Search found 2311 matches

by speising
Mon Oct 29, 2012 2:05 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

steve, if you had actually read the article, you would know that v is the wind speed of the luminiferous ether. now guess what that speed turned out to be? MY guess? Emission theory was ignored. and there i thought that my question was formulated simple enough so nobody could not understand it. a n...
by speising
Mon Oct 29, 2012 1:18 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

steve, if you had actually read the artice, you would know that v is the wind speed of the luminiferous ether. now guess what that speed turned out to be?
by speising
Sun Oct 28, 2012 3:07 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

http://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experiment scroll down to figure 4 please during t1 - t2, let L as depicted = the transmission signal length traveling at c ( the solid red line ) during t1 - t2, let O = the length observed in the moving frame [ so where the letter c now is in ...
by speising
Sat Oct 27, 2012 11:00 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

Oh, dear.
No one observes their own clock to run at anything but normal speed. How woud that even work? Slow compared to what?
by speising
Sat Oct 27, 2012 10:13 pm UTC
Forum: Science
Topic: Gravity Doppler Effect
Replies: 65
Views: 11136

Re: Gravity Doppler Effect

Gravity induces a frequency shift in light, as explained in this link.
But gravity itself (as i believe the OP meant) cannot undergo a doppler effekt, since it isn't an oscillation. Doppler effect means a change of frequency or wavelengh of a radiation, gravity is a field.
by speising
Sat Oct 27, 2012 10:05 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

Yes. Of course. The fundamental laws of physics are a highly arbitrary thing and really olny a matter of choosing.
Naturally, in a real rocket ship, the captain would make that decision.
by speising
Fri Oct 26, 2012 9:45 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 0969: "Delta-P"
Replies: 181
Views: 52594

Re: 0969: "Delta-P"

Biggest problem with the formula: wouldn't all those fur coats slow the flow considerably?
by speising
Fri Oct 26, 2012 8:00 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1125: "Objects In Mirror"
Replies: 70
Views: 25095

Re: 1125: "Objects In Mirror"

steve, c is not a rate, but that's beside the point. imagine our universe as the surface of a balloon. if that balloon gets blown up, evry point on the surface receedes from every other point. in this 2D universe, there is no center. similarily, the earth is not the center of our real universe, butr...
by speising
Fri Oct 26, 2012 7:36 pm UTC
Forum: Individual XKCD Comic Threads
Topic: 1125: "Objects In Mirror"
Replies: 70
Views: 25095

Re: 1125: "Objects In Mirror"

i have trouble believing that russians would post an english joke in their vehicle. Because, of course, there are no multilingual Russians. :roll: Of course there are. But there are no multilingual space Russians. that may be. there may also exist american astronauts who speak russian. but you woul...
by speising
Thu Oct 25, 2012 10:02 pm UTC
Forum: Science
Topic: Train Animals to pick fruit?
Replies: 32
Views: 4397

Re: Train Animals to pick fruit?

Is that (in principle) different from a dog scapping the door or a horse jumping it's paddock?

Where do you draw the line between husbandry and slavery?
I'd guess at animal vs. Human.
by speising
Thu Oct 25, 2012 9:55 pm UTC
Forum: Science
Topic: Black Holes - not (yet) possible?
Replies: 279
Views: 45795

Re: Black Holes - not (yet) possible?

2*inf is still inf.
So (2*inf)/inf=inf/inf=2
by speising
Thu Oct 25, 2012 5:36 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

Ok, maybe it's because i'm not a native english speaker, but to me, "no extent in time" means the opposite of "lasts forever".
by speising
Thu Oct 25, 2012 1:19 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

it looks to me like you confuse doppler effect with speed again.
by speising
Thu Oct 25, 2012 9:57 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1125: "Objects In Mirror"
Replies: 70
Views: 25095

Re: 1125: "Objects In Mirror"

i have trouble believing that russians would post an english joke in their vehicle.
by speising
Wed Oct 24, 2012 11:34 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

Thinking about it, i wanted to add that resolving apparent paradoxes like the OP's one is in fact the way one arrives at those weird concepts. You see that both see the other as slower, so you conclude that they can not possibly have started at the same time if consistency is to hold.
by speising
Wed Oct 24, 2012 11:13 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

England is not pulled away. Thanks to contraction, it actually moves closer.
by speising
Wed Oct 24, 2012 10:49 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

All events at the same point in space-time occur at the same point in space an time.

Edit: right, actually the order is preserved for all events that are time like separated, ie light had enough time to reach fromone event to the other.
by speising
Wed Oct 24, 2012 10:44 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

This is not dilation. It is simultaneity. You see, SR predicts a few different effects, and you have to factor in all of them.

And i think it's pretty beautiful, when you think you can derive *all* of it from one concept alone, ie the constant speed of light.
by speising
Wed Oct 24, 2012 10:39 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

Why do you think you see future france?
The distance to england is important!
Only the english clock "jumps" to the future.
Which you can't see, since you are space like separated from it.

Edit: what douglasm said
by speising
Wed Oct 24, 2012 10:22 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

We'll presume that "picking up the clock" takes a billionth of a second. So either he is picking up the clock from a distance of less than 0.33 meters*, or he is somehow performing the pickup maneuver faster than C. :? * Light travels one meter in approximately 3.3 billionths of a second....
by speising
Wed Oct 24, 2012 10:03 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

snow5379 wrote:
I get what you're saying about them not being able to see each other. Can we, for the sake of argument, have some instantaneous communication between the clocks?


no. FTL breaks relativity.

