Path: csiph.com!aioe.org!.POSTED!not-for-mail From: The Starmaker Newsgroups: sci.physics.relativity Subject: Re: The correct explanation for the twin paradox Date: Sun, 23 Jul 2017 10:56:03 -0700 Organization: Aioe.org NNTP Server Lines: 75 Message-ID: <5974E333.20CF@ix.netcom.com> References: <086f7a5d-bd46-44dc-abf3-98488917a499@googlegroups.com> <7ecda924-3461-419e-84c9-7b4800de7bf7@googlegroups.com> <2764577b-f7d5-441a-97ca-4b070507f5b8@googlegroups.com> <57790307-91c3-4956-a8e3-ed07c8b92573@googlegroups.com> <7e69dc9d-5173-43bf-9167-7dcacacbc713@googlegroups.com> <0d4ffa90-a36f-4ea0-86d3-eb8956d94861@googlegroups.com> <0e54850b-ea98-4902-b7b2-85ef765772f2@googlegroups.com> <2057cab3-d71d-4bcc-8728-5cac413e935d@googlegroups.com> <13af5343-27eb-4565-877d-94ea6ba19f6c@googlegroups.com> Reply-To: starmaker@ix.netcom.com NNTP-Posting-Host: X9ItFNC7Zcz4l6MobL/YRA.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org X-Antivirus-Status: Clean X-Antivirus: Avast (VPS 170722-0, 07/22/2017), Outbound message X-Notice: Filtered by postfilter v. 0.8.2 X-Mailer: Mozilla 3.04Gold (WinNT; U) Xref: csiph.com sci.physics.relativity:425911 Nicolaas Vroom wrote: > > On Friday, 21 July 2017 16:29:29 UTC+2, tjrob137 wrote: > > On 7/20/17 7/20/17 2:50 PM, Nicolaas Vroom wrote: > > > My understanding is that an odometer is used to measure distance. > > > [...]What is your point? > > > > The point is that odometers measure distance, while clocks measure > > elapsed (proper) time. This is an ANALOGY. > okay. IMO you have to be carefull to use such an ANALOGY. > > On Thursday, 20 July 2017 17:08:45 UTC+2, Paparios wrote: > > Let again try the car odometer analogy. Two identical cars make a trip > > from Chicago to New York, but they use different routes. > Consider the following 2 options: > One car travels straight from Chicago to New York. The odometer will > show 600 miles. > Car two travels from Chicago to Houston and then straight to New York. > The odo meter will show 600 + 600 = 1200 miles. > Both car will start at the same moment and arrive at the same moment. > This implies that the second car drives the fastest. > Both cars have a clock. Both clocks are reset at the start of the experiment. > Question: when both cars are in New York will both clocks show the > same reading? > > > The usual twin paradox with > > instantaneous accelerations is a triangle, and the clocks measure > > the elapsed (proper) time along each path. As the geometry is > > hyperbolic, the one that traversed two sides of the triangle > > experienced less elapsed (proper) time than the one who traversed one. > > This implies (if my understanding is correct) that the second clock should > show less elapsed proper time. > In simple terminology; the second clocks runs behind > > > Each odometer measured 1 meter for every meter traversed. > Okay > > Each clock measured 1 second for every second traversed. > Here we have a problem. What do you mean? > > To solve the issue "how clocks perform" we have to made two (4) assumptions: > 1) We agree that every where, the universe, at this moment > has the same time after the Big Bang. This implies that the Universe > has everywhere the same age. > 2) We agree that every where in the universe at this moment, > all events that can be be indentified, are simultaneous events. > 3) As such we also agree that a self centered view of the Universe > (of what I see and observe) is irrelevent. > 4) As such it is our responsible to define a clock which shows > the age of the Universe. > > The problem is that an odometer is not very helpfull in this > exercise, which as far as I understand can only be used to measure > distances here on earth (?) and not in space. > > When you want to study the twin "paradox" different identical clocks > with different speeds are used. Different speeds require accelerations > and these accelerations change the performs of the clocks. > At the pages 26 and 27 in the book GRAVITATION the concept "good" and > "bad" clocks is introduced. "Bad" clocks undergo accelarations. > Accelerations imply different speeds. IMO when you change the speed > it is the inner workings of the clock that changes. This is important > for a clock which uses lightsignals to function, because the speed > of light does not change. The result is that the usual clock rate > changes. The most important lesson is "not" to use clocks with > different speeds when you want to unravel the laws of nature. > > A very interesting article to study is this: > http://www.nature.com/news/witness-gravity-s-quantum-side-in-the-lab-1.22273 > > Nicolaas Vroom wat kind of clock was einstein using in his twin paradox thought experiment, a "good" clock or a "bad" clock?