The Flat Earth Society
Flat Earth Discussion Boards => Flat Earth Theory => Topic started by: TomInAustin on October 02, 2020, 04:03:53 PM
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Pete and I have discussed this a few times, with his trump card always being something along the lines of proving Einstein wrong. Something never seemed right about falling vs acceleration and using the Zetetic method I now know why. Having 920ish skydives and a Master D license, I can testify that one can't feel freefall. Terminal velocity ( the result of mass vs drag) feels like floating. In a run of the mill skydive, one exits the aircraft around 90 mph and over 9 seconds accelerates to terminal velocity. Basically transitioning from 90ish to 120ish (terminal is not a constant) over 9 seconds is a pretty tame experience. No feeling of falling What is the sticking point in my head is that we can feel the acceleration of a jump from a stationary or near stationary start point, hot air balloon, helicopter, cutting away a low-speed malfunction and even stalling the canopy. You jump out of a balloon and you feel the acceleration. Not being a fan of negative G, I hated doing stalls. I can think of no better Zetetic evidence that UA is false. Pure observation.
Why did I, again pure Zetetic observation, feel the acceleration? Occam's Razor would say I was falling, not witnessing the earth coming at me.
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Why did I, again pure Zetetic observation, feel the acceleration?
I've said this before, but I feel you misunderstood. The term "feeling acceleration" is extremely vague - it's a term you've created to make a sensation seem intuitive. What you actually perceive is your acceleration relative to the air around you. Because motion is always relative, this is exactly the same as the air accelerating relative to you - there is no universal frame of reference from which you could distinguish the two. That is the sticking point - you feel "the acceleration", but there is no objective answer as to what's accelerating relative to what.
Because motion is relative, you could also completely rephrase UA to mean something like "anything other than sufficiently massive celestial bodies is accelerating downwards at 9.81m/s2 relative to the otherwise stationary bodies". Physically, the two are one and the same. All that changes is the frame of reference you chose.
Perhaps a different thought experiment will help here. Try to imagine the sensation of your body being held down in a river, well under the surface. Imagine how the water would feel against your body. Now, imagine a separate situation. You're submerged in water which is not flowing, like a lake, and you're being pulled through the water.
Without external information, you would not be able to tell the difference by the sensation alone. This is exactly the same here.
And yes, your comment about Einstein is correct. According to the Equivalence Principle, it MUST be the case that you won't be able to tell the two apart. Basic physics would break if this wasn't the case.
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The feeling of free-fall is the feeling of weightlessness, not acceleration.
In this example the balloon reverts to its relaxed state while in free-fall.
(https://i.imgur.com/DQY3XYq.png)
In a Zero-G plane the craft is in free-fall and its occupants feel weightless.
(https://i.imgur.com/Fu6mgAK.jpg)
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The feeling of free-fall is the feeling of weightlessness, not acceleration.
In this example the balloon reverts to its relaxed state while in free-fall.
(https://i.imgur.com/DQY3XYq.png)
In a Zero-G plane the craft is in free-fall and its occupants feel weightless.
(https://i.imgur.com/Fu6mgAK.jpg)
Exactly as I said. "I can testify that one can't feel freefall. " We are not talking freefall, we are talking about transition to freefall.
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Why did I, again pure Zetetic observation, feel the acceleration?
I've said this before, but I feel you misunderstood. The term "feeling acceleration" is extremely vague - it's a term you've created to make a sensation seem intuitive. What you actually perceive is your acceleration relative to the air around you. Because motion is always relative, this is exactly the same as the air accelerating relative to you - there is no universal frame of reference from which you could distinguish the two. That is the sticking point - you feel "the acceleration", but there is no objective answer as to what's accelerating relative to what.
Because motion is relative, you could also completely rephrase UA to mean something like "anything other than sufficiently massive celestial bodies is accelerating downwards at 9.81m/s2 relative to the otherwise stationary bodies". Physically, the two are one and the same. All that changes is the frame of reference you chose.
Perhaps a different thought experiment will help here. Try to imagine the sensation of your body being held down in a river, well under the surface. Imagine how the water would feel against your body. Now, imagine a separate situation. You're submerged in water which is not flowing, like a lake, and you're being pulled through the water.
Without external information, you would not be able to tell the difference by the sensation alone. This is exactly the same here.
And yes, your comment about Einstein is correct. According to the Equivalence Principle, it MUST be the case that you won't be able to tell the two apart. Basic physics would break if this wasn't the case.
Thanks for the thoughtful response. Due to the obvious climate we live in, I am just done with arguing but a polite debate is always welcome.
I did not create the term, I paraphrased it... from the Wikipedia on Falling (sensation)
A sensation of falling occurs when the labyrinth or vestibular apparatus, a system of fluid-filled passages in the inner ear, detects changes in acceleration
To be more clear I should have said "detecting changes in acceleration" instead of "feeling acceleration".
I have googled and not found Einstein's direct quote but I see a lot of interpretations. One is the Elevator cable breaking. I submit from my direct observations that you would indeed sense the acceleration. One almost all of us have experienced is turbulence in an airplane. A common turbulence situation is an aircraft loses lift and you feel it. No air movement. Not external references. You just feel it. As part of pilot training, learning to recover from a stall is standard practice. If you have ever been in a stalled aircraft you felt it too.
https://en.wikipedia.org/wiki/Falling_(sensation)
you feel "the acceleration", but there is no objective answer as to what's accelerating relative to what
What we sense is a velocity change relative to our current velocity vector. The inner ear is made to do just that, without that you couldn't walk, jump or do much else besides lay there. People with inner ear problems sometimes report that feeling of falling, for the ear to falsly report that would suggest that it is a real feeling for a real purpose.
So no, I am not convinced. Again not from youtube videos, or literature, but direct observation.
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What we sense is a velocity change relative to our current velocity vector.
All velocity is relative to a frame of reference. This isn't a question of what you do and don't find convincing, or what you do or don't feel, it's a physical fact. You have a velocity vector relative to the air. This is the same as the air having a velocity vector relative to you. The two aren't just indistinguishable, they're precisely the same.
