Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken)

Wow . . . I haven't been following this thread for a week or so and it make me wonder how it got from a jammed sheave to the theory of relativity and GPS systems LOL. No worries I was just checking in what we could possibly still be talking about for such a simple problem and now I know ;-). Paul In a message dated 9/7/2010 1:05:01 P.M. Eastern Daylight Time, al… [at] PaloAltoPhoto.com writes: That may be it but I seem to remember something about the orbit being a circle implied constant acceleration and that had something to do with it. I understand the idea that a clock made of two mirrors with a light pulse going between them at the speed of light implies that time is different for a person on a train with the light clock then for an observer on the ground watching the train and the clock go by. That is pretty simple as the stationary observer sees the path between the mirrors as longer and if light speed is constant, time is longer for him. Or is it shorter??? My boat isn't that fast so I don't worry about it although I am happy that my old boss worried about it when they designed the GPS system. I just ordered a Foretrex 301 so that I can have my GPS on my wrist and see it when I am on the rail. I can put VMG, TURN, Time to Next, and SPEED on it at one time. Can't wait until the next race. TURN is a great function that I just discovered. It tells you what direction to turn the boat to get to the mark and how much. The other GPS function that I just learned is to set a route between the committee boat and the pin. Then set the GPS to OFF COURSE and it will tell you how far you are away from the starting line. Way cool. Allen On Tue, Sep 7, 2010 at 8:08 AM, Husar, Charlie [USA] <_h… [at] bah.com_ (mailto:hu… [at] bah.com) > wrote: Allen, since the orbital speed gets lower as the orbit gets larger, one orbit means more time at less speed. Is it possible that the time of orbit and the speed (note I am saying scalar speed instead of vector velocity) of the object offset each other? That is, is it possible that the speed drops out of the computation and we can just count orbits to determine relativistic effects? Haven't screwed around with my math in a while. Maybe if things get real dull... I am desperately seeking a sailing connection here. Cheers, Anyway Charlie From: _C… [at] yahoogroups.com_ (mailto:Ca… [at] yahoogroups.com) [mailto:_C… [at] yahoogroups.com_ (mailto:Ca… [at] yahoogroups.com) ] On Behalf Of Allen Edwards Sent: Monday, September 06, 2010 10:09 AM To: _C… [at] yahoogroups.com_ (mailto:Ca… [at] yahoogroups.com) Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) Did you know that the GPS you use is a demonstration of Einstein's theory of relativity? To achieve the required GPS accuracy, the speed of the satellites requires that the clocks be compensated because time slows down as speed increases. The satellites are doing about 18,000 mph. Funny you should say that. I worked for one of the the guys who invented GPS for a few years and he tried to explain it to me once. I thought I understood relativity but when he said the clock would lose the same time per orbit regardless of its speed... something about the angular acceleration, my response was... huh? I don't understand it so don't ask. Allen

Sorry, Paul. My fault. I've hanging around a lot with this hip replacement recovery, and maybe the Wheeee! pills are causing some strange banging around with the old physics neurons in my head. Cheers Charlie From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of pw… [at] aol.com Sent: Tuesday, September 07, 2010 1:22 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) Wow . . . I haven't been following this thread for a week or so and it make me wonder how it got from a jammed sheave to the theory of relativity and GPS systems LOL. No worries I was just checking in what we could possibly still be talking about for such a simple problem and now I know ;-). Paul In a message dated 9/7/2010 1:05:01 P.M. Eastern Daylight Time, al… [at] PaloAltoPhoto.com writes: That may be it but I seem to remember something about the orbit being a circle implied constant acceleration and that had something to do with it. I understand the idea that a clock made of two mirrors with a light pulse going between them at the speed of light implies that time is different for a person on a train with the light clock then for an observer on the ground watching the train and the clock go by. That is pretty simple as the stationary observer sees the path between the mirrors as longer and if light speed is constant, time is longer for him. Or is it shorter??? My boat isn't that fast so I don't worry about it although I am happy that my old boss worried about it when they designed the GPS system. I just ordered a Foretrex 301 so that I can have my GPS on my wrist and see it when I am on the rail. I can put VMG, TURN, Time to Next, and SPEED on it at one time. Can't wait until the next race. TURN is a great function that I just discovered. It tells you what direction to turn the boat to get to the mark and how much. The other GPS function that I just learned is to set a route between the committee boat and the pin. Then set the GPS to OFF COURSE and it will tell you how far you are away from the starting line. Way cool. Allen On Tue, Sep 7, 2010 at 8:08 AM, Husar, Charlie [USA] <hu… [at] bah.com<mailto:hu… [at] bah.com>> wrote: Allen, since the orbital speed gets lower as the orbit gets larger, one orbit means more time at less speed. Is it possible that the time of orbit and the speed (note I am saying scalar speed instead of vector velocity) of the object offset each other? That is, is it possible that the speed drops out of the computation and we can just count orbits to determine relativistic effects? Haven't screwed around with my math in a while. Maybe if things get real dull... I am desperately seeking a sailing connection here. Cheers, Anyway Charlie From: Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com> [mailto:Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com>] On Behalf Of Allen Edwards Sent: Monday, September 06, 2010 10:09 AM To: Ca… [at] yahoogroups.com<mailto:Ca… [at] yahoogroups.com> Subject: Re: [Cal_Boats] Re: Main halyard pulley?? is stuck at top of mast. (Harken) Did you know that the GPS you use is a demonstration of Einstein's theory of relativity? To achieve the required GPS accuracy, the speed of the satellites requires that the clocks be compensated because time slows down as speed increases. The satellites are doing about 18,000 mph. Funny you should say that. I worked for one of the the guys who invented GPS for a few years and he tried to explain it to me once. I thought I understood relativity but when he said the clock would lose the same time per orbit regardless of its speed... something about the angular acceleration, my response was... huh? I don't understand it so don't ask. Allen

On 9/7/2010 11:17 PM, Husar, Charlie [USA] wrote: > > Sorry, Paul. My fault. I've hanging around a lot with this hip > replacement recovery, and maybe the Wheeee! pills are causing some > strange banging around with the old physics neurons in my head. > Don't apologize. Sailing is a wonderful thing to experience. It can be sort of dull to talk about if the subject doesn't lead us to other subjects. The other subjects help us learn. Chris Campbell