[hamdani yusuf]

Any thoughts about this?

Here's another video responding to those in the op.

The REAL Reason You Don't Understand Relativity

Think Relativity is confusing? Well, it's not just you -- even the experts can't seem to agree on its meaning, and often get basic facts about the formalism completely wrong. Here, we critique one such renowned professional who, in claiming to be clarifying the standardized theory of relativity, turns out to actually be promoting a misguided personal interpretation. What is this expert's confusion exactly, and why are such misconceptions so prevalent amongst the physics community?

Indeed, be cautious of posturers, gaslighters, stigmatizers, and Giordano-Bruno-burners who want to convince you that your inability to understand Relativity stems from your own deficient reasoning -- because when even the experts can't agree, you know there is something up...

Contents:
00:00 - Intro
01:11 - The Many Interpretations of Relativity
04:55 - Examining Sabine's Interpretation, Pt. 1
08:30 - Examining Sabine's Interpretation, Pt. 2
10:58 - The Source of Confusion
12:12 - Are There Better Interpretations?

Don Lincoln posted another follow up video, which seems to undercut the response video from Dialect above.
Does acceleration solve the twin paradox?

Special relativity is known to make mind-blowing predictions, perhaps most notably the Twin Paradox, in which two individuals claim that the other person?s clock is doing something funny. There have been many explanations, including two videos, one here on the Fermilab channel and one by fellow YouTuber Sabine Hossenfelder. These two videos seem to contradict each other, but they really don?t. In this video, Fermilab?s Dr. Don Lincoln explains how the two videos can be reconciled.

[Origin]

Google Bard is just a chatbot and not going to be very good for science other than just general info.

[Halc]

I asked Google Bard, what's the best explanation to the twin paradox?

Which is a good reason not to ask a chatbot for correct answers. It gave a terrible one. The bits about the history and the scenario are correct, as is the bit about the asymmetry, but asymmetry isn't the cause since two objects can take asymmetrical paths but still find their respective ages the same upon reuniting.
A good answer would be one that can be generalized, that isn't specific to this one particular case. It didn't give that.

The site you linked seems only relevant to instant-acceleration cases (discontinuous velocity), but to be honest I didn't read it. The diagram is accurate.
Please don't go to Sabine on this one. I've show that hers not only fails to generalize, but it is actually wrong. I find that horribly disappointing. She apparently doesn't peer review her videos before releasing them.

Origin's answers are spot on.

If the travelling twin brings a smaller clock which is synchronized to the earth clock at the beginning of the trip, what does it read when he's passing the giant clocks?

He ages ~130 days through the whole thing. That gets divided into 8 equal portions as the 8 clocks are 'passed'. From his point of view, it is the clocks that pass him, one every 16.3 days, not the other way around.

[hamdani yusuf]

Google bard is just a chatbot and not going to be very good for science other than just general info.

I think it will, eventually. And that won't be long, considering the exponential progress in AI. Even if Bard turns out to be a failure, its competitor will take its place. BTW, here's a message when I opened a new chat with Bard.

Bard is still in its experimental phase. Chatting with it and rating its responses will help improve the experience.

[hamdani yusuf]

The site you linked seems only relevant to instant-acceleration cases (discontinuous velocity), but to be honest I didn't read it. The diagram is accurate.

The diagram is similar to the explanation by Minutephysics.

Complete Solution To The Twins Paradox

This video is about the famous ?Twins paradox? of special relativity, how time can appear to be faster for two different observers at the same time, and which twin really is older (or younger) ? the one who stays on earth or the one who flies in a rocket ship to the stars?

REFERENCES

Muon lifetime and time dilation/relativity: http://hyperphysics.phy-astr.gsu.edu/hbase/Relativ/muon.html#c2
Paper on twin paradox under constant acceleration: https://arxiv.org/pdf/physics/0604025v3.pdf
Taking Cesium atomic clocks aboard airplanes: https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment

[hamdani yusuf]

If the travelling twin brings a smaller clock which is synchronized to the earth clock at the beginning of the trip, what does it read when he's passing the giant clocks?

