[Origin]

Hi,

The illusion is caused by the velocity of the particle. In other words, the displacement of the particle through the velocity intrinsically generates space and time in its frame reference.

We could refer to an oscillator to be able to interpret this. Indeed and in second quantification the contraction of the particle in its point of origin corresponds to the annihilation, until the expansion of the particle in space as a creation operator.

Reported for hijacking the thread.  Please only one preposterous, outlandish claim per thread.

[Kartazion]

Reported for hijacking the thread.  Please only one preposterous, outlandish claim per thread.

New thread related to it: https://www.thenakedscientists.com/forum/index.php?topic=83945.0

[Centra (OP)]

I'd like to address something which is related to this discussion, it's the Michelson conjecture about velocity addition/subtraction which was the basis of his experiment with the light beams being reflected off mirrors in E/W and N/S directions. The reason for the null result is that he was simply wrong about things going back and forth in a direction of motion and against it being different from the same thing without the motion. Here's what Michelson thought.

Swimmer speed: 5 ft/s, river speed: 3 ft/s, swim course length:100 ft each way. Going downstream the swimmer’s speed is the sum of his speed plus the river’s flow 5 + 3= 8, and going upstream his speed is his rate minus the river’s flow 5 – 3= 2.The time downstream is 100/8 = 12.5 seconds and the time upstream is 100/2 = 50 seconds. The total time is therefore 62.5 seconds.

In reality, it's simply the average of 8 plus 2. There's no difference in the round trip time compared to the water being completely still, the two directions just average out to 5 ft/s. It might not seem like it from the equations in that quote but if you think about it, it makes sense. Do you seriously think it's going to change from 40 to 62.5 seconds just from it being 8 and 2 instead of 5 and 5? The Michelson-Morley experiment proved it conclusively too. That's the only reasonable explanation for the null result because we now know from actual tests that earth's rotation does affect the time light takes to travel a certain distance East or West. It has been proven with radio transmissions, which are the same speed as light, between NY and San Francisco, 14 nanoseconds are gained going West and lost going East.

[Origin]

I'd like to address something which is related to this discussion, it's the Michelson conjecture about velocity addition/subtraction which was the basis of his experiment with the light beams being reflected off mirrors in E/W and N/S directions. The reason for the null result is that he was simply wrong about things going back and forth in a direction of motion and against it being different from the same thing without the motion.

You are misinterpreting the experiment.  Look at this link http://galileo.phys.virginia.edu/classes/252/michelson.html, I think it will help you understand the experiment.

[Bored chemist]

In reality, it's simply the average of 8 plus 2.

You calculated the "wrong" average.

[Halc]

Well what they did was record the time showing on clock A when the beam was fired to clock B, recorded the time showing on clock B when it arrived/reflected back to clock A and they recorded that time of arrival at clock A. They had recorded three times, two for clock A and one for clock B.

OK. So now we have 3 different measurements. I agree with this, except I'd reword the last (bold) bit as the "time showing on clock A at the arrival event there". Your wording presumes that the clock there actually shows 'the time' which is meaningless in this context.

For them to conclude that the clocks were not synchronous, the time shown on clock B when the beam arrived/reflected minus the time shown on clock A when the beam was fired would have to be different from the time shown on clock A when the beam returned to it minus that same time that had been recorded at the arrival/reflection time on clock B.

Close. From this, everybody concludes that the clocks are not synchronous relative to the frame in which they are stationary. Without the frame reference, the part I bolded above is meaningless.

There is no way that can be considered a logical thing to have happened

Under relativity theory, I agree, which is why I had to fix your comment to make it meaningful. With the frame reference, it becomes a logical thing which can be considered to have happened.

because supposedly you can't tell if you're in uniform motion or stationary by any test.

Nobody concluded that.

We know the clocks had been synchronized before they started moving

Meaningless statement actually. Needs a frame reference, and then it would still be wrong.
If you read the paper, the clocks were not synchronized until after the rod was moving, and then they were synchronized to local clocks stationary in the first frame. In other words, they looked 'out the window' and set each clock to the value they saw going by just then. This sort of syncs them to the first frame, not to the frame of the rod. I say 'sort of' because while both clocks A and B will always read the same value relative to the original frame, they will not continue to read the same value as the clocks they pass by. They will fall behind them.

so how could they have produced different elapsed times for the two directions of the light beam?