Once again - there is no physical difference between stating that the Earth and air are accelerating up towards you, and stating that you are accelerating towards the Earth. That's the frustration with your argument. You're basically saying "It's not apples, it's apples!"
So no, I am not convinced. Again not from youtube videos, or literature, but direct observation.
Your direct observation is that your velocity relative to your surroundings changes. This is not in conflict with UA.
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Exactly as I said. "I can testify that one can't feel freefall. " We are not talking freefall, we are talking about transition to freefall.
There is a transition under UA. The Earth is pushing up the atmosphere. The plane is riding on the atmosphere via lift. The floor of the plane is pushing and accelerating you upwards.
When you jump out you will transition from being accelerated upwards to zero acceleration (ignoring air resistance), as you are no longer connected to the floor of the plane.
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What we sense is a velocity change relative to our current velocity vector.
All velocity is relative to a frame of reference. This isn't a question of what you do and don't find convincing, or what you do or don't feel, it's a physical fact. You have a velocity vector relative to the air. This is the same as the air having a velocity vector relative to you. The two aren't just indistinguishable, they're precisely the same.
Once again - there is no physical difference between stating that the Earth and air are accelerating up towards you, and stating that you are accelerating towards the Earth. That's the frustration with your argument. You're basically saying "It's not apples, it's apples!"
So no, I am not convinced. Again not from youtube videos, or literature, but direct observation.
Your direct observation is that your velocity relative to your surroundings changes. This is not in conflict with UA.
If I was suspended in a fixed spot and the floor was rushing up to me, I could not tell the difference between that and being in freefall toward the same floor assuming relative wind was the same in both cases. If the same experiment had me drop towards that floor my inner ear would detect the change. Unless we are debating about function of the inner ear, I don't see your point.
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Damn, I hate it when the obvious is right in front of me.
Here is an experiment that anyone can do. Go to an amusement park and get on one of the tower drop rides. If you have been on one you know you damn near spit your guts out your mouth when it drops. There is one, in Orlando I think, that is an elevator, you are in an enclosed room so to speak when it drops.
Any takers, report if you feel yourself falling.
Note: Record number of typo edits.
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Yeah, I definitely get the EP side of things here, but agree with Tominaustin...
Imagine being in a vacuum chamber, standing on a platform with a trap door. What would your body sense when that trap door is instantaneously released?
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If the same experiment had me drop towards that floor my inner ear would detect the change.
This is incorrect. You have to compare two scenarios:
- You jump off a plane and accelerate to terminal velocity.
- You're suspended in the air while weightless, and a fan blows upward at you with increasing speed unless the air around you reaches the equivalent of your terminal velocity.
The two must be indistinguishable, because physics. Again, the question isn't of how the human body functions, or what you perceive. It's also not a RE vs FE question. The two scenarios are physically identical.
Any takers, report if you feel yourself falling.
You continue to miss the point. You would "feel yourself falling" (a vague term with no meaningful definition) in both scenarios. You're doubling down on what you find intuitive, which is human nature, but there is no justification in physics for why the two would feel any different.
What would your body sense when that trap door is instantaneously released?
RE: Acceleration due to gravitation
FE: Deceleration (i.e. acceleration) due to inertia
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I have an experiment too.
Obtain a bowling ball and a marble. Test to see if it takes more force and effort to roll a bowling ball across the floor than a marble. You should be able to verify Newton's second law, that it takes more force to move a more massive object through space.
If some invisible phenomena is pulling them downwards through space, when you drop a bowling ball and a marble they should hit the ground at different times, as it takes more force to move a more massive object through space.
So why is it that Galileo in found in his drop experiments that weights of different masses fall at the same rate? Why should gravity ignore the mass of a body when pulling things down, or treat all masses the same? We verified that it takes more force to move a more massive object through space, so why is gravity applying different amounts of force to different objects depending on their mass to get them to fall at the same rate? Pretty ludicrous.
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You can derive the mathematical reason for why the two different masses are accelerated at the same rate in grade 11 physics though.
The little m for the mass of any falling object - you, me, a marble, a bowling ball, the ISS - would appear on both sides of the equation, so that value cancels out, regardless of its value.
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You can derive the mathematical reason for why the two different masses are accelerated at the same rate in grade 11 physics though.
The little m for the mass of any falling object - you, me, a marble, a bowling ball, the ISS - would appear on both sides of the equation, so that value cancels out, regardless of its value.
I agree - Tom's argument defies basic physics just as much as Tom's.
We shouldn't distract from the point here. Per the Equivalence Principle, there are no physical differences between the two scenarios. If you try to present a difference, you've already failed, because you've already assumed that basic physics is broken.
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Incorrect. There is no reason for why two bodies of different masses should be accelerated at the same rate if there is an invisible phenomena pulling them downwards through space.
Introduction to Cosmology by the 4th Cosmology School at Cracow, Portland (http://cosmoschool2018.oa.uj.edu.pl/pdfs/day3/CosmoSchool_Cracow2018_PiorkowskaKurpas.pdf)
(https://wiki.tfes.org/images/thumb/5/54/Gravity_coincidence.png/900px-Gravity_coincidence.png)
Introductory Physics: Building Models to Describe Our World (https://openlibrary-repo.ecampusontario.ca/jspui/bitstream/123456789/615/1/BuildingModelsToDescribeOurWorld.pdf), p.112, by astrophysicist Ryan Martin, Et al.
" As you recall, the weight of an object is given by the mass of the object multiplied by the strength of the gravitational field, g. There is no reason that the mass that is used to calculate weight, Fg = mg, has to be the same quantity as the mass that is used to calculate inertia F = ma. Thus, people will sometimes make the distinction between “gravitational mass” (the mass that you use to calculate weight and the force of gravity) and “inertial mass” as described above. Very precise experiments have been carried out to determine if the gravitational and inertial masses are equal. So far, experiments have been unable to detect any difference between the two quantities. As we will see, both Newton’s Universal Theory of Gravity and Einstein Theory of General Relativity assume that the two are indeed equal. In fact, it is a key requirement for Einstein’s Theory that the two be equal (the assumption that they are equal is called the “Equivalence Principle”). You should however keep in mind that there is no physical reason that the two are the same, and that as far as we know, it is a coincidence! "
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Exactly as I said. "I can testify that one can't feel freefall. " We are not talking freefall, we are talking about transition to freefall.
