time and speed

[orin stepanek]

If the Earths equatorial speed is 1,674.4 km/h or 1,040.4 mi/h.* and orbital speed of 29.77kps 18.5mps or 2572128kmph and 113040 mph.** and speed around the galaxy at 254kps or 21945600 kph* which is 13636400mph and the galaxy speeding through the universe at 300 kps or 29520000 kph or 18342900 mph**
Does the Milky Way move in space or does it just stay put? Archive of Ask the Space Scientist FAQs. NASA/GSFC. "The total speed is about 300 kilometers per second or so." 300 km/s*. Than it would seem that an astronaut moving around the earth would gain very little as far as not aging as much as people on Earth. (Hope I said that right.) Yet; if I remember right. it was measured as to how much less time an astronaut lived compared to the time we Earthbound people did? Any thoughts on this!
** hypertextbook.
* Wikipedia;
any computation errors are my own.
Orin

[Chris Peterson]

If the Earths equatorial speed is 1,674.4 km/h or 1,040.4 mi/h.* and orbital speed of 29.77kps 18.5mps or 2572128kmph and 113040 mph.** and speed around the galaxy at 254kps or 21945600 kph* which is 13636400mph and the galaxy speeding through the universe at 300 kps or 29520000 kph or 18342900 mph**
Does the Milky Way move in space or does it just stay put? Archive of Ask the Space Scientist FAQs. NASA/GSFC. "The total speed is about 300 kilometers per second or so." 300 km/s*. Than it would seem that an astronaut moving around the earth would gain very little as far as not aging as much as people on Earth. (Hope I said that right.) Yet; if I remember right. it was measured as to how much less time an astronaut lived compared to the time we Earthbound people did? Any thoughts on this! :?

Everything moves relative to something. Some motion is absolute, as when rotation is involved. The Milky Way is certainly moving linearly with respect to other objects, and is presumably orbiting other objects as well.

An astronaut should actually live longer because of his motion; he is, in effect, younger than the people back home. But it's a difference measured in fractions of a second, and most likely he'll live a shorter life due to increased exposure to cosmic rays and other radiation in space.

[neufer]

An astronaut should actually live longer because of his motion; he is, in effect, younger than the people back home. But it's a difference measured in fractions of a second, and most likely he'll live a shorter life due to increased exposure to cosmic rays and other radiation in space.

Astronauts on the ISS age faster because of their weightless motion. I once worked for a Prof. Carroll 0. Alley at the Univ. of Md. who sent atomic clocks on jet aircraft such that the eastbound clocks were closer to being in free fall and hence ran faster than gravitationally slowed earth clocks or clocks on westbound jet aircraft:

In 1972, scientists flew extremely accurate clocks around the world in both directions on commercial airlines, and were directly able to observe the relativistic "twin paradox" the eastbound clock gained 273 ns and the westbound clock lost 59 ns, matching the predictions of general relativity to within experimental accuracy.

[orin stepanek]

Astronauts on the ISS age faster because of their weightless motion. I once worked for a Prof. Carroll 0. Alley at the Univ. of Md. who sent atomic clocks on jet aircraft such that the eastbound clocks were closer to being in free fall and hence ran faster than gravitationally slowed earth clocks or clocks on westbound jet aircraft:

An astronaut should actually live longer because of his motion; he is, in effect, younger than the people back home. But it's a difference measured in fractions of a second, and most likely he'll live a shorter life due to increased exposure to cosmic rays and other radiation in space.

So which way is it; longer or shorter. Does that mean that if we weren't moving at all we would live forever or???

Orin

[neufer]

So which way is it; longer or shorter.

ISS astronauts have shorter lives compared with their twins on earth.

Does that mean that if we weren't moving at all we would live forever or???

Take the trip to the center of the Milky-Way as suggested in today's APOD

As you go hurdling to you spaghettified doom near the black hole singularity folks on the outside will observe you freezing in place just outside the Milky Way Schwarzschild radius and living there forever like a squashed (but still living) bug on a windshield.

[orin stepanek]

from another post we were discussing traveling at the speed of light!

Edit postReport this postReply with quoteby orin stepanek on Mon Nov 06, 2006 2:11 am

ckam wrote:
orin stepanek wrote:
ckam wrote:
orin, zero cant be longer than another zero.
True! But how do you arrive at 0?flying through space with c, you could arrive anywhere at no time (literally).

