# Astronauts' time vs. Earth time \[new title\] **URL:** \ **Category:** Factual Questions\ **Created:** [March 21, 2003, 3:01pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099 "2003-03-21T15:01:51Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Bootieman](https://avatars.discourse-cdn.com/v4/letter/b/ecd19e/32.png) [@Bootieman](https://boards.straightdope.com/u/Bootieman)\ **Post date:** [March 21, 2003, 3:01pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/1 "2003-03-21T15:01:51Z")
Hey folks… this is gonna sound REALLYY dumb… but… I can’t seem to wrap my brain around the correct concept here… any help for a newbie? Here’s my question… If Astronauts circle the globe once every 90 minutes, haven’t we, on the planet surface aged 24 hours during that time? What I’m suggesting is obvious, and I know it can’t be right, but why doesn’t it work out that way? I’m probably gonna get flamed for asking such a dumb question, but I’m losing sleep and desparate… help!! Thanks everyone… 😃 ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 21, 2003, 3:07pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/2 "2003-03-21T15:07:11Z")
Nah, we don’t flame here for asking questions, no matter how dumb. 😉 To answer your question, no. Effects of relativity aside, we age 90 minutes here on earth, same as the astronauts in orbit. In short, 90 minutes is 90 minutes. Remember, the space vehichle the astronauts are in is moving much faster than a fixed on the ground. ---
**Author:** ![micco](https://avatars.discourse-cdn.com/v4/letter/m/5f8ce5/32.png) [@micco](https://boards.straightdope.com/u/micco)\ **Post date:** [March 21, 2003, 3:10pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/3 "2003-03-21T15:10:21Z")
No flames here, sorry… Until the astronauts approach relativistic speeds, their time is the same as ours. The fact that they circle the globe in 90 minutes doesn’t mean that the earth completed a total revolution in that time. The earth turned some (about 22 degrees) but didn’t complete a day’s revolution. Picture it like this: say you’re walking around a track at one lap per hour. A jogger runs past you at 10 laps/hour and pretty soon he catches up an passes you again. You’ve only gone around 1/10th of the track between the two times he passed you. The fact that he passed you doesn’t count as a whole lap for you, so only six minutes passed for each of you. ---
**Author:** ![Bootieman](https://avatars.discourse-cdn.com/v4/letter/b/ecd19e/32.png) [@Bootieman](https://boards.straightdope.com/u/Bootieman)\ **Post date:** [March 21, 2003, 3:16pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/4 "2003-03-21T15:16:34Z")
Ahhhh… my brain is beginning to wrap around it now… I wasn’t thinking about how much the earth was turning …lol Thanks for not flaming… I’m squeamish when it comes to burns… 😃 ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 21, 2003, 3:19pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/5 "2003-03-21T15:19:33Z")
Not quite, **micco**. Gravity plays a role in the passage of time, per relativity: [quote] According to Einstein’s theory of gravity and space-time – called “general relativity” – clocks in strong gravity tick slower than clocks in weak gravity. Because gravity is weaker on the ISS than at Earth’s surface, PARCS should accumulate an extra second every 10,000 years compared to clocks ticking on the planet below. PARCS won’t be there that long, but the clock is so stable that it will reveal this effect in less than one year.\*\* From [url=http://science.nasa.gov/headlines/y2002/08apr\_atomicclock.htm[this article. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 21, 2003, 3:20pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/6 "2003-03-21T15:20:42Z")
Oops. [Fixed link](http://science.nasa.gov/headlines/y2002/08apr_atomicclock.htm) ---
**Author:** ![NYR407](https://avatars.discourse-cdn.com/v4/letter/n/bbe5ce/32.png) [@NYR407](https://boards.straightdope.com/u/NYR407)\ **Post date:** [March 21, 2003, 3:26pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/7 "2003-03-21T15:26:03Z")
Welcome aboard **Bootieman**. Just as an FYI, when you start a thread you should make the title more descriptive to the question. Generic titles may not attract the members with knowledge of a specific topic to read your thread. A Mod may stop by and change the title for you. Anyway, it takes the Earth 24 hours to circle the **sun**. A space craft orbiting the Earth in 90 mins is still 90 mins in Earth time. I think the better question is if the space craft circled the sun in 90 mins would they have aged a day? ---
**Author:** ![micco](https://avatars.discourse-cdn.com/v4/letter/m/5f8ce5/32.png) [@micco](https://boards.straightdope.com/u/micco)\ **Post date:** [March 21, 2003, 3:27pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/8 "2003-03-21T15:27:51Z")
> [@](#): > > \*Originally posted by Q.E.D. \* > \*\*Not quite, **micco**. Gravity plays a role in the passage of time, per relativity: \*\* Sorry for my negligence. Next time I won’t bother to reply until I’ve composed a completely thorough and referenced thesis. I foolishly believed a simple analogy would be more helpful than a discourse on relativity. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 21, 2003, 3:29pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/9 "2003-03-21T15:29:07Z")
> [@](#): > > \*Originally posted by NYR407 \* > \*\*Anyway, it takes the Earth 24 hours to circle the **sun**. A space craft orbiting the Earth in 90 mins is still 90 mins in Earth time. \*\* Huh? Go have some coffee. I’ll wait while you figure out what’s wrong with that sentence. 😉 ---