There is a transition under UA. The Earth is pushing up the atmosphere. The plane is riding on the atmosphere via lift. The floor of the plane is pushing and accelerating you upwards.
When you jump out you will transition from being accelerated upwards to zero acceleration (ignoring air resistance), as you are no longer connected to the floor of the plane.
I like where you are going with this. You are saying I am experiencing deceleration and not acceleration? Fascinating logic I did not consider.
What I don't like about that answer is that it ignores mass. Since terminal velocity is the point where drag overcomes the acceleration of mass, how could that explain the fall rates of same sized objects of differing mass? Object of the same mass but differing drag is an easy explanation.
Real world example: In relative work, a skydive thing where people do what amounts to tricks with each other, fall rates matter. The guys I jumped with were fairly stocky. Being tall and thin, I would wear a weight vest of up to 15 lbs to keep up with their fall rate. How could your explanation account for the change in terminal velocity when I was 15 lbs heavier yet maintained the same drag if not a tiny bit more based on the profile of the vest?
Assuming that the air is indeed pushed via UA there would have to be something to keep the air from going over the edge. A wall or dome perhaps? But, if that is the case, why would there be air pressure differences at differing altitudes? I just started thinking about this so forgive me asking what could be obvious questions.
Again the usefulness of this site to me is as a thought experiment.
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If the same experiment had me drop towards that floor my inner ear would detect the change.
This is incorrect. You have to compare two scenarios:
- You jump off a plane and accelerate to terminal velocity.
- You're suspended in the air while weightless, and a fan blows upward at you with increasing speed unless the air around you reaches the equivalent of your terminal velocity.
The two must be indistinguishable, because physics. Again, the question isn't of how the human body functions, or what you perceive. It's also not a RE vs FE question. The two scenarios are physically identical.
Any takers, report if you feel yourself falling.
You continue to miss the point. You would "feel yourself falling" (a vague term with no meaningful definition) in both scenarios. You're doubling down on what you find intuitive, which is human nature, but there is no justification in physics for why the two would feel any different.
What would your body sense when that trap door is instantaneously released?
RE: Acceleration due to gravitation
FE: Deceleration (i.e. acceleration) due to inertia
So on one hand you say that I feel "Deceleration (i.e. acceleration) due to inertia" while saying there is no feeling of falling, again a paraphrase of sensing acceleration? "Does the inner ear sense acceleration or not?" seems to be the real and pertinent question.
Tom B is being more consistent.
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while saying there is no feeling of falling
I'm not saying that. I'm saying that your interpretation of that feeling is overly specific, and poorly defined.
"Does the inner ear sense acceleration or not?" seems to be the real and pertinent question.
It's not pertinent at all. It blatantly does sense acceleration, relative to the ear itself. The problem with your logic is that that acceleration does not change in any way between the two scenarios.
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while saying there is no feeling of falling
I'm not saying that. I'm saying that your interpretation of that feeling is overly specific, and poorly defined.
"Does the inner ear sense acceleration or not?" seems to be the real and pertinent question.
It's not pertinent at all. It blatantly does sense acceleration, relative to the ear itself. The problem with your logic is that that acceleration does not change in any way between the two scenarios.
That is plainly wrong. If I am suspended in the air and the floor starts rushing up there is no device in the inner ear to sense that floor moving. In fact if I was in a sealed tube that blocked all vision, hearing, and airflow I would not even know the floor was coming at me. If however I was suddenly dropped for the same point towards the floor the inner ear would know and tell me so.
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If I am suspended in the air and the floor starts rushing up there is not device in the inner ear to sense that floor moving.
Indeed - if you weren't accelerating in the first place (i.e. no UA and no gravity - a scenario neither of us should be considering). If you were, and you were suddenly released, you would sense deceleration due to inertia.
Once again - thanks to the Equivalence Principle, we know there would be no physical difference between the two scenarios. Every time you think you found a difference, you are necessarily wrong, unless you want to discard basic physics. Note that discarding basic physics immediately disproves RET, and thus doesn't advance your goal.
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If I am suspended in the air and the floor starts rushing up there is not device in the inner ear to sense that floor moving.
Indeed - if you weren't accelerating in the first place (i.e. no UA and no gravity - a scenario neither of us should be considering). If you were, and you were suddenly released, you would sense deceleration due to inertia.
Once again - thanks to the Equivalence Principle, we know there would be no physical difference between the two scenarios. Every time you think you found a difference, you are necessarily wrong, unless you want to discard basic physics. Note that discarding basic physics immediately disproves RET, and thus doesn't advance your goal.
So you are telling me to belive the text and not my own senses? Zetetic methodology be damned?
Also please take a crack at my freefall speed changes by mass changes question. The bottom line is I fell a lot faster with the added mass of a weight vest with marginally more drag.
You might have missed this in my OP but I have not found the exact quote from Einstein, got it handy? In his examples, who and where were the observers that could not tell a difference?
And I have no other goal but to think different ideas through and so far it is not convincing.
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So you are telling me to belive the text and not my own senses? Zetetic methodology be damned?
There are two things here:
- Your own senses do not contradict the text. You don't have to choose between the two.
- Yes, fanatical Zeteticism is just as bad as fanatical anything else.
Point #1 is the one to pay attention to, mainly. You are presenting the same scenario twice using different words, and claiming that there is a difference. There isn't. Your intuition is failing you (and I don't blame you for it - relativity is unintuitive. Many things about our surroundings aren't intuitive, that's why it took humanity thousands of years to figure them out), and you're refusing to patch up the gaps in your understanding, just defaulting to a response of "nuh uh i know what i felt". If you don't want to be helped, nobody will be able to help you.
