Properties of a preferred frame, an inertial frame in SR and
in [Relativity]
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From: JT on 19 Jul 2010 06:41 On 19 Juli, 00:56, "whoever" <whoe...(a)whereever.com> wrote: > "JT" wrote in message > > news:8184e5eb-4594-494f-a73b-e9ab4388cc78(a)c10g2000yqi.googlegroups.com... > > > > >Temporalorder of spatial separated events is absolute > > Because you say so. Any proof other than you deciding how nature MUST work? > > --- news://freenews.netfront.net/ - complaints: n...(a)netfront.net --- Yes the law of casuality. JT
From: kenseto on 19 Jul 2010 08:03 On Jul 18, 8:38 pm, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: > kenseto says... > > > > > > > > >On Jul 18, 11:05=A0am, stevendaryl3...(a)yahoo.com (Daryl McCullough) > >wrote: > >> Let's go through an example: Suppose in one frame we have two > >> synchronized clocks at rest, C1 and C2, lined up left-to-right, > >> with C1 to the left of C2. > >> In another frame, we also have two synchronized clocks at rest, > >> D1 and D2, that are also lined up left-to-right. Clocks D1 and D2 > >> are traveling at 0.866c relative to clocks C1 and C2, and their > >> velocity is left-to-right. They are traveling so that D1 & D2 > >> pass very close to C1 and C2. > > >> So here are some events involving these two pairs of clocks: > > >> e1: D1 passes C1, and they both show time 12:00 > > >OK....this is an assumption. > > >> e2: D2 passes C2, and D2 shows time 11:50, while C2 shows time 12:10 > > >No....at this event D2 must agree with what D1 read: 12:00. Why? > >Because D1 and D2 are in the same frame and they are synchronized. > >Also C2 must agree with what C1 read which is 12:00. > > You are confused. I didn't say that e1 and e2 are simultaneous! Either did I....what I said is that when D1 reads 10:00 D2 must alos read 10:00. > > In frame D (the frame in which the D-clocks are at rest), e2 > takes place 10 minutes before e1. In this frame, the D-clocks > are correctly synchronized, but the C-clocks are not. Right....the D1/D2 clocks read 10 minutes at e2. But the C1/C2 clocks have a different reading of 20 minutes at e2 because they are running at a faster rate as specified by you. > > In frame C (the frame in which the C-clocks are at rest), e2 > takes place 10 minutes *after* e1. In this frame, the C-clocks > are correctly synchronized, but the D-clocks are not. No....you already specified that the C1/C2 clcoks are running faster....therefore at e2 the C1/C2 clocks will show 20 minutes after 12:00. Ken Seto
From: Sam Wormley on 19 Jul 2010 09:16 On 7/19/10 5:41 AM, JT wrote: > Yes the law of casuality. > > JT Ref: http://en.wikipedia.org/wiki/Causality According to Sowa (2000),[5] up until the twentieth century, three assumptions described by Max Born in 1949 were dominant in the definition of causality: 1. "Causality postulates that there are laws by which the occurrence of an entity B of a certain class depends on the occurrence of an entity A of another class, where the word entity means any physical object, phenomenon, situation, or event. A is called the cause, B the effect. 2."Antecedence postulates that the cause must be prior to, or at least simultaneous with, the effect. 3. "Contiguity postulates that cause and effect must be in spatial contact or connected by a chain of intermediate things in contact." (Born, 1949, as cited in Sowa, 2000) However, according to Sowa (2000), "relativity and quantum mechanics have forced physicists to abandon these assumptions as exact statements of what happens at the most fundamental levels, but they remain valid at the level of human experience."
From: artful on 19 Jul 2010 09:37 On Jul 19, 8:41 pm, JT <jonas.thornv...(a)hotmail.com> wrote: > On 19 Juli, 00:56, "whoever" <whoe...(a)whereever.com> wrote: > > > "JT" wrote in message > > >news:8184e5eb-4594-494f-a73b-e9ab4388cc78(a)c10g2000yqi.googlegroups.com.... > > > >Temporalorder of spatial separated events is absolute > > > Because you say so. Any proof other than you deciding how nature MUST work? > > > --- news://freenews.netfront.net/ - complaints: n...(a)netfront.net --- > > Yes the law of casuality. Doesn't make any difference. Causality is limited in speed .. the maximum speed at which information can be send. Unless you think it is possible for an action on one 'side' of the universe to instantly affect something on the other side. That speed limit (in relativity) is what we call c. If two events are far enough apart in distance and close enough in time .. nothing that happens at one event can effect the other .. because the information (the cause and effect) cannot travel fast enough. It is only events that are unrelated (wrt cause and effect) that can have different orders depending on frame of reference. Seeing its events that are not causally related, that means the causality does NOT demand that event ordering is absolute. Try again.
