Astronomy - General Relativity (8 of 17) Proof of Theory: Time Shift
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- čas přidán 23. 07. 2020
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We will learn of the theory of Time Shift was proved using a spinning disc and 3 very accurate atomic clocks and observing that the clocks away from the center of the spinning disc clock slows down.
Next video in this series can be seen at:
• Astronomy - General Re...
Sir iam ur big fan.... hope ur taking care of ur health during this pandemic......
Thank you. We are trying to. So far so good.
@@MichelvanBiezen 👍
Can't wait for next exciting video 😄
So I imagine if you took two electrons spinning around a couple of protons and removed one, then it’s clock would be faster than the one that continues to spin.
Can atomic particles be frozen in time?
Or are they whirlpools of time?
What use would that be?
What’s the gravitational force on your average electron?
-see, once you start asking questions!
(thanks)
I still do not understand how an object that rotates - with no windows to look out of at other objects in the universe for reference - "knows" it is rotating. Direct observation - I close my eyes and spin - I feel it - tells me otherwise.
But, how does Newtonian mechanics show the object rotates? I could just use another reference frame that rotates with me relative to absolute fixed space. But, since there is no such thing as absolute fixed space, I could choose this alternative "rotating frame" as my rest frame. Now, I am at rest relative to it: i.e. I am not rotating.
I imagine: from just your lecture on frame-dragging, that GR will enable me to detect a difference between me standing still vs me rotating: we could somehow measure the drift of spacetime with me, although I don't see how one could do even THAT from WITHIN the rotating object itself: I'd assume you'd have to be outside of it measuring things like redshift / blueshift.
Thank you
You're welcome 🙂
Another thought experiment.
Three masses in a vacuum, two are touching. The two suddenly fire away from each other along a line perpendicular to the third.
Does the third feel a force towards what would be a long split in space time? a sort of negative gravity ripple?
wow ty Michel
A second is difference between two excited levels of cesium atom, how that will change with anything thats rotating or having more mass
That is the mystery of space and the universe. Maybe one day we'll figure out the why. Now we are observing it and we can measure the effects.
Well, if gravity is warping space-time, is acceleration then also warping space-time (since we experiencing the same effect)?
Yes, that appears to be the case, but on Earth the effects are very small.
@@MichelvanBiezen Following thought experiment: Two masses close to each other in Vacuum, one departs away with very high acceleration. Is the resting mass dragged (accelerated) into moving direction of first mass, certainly with decreasing acceleration due to increasing distance between masses? (neglecting that masses attracted each other due to gravity (warping of space time)).
@@criticalthinker2896 no. Pretty sure there was an experiment where they disproved that thought experiment with light
@@criticalthinker2896 That's a great thought experiment TY & IMO yes the acceleration will cause gravity but it will be barely noticeable because Earth's mass = a VAST amount of energy due to c² in E = mc²
Earth's mass ≈ 10²⁵ Kg so Earth's mass energy ≈ 10⁴⁰ joules
Energy = force x distance = ma x distance so to produce the same gravitational effect as Earth you'd need
an acceleration = 10⁴⁰ msᐨ²
divided by (the mass of the thing that you are accelerating x the distance that you accelerate it)
but i suppose that distance would have to be short otherwise the gravitational effect would be spread out over a long distance whereas we want the acceleration to happen abruptly & suddenly so that all the energy is concentrated into a small area
Basically you'd need a shedload of acceleration merely to produce the 10 N of gravity that the Earthlings normally experience every day.
Susskind said: _"We see that, in general, the source of the gravitational field is not just energy density, but it can involve energy flow; it can involve momentum density & they can even involve momentum flow. Now as a rule, the momentum flow or even the energy flow, certainly the momentum flow but even the momentum density, are much smaller than the energy density."_
_"Why do I say that? It has to do with the speeds of light in the formulas. If you put the speeds of light into the formulas, just like energy is always huge because it gets multiplied by: c² but on the other hand momentum is typically not huge because it's just mass times velocity, so velocity is slow if you're in the non-relativistic situation, when velocity is slow, energy is big; energy density is by far the biggest thing, the other components of the energy momentum tensor are much smaller typically decreased by powers of the speed of light."_
from 1:14:48 of the YT vid 'General Relativity Lecture 9' from Dec 2012 (not the 2009 video)
@@MichelvanBiezen TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE, AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE).
