Did the military top-brass behind the GPS system really doubt relativistic effects ?

I was just watching Brain Cox on the BBC show QI, and he made a claim when talking about how relativistic affects have to be taken into account in GPS tracking.

He claimed that when the system was first proposed by the US military, the top brass found this whole “relativity” thing a bit far fetched and were skeptical that time would really run faster for a satellite in orbit than an observer on the surface of the Earth.

Is did this actually happen ? Is it apocryphal or just a distortion of a more sensible discussion that happened when the GPS system was being put together?

My WAG is that they didn’t think the effects would be signficant. Which they really arent IMO, except for the fact that for GPS to work to a high degree of accurracy your timing needs to be spot on.

Or in other words, they where sorta right, except they also didn’t realize how damn fast light is, which made them wrong.

Then again they could have been buttheads for that matter.

You know how you know that stories like this are nonsense? Because it assumes that the “top brass” would be interested enough in the finer details of GPS technology for the topic of relativity to even come up.

That’s not to say that those folks aren’t smart - you have to be extremely capable to make it to the upper ranks of the military - just that that’s not the kind of thing those people concern themselves with.

The wiki article on GPS and Relativity does not mention what the top brass thought about relativistic effects but I’ll post it here for completeness.

If it was a guy in the pub I would have written it off as nonsense, but it was a professor of the Royal Society on a BBC show dedicated to revealing interesting facts.

My money is on it being an distortion of something that actually happened. Presumably at some point a member top brass had to sign off on a report that discussed relativistic affects to some degree.

Yeah, I picture the conversation going something like this:

Dr. Nerdhead Inventorman: Sir, we’re working on a new system using satellites that can, with a lot of complicated math, let our soldiers figure out exactly where they are.

General Alloy McCoppertin: And you understand this complicated math, and can make handheld devices that can do it?

Dr. Inventorman: Yes, sir, of course.

General McCoppertin: Very good, then. Let me know when it’s ready for rollout.

It was a multi-billion dollar program requiring years of research, dozens of dedicated satellites, with political implications going all the way to president, and involving cold-war politics.

I’m fairly sure it involved a LOT more than that to sell it to the top brass.

For the information of those whose image of US military brass is derived solely from the movies,
USAF General Lew Allen had a PhD in nuclear physics, and he was 1970-73 Director of Special Projects
and Deputy Commander for Satellite Programs of the Space and Missile Systems Organization.

In 1973 he went on to be DCI, then to DNSA, then to Chief of Staff of the Air Force/JCS.

Since GPS development began in 1973 I would say having a man like Allen in such positions is all it takes
to reduce the credibility of the OP thesis to zero.

Of course, it’s more fun to imagine the putative conversation from the OP.

General Alloy McCoppertin: What kind of crazy talk is this about time going more slowly? You’ll never convince me that pointy-headed professors’ crazy ideas about relativity mean more than good old military common sense.

Dr. Inventorman: Well, sir, Hiroshima and Nagasaki disagree.

I still suspect the OP’s situation is a distortion of real facts.

For example, I can see a General-Allen-type-person getting a report from Expert A titled “Relativistic effects on GPS chronometers” and then asking for a second opinion or peer review from Expert B. If you’re distorting facts to play up how dumb the brass are, you could construe this request as “doubting relativity,” when it may not be motivated by doubt at all.

I don’t find the story altogether improbable.

Among the top brass you have scientists like Allen who understand science and can lead the team that designs aned builds the project.

Also among the top brass You have accountants who control the funding for such projects. They may be clever men in their own field, but can’t be expected to know all the various science stuff.

So, if Allen went to the accountants, saying “We need $X million to build a clock that runs at a different speed to clocks on Earth” you can bet that he’d be questioned on it. And he might have a hard time explaining the concept.

Maybe, but I think it is more likely that the events related by OP do not even
have that little a basis in reality.

I would say that that there were probably many PhD level experts, including
some in uniform, who reported to General Allen on this matter, and that they
were good enough to get it so obviously right the first time that Allen would
not consider further vetting the issue. One of those experts might have been
USN Adm. John Poindexter, also a PhD physicist.

On the other hand, the calculations at issue might have been so elementary
for a person of Allen’s ability and education that he did them himself, while
the project was just getting off the ground.

I posted this on the QI forumand got this response:

So my money is still on some kernel of truth mixed in with a lot of exaggeration (Having a committee studying the “Accuracy of Time Transfer in Satellite Systems” does not mean you don’t believe relativity).

I would doubt this. The calculation is rather elementary, for someone versed in GR, but few nuclear physicists have any real background in GR at all. It’s possible, of course, that Allen might have taken a course or two in GR just out of general interest, but it’s unlikely.

The scenario you suggest scarecely resembles that made in the OP.

I do not think an accountant would presume to question a physicist on
a matter of physics. It then becomes a matter of cost-effectiveness,
which lies outside the OP theme.

Also, if there is one organization of the federal government which can
write its own checks, bulldozering any accountant who tries to get in
the way that would be NSA, and Allen was DNSA 1973-77.

Thank you for the interesting information with the link to what looks like a site
I should add to my favorites list.

Thank you for the clarification. I assumed those 1-2 GR courses would have been required.

Even though they were not required do you think a nuclear physicist such as Allen or Poindexter
would have appeciated from the start a need to explore GN effects?

Yeah, but I’d bet money he knew about that amazing time dilation thingy even if he most likely couldnt do the calcs. Hell, I knew about it in the 70’s and lets just say I wasnt even in grad school at that point. And I’d certainly be surprised if a physicist working for him said “we gotta take time dilation into account” and he refused to believe such things even happened. I mean, seriously all you gotta do is throw out the “Einstein said” card :slight_smile:

Seems there is some truth to the story. From an article cited on a recent thread, Relativity in the Global Positioning System by Neil Ashby.

The article goes on further to describe a disagreement about a more detailed question about the exact correction of GR effects, and an experiment to verify the understanding.

Thanks for this. I wonder who those people were, and whether they correspond to the “top brass” in question.