Dear Long Live Yorke

[speedz99 145]

so politically correct, then sooooo not politically correct. nice.

Thank you. I wrote "black", then realized that there are probably plenty of non-american black physicists. I figured out who he is: http://www.physics.uconn.edu/~mallett/main/main.htm

[Balloon guy 158]

Dear LLY,Which, in your educated opinion, came first, the chicken or the egg? And as a follow up, how? Thank you.

The chicken is just the process the egg uses to reproduce itself

[KramitDaToad 0]

Using relativity doesn't count. I assume that's what you mean.edit: I'm referring to using relativity by just jumping on a ship and going really fast. I feel like that's not time travel by the popular definition of the phrase.

I think LLY was alluding to the fact that we are all constantly travelling 'forward' through time simply by existing ;)It's a loose link, but here is a story out today that relates to one-way time: http://newsvote.bbc.co.uk/1/hi/sci/tech/7440217.stmMore interestingly it discusses time and space prior to the Big Bang. LLY have you heard anything about this at all from a source a little more scientific than the BBC?

[timwakefield 68]

Using relativity doesn't count. I assume that's what you mean.edit: I'm referring to using relativity by just jumping on a ship and going really fast. I feel like that's not time travel by the popular definition of the phrase.

Meh, I think that is a perfect example of time travel, however impossible it is. Freezing yourself for 1000 years would be an example of "false" time travel, since all you really did was sleep for 1000 years. But if I hop on some sort of ship, fly around at practically the speed of light for say 3 years, and then come back to earth and it's 2957, I'd say that's exactly time travel.

[timwakefield 68]

I don't accept "because it would create paradoxes" as a reason why it's not possible. Maybe we just don't understand how the paradoxes would get resolved.

You might be interested in the Novikov self-consistency principle.

Stated simply, the Novikov consistency principle asserts that if an event exists and that would give rise to a paradox, or to any "change" to the past whatsoever, then the probability of that event is zero.

And on another note, I just found an awesome new word: autoinfanticide - traveling back in time and killing yourself as a baby.

[strategy 4]

I've long suffered from autoregicide

[timwakefield 68]

I've long suffered from autoregicide

Traveling back in time to kill your past self when you were king?

[qyayqi 11]

autoeroticide, travel back in time & f yourself to d.autoautocide, travel back in time to various of your past selves & runthemover.

[strategy 4]

Traveling back in time to kill your past self when you were king?

you know it.

[LongLiveYorke 38]

I think LLY was alluding to the fact that we are all constantly travelling 'forward' through time simply by existing ;)It's a loose link, but here is a story out today that relates to one-way time: http://newsvote.bbc.co.uk/1/hi/sci/tech/7440217.stmMore interestingly it discusses time and space prior to the Big Bang. LLY have you heard anything about this at all from a source a little more scientific than the BBC?

Well, you could check out the paper itself:http://arxiv.org/pdf/0806.0377Here's the abstract Measurements of temperature fluctuations by the Wilkinson Microwave Anisotropy Probe (WMAP) indicate that the fluctuation amplitude in one half of the sky differs from the amplitude in the other half. We show that such an asymmetry cannot be generated during single-field slow-roll inflation without violating constraints to the homogeneity of the Universe. In contrast, a multi-field inflationary theory, the curvaton model, can produce this power asymmetry without violating the homogeneity constraint. The mechanism requires the introduction of a large-amplitude superhorizon perturbation to the curvaton field, possibly a pre-inflationary remnant or a superhorizon curvaton-web structure. The model makes several predictions, including non-Gaussianity and modifications to the inflationary consistency relation, that will be tested with forthcoming CMB experiments.Incidently, Sean Carrol, one of the coauthors, is a really, really smart guy and knows almost all there is to know about general relativity and cosmology, so I trust what he has to say.