By Frank Martin DiMeglio
What is here actually measured, the speed of the atomic clock frequenty or the change of time duration? A metal ruler of 1 meter heated up will not change the actiual lengte of a defind meter.
Think of it this way. The clock being subjected to gravity (or the equivalent of gravity) is in a region of the universe where time runs slower. If you placed 2 people in the place of the 2 clocks, one person (where time runs faster) will be older than the person where time is slower after the experiment. (By the way, you have an interesting on screen name)
What's the difference between clock 2 slowing down to artificial gravity and clock 2 slowing down due to its speed (general versus special relativity)?
That is a VERY good question. If we calculate the velocity need (for a radius of 1 m) to simulate the gravitational pull of a black hole at the event horizon, it is surprisingly only 3.9 x 10^6 m/sec, which is far lower than the speed of light, so that almost the entire effect is due to the simulated gravity, rather than the speed of the clock. We should make a video on that to make it clear.
@@MichelvanBiezen yes please
@Robert Zanatta - There's not a lot of difference. DrPhysicsA explained SR time dilation very nicely. PBS extended the same principle to GR.
DrPhysicsA said:
_"...you could invent a very simple clock. It would consist of 2 mirrors. & what you do is you simply bounce light up & down between the 2 mirrors & every time the light beam hits a mirror it essentially causes a counter to move on."_
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_"& since the distance is known & since the speed of light is invariant, we know that the time to travel from the bottom mirror to the top mirror is going to be the distance d divided by c the speed of light. & that becomes, in a sense, our time measure: 1 movement from the bottom mirror to the top mirror constitutes a time interval which equals: d divided by c. Now suppose that apparatus is in a rocket that is going past the Earth. So here's the Earth with an observer on the Earth. & here's the rocket. & here's the mirror in the rocket."_
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_"Now, the rocket is moving at velocity: v. & for these purposes v will have to be pretty fast: approaching the speed of light. Maybe ½ the speed or ⅗ the speed of light. So what happens? The light leaves the bottom mirror on its way up to the top mirror. But before it gets there, the rocket has moved so that by the time it gets to the top mirror, that top mirror is now here inside the rocket."_
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_"So to the observer on the Earth, what the light beam has appeared to do, is not gone up & down but gone like that."_
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_"So how do the 2 observers, 1 of them inside the rocket & 1 of them on the Earth, compare these 2 events? Well the person inside the rocket says the light simply went up like that."_
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_"The person on the Earth says: 'no it didn't - it went like that'."_
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_"Now we can do some geometry. What we're going to do is we're going to create a right-angled triangle. This is distance: d that was the distance we had here."_ [He points back to the light clock at the beginning]
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_"What is this distance here? Well, it's the velocity of the rocket, which is: v times: the time it took to get from here to here, which we're going to call: t prime. It's the time which the observer on the Earth will reckon that the rocket took to get from here to here. Well now we can do some basic Pythagoras."_
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🖕🖕🖕🖕🖕🖕🖕🖕🖕🖕
d'² = d² + (vt')²
_"But if it takes: t' for the rocket to get from here to here, then..."_
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_"..it also takes: t' for light to get from here to here, & that means that: d' is simply: c times: t prime._
______ ______
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_"....Well we calculated: d_ [He points back to the light clock at the beginning]
_"d is: c times: t_
(ct')² = (ct)² + (vt')²
(ct)² = (ct')² - (vt')²
c²t² = c²t'² - v²t'²
c²t² = t'²(c² - v²)
t² = t'²(1 - v²/c²)
__________
t = t'√ 1 - v²/c²
(From 9:52 of the YT vid 'Spacetime & the Twins Paradox')
So as v approaches c the equation because t = t' times zero. This means when Earth uses telescopes to look onboard the spaceship, they see Picard's crew frozen in time. However, onboard Picard sees his crew running about in normal speed
@Robert Zanatta - In DrPhysicsA's explanation the light clock is moving sideways. PBS in 'When Time Breaks Down' says that a light clock accelerating upwards will also tick slower
let's consider a light clock moves upwards at 1 m/s
2 mirrors are 1 m apart
Light bounces between the mirrors.
