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Atomic clock time dilation

  1. Jul 8, 2004 #1
    Did they take an atomic clock on one of the Apollo missions for time dilation experiment if not why not ?
  2. jcsd
  3. Jul 8, 2004 #2


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    No atomic clock went on an Apollo mission. Check the history of Atomic clocks, what was the state of the art in 1970? I'll bet they were pretty big. The Apollo missions had very little meaningful scientific payload, the majority of the payload was devoted to life support for the tourists.
  4. Oct 6, 2008 #3
    Hi. I'm not a science guy but know for certain my dad was leader of the engineering group that built the instruments used for the time dilation experiment. They were sent on jets at high altitude several times around the world. The state of the art in 1970 was that the clocks were easily rack mounted or placed in a slightly oversize padded suitcase and could be picked up by one man. The display and output processing equipment was often huge, several times the size of the clock, but was not needed in every testing situation. Several of a similar style clock was sold to the NBS in Colorado and was later available through HP's T&F division. I was told by dad in the 1990's a clock was sent on the Apollo mission but used for different purposes and classified as top secret. (but the return data backed up the air flight data and had a longer/faster base line so it started the rumor that an atomic clock was sent for that test) In 1965 dad and I discussed using several clocks as part of a collision avoidance and navigation system for military applications in jets (strategic bombers) and ballistic missiles......the beginnings of GPS. While he seldom brought his work home I saw a drawing of orbiting satellite clocks sending synchronous signals coupled to radar transponders at breakfast one morning. He was quite proud of the idea and we talked about it for an hour or so before I left for high school. He thought the private use of atomic clock navigation might be far better than military ones because he felt it could be made accurate enough to prevent commercial mid air collisions. I think the direction that it was headed for the military (aside from missiles) was for aerial refueling in foul weather. The aircraft had to "find" each other to within a few yards to let the coupling hardware work. The military didn't give a damn about time dilation. That was something dad and a few buddies realized was possible to test so they wrote a proposal with some other guys interested in science and got approval for a flight to prove/promote the products accuracy to potential instrument buyers.
  5. Oct 7, 2008 #4


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    Hi Ladd,
    thanks for your interesting little historical note.

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