Than if we had a machine [ship?] that could bend the space time continuum; [literally create our worm holes;] we could own the deepest reaches of the universe? But what would happen to the time everyone else lived in while we were [maybe weren't] gone? If that's true then the photons life across the universe is 0 time. Interesting!
Orin

So if you can go at c no time exists! I'm thinking time is relevant; an hour is perceived as an hour whether your going as a faster pace of a slower pace. But in reality an hour may be slower of faster. Make sense.
I'm sure if you got caught in a black hole things would start to go pretty fast! but that is theory. I'm not sure how we would perceive it and I don't want to find out.
Orin

[Chris Peterson]

So which way is it; longer or shorter. Does that mean that if we weren't moving at all we would live forever or?

I'll take Neufer's word that it's shorter, since he's looked closely at the problem. In general, if you move away from someone and back, you will be younger than they are. Everybody lives their own lifespan in their own frame; if you move away from the Earth very fast and then return, you may find that everybody you knew has grown old and died, but you will have experienced just a short time, and after you've experienced your allotted 70 or 80 years, you'll die too. Your motion doesn't change the length of your lifetime.

[orin stepanek]

So which way is it; longer or shorter. Does that mean that if we weren't moving at all we would live forever or?

I'll take Neufer's word that it's shorter, since he's looked closely at the problem. In general, if you move away from someone and back, you will be younger than they are. Everybody lives their own lifespan in their own frame; if you move away from the Earth very fast and then return, you may find that everybody you knew has grown old and died, but you will have experienced just a short time, and after you've experienced your allotted 70 or 80 years, you'll die too. Your motion doesn't change the length of your lifetime.

Hey Chris; I'll be 70 in June. Hope I at least get to see Pluto!
There must be a ratio between time and speed; or so I would suppose. Or a bell curve, maybe. It is confusing. http://thefutureofthings.com/video/7962 ... ation.html
I often wondered why a photon moving at the speed of light doesn't run out of energy and simply die; or turn off so to speak. So if it travels across the universe and it had no time it would still be just born. No energy needed.??? Yet it is so easy to stop a beam of light. If you could put a photon inside a ball that had a perfect mirror finish on the inside surface; It ought to stay lit forever in a complete vacuum??? If a complete vacuum were possible.

Orin

[Chris Peterson]

There must be a ratio between time and speed; or so I would suppose.

There is a simple relationship, defined by special relativity.

I often wondered why a photon moving at the speed of light doesn't run out of energy and simply die; or turn off so to speak.

A photon is the carrier of energy; it doesn't "use" energy, any more than any moving object uses energy to keep moving. A photon can, of course, transfer energy to something else.

If you could put a photon inside a ball that had a perfect mirror finish on the inside surface; It ought to stay lit forever in a complete vacuum?

The actual photon will be lost with the first reflection. Photons interact with matter through a scattering process. The photons you see when you look at a star don't come from the star at all, but from your eye. The original photons from the star don't survive to your retina.

[neufer]

I'll be 70 in June. Hope I at least get to see Pluto!

Well, ....have you been good or bad?

[orin stepanek]

The photons you see when you look at a star don't come from the star at all, but from your eye. The original photons from the star don't survive to your retina.

You may be right; how can that be. I would think that if the photons don't survive ; you wouldn't see any stars at all.

Orin

[Chris Peterson]

You may be right; how can that be. I would think that if the photons don't survive ; you wouldn't see any stars at all. :?

Because when a photon interacts with transparent matter what happens is that the photon is absorbed and another one with very nearly the same trajectory and energy is produced. That's actually what scattering is. The depth a photon can survive in a transparent medium is typically very shallow. Between the time a light "ray" enters a medium and leaves it again, there are many such scattering events- the thicker the medium, the more events.

So while the photons that strike your retina from a star will normally have about the same count, energy, and direction as those that left the star, they aren't actually the same photons.

[makc]

@neufer, if we could spin astronauts in an orbit a bit faster and maintain same radius using attached rocket, we could reverse this and go back to situation where they age less. it would be interesting to calculate how much additional speed would it take for them to cancel gravity effect exactly. shouldn't be a lot.

[Chris Peterson]

@neufer, if we could spin astronauts in an orbit a bit faster and maintain same radius using attached rocket, we could reverse this and go back to situation where they age less. it would be interesting to calculate how much additional speed would it take for them to cancel gravity effect exactly. shouldn't be a lot.

To a first order, I'd think this would be very close to canceling out the orbital motion completely, so you would remain over the same part of the Earth. For a low Earth position, this would result in your traveling about the same speed as those below you, and feeling about the same gravitational pull. The energy requirements of the rocket needed to maintain such a position would be huge, of course.

