Cap'n Refsmmat Posted February 1, 2004 Posted February 1, 2004 So the light goes light speed according to him, and to you, since time is just crawling, it is moving away fast. I'll think about it in bed. Don't worry, I can stand losing sleep.
JaKiri Posted February 1, 2004 Posted February 1, 2004 Cap'n Refsmmat said in post # :So the light goes light speed according to him, and to you, since time is just crawling, it is moving away fast. I'll think about it in bed. Don't worry, I can stand losing sleep. Basically, yeah. But the odd thing is that it works THE OTHER WAY AROUND too.
Cap'n Refsmmat Posted February 1, 2004 Posted February 1, 2004 WHAT? Now I'm doomed to confusion for life.
JaKiri Posted February 1, 2004 Posted February 1, 2004 Cap'n Refsmmat said in post # :WHAT? Now I'm doomed to confusion for life. SR basically says that all rest frames are equally valid. So no matter what speed someone else thinks you're going at, it's perfectly fine to assume that you're stationary and HE'S moving. The best example of this would be the two astronauts drifting past eachother. I drift past you at 20ms^-1. You're stationary. It's equally valid to say that you're drifting past me, and I'm stationary. Or that someone on a ship travelling close to lightspeed (relative to us) is stationary, and we're both moving very close to lightspeed, just with a 20ms^-1 (or thereabouts) difference. The mathematics all works. [edit] This only works for CONSTANT velocities. If you accelerate, then it all changes, and YOU'RE the one moving (basically). See the thread on the twins paradox (with no planet) for more on that.
Cap'n Refsmmat Posted February 1, 2004 Posted February 1, 2004 Yes, I might be moving, and you not, and you think YOU are moving. However, if our reference frame is Earth, for example, we know who is moving relative to Earth.
greg1917 Posted February 1, 2004 Posted February 1, 2004 Can I just take the chance to applaud MrL's patience for being asked exactly the same question repeatedly yet still posting answers? The problem here is people cant seem to comprehend mechanics outside the nice, closed newtonian world where everything is wonderful and predictable. if you are travelling at 99%c and turn on a torch, the photons from the torch will move away from YOU at c. To a person standing still as you shoot past them, the same photons will also appear to be travelling at c. For anyone else who happens to be jogging past this absurd scenario at ANY speed, the photons will be travelling at c. to accomodate this, crazy things like time dillation and length contraction occur. Well, crazy for a chemist anyway. we like to stick to things like deciding the best solvent sytems for a tricky TLC the next day
Cap'n Refsmmat Posted February 1, 2004 Posted February 1, 2004 See, these things always confuse me. If they are moving away from you at C, but relative to someone else, they are going at c, that is confusing. At least until you account the time changing and so on.
greg1917 Posted February 1, 2004 Posted February 1, 2004 Thats why physicists aren't normal people. They think outside the box then mutter to themselves all day and quaff real ale.
JaKiri Posted February 1, 2004 Posted February 1, 2004 Cap'n Refsmmat said in post # :Yes, I might be moving, and you not, and you think YOU are moving. However, if our reference frame is Earth, for example, we know who is moving relative to Earth. It gets a bit tricky with accelerations, as I said. You ARE moving on the earth, because you're undergoing acceleration (except in freefall, when you're not, sort of)
JaKiri Posted February 1, 2004 Posted February 1, 2004 greg1917 said in post # :Thats why physicists aren't normal people. They think outside the box then mutter to themselves all day and quaff real ale. I'm more of a guinness kind of chap.
JaKiri Posted February 1, 2004 Posted February 1, 2004 greg1917 said in post # :to accomodate this, crazy things like time dillation and length contraction occur. Well, crazy for a chemist anyway. we like to stick to things like deciding the best solvent sytems for a tricky TLC the next day I like to give my equations a bit of TLC too. Although that's frowned upon in the wider community. AND THEY CALLED ME A PERVERT! ME! A PERVERT! After I finish having sex with this sheep I'm going to go round there and TEACH THEM A LESSON
greg1917 Posted February 1, 2004 Posted February 1, 2004 Couldnt drink guinness myself, id let down my fellow Rangers fans by being associated with the dark side. Not that im pathetic or anything.
JaKiri Posted February 1, 2004 Posted February 1, 2004 greg1917 said in post # :Couldnt drink guinness myself, id let down my fellow Rangers fans by being associated with the dark side. Not that im pathetic or anything. Rangers eh? My team is single handedly responsible for knocking Celtic out of the Champions League.
greg1917 Posted February 1, 2004 Posted February 1, 2004 MrL a pervert? Ill alert lord Hutton right away to make sure your cleared of every charge and the BBC takes the rap!
JaKiri Posted February 1, 2004 Posted February 1, 2004 greg1917 said in post # :Your a lyon fan? Sunderland. We loaned em Mickey Gray.
greg1917 Posted February 1, 2004 Posted February 1, 2004 Lol Mind you, sunderland fans are still probably gutting themselves laughing at Newcastle getting knocked out by FK Partizan
JaKiri Posted February 1, 2004 Posted February 1, 2004 greg1917 said in post # :Lol Mind you, sunderland fans are still probably gutting themselves laughing at Newcastle getting knocked out by FK Partizan Nah, we've moved on to getting further than them in the FA Cup, when it was really really clear that Shearer and Robson wanted to win it oh so much, and Mick think's it's a bit of a laugh. [edit] Worst rumour of the season was that Arca was moving to Celtic (there was a link with Chelsea at one stage, but that's natural for every player)
greg1917 Posted February 1, 2004 Posted February 1, 2004 Oh bloody hell its almost 4am, im off to bed. frank de boers debut for Rangers tomorrow so im just hoping he hits the ground running.
-Demosthenes- Posted February 1, 2004 Author Posted February 1, 2004 Okay, I think I can barely understand, but maybe not. You must have some kind of degree in light travel or something, I 'm going to bed.
Cap'n Refsmmat Posted February 1, 2004 Posted February 1, 2004 Good for you. I must be amazing. I actually figured out how it worked! (not that I'm not confused)
YT2095 Posted February 2, 2004 Posted February 2, 2004 Hmmm... your post #75 makes a little more sense of it all now (to me anyway). but what happens when you shine a torch or a laser at one star (say our sun for example), and then move it across the sky to another, the end of the beam moves several thousand light years in less than a second, alot faster than light itself can. if you could look from the top down at this beam originating from earth, what would the beam appear like when you moved it from the sun to another star a million light years away?
Sayonara Posted February 2, 2004 Posted February 2, 2004 It made sense when I started, then gradually... less so
YT2095 Posted February 2, 2004 Posted February 2, 2004 I envisage someling like an arc, and taken to the ultimate degree, if the laser were to be spun in motor, I`de imagine a catherine wheel spiral effect that radiates outwards. having said that, that`s obeying the physical laws that I KNOW and understand. I see the problem arrise when this laser is spun SO fast that the light radiating outwards would be traveling almost sideways, and that I can`t picture?
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