You might have missed this in my OP but I have not found the exact quote from Einstein, got it handy? In his examples, who and where were the observers that could not tell a difference?
It's not a "quote", it's a principle of physics. RE gravitational mass is identical to inertial mass. Without it, the RE gravitational model cannot work. You'll find comprehensive descriptions of it in any high school physics textbook, and on Wikipedia (https://en.wikipedia.org/wiki/Equivalence_principle).
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Exactly as I said. "I can testify that one can't feel freefall. " We are not talking freefall, we are talking about transition to freefall.
There is a transition under UA. The Earth is pushing up the atmosphere. The plane is riding on the atmosphere via lift. The floor of the plane is pushing and accelerating you upwards.
When you jump out you will transition from being accelerated upwards to zero acceleration (ignoring air resistance), as you are no longer connected to the floor of the plane.
I like where you are going with this. You are saying I am experiencing deceleration and not acceleration? Fascinating logic I did not consider.
What I don't like about that answer is that it ignores mass. Since terminal velocity is the point where drag overcomes the acceleration of mass, how could that explain the fall rates of same sized objects of differing mass? Object of the same mass but differing drag is an easy explanation.
Real world example: In relative work, a skydive thing where people do what amounts to tricks with each other, fall rates matter. The guys I jumped with were fairly stocky. Being tall and thin, I would wear a weight vest of up to 15 lbs to keep up with their fall rate. How could your explanation account for the change in terminal velocity when I was 15 lbs heavier yet maintained the same drag if not a tiny bit more based on the profile of the vest?
Assuming that the air is indeed pushed via UA there would have to be something to keep the air from going over the edge. A wall or dome perhaps? But, if that is the case, why would there be air pressure differences at differing altitudes? I just started thinking about this so forgive me asking what could be obvious questions.
Again the usefulness of this site to me is as a thought experiment.
Well, this is related to what I posted about different masses falling at the same rate. There isn't a fall difference with bodies of different masses in a vacuum. All bodies fall at the same rate regardless of mass in a vacuum according to current experiments.
The reason why heavier things fall faster in the atmosphere is because of air resistance. It requires more force from air particles to move a more massive object.
When you jump out of the plane the earth is still accelerating upwards. It is pushing up the atmosphere. The air is rushing up against you. While in free fall you are otherwise weightless and the atmospheric resistance is pushing you upwards. It takes more force to move a more massive object, so it will push heavier and lighter objects differently.
(https://i.imgur.com/pKdj0px.png)
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So you are telling me to belive the text and not my own senses? Zetetic methodology be damned?
There are two things here:
- Your own senses do not contradict the text. You don't have to choose between the two.
- Yes, fanatical Zeteticism is just as bad as fanatical anything else.
Point #1 is the one to pay attention to, mainly. You are presenting the same scenario twice using different words, and claiming that there is a difference. There isn't. Your intuition is failing you (and I don't blame you for it - relativity is unintuitive. Many things about our surroundings aren't intuitive, that's why it took humanity thousands of years to figure them out), and you're refusing to patch up the gaps in your understanding, just defaulting to a response of "nuh uh i know what i felt". If you don't want to be helped, nobody will be able to help you.
You might have missed this in my OP but I have not found the exact quote from Einstein, got it handy? In his examples, who and where were the observers that could not tell a difference?
It's not a "quote", it's a principle of physics. RE gravitational mass is identical to inertial mass. You'll find comprehensive descriptions of it in any high school physics textbook, and on Wikipedia (https://en.wikipedia.org/wiki/Equivalence_principle).
"nuh uh i know what i felt"
LOL, really? So much for polite debate.
In the last post you said "Once again - thanks to the Equivalence Principle, we know there would be no physical difference between the two scenarios." Like you said, if you will not listen no one can help you. There is a huge physical difference in the question of what is moving, me or the floor. Saying I am denying basic physics is a BS excuse for not addressing the actual questions, it is way more of a "nuh uh" than I did.
So again, in my 2 scenarous, sealed in a tube, one falling and the other the floor rushing up, that is the same? You are telling me I would feel the same exact sensations?
You also seem to discount the bodies ability to detect a change in velocity, at least until Tom Bs version came out. Dishonest. Had you presented that like he did it would be different.
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So again, in my 2 scenarous, sealed in a tube, one falling and the other the floor rushing up, that is the same? You are telling me I would feel the same exact sensations?
No, I already told you what the missing link was in your scenarios. In the "floor rushing up" scenario, you neglected to include the fact that the observer would have to be accelerating upwards prior to being released.
There is a huge physical difference in the question of what is moving, me or the floor.
Motion is relative. There is no correct answer to your question, and there is no physical difference between the two scenarios. All that changes is the frame of reference.
You also seem to discount the bodies ability to detect a change in velocity, at least until Tom Bs version came out. Dishonest.
I never did that. If you think I did, you misunderstood. If you're going to accuse me of being dishonest when the issue is simply your misunderstanding of the very physics RET relies on, there is no point in further discussion.
If you don't want to be helped, nobody will be able to help you. This stuff is difficult, and I'm happy to help you work through it, but you're gonna have to try and work with me.
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Exactly as I said. "I can testify that one can't feel freefall. " We are not talking freefall, we are talking about transition to freefall.
There is a transition under UA. The Earth is pushing up the atmosphere. The plane is riding on the atmosphere via lift. The floor of the plane is pushing and accelerating you upwards.
When you jump out you will transition from being accelerated upwards to zero acceleration (ignoring air resistance), as you are no longer connected to the floor of the plane.
I like where you are going with this. You are saying I am experiencing deceleration and not acceleration? Fascinating logic I did not consider.
What I don't like about that answer is that it ignores mass. Since terminal velocity is the point where drag overcomes the acceleration of mass, how could that explain the fall rates of same sized objects of differing mass? Object of the same mass but differing drag is an easy explanation.
