Yes. You are suggesting that the whole paper is flawed when in reality they acknowledge that there are things beyond the scope of what they were researching.
Quote:The central claim of the paper is that our understanding special relativity is wrong. Instead of all motion being relative, which causes time dilation between objects and means that there is no absolute cosmic time frame, the author argues that all motion is measured relative to some absolute time frame. This means that motion can be measured relative to this absolute frame, and things like time dilation only occurs relative to that absolute cosmic frame.
Those are your blogger's exact words. Read them carefully. He is saying that HE thinks motion is relative, but that somehow the paper he is addressing doesn't. "Instead of all motion being relative (as your blogger believes it to be]...the author [the one he is attacking] argues....
The central claim of the paper is that our understanding special relativity is wrong. Instead of all motion being relative, which causes time dilation between objects and means that there is no absolute cosmic time frame, the author argues that all motion is measured relative to some absolute time frame. This means that motion can be measured relative to this absolute frame, and things like time dilation only occurs relative to that absolute cosmic frame.
Imagine you are traveling in a train. If you were to walk down the aisle of the train, you would be moving at a walking pace relative to the other passengers, but someone watching the train go by would see you and all the other passengers race by at great speed. In other words, your speed is relative. It depends on what you are measuring it against. Relative to another passenger your speed is slow, but relative to the ground your speed is fast. That, in a nutshell, is relativity.
This concept of relativity dates back at least as far as Galileo (which is why it is sometimes called Galilean relativity). Before Galileo’s time it may have been known, but it wasn’t a big deal because motion could always be measured relative to the fixed Earth. But as we learned the Earth moves around the Sun, this raised an interesting philosophical puzzle. Is there some great cosmic vantage point against which all speeds can be measured, or is it really the case that speed is always relative? Is there such a thing as absolute speed?
In the mid-1800s, physicists came to understand that light was a wave. At the time it was thought that all waves travel through a medium. Sound waves travel through air, water waves travel through water, and so on. That means there must be a medium through which light travels. Physicists couldn’t observe this medium, but they called it the luminiferous (light-bearing) ether. There soon began a hunt to observe the ether, because the ether was a way to measure absolute speed.
If you drop a pebble in a calm lake, you can see the ripples flow outward at a particular speed. The ripples flow with the same speed in every direction. But if you were moving in a boat and dropped a pebble into the water, the ripples would seem to move slower in the direction of the boat’s motion, and faster in the opposite direction. Because of the boat’s motion the speed of the ripples would be different in different directions. The same would be true with the ether. Since the Earth must be moving through the ether, the speed of light must be different in different directions.
In 1887, Albert Michelson and Edward Morley performed an experiment to measure this difference in the speed of light. But what they found was the speed of light was always the same. No matter what direction light travelled, no matter how they oriented their experiment, the speed of light never changed. This was not only surprising, it violated the principle of relativity. After all, if you stand on a moving train and toss a ball, the speed of the ball relative to the ground is the speed of the ball plus the speed of the train, not just the speed of the ball. Basically what Michelson and Morley found was that if your “ball” was light, the speed of your ball relative to the train and the speed of the ball relative to the ground is the same. It seemed the speed of light (and only the speed of light) is absolute, and this made no sense at all.
Then in 1905 Albert Einstein published a solution to the problem, known as special relativity. He demonstrated that if the speed of light is absolute, then time must be relative, as given in the equation above. It relates the different times of two observers, say you and me. In this case, T’ is your time as you measure it, T is your time as I measure it, V is your speed relative to me, and C is the speed of light. What it says is that your time appears slower to me than it does to you. The faster you move relative to me, the slower your time appears to me. This sounds insane. How can time be relative? It is, however, very real.
We can see how this works if we imagine a clock made with light. Take two mirrors and place one above the other and facing each other, then bounce a pulse of light between them. We can measure time by counting the number of times the light bounces off a mirror. Each bounce is like the tick or tock of a mechanical clock. If you could watch the pulse of light, you would see it move up and down between the mirrors at the speed of light. Up and down at a constant rate. Now suppose you took your clock on a fast moving train. Standing in the aisle of the train, you would see the light pulse move up and down at the same rate as before. Up and down at the speed of light.
But as I watch you speed past, I see something slightly different. I would also see the pulse move at the speed of light, but from my view the light can’t move straight up and down because it must also be moving along with you. I would see the pulse move diagonally up then diagonally down, which is a slightly longer distance between each bounce. That means it would take the light longer to travel from bounce to bounce. So from my point of view the ticks and tocks of your clock are slower than the ticks and tocks as you see them. Your clock appears to be running slow because of your motion relative to me. The faster you move relative to me, the more your clock will slow down from my point of view.
You might think this effect only occurs because the clock relied on light to tell time, but this effect is real for everything. If you have a GPS in your phone or car, you rely on relative time being true every time you use it. A GPS determines your location by receiving signals from satellites orbiting the Earth. Those satellites broadcast their time and location, which your GPS uses to determine your position, so it is vitally important that the satellites broadcast the proper time. But the satellites are moving at high speed relative to you, which means their clocks run slightly slow. To give you the accurate time the satellites have to account for that slowdown effect. When your phone tells you where the nearest coffee shop is, it’s using special relativity to do it.