[LongLiveYorke 38]

Oh, and in general, this is the easiest way to find physics papers:http://arxiv.org/

[qyayqi 11]

dear lly:i noticed that you recently discovered x boxes. while you are working on ATLAS, could you smuggle in a toaster, a paper shredder, and 3 sticky notes?affix the first sticky note to the toaster. write on it: [ ] ATLASaffix the second sticky note to the shredder. write on it: [ ] ATLASaffix the third sticky note to ATLAS. write on it: [x] ATLASplease try to have these in place during the next documentary.sincerely,Q

[KramitDaToad 0]

Well, you could check out the paper itself:http://arxiv.org/pdf/0806.0377

Cheers geezer. I tried, but right about here...

The mechanism requires the introduction of a large-amplitude superhorizon perturbation to the curvaton field, possibly a pre-inflationary remnant or a superhorizon curvaton-web structure.

I went cross-eyed and lost my balance for a moment

Incidently, Sean Carrol, one of the coauthors, is a really, really smart guy and knows almost all there is to know about general relativity and cosmology, so I trust what he has to say.

This was what I was after - you know, the gossip

[Vandees 0]

3 guys split a hotel room, $10 each $30 total.They go to the room, and the desk guy finds out they should have been charged $25. He gives the bellboy $5 to take back to them. He does, and the 3 guys all take $1 back and give the bellboy the $2 for a tip.Now, they all paid $9 for the room. $10 and $1 back. Plus $2 for the bellboy. Thats $29. Where did the other dollar go??

[Actuary 3]

3 guys split a hotel room, $10 each $30 total.They go to the room, and the desk guy finds out they should have been charged $25. He gives the bellboy $5 to take back to them. He does, and the 3 guys all take $1 back and give the bellboy the $2 for a tip.Now, they all paid $9 for the room. $10 and $1 back. Plus $2 for the bellboy. Thats $29. Where did the other dollar go??

too old!Desk has $$25Guests have $3Bellboy has $2 = $30Or, men paid $27, $2 of which Bellboy now has, and have $1 each = $30 total

[Vandees 0]

too old!Desk has $$25Guests have $3Bellboy has $2 = $30Or, men paid $27, $2 of which Bellboy now has, and have $1 each = $30 total

Thanks, I knew it had been answered here, but it mind f*cks me every time.

[coesillian 0]

here's a laymen explanation about the LHC

[speedz99 145]

And on another note, I just found an awesome new word: autoinfanticide - traveling back in time and killing yourself as a baby.

I can't believe there's a word for that.And I still don't buy your example of going in a ship as "time travel". I'm not sure why, I just don't.

[Max_Powers 0]

So I "stumbled upon" a thread. The OP posed the following thought experiment:Nothing can travel faster than the speed of light. Right? I imagine sitting on the sun and discovering that in about one minute the sun will explode and disappear. Now, it takes about eight minutes for light to travel to earth, and nothing, not even gravity, can move at a greater speed. This gives my fellow humans a little over eight minutes to act (eight minutes + the several seconds before the explosion). Can I warn them? No, I can’t. Any kind of communication would take more than eight minutes. But! What if I had a pencil long enough to reach the earth? (Already in place, ready to start writing.) The humans can read my message as I am writing it. Would this work? Could we say that in this case a thought would travel faster than the speed of light? Guy 1's answer was:Wouldn’t work. As you move your end of the pencil, a wave is created along its length. That wave can’t move faster than light. Guy 2's answer was:This is incorrect, the movement of all points along the pencil would (more or less) simultaneously since the electrostatic attraction exchange particles are gamma photons generated as one charge moves within the field of another. since the particles at your end are moveing, they move their neighbouring particles by means of exchange gamma photons travelling between them. However, those particles are also moving relative to their nearest and are generating exchenge particles with them almost simultaneously. The generating pairs will altenate along the length of the pencil simultaneously rather than sequentially because when a pair is repelling, the individual atoms that make up this system may be either attracting or repelling a neighbour on a different face. So, yes George, in theory you could communicate faster than light in this way.What do you say? Obviously the set up itself is impossible for many reasons, but if we set aside the difficulties of a 93 million mile long pencil could we communicate faster than light with it?

[ice4804 0]

Guy 1's answer doesn't really make much sense to me...what does a wave traveling along the length of a pencil as you move it have anything to do with how fast you are able to write?Also, quantum entanglement does allow for (seemingly) "communication" faster than the speed of light, but at the risk of messing up the details, I will let LLY further this point if it's even relevant.

