How To Do Astronauts Experience Time Differently in Space?

[David-J-Franks]

Truthseeker007

You asked: "On that matter I heard somewhere isn't the light from the sun we are getting today from 1,000 years ago or so? So we won't even live in this time to get the light that the energy the sun has now. What do you make of that?"

It is difficult to follow the path of any one photon (if, indeed, that statement means anything at all) but, as theory goes, energy swaps around between photons for (what I regard as) an absurdly long time in the radiative zone (1000 years may be a puny estimate) but once it leaves the photosphere I think it only takes 8 minutes or so to reach us.

As I said, it may be meaningless to try to follow the existence of a single photon as it begins in the gamma ray part of the electromagnetic spectrum and gradually 'degrades' (but not as the same photon) until emitted in visible wavelengths.

Oh well, more coffee is what I need right now ...

Cat

You've got me interested now:

(1000 years may be a puny estimate) but once it leaves the photosphere I think it only takes 8 minutes or so to reach us.

Looks right on both counts.

it begins in the gamma ray part of the electromagnetic spectrum and gradually 'degrades' (but not as the same photon) until emitted in visible wavelengths.

Interesting about the gamma-ray, to be honest, it never even occurred to me that the light came from the core. Do you think some is coming from the surface as well? The only problem is that all the articles I found on it seemed to assume or imply it's the same photon and it just changes frequency with each collision - needs more checking?

I'm propping myself up with 50% cocoa dark chocolate (dark energy)

'Steady State of The Infinite' theory
infinite space - infinite universes - no beginning - no end​

 

[David-J-Franks]

Yes you are correct I was thinking of how long it takes light to get out from the inside of the Sun. Which I found this:

According to the famous 'drunkard's walk' problem, the distance a drunk, making random left and right turns, gets from the lamp post is his typical step size times the square root of the number of steps he takes. For the sun, we know how far we want to go to get out....696,000 kilometers, we just need to know how far a photon travels between emission and absorption, and how long this step takes. This requires a bit of physics!

The interior of the sun is a seathing plasma with a central density of over 100 grams/cc. The atoms, mostly hydrogen, are fully stripped of electrons so that the particle density is 10^26 protons per cubic centimeter. That means that the typical distance between protons or electrons is about (10^26)^1/3 = 2 x 10^-9 centimeters. The actual 'mean free path' for radiation is closer to 1 centimeter after electromagnetic effects are included. Light travels this distance in about 3 x 10^-11 seconds. Very approximately, this means that to travel the radius of the Sun, a photon will have to take (696,000 kilometers/1 centimeter)^2 = 5 x 10^21 steps. This will take, 5x10^21 x 3 x10^-11 = 1.5 x 10^11 seconds or since there are 3.1 x 10^7 seconds in a year, you get about 4,000 years.

NASA IMAGE satellite,Ask the Space Scientist Archive

I love coffee.lol!

Last night I found a video about the sun ready to post today. I looked on your image link and noticed a coincidence. They're both by Dr. Sten Odenwald! Now here's the really odd bit, His image says 4000 years and his video says 170,000 years! It's a great video anyway:

View: https://www.youtube.com/watch?v=Z-UO-RZBQ3U


Dark chocolate anyone?

'Steady State of The Infinite' theory
infinite space - infinite universes - no beginning - no end​

 

[Catastrophe]

Hi. You wrote"
Interesting about the gamma-ray, to be honest, it never even occurred to me that the light came from the core. Do you think some is coming from the surface as well? The only problem is that all the articles I found on it seemed to assume or imply it's the same photon and it just changes frequency with each collision - needs more checking?"

I think you can take it as OK..
You have the nuclear reactions in the core which provide high energy particles. These enter the 'random walk' which takes a long time during which photons cross the radiative zone. Above this is the convective zone which brings photons to the photosphere where they give energy to other photons which are emitted. The donors return to the radiative zone where they receive energy and return to the photosphere.

Think of it as a crowd of people. Someone in the centre gets a big shove and they bump into a neighbour. This process continues as the random walk until someone on the outskirts gets pushed out of the crowd. I apologise for the over-simplistic analogy but it is easy to see that the person receiving the initial shove is not the same one who is ejected from the crowd.

I mentioned above the Open University (Cambridge University Press) publication "An Introduction to the Sun and Stars" which ;has been designed for elementary University courses in Astronomy and Astrophysics … suitable for self-study and will appeal o amateur astronomers as well as undergraduate students. I can thoroughly recommend it.
ISBN-13: 978 0 521 54622 5. Info: www.open.ac.uk or email general-enquiries@open.ac.uk .

Hope this helps

Cat