30 Mar 18
Originally posted by @deepthoughtActually you did not explain why it means that it is difficult to build an account of curvature. You said it, but did not explain it.
I did say that time dilation is a scalar. I explained what I meant (described by a single number rather than needing several like a vector does) and why it means that it is difficult to build an account of curvature, a tensor quantity, based on it.
30 Mar 18
Originally posted by @metal-brainThere aren't enough degrees of freedom. The curvature tensor has 20 independent components, time dilation only one.
Actually you did not explain why it means that it is difficult to build an account of curvature. You said it, but did not explain it.
What I'm saying is an oversimplification. David Hilbert produced a derivation of the Einstein Field equations starting with scalar quantities. But the scalar curvature is not the same quantity as time dilation, it is the same in all frames of reference which time dilation is not. Basically, it won't work at the level of the Hilbert derivation because time dilation depends on what frame of reference the observer is in. It won't work in a frame dependent way because of this problem with the number of degrees of freedom. I'll write another post later, I'm on a smartphone now and typing lots is a pain.
05 Apr 18
Originally posted by @deepthoughtYou said you would write another post. Did you change your mind?
There aren't enough degrees of freedom. The curvature tensor has 20 independent components, time dilation only one.
What I'm saying is an oversimplification. David Hilbert produced a derivation of the Einstein Field equations starting with scalar quantities. But the scalar curvature is not the same quantity as time dilation, it is the same in all ...[text shortened]... of freedom. I'll write another post later, I'm on a smartphone now and typing lots is a pain.
Someone said that time dilation was predicted as a result of GR theory. Is that true? If so how did that evolve? Was it Einstein himself that predicted that or other physicists?
05 Apr 18
2 edits
Originally posted by @metal-brainBig Al in fact made the formula for time dilation:
You said you would write another post. Did you change your mind?
Someone said that time dilation was predicted as a result of GR theory. Is that true? If so how did that evolve? Was it Einstein himself that predicted that or other physicists?
"
Time Dilation
It turns out that as an object moves with relativistic speeds a "strange" thing seems to happen to its time as observed by "us" the stationary observer (observer in an inertial reference frame). What we see happen is that the "clock" in motion slows down according to our clock, therefore we read two different times. Which time is correct??? well they both are because time is not absolute but is relative, it depends on the reference frame. Let's look at the following classic example. There is a set of twins, one an astronaut, the other works for mission control of NASA. The astronaut leaves on a deep space trip traveling at 95% the speed of light. Upon returning the astronauts clock has measured ten years, so yhe astronaut has aged 10 years. However, when the astronaut reunites with his earth bound twin, the astronauthe sees that the twin has aged 32 years! This is explained due to the fact that the astronaut's twin is traveling at relativistic speeds and therefore his "clock" is slowed down.
Let's see how we can calculate the time "difference". The equation for calculating time dilation is as follows:
t = t0/(1-v2/c2)1/2
where: t = time observed in the other reference frame
t0 = time in observers own frame of reference (rest time)
v = the speed of the moving object
c = the speed of light in a vacuum
so in our problem we will let v = .95c, t0 = 10 years and we will solve for t which is the time that the earth bound brother measures.
t = 10/(1- (.95c)2/c2)1/2
t = 10/(1- .952)1/2
t = 10/ .312
t = 32 years
(the time the earth bound brother measures)"
From this site:
http://www.phy.olemiss.edu/HEP/QuarkNet/time.html
In the example given, the Earthbound twin ages 32 years while the astronaut ages 10 and for the astronaut he effectively (From his POV) is going 3 times the speed of light. Of course that is only for him and the ship, if he goes out 32 light years and stays a year, he then goes back, 65 years will have gone by on Earth but 21 years goes by for the astronaut. That is at .95c. it gets more extreme if you can manage to go say .999c which puts the astronaut going effectively 22 times the speed of light so now say he goes out 22 light years away, stays for 1 year, comes back, he ages 3 years but the Earth bound dude ages 45 years. Great for the astronaut except he comes home to a time where everything changed.
Compare that to a Rip Van Winkle spending 50 years or so starting in 1968, wakes up now in 2018. He would be a bit confused, eh. 'what the hell is a cell phone' and we landed on the MOON?
https://www.scientificamerican.com/article/einsteins-time-dilation-prediction-verified/
05 Apr 18
Originally posted by @sonhouseNo, that is special relativity. I said GR. Has to be about gravity.
Big Al in fact made the formula for time dilation:
"
Time Dilation
It turns out that as an object moves with relativistic speeds a "strange" thing seems to happen to its time as observed by "us" the stationary observer (observer in an inertial reference frame). What we see happen is that the "clock" in motion slows down according to our clock, there ...[text shortened]... MOON?
https://www.scientificamerican.com/article/einsteins-time-dilation-prediction-verified/
05 Apr 18
6 edits
Originally posted by @metal-brainTime dilation effects are implies by BOTH special relativity AND general relativity.
No, that is special relativity. I said GR. Has to be about gravity.