No elapsed times were measured (well, except between the first and third measurement, and then only relative to the frame in which clock A was stationary). All we had is 3 specific clock readings, which is different than having 3 times or two elapsed times.

Now if you say "Nobody saw any times in that description", which you did, then how did they have tA and tB for the equations "tB − tA = rAB/c − v and t′A − tB = rAB/c + v"? What did you think t stood for, tribbles?

As you said in the first sentence, they're readings on a device. They're objective. Nobody in any frame disagrees what those clocks displayed at each of the respective events.

I'd like to address something which is related to this discussion, it's the Michelson conjecture about velocity addition/subtraction which was the basis of his experiment with the light beams being reflected off mirrors in E/W and N/S directions. The reason for the null result is that he was simply wrong about things going back and forth in a direction of motion and against it being different from the same thing without the motion.

Wow. You think you're smarter than a lot of people famous for being smarter than all of us. Mind you, I've pointed out errors in every paper you've linked, but those guys are known cranks. Michelson was not a crank.

Here's what Michelson thought.

Swimmer speed: 5 ft/s, river speed: 3 ft/s, swim course length:100 ft each way. Going downstream the swimmer’s speed is the sum of his speed plus the river’s flow 5 + 3= 8, and going upstream his speed is his rate minus the river’s flow 5 – 3= 2.The time downstream is 100/8 = 12.5 seconds and the time upstream is 100/2 = 50 seconds. The total time is therefore 62.5 seconds.

Exactly correct. Round trip time is 62.5 seconds, but if the river is stationary, the speed would be just 5 each way, or 20 + 20 = 40 seconds round trip.

In reality, it's simply the average of 8 plus 2.

His swimming speed relative to the water is, yes. His average speed relative to the 100 foot course is 200 feet/62.5 seconds = 3.2 feet/sec, not 5. If you assert otherwise, you must have failed an awful lot of algebra exams because they always put one like that in them.

There's no difference in the round trip time compared to the water being completely still

Now you're just making a total fool of yourself. Which figure is wrong? The 50 seconds to go upstream or the 12.5 to come back, or both? How do you justify a different number for the ones you feel a need to change? Maybe you're asserting that 50+12.5 = 40.
How can you presume to be even remotely competent at physics if you've not even a grasp on middle school mathematics?

[Centra (OP)]

Before I reply to other things I want to clear up the Michelson thing. Apparently he was right about the different times swimming upstream and downstream, I found a calculator that works out things like that for plane headwinds or water currents with boats and it was exactly like he said, BUT it's not analogous to speed on the rotating earth. When you drive West traveling at 100 mph you're not traveling at 1100 mph due to the earth rotating eastward at approximately 1000 mph, and going East you're not traveling at 900 mph.

It does not take you 6.66 minutes to drive 100 miles East and 5.45 minutes to drive 100 miles West, I think you'll agree. Well that's what you would get if you divided 1100 mph  and 900 mph by 100 miles and multiplied the results by 60 (minutes in an hour). That shows how Michelson made his error and it cost him the whole experiment. We know that light takes 14 nanoseconds less to go from NY to San Francisco than the reverse direction, so the different times of the East and West paths of the reflected beam in the experiment would exactly cancel out. THAT is why the results were null.

[Centra (OP)]

If you read the paper, the clocks were not synchronized until after the rod was moving, and then they were synchronized to local clocks stationary in the first frame. In other words, they looked 'out the window' and set each clock to the value they saw going by just then. This sort of syncs them to the first frame, not to the frame of the rod. I say 'sort of' because while both clocks A and B will always read the same value relative to the original frame, they will not continue to read the same value as the clocks they pass by. They will fall behind them.

I see what you mean in the first part of that quote, Einstein didn't actually say they were synchronized with the stationary clocks before starting to move. Einstein was not very clear in his description so it was easy to misinterpret. However I don't get the rest of the quote. Whenever they were synchronized to the stationary clocks, the hands still moved at the same rate on clocks A and B, so they still should have shown the same interval for the beams in each direction.

Einstein was saying, I presume, that the moving observers would see two different times showing on both moving clocks while the stationary observers would see the same times on both. That would be the reverse of what I saw in a video about a rocket with beams going to each end from the middle. It said the stationary observer would see different times on both clocks at each end while the moving observers would see the same times. So in the article it was simply changed around from that, the moving observers saw them with different times and the stationary observers saw them with the same times. I'll have to think this over some more before I comment further on it.

