ESA looking to define a time standard for the Moon - Page 1
Forum section: electronics / general

author: Halcyon
author_rank: Unknown
timestamp: March 02, 2023, 12:55:01 am
content: https://www.esa.int/Applications/Navigation/Telling_time_on_the_MoonReally interesting reading.I'd love to see what a "time zone" would look like outside of Earth.

author: coppercone2
author_rank: Super Contributor
timestamp: March 02, 2023, 04:15:10 am
content: They should put a LF time beacon on the moon too. I wonder if they can send the Loran hardware up there, must be some left in reserve.If you start small scale lunar manufacturing, a LF beacon would be perfect to allow for cheap precise easy to make lunar electronics.

author: SiliconWizard
author_rank: Super Contributor
timestamp: March 02, 2023, 05:48:42 am
content: Not sure I really see a point not being at Earth time, although I admit I don't know how "days" feel up there. That must be a harsh enough change that time itself is probably only a minor consideration.Anyway, I guessQuote

author: ConKbot
author_rank: Super Contributor
timestamp: March 02, 2023, 12:34:42 pm
content: Well I'm sure the people in the meetings needed something to do.

author: nctnico
author_rank: Super Contributor
timestamp: March 02, 2023, 01:34:23 pm
content: Quote from: Halcyon on March 02, 2023, 12:55:01 amAdd to that the fact that the moon is circuling around the earth so there will also be Lorenz contraction to account for. With missions to Mars in mind (different speed compared to earth so a different time -again-), it is time to think about a universal solar time which is equal within the entire solar system. A second isn't a fixed value...

author: xrunner
author_rank: Super Contributor
timestamp: March 02, 2023, 01:55:49 pm
content: MST - Moon Standard Time.

author: Stray Electron
author_rank: Super Contributor
timestamp: March 02, 2023, 02:28:45 pm
content: Quote from: xrunner on March 02, 2023, 01:55:49 pmMST is already taken; Mountain Standard Time.What's wrong with Coordinated Universal Time? Or this group just looking for an excuse to name something else for Martin Luther King, George Floyd or one of the other PC counter culture icons?

author: tggzzz
author_rank: Super Contributor
timestamp: March 02, 2023, 03:20:42 pm
content: I see three main issues:defining a time system for on and orbiting the moonaccounting for the astronomical and relativistic differencesdefining the time visible on earthThe first seems tractable, and relatively boring.The second is well known from physical principles, but the details are probably difficult to resolve.The third I simply don't understand. Imagine sending pings between the earth and moon. If someone sends ping1the earth at time t, the signal will take 1s to reach the moon, and an instantaneous ping2response would arrive back on earth at time t+2. Earth then sends ping3.At what time do all parties agree the ping1received on the moon?At what time do all parties agree the ping2received on earth?At what time do all parties agree the ping3received on the moon?There are already analogies on earth. For example, the high frequency trading mob have to deal with the latency between Chicago, New York and London - and use it to their benefit during arbitrage trades. On a smaller scale, the path delay across a modern IC is much longer than the gate delay, and can be several clock cycles.Leslie Lamport's seminal papers had something to say about this back in 1978http://research.microsoft.com/users/lamport/pubs/time-clocks.pdfHe won a Turing Award for that!https://amturing.acm.org/award_winners/lamport_1205376.cfm

author: MarkS
author_rank: Unknown
timestamp: March 02, 2023, 04:00:12 pm
content: Quote from: Stray Electron on March 02, 2023, 02:28:45 pmLST? Lunar Standard Time?

author: nctnico
author_rank: Super Contributor
timestamp: March 02, 2023, 05:11:16 pm
content: UST Universal Space Time

author: Stray Electron
author_rank: Super Contributor
timestamp: March 02, 2023, 05:47:26 pm
content: Quote from: tggzzz on March 02, 2023, 03:20:42 pmI wonder if they'll want to divide Moon Time into zones like they did with time zones on the earth? If local Moon Time roughly follows the lunar sun rise and sun set as it does on earth, then Moon Time Zones will be completely out of sync with anything that we're familiar with.It sounds like someone is about to propose a very complex answer to a problem that really doesn't exist yet.

author: tggzzz
author_rank: Super Contributor
timestamp: March 02, 2023, 08:03:59 pm
content: Quote from: karpouzi9 on March 02, 2023, 06:09:09 pmThat answer may turn out to be relevant to the part of my post that you didn't quote. It isn't relevant to the part you did quote.

author: tggzzz
author_rank: Super Contributor
timestamp: March 03, 2023, 09:55:56 pm
content: Quote from: karpouzi9 on March 03, 2023, 08:59:50 pmThat isadifference. It is not theonlydifference, nor is it the most interesting and difficult to resolve difference.

author: nctnico
author_rank: Super Contributor
timestamp: March 04, 2023, 10:36:12 pm
content: Quote from: karpouzi9 on March 03, 2023, 08:59:50 pmNot quite. Due to the rotational speed of the earth, network packets (or better put: the electrical or optical signals that represent the data) will move at different speeds depending on which direction they are travelling.https://en.wikipedia.org/wiki/Sagnac_effectPrecise time distribution systems have to compensate for this effect.

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: March 04, 2023, 10:53:59 pm
content: Will there also be a Moonlight Savings Time?