Real world example: In relative work, a skydive thing where people do what amounts to tricks with each other, fall rates matter. The guys I jumped with were fairly stocky. Being tall and thin, I would wear a weight vest of up to 15 lbs to keep up with their fall rate. How could your explanation account for the change in terminal velocity when I was 15 lbs heavier yet maintained the same drag if not a tiny bit more based on the profile of the vest?
Assuming that the air is indeed pushed via UA there would have to be something to keep the air from going over the edge. A wall or dome perhaps? But, if that is the case, why would there be air pressure differences at differing altitudes? I just started thinking about this so forgive me asking what could be obvious questions.
Again the usefulness of this site to me is as a thought experiment.
Well, this is related to what I posted about different masses falling at the same rate. There isn't a fall difference with bodies of different masses in a vacuum. All bodies fall at the same rate regardless of mass in a vacuum.
The reason why heavier things fall faster in the atmosphere is because of air resistance. It requires more force from air particles to move a more massive object.
When you jump out of the plane the earth is still accelerating upwards. It is pushing up the atmosphere. The air is rushing up against you. While in free fall you are otherwise weightless and the atmospheric resistance is pushing you upwards. It takes more force to move a more massive object, so it will push heavier and lighter objects differently.
(https://i.imgur.com/pKdj0px.png)
Good explanation, I'll accept that with all the enthusiasm that a minute of thinking about it can muster. I don't see any holes in it
To recap your explanations, the feeling of falling is just a sense of velocity change due to slowing, not speeding up. (The same thing as far as acceleration is concerned) The difference in the fall rates for objects of the same drag but differing mass is the amount of work by the moving air.
Sounds like a wiki entry to me.
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So again, in my 2 scenarous, sealed in a tube, one falling and the other the floor rushing up, that is the same? You are telling me I would feel the same exact sensations?
No, I already told you what the missing link was in your scenarios. In the "floor rushing up" scenario, you neglected to include the fact that the observer would have to be accelerating upwards prior to being released.
You also seem to discount the bodies ability to detect a change in velocity, at least until Tom Bs version came out. Dishonest.
I never did that. If you think I did, you misunderstood. If you're going to accuse me of being dishonest when the issue is simply your misunderstanding of the very physics RET relies on, there is no point in further discussion.
If you don't want to be helped, nobody will be able to help you. This stuff is difficult, and I'm happy to help you work through it, but you're gonna have to try and work with me.
Agree I did miss that part about the tube accelerating upwards. See the reply to Tom B, case closed as far as I am concerned. Again that is why I come here, aside from obvious trolling in AR, its a good thought exercise.
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I was still editing my post when you replied, so I'll just quote myself here to make sure you saw my most recent remark:
Motion is relative. There is no correct answer to your question, and there is no physical difference between the two scenarios. All that changes is the frame of reference.
And don't worry - I honestly get why you're asking these questions. When I say that I think you misunderstand something, I don't mean it in a mean, personal way - the whole point of this place is to further our understanding of things. And I'm happy to explain my position as best as I can, even if I come across as very blunt in the process.
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I was still editing my post when you replied, so I'll just quote myself here to make sure you saw my most recent remark:
Motion is relative. There is no correct answer to your question, and there is no physical difference between the two scenarios. All that changes is the frame of reference.
And don't worry - I honestly get why you're asking these questions. When I say that I think you misunderstand something, I don't mean it in a mean, personal way - the whole point of this place is to further our understanding of things. And I'm happy to explain my position as best as I can, even if I come across as very blunt in the process.
Oh I get it. No offense taken. I wish that all the debates would go like this one. Present question, get responses, ask for clarification and move on.
I seriously doubt many people have come here and said, "OMG the earth is flat" or the opposite. While I have given Tom a ton of crap, one has to admire his ability to research and present a case. He is not always on solid ground(IMHO) but he is consistent. In this case his points were spot on and concise. You go girl!
PS. You are a poopy pants (ship that to AR)
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When you jump out you will transition from being accelerated upwards to zero acceleration (ignoring air resistance), as you are no longer connected to the floor of the plane
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How can there be air resistance when there is no acceleration? If you aren’t being accelerated in any direction there is nothing to resist against.
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The Earth is accelerating upwards. The air is on top of the Earth. When you jump out of an airplane you are inert in space, weightless. The Earth pushes up the air into you. You feel air blowing up against your face and see the Earth accelerating up towards you.
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The Earth is accelerating upwards. The air is on top of the Earth. When you jump out of an airplane you are inert in space, weightless. The Earth pushes up the air into you. You feel air blowing up against your face and see the Earth accelerating up towards you.
I get that. My point is that air resistance can't be the reason the ground makes contact with a less massive object before it makes contact with a more massive object. Neither object is moving. As you say, both are inert, so what does air resistance have to do with anything? It isn't "slowing down" a more massive object if it isn't moving in the first place.
If a bowling ball and a feather are both inert in the air at the same elevation, the earth will reach both of them at the same time. Air resistance would have no effect.
EDIT: To be more clear. If UA is pushing the feather up, then it is being accelerated...it isn't inert.
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The bodies are inert in space while in free-fall. They are not slowing down, they are not moving. They are being pushed upwards by the air. The air is being pushed upwards by the accelerating earth, into the objects. The feather is going to experience more of an effect from the air pushing up against it than a massive bowling ball.
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They are not slowing down, they are not moving. They are being pushed upwards by the air.
How can they be "not moving" and be "pushed upwards" at the same time? If something is being pushed, it's moving. The only way it wouldn't be moving is if it is being pulled at the same time, with the same force, in the same opposite direction.
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They are not moving on their own accord. They are being pushed upwards by the air.
In a vaccum a bowling ball and a feather fall together. There are videos of that.
In a Zero G airplane a bowling ball and a feather float together, and are weightless together.
Only in the atmosphere that is pushed upwards by the earth do they not fall together.
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They are not slowing down, they are not moving. They are being pushed upwards by the air.