So how does all this relate to astrophysics? It’s one of the ways we know the universe is expanding. When we observe the light from distant galaxies, the light appears more red than we would expect. The more distant the galaxies, the more their light is redshifted. This effect is known as the Doppler effect, and it is due to the fact that the galaxy is moving away from us. The galaxies are moving away from us because the universe is expanding. But suppose over long periods of time light just naturally reddens? How do we know astronomers are not being fooled?
Special relativity tells us we’re not. We can observe supernovae in nearby and distant galaxies, and what we find is that when a supernova goes off in a distant galaxy it happens more slowly than a supernova in a closer galaxy. The time of a distant supernova appears slower to us because the distant galaxy is moving away from us at a faster rate than the closer galaxy.
Strange as it is, special relativity works. Time after time.
You are probably familiar with the basic idea of relativity, specifically the fact that a clock appears to tick more slowly if it is moving relative to you. This time dilation effect has been observed experimentally, and it has some interesting consequences.
When we talk about the age and history of the universe, we often use images such as the one above from HubbleSite, which traces the evolution of the universe from the big bang to the present.
These are cool illustrations, but they give the impression that the cosmos has a single universal age, and that it ticks and tocks uniformly everywhere. In reality, there is no cosmic clock. Observed time depends upon your motion, thus two galaxies moving at different speeds will have a slightly different time from the big bang. The age of the universe will be different for each of them.
Lest you think calculating the age of the universe is therefore meaningless, keep in mind that it is perfectly valid to speak of the age of the universe from our vantage point, and in reality, the difference in ages is quite small. As an example, we can measure our speed relative to the cosmic microwave background, and it turns out to be about 630 kilometers per second, or about 1.4 million miles per hour. This is actually surprisingly fast, and it means from our viewpoint the universe appears younger than it would if we weren’t moving relative to the cosmic background, a difference of about 30,000 years. That might seem large, but it is only a difference of about one five-thousandth of a percent of the total age of the universe. Even our best measurement of the age of the universe is only accurate give or take 60 million years.
Still, this notion of relative time is true for everything, including us. If you were to walk by me while I sit on a park bench, your time would be slightly different from mine because of our relative motion. In essence we each have our own private time.
no absolute cosmic time frame
As an example, we can measure our speed relative to the cosmic microwave background, and it turns out to be about 630 kilometers per second, or about 1.4 million miles per hour.
layman wrote:
From Stanford University:
Quote:Q: If astronomers can use the cosmic background radiation as a reference frame doesn't that invalidate special relativity?
A: Yes,...
https://einstein.stanford.edu/content/relativity/a10854.html
I post this again now because it is relevant to the "absolute simultaneity" issue discussed in the other article I just referred you to, Gent.
If astronomers can use the cosmic background radiation as a reference frame doesn't that invalidate special relativity?
Yes, because the expansion of the universe is not covered by special relativity, and is a property of the general relativistic treatment of motion which has features not present in special relativity, just as special relativity has features in it that are not compatible with newtonian physics. The cosmic background radiation will represent a fixed frame of reference for any object that is 'at rest' with respect to the expansion of the universe. In other words, if you are 'going with the flow' of the expansion, you will see the background radiation as a perfectly smooth surface. If you are moving with some peculiar velocity relative to the local 'Hubble flow' then this motion will be reflected in the cosmic background as a blue shift ( higher temperature) in the direction you are moving, and a redshift ( cooler temperature) in the direction you are coming from. This reference frame, however, is different for every observer in the universe so it does not qualify as a global frame of reference in the strictly special relativistic sence of 'reference frames'.
The cosmic background radiation will represent a fixed frame of reference for any object that is 'at rest' with respect to the expansion of the universe.
If you are moving with some peculiar velocity relative to the local 'Hubble flow' then this motion will be reflected in the cosmic background as a blue shift ( higher temperature) in the direction you are moving, and a redshift ( cooler temperature) in the direction you are coming from. This reference frame, however, is different for every observer in the universe so it does not qualify as a global frame of reference in the strictly special relativistic sence of 'reference frames'.
According to Einstein, Lorentz, Poncaire, and others, experiments such as the M-M led one to the conclusion that the motion of the earth could not be detected. They gave different theoretical reasons when explaining "why" this was true, but they agreed on that point. It was, supposedly, an unavoidable consequence of the principle of relativity.
The galaxies are moving away from us because the universe is expanding. But suppose over long periods of time light just naturally reddens? How do we know astronomers are not being fooled?
Special relativity tells us we’re not. We can observe supernovae in nearby and distant galaxies, and what we find is that when a supernova goes off in a distant galaxy it happens more slowly than a supernova in a closer galaxy. The time of a distant supernova appears slower to us because the distant galaxy is moving away from us at a faster rate than the closer galaxy.