Haven't you heard of 'gravitational time dilation'?
https://en.wikipedia.org/wiki/Gravitational_time_dilation
"..Gravitational time dilation is a form of time dilation, an actual difference of elapsed time between two events as measured by observers situated at varying distances from a gravitating mass. The higher the gravitational potential (the farther the clock is from the source of gravitation), the faster time passes. Albert Einstein originally predicted this effect in his theory of relativity and it has since been confirmed by tests of general relativity....
...
Gravitational time dilation was first described by Albert Einstein in 1907[3] as a consequence of special relativity in accelerated frames of reference. In general relativity, it is considered to be a difference in the passage of proper time at different positions as described by a metric tensor of space-time....
...
According to the general theory of relativity, gravitational time dilation is copresent with the existence of an accelerated reference frame.
..."
also see gravitational redshift;
https://en.wikipedia.org/wiki/Gravitational_redshift
because that is a DIRECT effect of gravitational time dilation (gravitational redshift also experimentally confirmed to exist)
05 Apr 18
Originally posted by @humyOf course. Just because you call me a moron out of frustration from time to time does not make me one. Sometimes I think you like to fool yourself into thinking I'm a moron. Why else would you overlook the obvious. Deepthought knows I understand that just fine. My reply to sonhouse should have been evident. I suppose you are fooling yourself into thinking I'm illiterate too. I don't know about you...
Time dilation effects are implies by BOTH special relativity AND general relativity.
Haven't you heard of 'gravitational time dilation'?
https://en.wikipedia.org/wiki/Gravitational_time_dilation
"..Gravitational time dilation is a form of time dilation, an actual difference of elapsed time between two events as measured by observers situated at varying di ...[text shortened]... t of gravitational time dilation (gravitational redshift also experimentally confirmed to exist)
The more you treat me like a moron the more I think you are one.
05 Apr 18
13 edits
Metal Brain
Absolutely nothing in that post of mine implies in any way or was meant to imply/insinuate in any way that you are a "moron" or "illiterate" or anything else more insulting other than my hint (my words of "Haven't you heard of..." ) that you think you know more about science than you actually do (that is all).
I apparently had the mistaken belief you could just for once actually want to learn something new about real science which is why I posted links containing info that I thought probably answers some of your questions but, apparently not. I give you educational scientific info and you still just completely trash it all (am I to assume you didn't even bother to read any of the links I provided let alone try and understand or learn any of it?) and throw it back in my face. Now, why do you think I often call you a moron? Hint: your last post is one clue.
05 Apr 18
Originally posted by @humyYou have a desire to teach me? You resent me too much to do that out of kindness. It seems like you are trying to fool yourself into thinking you are smarter than me by copy and pasting excerpts from wikipedia.
Metal Brain
Absolutely nothing in that post of mine implies in any way or was meant to imply/insinuate in any way that you are a "moron" or "illiterate" or anything else more insulting other than my hint (my words of "Haven't you heard of..." ) that you think you know more about science than you actually do (that is all).
I apparently had the mistaken beli ...[text shortened]... ck in my face. Now, why do you think I often call you a moron? Hint: your last post is one clue.
No, you are not helping. If you had followed this thread you would know I am already aware of these things. I think you know that though. These posts are the result of you interjecting into a question I asked Deepthought. I would never ask you. You are insulting and have a strong desire to bully me and others. I hate bullies. That is why I hate you. You are a kick down kind of guy.
05 Apr 18
Originally posted by @metal-brainSo if Hitler had been Einstein and did the relativity thing but still went out and killed 6 million Jews would you reject Relativity?
You have a desire to teach me? You resent me too much to do that out of kindness. It seems like you are trying to fool yourself into thinking you are smarter than me by copy and pasting excerpts from wikipedia.
No, you are not helping. If you had followed this thread you would know I am already aware of these things. I think you know that though. These ...[text shortened]... to bully me and others. I hate bullies. That is why I hate you. You are a kick down kind of guy.
06 Apr 18
Originally posted by @metal-brainSee the thread on "spin at the poles" to see how to get from the metric, a quantity that curvature can be calculated from, to an expression for time dilation.
You said you would write another post. Did you change your mind?
Someone said that time dilation was predicted as a result of GR theory. Is that true? If so how did that evolve? Was it Einstein himself that predicted that or other physicists?
20 Apr 18
1 edit
Originally posted by @metal-brainGravity is the result of quantum entanglement...."Gravitons" are just the term we use to explain how the information from one entangled particle is transfered to the other entangled particle instantaneously.
If space/time is discrete there might be no need for the graviton to explain gravity. My theory is that gravity is caused by the displacement of space/time by matter.
21 Apr 18
Originally posted by @uzlessI've never heard that theory. Is it your own?
Gravity is the result of quantum entanglement...."Gravitons" are just the term we use to explain how the information from one entangled particle is transfered to the other entangled particle instantaneously.
25 Apr 18
Originally posted by @metal-brainHe is talking out his ass, just spewing whatever BS comes to mind ATT, next month he will be back to conspiracy theories, nobody landed on the moon, Hoffa is buried inside Hoover dam, Earth is flat.......
I've never heard that theory. Is it your own?