How can they be "not moving" and be "pushed upwards" at the same time? If something is being pushed, it's moving. The only way it wouldn't be moving is if it is being pulled at the same time, with the same force, in the same opposite direction.
Obviously not defending UA, but Tom's explanation is consistent with the UA model. If the ground was indeed moving up pushing the air with it then an object of more mass would be more "work" than one of less mass.
I did not start this thread to argue UA yes or no, just what I felt was an inconsistency I couldn't wrap my head around based on personal observation. In fact, freefall speeds were not part of my OP but came up as part of the discussion.
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Well done TomInAustin, the first post is spot on in my perspective.
The diagram tom shared (with the balloon) and your experiential "accelerometer" are in accord. Gravity is not in any way an acceleration.
To further what tom said about inertia, this is yet another simple proof of gravity's fictional nature. When I learned about it, I was taught that gravity must travel faster than the speed of light because (effectively instantaneous) information transfer is required to know how much force to apply to each object of varying mass in the larger masses vicinity. Not unlike the sun and moon appearing the same size - the equivalence principle is preposterous coincidence as a lynch pin in mythology being disingenuously/erroneously presented as science.
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Well done TomInAustin, the first post is spot on in my perspective.
The diagram tom shared (with the balloon) and your experiential "accelerometer" are in accord. Gravity is not in any way an acceleration.
To further what tom said about inertia, this is yet another simple proof of gravity's fictional nature. When I learned about it, I was taught that gravity must travel faster than the speed of light because (effectively instantaneous) information transfer is required to know how much force to apply to each object of varying mass in the larger masses vicinity. Not unlike the sun and moon appearing the same size - the equivalence principle is preposterous coincidence as a lynch pin in mythology being disingenuously/erroneously presented as science.
If you were taught that gravity travels faster than light then you were taught wrong and might need to revisit the subject.
Gravity obeys the speed of light, if you move an object, other objects will not 'know' it moved until the information can reach them.
In fact, that's what gravitational waves are that the LIGO has been detecting for some time now. Those waves travel at the speed of light, so when we measure them we can see how quickly gravity changed for that event, such as two black holes colliding.
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Obviously not defending UA, but Tom's explanation is consistent with the UA model. If the ground was indeed moving up pushing the air with it then an object of more mass would be more "work" than one of less mass
.
I get that. I was just pointing out that something can't be at "zero acceleration" and be "pushed up" at the same time. Zero acceleration means no force is applied...when something is being "pushed up" there is a force.
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The bodies are inert in space while in free-fall. They are not slowing down, they are not moving. They are being pushed upwards by the air. The air is being pushed upwards by the accelerating earth, into the objects. The feather is going to experience more of an effect from the air pushing up against it than a massive bowling ball.
Do you believe in a physical dome?
If no then what is keeping the atmosphere in?
If you do then what material could possibly form a dome that size without breaking?
The trouble with the Zetetic method here is you make an observation - you step off a chair and you observe the ground rush towards you. I see you step off and I see you fall. Both are equally plausible explanations (leaving aside everything else) so how does the experiment lead you to one explanation over the other?
Variations in gravity are the discriminator between the two explanations.
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Gravity is not in any way an acceleration.
according to the accelerometer on my phone it is. Interesting experiment I just did. The app I have allows you to ignore or include gravity. When I used gravity and place the phone face up on the floor, it showed -1g. When I ignored gravity, it showed 0g.
Wondering how UA would account for those results?
the equivalence principle is preposterous coincidence as a lynch pin in mythology being disingenuously/erroneously presented as science.
Einstein solved the coincidence of the equality of inertial mass and gravitational mass with GR by unifying inertia and gravity into one field, like the electromagnetic field.
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@JSS
If you were taught that gravity travels faster than light then you were taught wrong and might need to revisit the subject.
I was taught that it must for the reasons I explained. You are welcome to try and explain how it can apply the correct and varying force to counter inertia of objects of varying weight instantaneously regardless of distance. It does not take any time for "information" to travel, this is demonstrable.
Those waves travel at the speed of light,
Whatever ligo and its sister picked up did seem to be going at the speed of light, if we can trust any of that data (highly unlikely). There is no gravity, they did not detect gravity, and interferometers measure motion. Trying to use them to measure something else is stupid and unscientific.
@fisherman
Look through this thread for toms water balloon diagram. You missed it.
Einstein solved the coincidence of the equality of inertial mass and gravitational mass with GR by unifying inertia and gravity into one field, like the electromagnetic field.
So he didn't so much "solve" the coincidence as depend on it further, working it into the fundamental fabric of the "theory"...
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So he didn't so much "solve" the coincidence as depend on it further, working it into the fundamental fabric of the "theory".
.
GR, at its core is an explanation as to why inertial and gravitational mass are indistinguishable. It's because they are the same thing. In a Nature article in 1921, AE said Can gravitation and inertia be identical? The question leads directly to the General Theory of Relativity.
In 1918, AE restated the equivalence principle as " Inertia and gravity are phenomena identical in nature. From this and from the special theory of relativity, it follows necessarily that the symmetric "fundamental tensor" determines the metric properties of space, the inertial behavior of bodies in this space, as well as the gravitational effects. We shall call the state of space which is described by this fundamental tensor the "G field".
In other words, the reason bodies fall independent of their mass is because mass is not what determines their behavior. The "G field" does.
This is not so different from the UA explanation, which is the acceleration of the earth that determines how things fall. The difference is that Einstein's g-field has been experimentally verified as the the curvature of spacetime, and the acceleration of earth has not.
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@JSS
If you were taught that gravity travels faster than light then you were taught wrong and might need to revisit the subject.
I was taught that it must for the reasons I explained. You are welcome to try and explain how it can apply the correct and varying force to counter inertia of objects of varying weight instantaneously regardless of distance. It does not take any time for "information" to travel, this is demonstrable.
Then you were not taught that gravity is instantaneous, you are misunderstanding how gravity works. It is not demonstrable that gravity is instantaneous, in fact we have demonstrated the opposite.