[LongLiveYorke 38]

I think the first answer is more or less correct. I'm not sure what the second answer is talking about, really (rather, I know what he's talking about, but I'm not sure that he knows what he's talking about).There's a finite prorogation time for information in the universe, and that of course is c. When you move the pencil, it reacts to your movement in finite time. Essentially, the pencil will deform in a way that is consistent with the speed of light. It will take some amount of time for the deformation in the pencil that you make on your side to propagate to the other side at Earth. Think of the pencil as being a giant game of "telephone" between the molecules that make it up. If you push on the pencil at one end, the molecules at your end will push on the molecules next to them, which will then push on the molecules next to them, and so on. So, you set off a chain reaction of pushing, or a wave, down the pencil. This wave propagates necessarily slower than the speed of light. So, all the molecules communicate to the molecules next to them, like telephone, and this message moves along the pencil.Obviously, for normal situations, we don't notice this. There are two scenarios. Either the person is pushing on the pencil, maybe to press a button on Earth or something, or he is moving it from side to side in an attempt to write. You can think of the pushing part as being a compression wave that must travel down the length of the pencil. You can think of the moving side to side part as something that will make the pencil bend. (If you've ever watched a golf club being swung in slow motion, you'll know what I mean. It really bends as you swing it down, but it does so really fast and we don't notice it in our daily life).So, information can't travel faster than light. But here's an interesting example of faster than light travel that is in some ways similar to the above.Imagine that, instead of a pencil, we have a laser light. We shine the laser on a big screen at Earth and they can see the dot. Now, imagine that I move the laser for some time with an angular frequency of w. In other worlds, I just turn my wrist at some speed. The dot will move on the screen with a velocity of w*r. But r can be arbitrarily large, and so large that v = w*r could be greater than c. Have we contradicted relativity?Certainly not. The reason is that what we are making move faster than light can't carry information. When we move our wrist, it will take r/c seconds for the movement in our wrist to become movement of the dot on the screen. So, the information that we send from the sun to the earth certainly propagates according to relativity.But you may ask, "The laser dot moves faster than light along the screen, so couldn't it be used to send information between one side of the screen and the other faster than the speed of light?" A good question, but the answer is still no. See, the information contained in the dot doesn't come from the screen itself, it comes from me sitting on the sun moving the laser with my wrist. So, one side of the sheet can not communicate with the other side since neither side actually controls the dot, they only see it and receive its information. Clearly it's okay for the two sides of the sheet to know the same information within a time that is smaller than it would take light to travel across the sheet, and this is all that's happening.

[LongLiveYorke 38]

Also, quantum entanglement does allow for (seemingly) "communication" faster than the speed of light, but at the risk of messing up the details, I will let LLY further this point if it's even relevant.

Yes, this is similar to the laser example I described above. The states of a particle far away can be determined by measuring the state of a particle that's entangled with it, but this in no way can carry information. In other words, you can't communicate by measuring the states of entangled particles, you can only learn something about something very far away.

[LongLiveYorke 38]

This is incorrect, the movement of all points along the pencil would (more or less) simultaneously since the electrostatic attraction exchange particles are gamma photons generated as one charge moves within the field of another. since the particles at your end are moveing, they move their neighbouring particles by means of exchange gamma photons travelling between them. However, those particles are also moving relative to their nearest and are generating exchenge particles with them almost simultaneously. The generating pairs will altenate along the length of the pencil simultaneously rather than sequentially because when a pair is repelling, the individual atoms that make up this system may be either attracting or repelling a neighbour on a different face. So, yes George, in theory you could communicate faster than light in this way.

Doesn't this guy totally contradict himself? He say that the molecules communicate with each other using photons (or gamma photons, as he calls them). This is true. But photons travel at the speed of light. So, according to his own theory, the movement of molecules should be at most the speed of light.

[Balloon guy 158]

What would you write anyway?"Quick, start another sun"?

[LongLiveYorke 38]

What would you write anyway?

"Everybody, put on sunblock. Lots of sunblock."