Every time the light hits the bottom mirror, a clock ticks forward 1 tick.
Inbetween the mirrors is a see-through plastic which has a high electrical permittivity => the light travels very slowly. It can only move 2 m/s
It starts from the bottom mirror & hits the top mirror after 1 s.
It's then reflected & takes some small amount of time to hit the bottom mirror.
Thus the time it takes the light to go up & down = 1 s + some small amount of time
The light clock stops. Again, the light's moving at 2 m/s & the mirrors are 1 m apart, but this time, the light takes 1 s to travel to the top mirror AND get reflected AND go back AND hit the bottom mirror.
Thus the clock ticks slower when it's moving upwards
Now the light clock starts moving again. However, this time it accelerates from 0 m/s & again the light reaches the top mirror after 1 s & again, it takes some small amount of time to hit the bottom mirror.
Thus a light clock that's accelerating upwards ticks slower than a stationary light clock (at least it does in this example)
Then PBS brings in the equivalence Principle:
A man steps off a roof. He sees himself as stationary like an astronaut floating in space. Earth accelerates upwards towards him. He sees a light clock on the ground. It accelerates towards him & therefore, it ticks slower. Just before he dies, he finds he can look into every neutron & proton. Inside he sees massless gluons bouncing around at speed c, therefore each neutron & proton is a light clock that ticks slowly near Earth.
In 'Does Time Cause Gravity?' PBS says the spacetime around Earth's a bit like mud. Why? Because objects move through time more slowly. It's like they're going through mud.
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You manage to make your car capable of space flight. It's moving through the time dimension near Earth. When your car reaches the mud the left wheel moves slower. Thus your car rotates towards Earth & moves towards the ground i.e. it falls
------------------------------------------------------------------------------------------------------------------
But I don't understand why the ground would accelerate towards him in the 1st place? It feels a bit circular
How would you create artificial gravity like that of 9.8 meters per second squared on earth where there is already gravity pulling down. You can’t take that gravity away so how would you make sure that the gravity of earth isn’t affecting the artificial gravity?
When people talk about "artificial" gravity they typically refer to the centripetal forces when objects are rotating.
@@MichelvanBiezen lol I get that. But what, you do the experiment in space? If you do it on earth does the gravity from earth not affect these measurements ? Or since you are rotating it something else? Love the videos btw!
The theory of general relativity is invalid because it predicts the angular difference between the aphelion and the perihelion to be 2 radian for the orbit of Mercury. The actual observation is about 6.28 radian. More in
'80. Schwarzschild's Geodesic and the Orbit of Mercury '
on this website:
sites.google.com/view/physics-news/home/updates
Hi sir, Omar present................
Hi Omar
TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE, AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE). Great.
By Frank Martin DiMeglio
As far as I know, E&M and energy have not been proven to be gravity
@@MichelvanBiezen Consider what is THE EYE ON BALANCE. Water comes from the eye. Consider what is the TRANSLUCENT AND BLUE sky ON BALANCE. Consider what is THE EARTH/ground !! Lava IS orange, AND it is even blood red. ON BALANCE, consider what is the orange (AND setting) Sun; AND then consider what is the fully illuminated (AND setting/WHITE) MOON ON BALANCE. They are the SAME SIZE as what is THE EYE. Consider what is BALANCED electromagnetic/gravitational SPACE AS balanced BODILY/VISUAL experience. ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE). Indeed, c squared CLEARLY represents a dimension of SPACE ON BALANCE. ON BALANCE, the rotation of WHAT IS THE MOON matches the revolution. It is proven. TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE.