Einstein's theories predict gravity moves ta the speed of light. We have confirmed this in experiments and observations.
The most recent and most accurate used the timings of a neutron star collision in October of 2017. There were multiple different methods used, but the most accurate compared the time that we recorded the gamma ray burst with the time that we recorded the gravitational waves.
That method came up with a result of gravity moving somewhere between -0.0000000000000003% and 0.0000000000000007% of the speed of light.
Those waves travel at the speed of light,
Whatever ligo and its sister picked up did seem to be going at the speed of light, if we can trust any of that data (highly unlikely). There is no gravity, they did not detect gravity, and interferometers measure motion. Trying to use them to measure something else is stupid and unscientific.
You should read up on what interferometers do and how they work, they don't measure motion, they measure distance. I've used interferometers, I've even built my own.
If you don't think interferometers measure distance but measure something else instead, that might be the source of your confusion on this subject.
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@JSS
It is not demonstrable that gravity is instantaneous, in fact we have demonstrated the opposite.
Absolutely untrue. What delay do you believe there is between dropping an object and its falling (too much looney toons?)? You have been misinformed. You are still talking about LIGO, but you don't know enough about it (due to propagandist mass advertising under the guise of science). I am struggling to help you learn. You have an "adversarial" approach which is hindering you. Discuss, don't debate. Debate is not for intelligent people, and it has no place in effective communication or learning.
You should read up on what interferometers do and how they work, they don't measure motion, they measure distance. I've used interferometers, I've even built my own.
Interferometers are not used (typically, anyhow) nor designed/invented to measure distance, why you think that is beyond me - especially with your claim that you've built one. They are used to measure motion, which does - in fairness - correspond to an infinitesimal "distance" (distance between fringes). Using a laser and timing its return for distance estimation is in no way an interferometer. Perhaps you do not need this clarification, however there are likely some reading that do.
That method came up with a result of gravity moving somewhere between -0.0000000000000003% and 0.0000000000000007% of the speed of light.
Yep, they claim to have detected a vibration (motion) that traveled close to the speed of light and coincided with the gamma ray burst detection. No gravity involved in any way. Gravitational waves, are not gravity or gravity waves. They have played a semantic trick on you.
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@fisherman
The difference is that Einstein's g-field has been experimentally verified as the the curvature of spacetime
No, it most certainly has not. I entreat you to prove me wrong and let me know when and how this was "experimentally verified". Spacetime is so ridiculously stupid :(
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You should read up on what interferometers do and how they work, they don't measure motion, they measure distance. I've used interferometers, I've even built my own.
Interferometers are not used (typically, anyhow) nor designed/invented to measure distance, why you think that is beyond me - especially with your claim that you've built one. They are used to measure motion, which does - in fairness - correspond to an infinitesimal "distance" (distance between fringes). Using a laser and timing its return for distance estimation is in no way an interferometer. Perhaps you do not need this clarification, however there are likely some reading that do.
I'm not sure where you're getting all that from. But Interferometers certainly are all about distance (and size) measurements.
"The interferometer was invented by Albert A. Michelson in about 1880. It is an optical instrument that has been redesigned in numerous forms and has many applications in optics where precision measurements are required. Michelson originally designed the interferometer for ether-drift experiments to prove the existence of the medium, which was thought to explain the propagation of light. He also used the interferometer to define the International Standard Meter in terms of the red wavelength of cadmium light, to study the fine structure in spectral lines, to determine the degree of rigidity and elasticity of the earth, and to measure the angular diameters of the satellites of Jupiter and the diameters of several of the largest stars...
Interferometers are used as a tool for stellar astrophysics, principally for the measurement of the angular diameters of stars and for the measurement of binary star orbits."
https://www.scientificamerican.com/article/what-is-an-optical-interf/
Time Line for the Definition of the Meter
1892 Michelson used an interferometer that he developed to determine the length of
the International Prototype Meter in terms of the cadmium red line wavelength.
His measurements gave the meter a value of 1,553,164.13 times the wavelength
of cadmium red in air, at 760 mm of atmospheric pressure at 15 °C.
1925 The Michelson interferometer was in regular use at BIPM for measuring length.
https://www.nist.gov/system/files/documents/pml/div683/museum-timeline.pdf
Perhaps you do not need this clarification, however there are likely some reading that do.
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You should read up on what interferometers do and how they work, they don't measure motion, they measure distance. I've used interferometers, I've even built my own.
Interferometers are not used (typically, anyhow) nor designed/invented to measure distance, why you think that is beyond me - especially with your claim that you've built one. They are used to measure motion, which does - in fairness - correspond to an infinitesimal "distance" (distance between fringes). Using a laser and timing its return for distance estimation is in no way an interferometer. Perhaps you do not need this clarification, however there are likely some reading that do.
You are very confused. What does using a laser and timing how long a pulse takes have to do with an interferometer?
Interferometers measure distance, not motion. How can you be mixed up between distance and movement?
What you are saying is in effect, claiming a tape measure doesn't measure distance, it measures movement. That makes no sense, sure you can measure movement with a tape measure, but only by comparing multiple readings of distance over time... because DISTANCE is what it measures, just like an interferometer.
Try a little research.
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@stack
Interesting! I did not know about this! Thanks for sharing - I'll take a look.
The interferometer was not designed or invented to measure distance, at least initially - as it seems!
@JSS
What does using a laser and timing how long a pulse takes have to do with an interferometer?
Nothing. That's how you measure distances with lasers/electromagnetic waves. You time return pulses - obviously.
Interferometers measure distance, not motion.
It is interesting that interferometers are also (later after their invention for their primary purpose) used to measure distance (as I said they could potentially do - on infinitesimal scales), though irrelevant to our discussion. LIGO does not measure distance with interferometers. Interferometers are not commonly used for distance.
That makes no sense,
Well, stop talking nonsense to yourself then! Interferometers measure motion - that's their original purpose and that is by FAR their frequent usage today. Do you really not know that? Or are you simply disingenuous?