Cf. "space like separation"
by speising
Wed Oct 24, 2012 10:02 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

The French clock would, in the instant it accelerated to .9999c, "see" the English clock instantly change its current time. After that change, the French clock would then see the English clock ticking at a greatly reduced rate. Of course this sounds only so weird because of the unrealisti...
by speising
Wed Oct 24, 2012 9:57 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

The man is traveling at a significant fraction of c. We'll presume that "picking up the clock" takes a billionth of a second. Wouldn't both clock's time still read t=0 after the French clock is picked up even if the man was traveling at 0.9999c? The clocks are only accurate up to 0.001 se...
by speising
Wed Oct 24, 2012 9:27 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

I guess the end of this post http://forums.xkcd.com/viewtopic.php?f=7&t=85881&p=3154732&hilit=Twin#p3154699 , specifically the graphic, explains what happens to time when the ship changes velocity.
by speising
Wed Oct 24, 2012 9:13 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

Again aproblem of simulaneity. You keep changing definitions and refute arguments made to previous ones based on your new ones.

Anyway, in the last verion theres only one point intime left, so there can't be any faster or slower. Speed requires two point in time.
by speising
Wed Oct 24, 2012 9:06 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

Again it could be stated like this: 1. Ship and probe are stationary. Ship instantly accelerates to [arbitrary constant speed] towards probe. 2. At t=1 (ship's time) ship turns on shields. At t=1 (probe's time) probe fires laser. 3. They're in the same (arbitrary) location at this point in time so ...
by speising
Wed Oct 24, 2012 8:58 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

Again it could be stated like this: 1. Ship and probe are stationary. Ship instantly accelerates to [arbitrary constant speed] towards probe. 2. At t=1 (ship's time) ship turns on shields. At t=1 (probe's time) probe fires laser. 3. They're in the same (arbitrary) location at this point in time so ...
by speising
Wed Oct 24, 2012 8:47 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

But the problem arises from the velocity differences and the distance form a to b. if you remove a, what's relative to what?
by speising
Wed Oct 24, 2012 8:24 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

I said "if a had told"
They are not both acting after one sec in their frame. The laser fires in a's frame.

@meteoric: b would be quite some distance away by then, so the observation would be delayed. In fact, it would see a's clock reach 1 at the precise moment of the lasers impact.
by speising
Wed Oct 24, 2012 8:17 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

I think no one ever doubted that in a classical system the ordering of events was unique.
by speising
Wed Oct 24, 2012 8:14 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

B sees A as slower and A sees B as slower. You're presuming A sees B as slower and B sees A as faster which is incorrect. In my second example B's shields go up at t=1.1547 (A's time) and t=1 (B's time). A's probe fires at t=1 (A's time) and t=1.1547 (B's time). In other words each sees the other a...
by speising
Wed Oct 24, 2012 7:51 pm UTC
Forum: Science
Topic: Paradox?
Replies: 82
Views: 11707

Re: Paradox?

snow5379 wrote:1 second later (A's time) or ~1.1547 seconds later (B's time)


Thats where you are messing it up.
B's frame is slower, so B time is less than 1. (.866)
by speising
Wed Oct 24, 2012 3:18 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

But when you come to "moving detectors", you get two CORRECT calculated coordinates and times. But they don't match. I find that to be a mathematical impossibility, moving detectors or not. just as it is impossible that 1 inch = 2.54 cm. different coordinate systems are like different uni...
by speising
Wed Oct 24, 2012 3:14 pm UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2934
Views: 701497

Re: RELATIVITY QUESTIONS! (and other common queries)

snow, get into a sportscar and floor the accelerator. i bet you'll feel it.
by speising
Wed Oct 24, 2012 3:09 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

B2 B1 B3 A2 A1 A3 This way we're consistent with the reception time labels below. 2 is the exact time recorded at receiver 5 = -0.82? Yes. At t=0, the clock at 5 (B3) reads -0.82. But note that at t'=0, this clock reads 0. t=0 and t'=0 define different slices through spacetime. i don't really under...
by speising
Tue Oct 23, 2012 3:49 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

@steve: do you believe that c is constant in all reference frames or not?
if not, how would you propose to show that experimentally?
if yes, how do you reconcile that with your constancy of time?

as i see the math, either c is constant, or time, but not both.
by speising
Sat Oct 20, 2012 5:08 pm UTC
Forum: Science
Topic: Do you lose or gain weight by exhaling?
Replies: 4
Views: 2211

Re: Do you lose or gain weight by exhaling?

Since exhaled air contains more co2, you lose the c. Hence, you lose weight.
by speising
Fri Oct 19, 2012 5:12 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

steve waterman wrote:
btw, the word "Detector" is ambiguous as to how many receivers, so, we merely need the word receiver to avoid this ambiguity.


what about "observer"?
by speising
Thu Oct 18, 2012 9:07 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

http://rschroll.github.com/relativity/ships.html transmission velocity is c First to last transmission took 9 seconds. To receive the SAME set of 10 transmissions.. The receiver moving towards the source took 6 seconds, so observes the speed of light = 1.5c The receiver moving away from the source ...
by speising
Thu Oct 18, 2012 8:19 pm UTC
Forum: General
Topic: Relativity or something [Split from "Pressures"]
Replies: 5149
Views: 486237

Re: 1067: "Pressures"

And that means that relativity theory is true. It has to be true, completely true, everywhere and always. It has been demonstrated experimentally that it is true everywhere and always, and this cannot be debated. If you disagree, then you are wrong. Science has spoken. I tried to remain distant fro...

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