[Bored chemist]

BUT it's not analogous to speed on the rotating earth.

Nobody said it was.
The MM experiment is designed to look at whether the Earth is moving through the ether.
And the analogy between swimmers on a moving river and light in a moving ether is quite good.
 The problem is that you were looking at the average speed measured WRT the water, when you should have been looking  at the average speed measured WRT the ground.

[Centra (OP)]

BUT it's not analogous to speed on the rotating earth.

Nobody said it was.
The MM experiment is designed to look at whether the Earth is moving through the ether.
And the analogy between swimmers on a moving river and light in a moving ether is quite good.
 The problem is that you were looking at the average speed measured WRT the water, when you should have been looking  at the average speed measured WRT the ground.

I see, well,  I guess they proved there's no aether then huh? But their experiment did not prove that light speed is not affected by earth's rotation.

[Centra (OP)]

I think Einstein wrote the moving rod thing wrong by mistake, because this quote from a page about SR says the exact opposite of what he wrote.

If, for example, a light signal bounces between ends A and B of a rod, an observer at rest on the rod judges the traversal times to be equal. But that is not so for an observer who judges the rod to move in the direction of A to B. For that observer, the light signal traversing from A to B needs more time to catch the fleeing end B; and the light signal traversing from B to A requires less time to meet the approaching end A. This disagreement immediately leads to the two observer's differing judgments concerning the simultaneity of the events at A and B; that is, to the relativity of simultaneity.

https://sites.pitt.edu/~jdnorton/Goodies/magnet_and_conductor/index.html

Einstein said observers WITH the rod, ie; "at rest" in regard to it, would NOT judge the traversal times to be equal.

[Centra (OP)]

I agree with none of the above. It all lacks frame references, and thus is no more than word salad.
Despite my continued pointing out of this error, you continue to make it and post meaningless stuff such as this:

So it's your contention that this is not true? You think you really would be traveling 100 miles in less that 7 minutes?

When you drive West traveling at 100 mph you're not traveling at 1100 mph due to the earth rotating eastward at approximately 1000 mph, and going East you're not traveling at 900 mph. It does not take you 6.66 minutes to drive 100 miles East and 5.45 minutes to drive 100 miles West.

 

[Centra (OP)]

I am travelling at less than a meter per second relative to the rotating frame of my laptop. Relative to the inertial frame of Earth, I travel 100 km in about 5 minutes. Relative to the sun, it takes about 3 seconds to go that far. Relative to the galaxy, it takes under half a second. But your statement above lacks a frame reference, hence is still meaningless, and not something with which I can agree.

The frame of reference would be the earth's surface. I know it's surprising that a person would be driving on the earth's surface but so it is, forgive me for not specifying that it wasn't driving on a cloud.

[Bored chemist]

But their experiment did not prove that light speed is not affected by earth's rotation.

What effect did the rotation of the Earth have on their experiment?

[Centra (OP)]

But their experiment did not prove that light speed is not affected by earth's rotation.

What effect did the rotation of the Earth have on their experiment?

None, because why would it? The beam gained maybe 0.00001 nanosecond going one way and then lost the same amount when it bounced back the other way.

[Halc]

The frame of reference would be the earth's surface.

Excellent! You're talking about the rotating frame. Yes, in that frame, it takes an hour to go 100 km in your car. In that frame, Neptune moves faster than c, and light takes longer to go from SF to NY than the other way around (assuming a reasonably straight path and not one that goes the long way around). Such is a known property of rotating frames. Einstein wasn't considering a rotating frame in the sections at which we've been looking. So for instance, relative to the inertial frame of Earth, your eastbound (near the equator) car really does go east at 1100 mph (sorry, I was using metric before), and the westbound car goes -900 mph westward, and thus isn't really westbound, is it?

With relativity discussions, confusion results from omitting frame references. You may think they're implied, but mistakes are made by assuming distances, durations, times, and locations are the same from one frame to the next. The references are absolutely necessary to make unambiguous statements.
So if you're discussing some value (say distance between events), it matters whether you're using the S coordinate system or the R coordinate system to express that distance. Without the reference, all you'll get is annoying replies saying that your statements lack meaning.