By Frank Martin DiMeglio
In understanding SPACE, what is gravity, TIME, AND time dilation (ON BALANCE), it is important is it to understand what is a BALANCED displacement of what is SPACE. ELECTROMAGNETISM/energy is gravity ON/IN BALANCE.
Consider what is E=MC2. TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. Consider TIME AND time dilation ON BALANCE. (c squared CLEARLY represents a dimension of SPACE ON BALANCE.) Indeed, the stars are POINTS in the night sky ON BALANCE. The rotation of WHAT IS THE MOON matches the revolution. Consider what is THE EYE, AND notice what is the TRANSLUCENT AND BLUE sky ON BALANCE. NOW, consider what is the BALANCED MIDDLE DISTANCE in/of SPACE. CLEARLY, BALANCED inertia/INERTIAL RESISTANCE is fundamental (ON BALANCE). “Mass"/ENERGY IS GRAVITY. ON BALANCE, consider what is the orange (AND setting) Sun. “Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/as what is BALANCED electromagnetic/gravitational force/ENERGY, AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE (ON BALANCE) consistent WITH E=MC2, F=ma, TIME, AND time dilation ON BALANCE. This CLEARLY AND NECESSARILY represents, DESCRIBES, AND INVOLVES what is possible/potential AND actual ON/IN BALANCE, AS ELECTROMAGNETISM/energy is CLEARLY (AND NECESSARILY) proven to be gravity (ON/IN BALANCE). Notice what is the fully illuminated (AND setting/WHITE) MOON ON BALANCE. Great. TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. Indeed, inertia/INERTIAL RESISTANCE is proportional to (or BALANCED with/AS) GRAVITATIONAL force/ENERGY; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE). This CLEARLY explains what is E=MC2 AND F=ma ON BALANCE, AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE !! (Consider TIME AND time dilation ON BALANCE.) Great. Indeed, consider WHAT IS THE EARTH/ground ON BALANCE. I have mathematically proven why the rotation of WHAT IS THE MOON matches the revolution, AS ELECTROMAGNETISM/energy is CLEARLY (AND NECESSARILY) proven to be gravity (ON/IN BALANCE). Consider TIME AND time dilation ON BALANCE, AS the stars AND PLANETS are POINTS in the night sky ON BALANCE; AS c squared CLEARLY represents a dimension of SPACE ON BALANCE. (Consider what is THE EYE ON BALANCE.) I have mathematically proven what is the fourth dimension, AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!! I have explained why what are OBJECTS may fall at the SAME RATE.
By Frank Martin DiMeglio
@@MichelvanBiezen It's proven now.
@@MichelvanBiezen WHY WHAT ARE OBJECTS MAY FALL IN RELATION TO WHAT IS THE EARTH/ground:
Consider what is the orange (AND setting) Sun, AND then consider what is fully illuminated (AND setting/WHITE) MOON ON BALANCE. They are the SAME SIZE as WHAT IS THE EYE. The reason that what are OBJECTS MAY fall to what is THE EARTH/ground IS WHAT IS E=MC2. What is E=MC2 is dimensionally consistent. What is THE EYE IS dimensionally consistent. Consider TIME AND time dilation ON BALANCE !!! Indeed, WHAT IS GRAVITY is, ON BALANCE, an INTERACTION that cannot be shielded or blocked; AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS the rotation of WHAT IS THE MOON matches the revolution; AS the stars AND PLANETS are POINTS in the night sky ON BALANCE !!! Consider what is the TRANSLUCENT AND BLUE sky ON BALANCE. Great. CLEARLY, ON BALANCE, I have MATHEMATICALLY solved the coronal HEATING “problem“. MAGNIFICENT.
By Frank Martin DiMeglio
Einstein never nearly understood gravity.
How to solve this problem?
prnt.sc/to7vbv
Here you have to set the torque in one direction equal to the torque in the other direction. mgr = FR F = mgr/R
@@MichelvanBiezen Thank you so
much.😍😍🤗😄😃😀😁😊
you are confusing by yourself