a second of time has *passed* humans need to remember that they started counting a second ago.

(As for mixing processes, well, it's fair to call me on that. My point was more to make you aware of what your squishy head organ does all the time. Smarter folks than me still don't know what all the bits do, anyway. On the other hand, I launched a shark out of a cannon to explain photons, so it's not like you didn't go into my explanation knowing that I mix my metaphors a bit. FOR SCIENCE.) ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305668#Comment_305668 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305668#Comment_305668 Wed, 10 Aug 2011 18:31:10 -0700 Artenshiur d' test for numbers flashing quickly on a small screen, just to the point where d' is within error (that is, the person can't tell what numbers are flashing). Then do it again, but just at the beginning of the test, drop the person into freefall. You will reliably get a (comparatively) high d' (that is, they will see what numbers are flashing). Can't find the paper, though. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305712#Comment_305712 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305712#Comment_305712 Thu, 11 Aug 2011 04:28:46 -0700 Finagle To point: a second is an *awful* lot of time -- 60 bpm is slooooow -- but in order to realize a second of time has *passed* humans need to remember that they started counting a second ago.

For further reading, Bergson's notion of time as duration may be relevant here. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305823#Comment_305823 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305823#Comment_305823 Thu, 11 Aug 2011 15:05:41 -0700 Jon Wake
With that in mind, remember that time you caught a baseball or dodged a flying shark. It happened on the unconscious level of reaction, but you remember the event as a series of decisions. What seems to be happening is your conscious memory is being back-dated to the appropriate time frame. In a very real sense you were not in the driver's seat for those hundredths of a second: training and instinct takes over. It's also why martial artists teach that action is better than reaction.

The kicker is, you're doing this constantly. Every waking moment is lived 1/2 second behind. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305863#Comment_305863 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305863#Comment_305863 Thu, 11 Aug 2011 20:36:21 -0700 taphead With that in mind, remember that time you caught a baseball or dodged a flying shark

Except Bob, of course. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305867#Comment_305867 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=305867#Comment_305867 Thu, 11 Aug 2011 21:14:15 -0700 BrianMowrey
What was this thread about again? ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310012#Comment_310012 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310012#Comment_310012 Thu, 22 Sep 2011 17:58:03 -0700 Oddcult
THE DUDE JUST TOTALLY SAW A SHARKTRINO GO WAAAAAAAAAAAAAAAAAAAAAAAAY FASTER THAN LIGHT!

http://www.reuters.com/article/2011/09/22/science-light-idUSL5E7KM3UU20110922

HAHAHA SUCKS TO BE YOU CHINESE SHARFIN EATING CRAPSCIENCE DUDES. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310081#Comment_310081 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310081#Comment_310081 Fri, 23 Sep 2011 13:03:17 -0700 Ninewhilenine83 Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310085#Comment_310085 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310085#Comment_310085 Fri, 23 Sep 2011 13:57:06 -0700 sellmeyoursoul confirmed to travel faster than Bob. ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310166#Comment_310166 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310166#Comment_310166 Sat, 24 Sep 2011 05:48:00 -0700 Lactamaeon
Particles found to break speed of light

Naughty 'Faster Than Light' Neutrinos a Reality?

PHANTOM of the OPERA

Faster-than-light travel discovered? Slow down, folks

Can Neutrinos be Superluminal? Ask OPERA!

Arriving Fashionably Late for the Party

What Have We Here?

Some Comments on the Faster Than Light Neutrinos

Superluminal muon-neutrinos? Don’t get your hopes up.

This Extraordinary Claim Requires Extraordinary Evidence!

Scientists Skeptical About "Faster Than Light" Particle

CERN neutrinos don’t “disprove” Einstein

Physicists explain controversial finding of faster-than-light particles


I really do hope that other theoretical physicists can actually verify the existance of superluminal muon-neutrinos.

I want to someday finally see the dinosaurs that built the Great Pyramids.


Tachyons ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310169#Comment_310169 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310169#Comment_310169 Sat, 24 Sep 2011 06:35:07 -0700 icelandbob
Alas this means i have a hangover. Can somebody do my thinking for me and explain a few of the implications if indeed neutrinos can travel faster than the speed of light. Will this be quantum, computing V2.0? ]]> Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310173#Comment_310173 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310173#Comment_310173 Sat, 24 Sep 2011 07:00:50 -0700 twentythoughts Chinese Physicists Prove Time Travel Impossible http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310175#Comment_310175 http://freakangels.com/whitechapel/comments.php?DiscussionID=10075&Focus=310175#Comment_310175 Sat, 24 Sep 2011 07:17:41 -0700 twentythoughts here.

Among other things: "If things could go faster than light, they wouldn't be able to see where they were going, and we'd have all these particles running into each other blindly, causing huge traffic jams. So a long time ago, all the fundamental particles in the universe got together and had a meeting where they agreed not to go faster than the speed of light, for safety. So now if you try, the other particles jump on you to slow you down, because it's not allowed." ]]>