Strange as it is, special relativity works.
The Earth is hurtling at about 1.4million miles per hour relative to the CMB. This is what the astrophysicist means when he says that Kiperos is arguing that the earth doesn't move in terms of the CMB. We are. That is why Einstein is correct and that answers your question.
layman wrote:
According to Einstein, Lorentz, Poncaire, and others, experiments such as the M-M led one to the conclusion that the motion of the earth could not be detected. They gave different theoretical reasons when explaining "why" this was true, but they agreed on that point. It was, supposedly, an unavoidable consequence of the principle of relativity.
I do not understand what you mean here that " the motion of the earth could not be detected. "
Quote:The Earth is hurtling at about 1.4million miles per hour relative to the CMB. This is what the astrophysicist means when he says that Kiperos is arguing that the earth doesn't move in terms of the CMB. We are. That is why Einstein is correct and that answers your question.
First of all, Gent, let me say that the point you are trying to make (or think your post makes) is NOT clear when you quote long passages. You don't explain the connection you see.
To the extent you insert the concluding sentence I quoted above, let me say this:
1. Yes, the earth is moving--a point I addressed in the prior post.
2. The author simply does NOT say what your blogger says what he says, so I can't really comment on "why" your blogger makes the claim he does in the first place. Did you ever read the paper, instead of just what your blogger says it says?
3. For the reasons I stated in the prior post, one must FIRST REJECT the SR claim (if that's what you mean by "Einstein") before you can assert this claim (that the earth is moving).
The observation of directional time dilation relative to the ECI indicates that the ECI functions locally as a PRF (broadly defined). Both the ECI and GPS satellites are in “free fall” inertial reference frames, and yet GPS satellites experience directional time dilation relative to the ECI. This indicates that directional time dilation is not limited to the interaction of non-inertial and inertial reference frames but is also observed between inertial reference frames. It therefore raises the issue of why the ECI functions as a PRF. The force of gravity connects the ECI and the objects that experience directional time dilation as a result of motion relative to the ECI. A plausible hypothesis is that the ECI functions as a PRF because it is the local center of mass with the dominant gravitational field in its local environment. The combination of ALT and PRFs linked to local centers of gravitational mass will be referred to as absolute simultaneity theory (AST).
This is important: "In reality, there is no cosmic clock. Observed time depends upon your motion, thus two galaxies moving at different speeds will have a slightly different time from the big bang. The age of the universe will be different for each of them."
This is why there is NO absolute cosmic time frame.
Well, OK. I'm not sure why you don't understand what it means. It just means what it says.
I could add this, I guess: M-M EXPECTED to be able to detect a time difference when light rays were projected either with or against the motion of the earth (it's presumed rate of speed as it revolves around the sun). The couldn't detect any such difference. A major scientific question then arose, to wit: "Why can't we detect our motion through space?"
As scientists grappled with this question, they agreed that any such motion, IF it existed (and they presumed it did--they believed in a heliocentric model), could not possibly be DETECTED. But that was, of course, BEFORE the CMB was discovered.
...two galaxies moving at different speeds will have a slightly different time from the big bang. The age of the universe will be different for each of them."[/quote[
To get just a little more concrete about it all, let's ask: What does that statement even MEAN?
Does it mean that there were in fact MANY different big bangs, all occurring at different times, so that each galaxy has a different age?
I don't think that's what it means, do you?
So what DOES it mean?
That is not what the Michelson and Morely experiments were trying to show at all. It had nothing to do with the movement of the Earth.
The Michelson–Morley experiment was performed over the spring and summer of 1887 by Albert A. Michelson and Edward W. Morley at what is now Case Western Reserve University in Cleveland, Ohio, and published in November of the same year.[1] It compared the speed of light in perpendicular directions, in an attempt to detect the relative motion of matter through the stationary luminiferous aether ("aether wind"). The result was negative,
Quote:The Michelson–Morley experiment was performed over the spring and summer of 1887 by Albert A. Michelson and Edward W. Morley at what is now Case Western Reserve University in Cleveland, Ohio, and published in November of the same year.[1] It compared the speed of light in perpendicular directions, in an attempt to detect the relative motion of matter through the stationary luminiferous aether ("aether wind"). The result was negative,
https://en.wikipedia.org/wiki/Michelson%E2%80%93Morley_experiment
What would you interpret those bolded words to mean there?
..relative motion of matter through the stationary luminiferous aether ("aether wind")
If you drop a pebble in a calm lake, you can see the ripples flow outward at a particular speed. The ripples flow with the same speed in every direction. But if you were moving in a boat and dropped a pebble into the water, the ripples would seem to move slower in the direction of the boat’s motion, and faster in the opposite direction. Because of the boat’s motion the speed of the ripples would be different in different directions. The same would be true with the ether. Since the Earth must be moving through the ether, the speed of light must be different in different directions.
But, you do understand what it was they were testing, right?
So, they were not searching for the movement of the Earth, they were trying to show the effect of the ether on the speed of light.