[Centra (OP)]

The frame of reference would be the earth's surface.

Excellent! You're talking about the rotating frame. Yes, in that frame, it takes an hour to go 100 km in your car. In that frame, Neptune moves faster than c, and light takes longer to go from SF to NY than the other way around (assuming a reasonably straight path and not one that goes the long way around). Such is a known property of rotating frames. Einstein wasn't considering a rotating frame in the sections at which we've been looking. So for instance, relative to the inertial frame of Earth, your eastbound (near the equator) car really does go east at 1100 mph (sorry, I was using metric before), and the westbound car goes -900 mph westward, and thus isn't really westbound, is it?

With relativity discussions, confusion results from omitting frame references. You may think they're implied, but mistakes are made by assuming distances, durations, times, and locations are the same from one frame to the next. The references are absolutely necessary to make unambiguous statements.
So if you're discussing some value (say distance between events), it matters whether you're using the S coordinate system or the R coordinate system to express that distance. Without the reference, all you'll get is annoying replies saying that your statements lack meaning.

I see, I didn't realize I was writing an article in Scientic American. Just kidding, I'll try to be more specific. Anyway, point being, on the earth's surface you don't get the swimming up and down a river effect, so Michelson's experiment would not show earth rotation effects on light, but would it show effects from earth's orbit around the sun? If there was aether, yes, because it would be the equivalent of the river bank. So Michelson did prove a lack of aether but not a lack of Sagnac effect from earth's rotation.

Apparently you agree that said Sagnac effect exists, but you explain it as a relativity consistent effect because it involves a rotating frame. It doesn't actually confirm relativity, it just doesn't necessarily disprove it either, Einstein just gave himself an out by saying that rotating frames are not inertial. I can agree with that, because an observer on a rotating disk could tell if it was rotating or not, by centrifugal force.

Now there's the conundrum of why a rotating frame can be confirmed to be in rotation like that, what is it in rotation relative to? The same would apply to binary stars in orbit with each other, what are they rotating in relation to? Presumably an imaginary point between them called the barycenter, but how is the barycenter a stationary reference? It seems counter to relativity theory. If there are two equal disks with the same axis, with a space between the two, what is the difference between one being stationary and the other rotating and the other way around, or both rotating in opposite directions at equal angular velocity?

The only difference between the two disk frames is that an observer on one would perceive centrifugal force and one on the other would not. What made them different in that way? The use of energy to create force to produce rotational motion in one. Kinetic energy had been stored in the disk as inertial motion. The disk would continue to rotate, assuming no external friction or resistance, until that kinetic energy was transferred to another mass by exerting a force moving it outward from a position close to the axis to one farther away from it.

[Halc]

Anyway, point being, on the earth's surface you don't get the swimming up and down a river effect, so Michelson's experiment would not show earth rotation effects on light, but would it show effects from earth's orbit around the sun?

It was designed to detect motion relative to the medium (aether) in any direction. If there was such a medium and the current Newtonian model was accurate, all orbits, spins, etc would involve daily and annual variations due to changes from spin and orbit. The instrument was sufficiently sensitive to detect 1500 mph changes, which is the typical change in velocity over the course of 12 hours.
The experiment measured isotropy in all frames, which resolved the conflict between Newton's equations and Maxwell's equation. They couldn't both be right. Newton's model had been falsified.

So Michelson did prove a lack of aether but not a lack of Sagnac effect from earth's rotation.

Yet again, no proof of lack of aether was made. It was simply demonstrated to be superfuous. No test for Sagnac was made since the experiment didn't involve a loop enclosing an area.

Apparently you agree that said Sagnac effect exists

It had better. There are devices in use every day that depend on it.

but you explain it as a relativity consistent effect because it involves a rotating frame.

One can explain any situation using one's choice of frame. Sagnac is no exception, and can be explained via the properties of rotating frames, or it can be explained using only an inertial frame.

It doesn't actually confirm relativity

Relativity has little to say about the Sagnac effec that Newtonian physics didn't already explain. Unless the device is rotated at relativistic speeds, there's no need to invoke relativity theory to predict the Sagnac effect, so no, it isn't really a test of relativity since relativity doesn't predict anything different.

Einstein just gave himself an out by saying that rotating frames are not inertial.