[neufer]

@neufer, if we could spin astronauts in an orbit a bit faster and maintain same radius using attached rocket, we could reverse this and go back to situation where they age less. it would be interesting to calculate how much additional speed would it take for them to cancel gravity effect exactly. shouldn't be a lot.

You mean TO ADD gravity:
http://www.youtube.com/watch?v=GdrqeAKNLM8
http://www.youtube.com/watch?v=bbUGT--UfJE

[makc]

spinning astronauts as described will obviously create centrifugal force, yes, but what I had in mind was that the effect can be seen as a consequence of gravity slowing our time here down, versus unaffected astronauts. i.e., word "cancel" was tied to "effect", and word "gravity" was tied to "effect", but there's no connection between "cancel" and "gravity" in my post

[neufer]

spinning astronauts as described will obviously create centrifugal force, yes, but what I had in mind was that the effect can be seen as a consequence of gravity slowing our time here down, versus unaffected astronauts. i.e., word "cancel" was tied to "effect", and word "gravity" was tied to "effect", but there's no connection between "cancel" and "gravity" in my post

Perhaps you can get SkyGazerGPS to drive you around in his Prius.

• Note: Gravitational wells result in time slowing down since photons must lose energy/frequency escaping from them. For objects in free fall (circular orbit or on escape trajectories) time runs somewhat faster in part because photons lose less energy/frequency escaping from such orbits to outer space.
  
  However, "centrifugal force," per se, has NO effect on time other than to clarify who is actually moving and who is stationary for "twin paradox" reunion situations. For example: particles running around circular particle accelerators undergo tremendous accelerations; however, particle accelerator time dilation is determined purely by special relativity. Highly radioactive particles can be sent on a journey in a circular particle accelerator and returned and they will have decayed much less than their "stay at home" twins as determined purely by special relativity.
  
  Folks in the 2001 rotating space station *WILL NOT* age as slowly as folks on earth simply because they feel 1g of "centrifugal force." Rather they will age just slightly slower than the folks in the center of the 2001 rotating space station due entirely to the special relativity "twin paradox effect." To age as slowly as the folks on earth the rotating space station would have to generate spin velocities comparable to the orbital motion itself.

[orin stepanek]

I'll be 70 in June. Hope I at least get to see Pluto!

Well, ....have you been good or bad?

I'm full of sugar; I'm full of spice; I'm kind of naughty; but I'm naughty and nice.

Orin

[orin stepanek]

So while the photons that strike your retina from a star will normally have about the same count, energy, and direction as those that left the star, they aren't actually the same photons.

I'm sorry Chris; but that's a little confusing. Your pretty up on this stuff; so your probably right. but to dwell a little deeper; how can they possibly find this out??? Thanks for patients with me.

Orin

[neufer]

Well, ....have you been good or bad?

I'm full of sugar; I'm full of spice; I'm kind of naughty; but I'm naughty and nice.

I though Orin was a boy's name.

[orin stepanek]

Well, ....have you been good or bad?

I'm full of sugar; I'm full of spice; I'm kind of naughty; but I'm naughty and nice.

I though Orin was a boy's name.

It is; and I'm straight. My spices are the hot peppers. I do get sugar cravings though! There was a song though; that had similar words in it. Your good or bad reference reminded me of it. I looked on the net; but I couldn't find it.

Orin

[geckzilla]

Ahaha, 70, really? You don't type like it, Orin. I've always wondered what the median age for this forum is. I get the feeling I'm the young and dumb one.

[makc]

Folks in the 2001 rotating space station *WILL NOT* age as slowly as folks on earth simply because they feel 1g of "centrifugal force." Rather they will age just slightly slower than the folks in the center of the 2001 rotating space station due entirely to the special relativity "twin paradox effect." To age as slowly as the folks on earth the rotating space station would have to generate spin velocities comparable to the orbital motion itself.[/list]

yes that is what I had in mind... but "comparable to the orbital motion itself"? feels like too much.

[orin stepanek]

Ahaha, 70, really? You don't type like it, Orin. I've always wondered what the median age for this forum is. I get the feeling I'm the young and dumb one.

That's because I'm still 69. What does a 70 year old type like; I'll be there soon. You should say young and innocent! It sounds better. 8)

Orin

[geckzilla]

Oh, I'll readily admit to being dumb but innocence is not an appropriate adjective for me any more. I'm young but not that young.

And I'm just being stereotypical about old people and computers.