He ages ~130 days through the whole thing. That gets divided into 8 equal portions as the 8 clocks are 'passed'. From his point of view, it is the clocks that pass him, one every 16.3 days, not the other way around.

So he sees the giant clocks tick faster than his onboard clock, both on going and return trips.
But that's not what the explanation shown by MinutePhysics' video.

[Origin]

But that's not what the explanation shown by MinutePhysics' video.

I come to the forum for discussions so I don't watch video recommendations.  If the video says that a clock (stationary relative to spaceship) located 1 ly from a spaceship traveling towards it at 0.999c would have an elapsed time other than 0.999 years when it passes the clock, then the video is wrong.  I doubt that is what the video says, but it could be a bad video.

[hamdani yusuf]

The twins scenario illustrates time differential, which is an objective (frame independent) fact. Time dilation is a coordinate effect and is entirely frame dependent. Just pointing this part out so hopefully the terms get used more correctly.

Most of sources I've seen on special relativity don't distinguish them, and only use time dilation term, such as the case with muons.

[hamdani yusuf]

So he sees the giant clocks tick faster than his onboard clock, both on going and return trips.

It only appears to run fast if it is approaching you, which is true only half the time. I didn't offer an explanation. You asked what the rocket guy would see on the clocks as they passed by, and I answered that.

More details: Suppose he always watches the Earth clock. For 65 days it is receding and during those 2+ months it appears to advance about 4 minutes, 22500x slower. On the 2nd leg, Earth is approaching and it appears to run about 45 times faster, so it appears to gain about 8 years in those 65 days.
The Earth observer sees the same thing if he watches the ship clock. 22500x slower when outbound and 45x faster when it is returning, but in his case, the vast majority of the time (over 8 years) is spent watching it recede, and the return leg appears to take only a day and a half.

Let me rephrase my statement you quoted.
His onboarding clock ticks slower on average than the giant clocks.
Traveling twin sees the giant clock the he is passing by showing the time according to Origin's calculation.
Earth clock ~ 4
Second clock ~ 5
Third clock ~ 6
Fourth clock ~ 7
Star clock ~ 8, then return.
Fourth clock ~ 9
Third clock ~ 10
Second clock ~ 11
Earth clock ~ 12
According to the diagram, his own clock ticks 22.4 times faster during first leg as well as second leg of the journey. But somehow at the turning point, the clock changes its reading to compensate for the difference, hence in the end, traveling clock shows smaller value than earth clock.
Lorentzian relativity says that traveling clock ticks slower than giant clocks in both legs, and in the end both twins agree what their clocks would read when they reunite, as well as in each milestones. The asymmetry is caused by relative motion through aether. But special relativity tells a different story.

[Halc]

So he sees the giant clocks tick faster than his onboard clock, both on going and return trips.

It only appears to run fast if it is approaching you, which is true only half the time. I didn't offer an explanation. You asked what the rocket guy would see on the clocks as they passed by, and I answered that.

More details: Suppose he always watches the Earth clock. For 65 days it is receding and during those 2+ months it appears to advance about 4 minutes, 22500x slower. On the 2nd leg, Earth is approaching and it appears to run about 45 times faster, so it appears to gain about 8 years in those 65 days.
The Earth observer sees the same thing if he watches the ship clock. 22500x slower when outbound and 45x faster when it is returning, but in his case, the vast majority of the time (over 8 years) is spent watching it recede, and the return leg appears to take only a day and a half.

But that's not what the explanation shown by MinutePhysics' video.

The video is a pretty good one and I have no objections to it. It doesn't in any way describe what either observer sees when looking at distant clocks or when passing moving clocks. They're different questions. The video is trying to explain the time differential (them being different ages upon meeting later on). It isn't about appearances at all.

The twins scenario illustrates time differential, which is an objective (frame independent) fact. Time dilation is a coordinate effect and is entirely frame dependent. Just pointing this part out so hopefully the terms get used more correctly.

Let me rephrase my statement you quoted.
His onboarding clock ticks slower on average than the giant clocks.