From: kenseto on 19 Jul 2010 09:49
On Jul 18, 9:33 pm, stevendaryl3...(a)yahoo.com (Daryl McCullough) wrote: > kenseto says... > > I'm going to try again to explain what's going on with > mutual time dilation. > > Let's assume that there is a frame C such that: > > There are two clocks, C1 and C2 at rest in this > frame. They are lined up left-to-right, with C1 to the left of C2. > Initially, clocks C1 and C2 are set to the same time, > 12:00. > > There are two more clocks, D1 and D2 which are lined > up left-to-right, and are moving to the right. They > are traveling at the same rate of speed such that it takes > 20 minutes to travel between clocks C1 and C2. > > Initially, D1 is set to 12:00 and initially D2 is set > to 11:45 (why this discrepancy? I can explain later, but > for now, let's just assume that whoever was setting the clocks > set them that way, for whatever perverse reason). Then D1 and D2 are not synchronize. Also if D1 is set to 12:00 then D2 must also set to 12:00 initially. > > Clocks D1 and D2 run at 1/2 the rate of C1 and C2. > Initially, D1 is lined up with C1, while D2 is halfway > between C1 and C2. In your initial example you said that the distance between D1 and D2 is the same as the distance between C1 and C2. > > This is all just assumptions. Surely it is *possible* > to arrange things so that all of the above is true. > You can set clocks to whatever times you like. You > can adjust the rates on clocks. It is certainly possible > for the above description to be true. Right? If you > think otherwise, then let's stop here and discuss it > further. Of *course* it is possible to set things up > this way. This is artificial....also if it is applicable in one secenario it should also applicable to all scenarios. > > Now, at 12:00, we have the following situation: > 1. D1 is lined up with C1. They both show time 12:00. > 2. D2 is halfway between C1 and C2. It shows time 11:45. No D2 must read the same as D1 because they are sunchronized. > 3. C2 shows time 12:00 > > At 12:10, we have the situation: > 1. C1 shows time 12:10 > 2. D1 is halfway between C1 and C2. It shows time 12:05. > 3. D2 is lined up with C2. D2 shows time 11:50, while > C2 shows time 12:10. What D2 show is irrelevant....since you specified that it has a different starting time than D1. > At 12:20, we have the situation: > 1. C1 shows time 12:20. > 2. D1 is lined up with C2. D1 shows time 12:10, while > C2 shows time 12:20 > 3. D2 is past C2, a distance equal to 1/2 the distance > between C1 and C2. It shows time 11:55. Again what D2 show is irrelevant because you specified that it has a different starting time than D1. > > Surely you agree that it is *possible* to set things > up so that all the above are true? Right? No I don't agree. > > Now, from all the facts above, let's extract those > facts that are independent of any coordinate system, > that everyone agrees on: > > e1: When clocks C1 and D1 are lined up, they both > show time 12:00. > > e2: When clocks C2 and D2 are lined up, clock C2 > shows time 12:10, while D2 shows time 11:50. The time show by D2 is not related to any clocks (D1, C1, and C2). > > e3: When clocks C2 and D1 are lined up, clock D1 > shows time 12:10, while C2 shows time 12:20. OK I agree to that. > > Do you agree with these coordinate-independent facts? No I don't agree. > > These facts were all derived in frame C, in which > the C-clocks are at rest, and are synchronized, > and the D-clocks are traveling, are time-dilated, > and are not synchronized. But you said that D1 and D2 are synchronized. > > But there is a frame D consistent with facts e1, e2, and e3 > such that: the D-clocks are at rest, and are synchronized, > the C-clocks are traveling, are time-dilated, and are > not synchronized. > > Here's the same story, told from the point of view of > frame D: > > At 11:50: > 1. Clock D1 is to the left of C1. D1 shows time 11:50 > 2. Clock C1 is halfway between D1 and D2, and shows time 11:55. > 3. Clock C2 is lined up with D2. C2 shows time 12:10, while > D2 shows time 11:50. This is irrelevant. > > At 12:00: > 1. Clock C1 has moved to the left to line up with D1. > They both show time 12:00. They both set their to 12:00 at this event.....D1 and C1 line up. > 2. Clock C2 has moved to the left, and is now half-way > between D1 and D2. C2 shows time 12:15. No C2 must agree with what C1 read which is 12:00 > 3. Clock D1 shows time 12:00. The rest of your scenario is based on your faulty and artificial clock setting. of D2 and C2. Ken Seto > > At 12:10: > 1. Clock C1 has moved to the left of D1. It shows time 12:05. > 2. Clock C2 has moved to the left, and is now lined up with > clock D1. C2 shows time 12:20, while D2 shows time 12:10. > > These two wildly different stories for what goes on have > *exactly* the same coordinate-independent facts: > e1: When D1 and C1 are lined up, they both show time 12:00 > e2: When D2 and C2 are lined up, D2 shows time 11:50, while > C2 shows time 12:10. > e3: When D1 and C2 are lined up, D1 shows time 12:10, > while C2 shows time 12:20. > > But in the first story, it is the D-clocks that are > unsynchronized, and running slow, while in the second > story, it is the C-clocks that are unsynchronized and > running slow. > > Both stories are consistent with all the coordinate-independent > facts, but they disagree about which clocks run slower than > which other clocks. > > -- > Daryl McCullough > Ithaca, NY |