Time standing still?

[jajrussel]

What conditions are needed in order for time to stand still. Theoretically, I thought that all that was needed is to travel at c. When I try to Invision this the only way I can think to start to give such a place dimension is using c as a measure of distance.

Mentally it doesn't seem to work. The world gets very large but then you have to stop because time stops. But... The speed of light is invariant this indicates that turning on a flash light so that I can see what I want to measure would still produce a beam if light traveling at c. This thought seems to me to create an endless loop, but when I think infinite? Infinite loops of c? And if there is a light beam for the traveler at c how can time be said to stop? Don't you need time to measure c?

Mentally I want to insist that if time stops then there is no light. I may be completely wrong in the thinking but light seems to be necessary for measuring in our world, but then I think a blind person doesn't require light to measure, but they have been taught to use a sited persons way of measure, which seems limited by c? Which seems to suggest that because c is invariant, time cannot stand still. The light beam still shines at c.

If time cannot stand still then then next thought is we obviously cannot travel at c. Nothing new... This seems to suggest a numbering system. Like c is as close as you can get to something. If c is not that something, but is as close as you can get to it then what is it that you can not achieve? it seems to me that time standing still might be it. So, can time stand still if c is the limit?

I was reading another thread about the big bag/sudden expansion and the above is where my thoughts ended up.

Note I may not actually need to use c as a units of measure, but I'm not sure that would change how I got to the question.

Edited March 27, 2019 by jajrussel
A second thought

[nevim]

Sometimes, I think you get a little too deep . But what would I know .

 

[beecee]

52 minutes ago, jajrussel said:

What conditions are needed in order for time to stand still. Theoretically, I thought that all that was needed is to travel at c. When I try to Invision this the only way I can think to start to give such a place dimension is using c as a measure of distance.

Mentally it doesn't seem to work. The world gets very large but then you have to stop because time stops. But... The speed of light is invariant this indicates that turning on a flash light so that I can see what I want to measure would still produce a beam if light traveling at c. This thought seems to me to create an endless loop, but when I think infinite? Infinite loops of c? And if there is a light beam for the traveler at c how can time be said to stop? Don't you need time to measure c?

Mentally I want to insist that if time stops then there is no light. I may be completely wrong in the thinking but light seems to be necessary for measuring in our world, but then I think a blind person doesn't require light to measure, but they have been taught to use a sited persons way of measure, which seems limited by c? Which seems to suggest that because c is invariant, time cannot stand still. The light beam still shines at c.

If time cannot stand still then then next thought is we obviously cannot travel at c. Nothing new... This seems to suggest a numbering system. Like c is as close as you can get to something. If c is not that something, but is as close as you can get to it then what is it that you can not achieve? it seems to me that time standing still might be it. So, can time stand still if c is the limit?

I was reading another thread about the big bag/sudden expansion and the above is where my thoughts ended up.

Note I may not actually need to use c as a units of measure, but I'm not sure that would change how I got to the question.

Time always passes at one second per second, period, in your own frame of reference. It is only when observing the passage of time in another frame that dilation and length contraction occurs. And in that other frame, according to whoever resides there,  he or she will like you see time also passing at one second per second in that frame. Like you though, if he observes your passage of time, he will see it dilated and length contracted. Each frame of reference is as valid as the other.

Edited March 27, 2019 by beecee

[Ghideon]

 

41 minutes ago, beecee said:

Time always passes at one second per second, period, in your own frame of reference. It is only when observing the passage of time in another frame that dilation and length contraction occurs. And in that other frame, according to whoever resides there,  he or she will like you see time also passing at one second per second in that frame. Like you though, if he observes your passage of time, he will see it dilated and length contracted. Each frame of reference is as valid as the other.

Good explanation. +1

1 hour ago, jajrussel said:

And if there is a light beam for the traveler at c how can time be said to stop? Don't you need time to measure c?

Note that the photon is not a valid frame of reference in relativity. As far as I know the math of SR and GR does not describe what is happening from the photons point of view. 

[jajrussel]

1 hour ago, nevim said:

Sometimes, I think you get a little too deep . But what would I know .

 

before I post something I always worry because I know the limit of my intellect. Memory is the limit. Mine sucks. If it didn't I'd be able to read ( on the shoulders of Giants ) then be fairly confident that I would never have to ask another question because I would be able to figure things out on my own without, but then I would be in the same position I am now. Do I allow my limit to prevent me from participating?