Which clock ticks faster is a frame dependent thing, and no frame was specified, so no, this isn't correct.
Relative to Earth, the ship clock ticks slower. Relative to some inertial frame in which the ship is stationary, the Earth clock and all the giant clocks tick slower.

 

Traveling twin sees the giant clock the he is passing by showing the time according to Origin's calculation.
Earth clock ~ 4
Second clock ~ 5
Third clock ~ 6
Fourth clock ~ 7
Star clock ~ 8, then return.
Fourth clock ~ 9
Third clock ~ 10
Second clock ~ 11
Earth clock ~ 12

Yes. This is consistent with the numbers in my prior post.
For instance, from the ship PoV, at the start, the 2nd clock appears to read 3 (just like you said in post 36).  16.3 days later when the 2nd clock passes by, it reads 5, which means it appears to run ~45x  as fast because it is approaching, exactly the rate that I posted.

[hamdani yusuf]

Which clock ticks faster is a frame dependent thing, and no frame was specified, so no, this isn't correct.

According to traveling twin, his own clock ticks faster than the giant clocks, which is moving relative to him. I think this is the consensus among modern physicists.

For instance, from the ship PoV, at the start, the 2nd clock appears to read 3 (just like you said in post 36).  16.3 days later when the 2nd clock passes by, it reads 5, which means it appears to run ~45x  as fast because it is approaching, exactly the rate that I posted.

[hamdani yusuf]

Imagine we have CCTV in every giant clock.
What's the rocket clock showing when it's passing the second giant clock, as seen by the CCTV on it?
What's the rocket clock showing when it's passing the giant clock at the turning point, as seen by the CCTV on it?

[Origin]

Imagine we have CCTV in every giant clock.

Why?  What would be the point? 

[hamdani yusuf]

Imagine we have CCTV in every giant clock.

Why?  What would be the point? 

So we can get the observations from both frames of reference locally, where the events take place, ie, when the spaceship is passing a giant clock. So we can compare them in order to determine which side of the paradox is invalid.

[Origin]

So we can get the observations from both frames of reference locally, where the events take place, ie, when the spaceship is passing a giant clock.

I don't understand.

[hamdani yusuf]

In minutephysics' video, there are only two clocks, and the events are only observed from two observers, which are the bare minimum to describe the situation.

Earth twin represents non-changing frame of reference. Traveling twin represents changing frame of reference. Unless when they are meeting on earth in the beginning and end of the journey, the earth twin only observes the key events remotely, especially at the turning point.

Spaceship clock is in two different inertial frame of reference, one during outgoing trip, and the other during return trip.

All giant clocks are in the same inertial frame of reference, despite being in vastly different positions. They allow the traveling twin to trace the events locally from his own position, without having to observe distant events like the reading of earth clock.
The CCTV s allow the earth twin to trace the events locally in his own frame of reference, and compare the reading of spaceship clock and giant clocks as they are passing by.

[Origin]

The CCTV s allow the earth twin to trace the events locally in his own frame of reference, and compare the reading of spaceship clock and giant clocks as they are passing by.

I don't see how that would be possible.  If the transmitter of the CCTV is 2 ly away the person on earth won't receive the transmission for 2 years, so what's the point?

[hamdani yusuf]

The CCTV s allow the earth twin to trace the events locally in his own frame of reference, and compare the reading of spaceship clock and giant clocks as they are passing by.

I don't see how that would be possible.  If the transmitter of the CCTV is 2 ly away the person on earth won't receive the transmission for 2 years, so what's the point?

The point is to capture the events locally, which will be investigated later on. They're for matching up between  traveling clock and giant clock as they are passing by. That becomes necessary since the video mentions that the clock reading can be affected by observer's motion and position when done remotely.
The CCTV can be replaced by independent observers which will communicate the results. When the information arrive isn't important, but what they tell is what's important.

[Origin]

The CCTV can be replaced by independent observers which will communicate the results.

I see, there is no point to having a CCTV.
Actually there is no point in running this impossible experiment anyway since we already know what the results will be.

[hamdani yusuf]

Thought experiments are only useful to examine consistency among many assumptions taken to build a model. It can't check if the model accurately represent physical reality. That would take physical experiments.