**Author:** ![Early\_Out](https://avatars.discourse-cdn.com/v4/letter/e/6f9a4e/32.png) [@Early\_Out](https://boards.straightdope.com/u/Early_Out)\ **Post date:** [March 21, 2003, 3:29pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/10 "2003-03-21T15:29:20Z")
> [@](#): > > \*Originally posted by NYR407 \* > Anyway, it takes the Earth 24 hours to circle the **sun**. We’ll all let you think about that for a few minutes before the pile-on starts! ---
**Author:** ![micco](https://avatars.discourse-cdn.com/v4/letter/m/5f8ce5/32.png) [@micco](https://boards.straightdope.com/u/micco)\ **Post date:** [March 21, 2003, 3:30pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/11 "2003-03-21T15:30:08Z")
> [@](#): > > \*Originally posted by NYR407 \* > \*\*I think the better question is if the space craft circled the sun in 90 mins would they have aged a day? \*\* Relativistic quibbles aside, motion around the sun has nothing whatsoever to do with the passage of time. The earth’s rotation about its axis and about the sun are simply mechanisms we use to measure time. You could move arbitrarily through the universe and time would still pass. ---
**Author:** ![Early\_Out](https://avatars.discourse-cdn.com/v4/letter/e/6f9a4e/32.png) [@Early\_Out](https://boards.straightdope.com/u/Early_Out)\ **Post date:** [March 21, 2003, 3:30pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/12 "2003-03-21T15:30:39Z")
Oh, I may have spoken too late! ---
**Author:** ![Bootieman](https://avatars.discourse-cdn.com/v4/letter/b/ecd19e/32.png) [@Bootieman](https://boards.straightdope.com/u/Bootieman)\ **Post date:** [March 21, 2003, 3:35pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/13 "2003-03-21T15:35:28Z")
I wasn’t aware of the whole 24 hours to orbit the sun thing… I think Micco made a lot of sense in layman’s terms (which is what I needed… or a swift kick in the pants…lol) If I stood at one spot lets say… Portland, Maine and watched the shuttle fly over head… 90 minutes later, I’d get to watch it fly over me again… assuming the same trajectory, and I’d have aged 90 minutes… simple when put into simple terms that I can understad… duh!!.. Thanks all!! ---
**Author:** ![Bootieman](https://avatars.discourse-cdn.com/v4/letter/b/ecd19e/32.png) [@Bootieman](https://boards.straightdope.com/u/Bootieman)\ **Post date:** [March 21, 2003, 3:38pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/14 "2003-03-21T15:38:13Z")
Ohhh and I will try and remember to be more desriptive in my headers… 🙂 ---
**Author:** ![NYR407](https://avatars.discourse-cdn.com/v4/letter/n/bbe5ce/32.png) [@NYR407](https://boards.straightdope.com/u/NYR407)\ **Post date:** [March 21, 2003, 3:39pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/15 "2003-03-21T15:39:18Z")
:smack: Doh!! 24 hours, 3651/4 days. What’s the difference. 🙂 See what happens when you don’t title threads correctly.😃 ---
**Author:** ![Early\_Out](https://avatars.discourse-cdn.com/v4/letter/e/6f9a4e/32.png) [@Early\_Out](https://boards.straightdope.com/u/Early_Out)\ **Post date:** [March 21, 2003, 3:39pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/16 "2003-03-21T15:39:59Z")
> [@](#): > > \*Originally posted by Bootieman \* > \*\*I wasn’t aware of the whole 24 hours to orbit the sun thing… \*\* And a good, thing, too, since it ain’t so. The Earth takes one year to orbit the sun. It takes 24 hours to spin around once on its own axis. But you’ve clearly grasped the answer to your original question, so as long as you can ignore whatever misinformation has been tossed your way, you’ll be just fine! ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 21, 2003, 3:40pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/17 "2003-03-21T15:40:48Z")
The earth _doesn’t_ orbit the sun in 24 hours. I think what **NYR407** was trying to say is sun _appears_ to go around the Earth in 24 hours from the point of view of an observer on the ground, but his tang got all tonguled up. The time it takes for the earth to orbit the sun is called a year. ---
**Author:** ![Early\_Out](https://avatars.discourse-cdn.com/v4/letter/e/6f9a4e/32.png) [@Early\_Out](https://boards.straightdope.com/u/Early_Out)\ **Post date:** [March 21, 2003, 3:41pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/18 "2003-03-21T15:41:55Z")
> [@](#): > > \*Originally posted by NYR407 \* > \*\*:smack: Doh!! 24 hours, 365 1/4 days. What’s the difference. 🙂 \*\* Well, I guess 24 hours in Queens just _seems_ like a year.😉 ---
**Author:** ![Tony\_Montana](https://avatars.discourse-cdn.com/v4/letter/t/278dde/32.png) [@Tony\_Montana](https://boards.straightdope.com/u/Tony_Montana)\ **Post date:** [March 21, 2003, 3:46pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/19 "2003-03-21T15:46:00Z")
I _thought_ it took earth 364.25 _days_ to orbit the sun. FYI it’s spelled _Bootyman_ (booty as in arse right?) ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [March 21, 2003, 3:53pm UTC](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099/20 "2003-03-21T15:53:28Z")
And my apologies, **micco** if I came off sounding snarky. I was merely trying to point out for those interested that it’s the gravity difference, rather than the velocity, that creates the relativistic time difference you and I alluded to. [Next page](https://boards.straightdope.com/t/astronauts-time-vs-earth-time-new-title/163099.md?page=2)