I used to have to swim across a river to get home. I had another choice I could have walked a very long way round to the nearest bridge to get to the other side. But every day after washing the boat I would check the tide, walk in the appropriate direction the distance I needed then enter the river and swim across to the other side so that when I exited the river I would be as directly across the boat as possible, cause I got there home was half a block directly away from the river.

Occasionally, I would start to worry and just sit on the boat and look at the other side of the river. Until l finally decided that sitting there wasn't getting me home. Someone could have rowed across in a dingy and and picked me up, but that only happened once it had been a tough day out the tide was running fast and he was afraid that I would drown. At least that is what he said when I asked what the special occasion was.

We always offloaded on the other side before putting the boat where it was kept and at the last minute the party decided they wanted their catch cleaned, so I think he just wanted help cleaning the rather large catch of that day, but he gave me an extra forty dollars for a half an hour's work and I got home dry.

Your right... I do get a little too deep... But do I delete what I've written? No one has to really know the limit of my intellect but I post anyway, usually. Not always...

Sometimes the only thing that stops me from rambling on is the notification that someone has replied to my post, so I'll stop here to see what they have said... 

Edited March 27, 2019 by jajrussel

[nevim]

Oh my Dog!!!

What an experience!!! Sorry that you went through that.

No, don’t ever stop either participating or imagining .

[jajrussel]

1 hour ago, beecee said:

Time always passes at one second per second, period, in your own frame of reference. It is only when observing the passage of time in another frame that dilation and length contraction occurs. And in that other frame, according to whoever resides there,  he or she will like you see time also passing at one second per second in that frame. Like you though, if he observes your passage of time, he will see it dilated and length contracted. Each frame of reference is as valid as the other.

I thought of an explanation of time standing still that only requires momentum. Not a theoretical travel of c, but right in the middle of explaining the thought my tablet shut down and all was gone. Probably a blessing for all...

1 hour ago, Ghideon said:

Note that the photon is not a valid frame of reference in relativity. As far as I know the math of SR and GR does not describe what is happening from the photons point of view

What theoretically happens to someone entering a sufficient sized gravity well. I've read that for them time would stop. Wouldn't that be in their reference frame as well as the observers?

15 minutes ago, nevim said:

What an experience!!! Sorry that you went through that.

Actually, now I dream of days off endless Summers. I want it back. Oh well... Sigh!

Edited March 27, 2019 by jajrussel

[dimreepr]

6 hours ago, jajrussel said:

before I post something I always worry because I know the limit of my intellect. Memory is the limit. Mine sucks. If it didn't I'd be able to read ( on the shoulders of Giants ) then be fairly confident that I would never have to ask another question because I would be able to figure things out on my own without, but then I would be in the same position I am now. Do I allow my limit to prevent me from participating?

 

Why worry? self-deprecation is cute but never an excuse.

We all have our limits. 

[Ghideon]

5 hours ago, jajrussel said:

What theoretically happens to someone entering a sufficient sized gravity well. I've read that for them time would stop. Wouldn't that be in their reference frame as well as the observers?

If I interpret "a sufficient sized gravity well" as "close to a black hole" then a short* attempt to explain would be:
For an observer far away from the black hole the time would seem to slow down for the individual heading towards the black hole. When the individual is close to the event horizon of the black hole the distant observer would see individual age slower and slower; time "almost" freezes but it would not seem to stop completely**.
But to the individual close to the black hole the time still runs as usual, a watch would seem to run at normal speed with time passing at one second per second in that frame.
As far as I know, when the individual close to the black hole looks up, the incoming light would look blue shifted and distant events would seem to happen faster. 
For more details the concept of proper time might be of interest: https://en.wikipedia.org/wiki/Proper_time 

 

*) The math of GR including Schwarzschild coordinates, Kruskal–Szekeres coordinates and more explains details. But I better leave those topics to other forum members with more knowledge.
**)  There are also red shift and other effects due to strong gravitation, out of scope for this simple post

[beecee]

1 hour ago, Ghideon said:

If I interpret "a sufficient sized gravity well" as "close to a black hole" then a short* attempt to explain would be:
For an observer far away from the black hole the time would seem to slow down for the individual heading towards the black hole. When the individual is close to the event horizon of the black hole the distant observer would see individual age slower and slower; time "almost" freezes but it would not seem to stop completely**.

Just adding to your answer, from the observers point of view, the foolhardy person approaching the BH, besides seeing time slow down, would see him or her  gradually further and further redshifted until fading from the viewing capabilities of the instruments of the observer. Again, from that foolhardy person's point of view, he would continue approaching and crossing the EH into the BH, as though nothing has happened...ignoring tidal gravitational effects.