Newton said that actually. He demonstrated that rotation is absolute, while linear velocity is not necessarily so (per Galileo).

Now there's the conundrum of why a rotating frame can be confirmed to be in rotation like that, what is it in rotation relative to?

No relation needed in the case of rotation. That's what it means to say rotation is absolute. The rate of rotation of a closed system can be determined from within a box.

The same would apply to binary stars in orbit with each other, what are they rotating in relation to? Presumably an imaginary point between them called the barycenter, but how is the barycenter a stationary reference? It seems counter to relativity theory.

Well, for a closed system, there is a frame independent worldline for the center of gravity of the system which does not accelerate, so is stationary in the frame of the system. The word 'barycenter' only applies to two-body system since with more bodies, nothing necessarily moves in a predictable path about the center of gravity, nor is even particularly attracted in its direction.
Picture a rock in space, not rotating. It has zero angular momentum relative to its center of gravity, and for that matter, relative to any point in space in the frame where that rock is stationary. But in a frame where the rock is moving, the rock has angular momentum relative to any point in space that is not on the line of its motion. So in that sense, angular energy and momentum about random points in space are frame dependent.

If there are two equal disks with the same axis, with a space between the two, what is the difference between one being stationary and the other rotating and the other way around, or both rotating in opposite directions at equal angular velocity?

The first system has nonzero angular momentum. The 2nd system has zero angular momentum. Remember that momentum, like velocity, is a vector, and one must use vector addition when adding up the momentums of the respective parts.

To illustrate this, you can have a small box with two disks in it spinning on an axis fixed to the box. In the first case, the box has angular momentum and if you hold it, you'll notice a resistance to turning it due to gyroscopic effects. In the second case with the disks spinning in opposite directions, the box has zero angular momentum and will not resist being turned this way and that. There would be an effortless test to determine which case is which, without having to look inside the box.

Another test: if you're on the ring of a windowless space station rotating for gravity, you can tell the direction of rotation by peeing in a bucket and seeing which way the stream curves. Even light bends to the side due to Coriolis forces.

The only difference between the two disk frames is that an observer on one would perceive centrifugal force and one on the other would not.

There you go. It's not the only difference, but it's the most obvious. You could do really subtle special relativity stuff like measure the diameter and circumference of the disk, which will have a ratio of π only for a non-rotating disk, but to get a measurable difference with say just a tape measure, you'd have to spin it at a rate which would kill a human.

The use of energy to create force to produce rotational motion in one.

Force (torque actually) is only needed to change the angular momentum of the thing. No torque is needed to keep it spinning, per Newton's laws.

Kinetic energy had been stored in the disk as inertial motion. The disk would continue to rotate, assuming no external friction or resistance, until that kinetic energy was transferred to another mass by exerting a force moving it outward from a position close to the axis to one farther away from it.

To move mass inward, energy needs to be imparted to the system. The ice skater needs to perform work to pull her arms in and spin faster. Likewise, to move outward, excess energy must go somewhere. So for example, the spin of Earth momentum is slowly being transferred to the moon, raising its orbital radius. Of all the energy Earth loses in this process, only about 3% of it goes to the moon (a higher radius orbit is a higher energy orbit) and the excess is radiated away as heat.

We're getting pretty off topic here. OK, a lot of this is discussion of relations, and that's good. But very little of it differs between Einstein's physics and what came before. Newton may have been falsified for the boundary cases, but they very much still teach Newtonian physics in schools. It works just fine for most applications, and nobody needed to apply relativity theory to get a man on the moon.

[Origin]

It was designed to detect motion relative to the medium (aether) in any direction.

Excellent post, too bad Centra won't read it with an open mind, I have no doubt many of the members and guests will however.  I admire your patience with posters like Centra, keep up the good work.

[Centra (OP)]

That last post was actually somewhat informative, Halc, which is a nice change from the usual insulting. As a brief aside from relativity, something I find interesting involving rotation is that to equal earth's gravitational acceleration of 9.807 m/s² with rotation all that's required is a 10 m diameter and an angular velocity of 13.374 rpm. That's slow, over 4 seconds per rotation, you could easily achieve that by manually pushing it around. It seems like earth gravity is strong when you think of a boulder or something heavy like that but it's surprisingly weak if you look at it as the equivalent of centrifugal force.