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It is interesting that interferometers are also (later after their invention for their primary purpose) used to measure distance (as I said they could potentially do - on infinitesimal scales), though irrelevant to our discussion. LIGO does not measure distance with interferometers. Interferometers are not commonly used for distance.
The LIGO detects gravitational waves by measuring the distance of the two arms. Large gravitational waves change the distances, which the interferometers can detect. We call changes in distance over time motion, which seems to be what has you hung up over the whole measuring movement vs distance. It's comparing the length of the two arms.
This whole side-discussion is indeed irrelevant.
LIGO detects gravitational waves. Why do you think it does not?
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@JSS
LIGO detects gravitational waves. Why do you think it does not?
Firstly, gravitational waves are fiction. Secondly, interferometers measure motion. The length of the arms of the interferometer do not change or move - great pains are taken to assure this (when you aren't using it to measure distance). Thirdly, gravitational waves are not gravity, nor gravity waves - they have played a semantic trick on you.
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@JSS
LIGO detects gravitational waves. Why do you think it does not?
Firstly, gravitational waves are fiction.
This is just a statement, it's not evidence or an explanation.
Secondly, interferometers measure motion.
We have been down this road already. Interferometers measure the interference pattern of two waves of light. In the case of LIGO, it's two beams bouncing off a pair of mile long tunnels at 90 degree angles. They are calibrated so the interference patterns cancel out. If the distance of one of the tunnels change, then the interference no longer cancels out and you get a signal. This is how it detects gravitational waves. What do you think it's measuring instead?
The length of the arms of the interferometer do not change or move - great pains are taken to assure this (when you aren't using it to measure distance).
If they did not change, what is causing the interference pattern? How come the measurements match up with predictions for what we should see for such events?
Thirdly, gravitational waves are not gravity, nor gravity waves - they have played a semantic trick on you.
Again, this is just a statement, not evidence or an explanation.
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@stack
Interesting! I did not know about this! Thanks for sharing - I'll take a look.
The interferometer was not designed or invented to measure distance, at least initially - as it seems!
You are incorrect. The whole point of the interferometer was to measure minute distance, not motion. Motion calculations were a byproduct of the device's exacting distance measurement capabilities.
"The Michelson interferometer (invented by the American physicist Albert A. Michelson, 1852–1931) is a precision instrument that produces interference fringes by splitting a light beam into two parts and then recombining them after they have traveled different optical paths...
The path difference of the two beams when they recombine is 2{d}_{1}-2{d}_{2}, where {d}_{1} is the distance between M and {\text{M}}_{1}, and {d}_{2} is the distance between M and {\text{M}}_{2}. Suppose this path difference is an integer number of wavelengths m{\lambda }_{0}. Then, constructive interference occurs and a bright image of the point on the source is seen at the observer. Now the light from any other point on the source whose two beams have this same path difference also undergoes constructive interference and produces a bright image. The collection of these point images is a bright fringe corresponding to a path difference of m{\lambda }_{0} ((Figure)). When {\text{M}}_{1} is moved a distance \text{Δ}d={\lambda }_{0}\text{/}2, this path difference changes by {\lambda }_{0}, and each fringe moves to the position previously occupied by an adjacent fringe. Consequently, by counting the number of fringes m passing a given point as {\text{M}}_{1} is moved, an observer can measure minute displacements that are accurate to a fraction of a wavelength, as shown by the relation."
https://opentextbc.ca/universityphysicsv3openstax/chapter/the-michelson-interferometer/
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@JSS
If the distance of one of the tunnels change, then the interference no longer cancels out and you get a signal. This is how it detects gravitational waves. What do you think it's measuring instead?
That is true, however there is nothing adjusting the length of the arms. The arms stay fixed, and insulated from noise/seismic vibration. You cannot understand the interferometer or what it does in the currently taught framework of physics. Perhaps that is why they had you build one for measuring distance - that IS explainable in the current framework. The era of aether-mcarthyism must come to an end. It measures motion; Why will undoubtedly take some time and repetition to convey to you - but I'm game if you are! In the specific case of LIGO, it's irreproducible and hardly worth evaluating until that changes (science MUST be repeatable and repeated rigorously)
If they did not change, what is causing the interference pattern
The speed of the light in each arm. The amount of time that the light takes to travel in each identical arm is different. Excellent question.
Again, this is just a statement, not evidence or an explanation.
It's an important point that you have missed, and were intended to. Cutting edge science is never headline news - ever. LIGO is a fraud, wether they detected something or not. It was presented as if "gravity" were finally found - it hasn't of course, because gravity is fiction. Gravitational waves are not gravity or gravity waves. They played a semantic trick on the gullible public through mass media. I doubt the LIGO "researchers" have anything at all to do with it - they are far too poor and have no "pull" to achieve such a result.
@stack
You are incorrect. The whole point of the interferometer was to measure minute distance, not motion
The interferometer was first designed and invented for a purpose. Do you know what that purpose was? I'll give you a hint - it wasn't measuring distance... If you do have any evidence to support your assertion, I'd be very interested!
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@stack
You are incorrect. The whole point of the interferometer was to measure minute distance, not motion
The interferometer was first designed and invented for a purpose. Do you know what that purpose was? I'll give you a hint - it wasn't measuring distance... If you do have any evidence to support your assertion, I'd be very interested!
The experiment was to determine whether the aether was in motion or stationary.
The instrument devised (interferometer) for the experiment was designed to measure very hyper-exacting distance to derive motion calculations/results. How is that lost on you? How does one measure motion over time? Think about it.
And I already gave you the evidence:
The path difference of the two beams when they recombine is 2{d}_{1}-2{d}_{2}, where {d}_{1} is the distance between M and {\text{M}}_{1}, and {d}_{2} is the distance between M and {\text{M}}_{2}. Suppose this path difference is an integer number of wavelengths m{\lambda }_{0}. Then, constructive interference occurs and a bright image of the point on the source is seen at the observer. Now the light from any other point on the source whose two beams have this same path difference also undergoes constructive interference and produces a bright image. The collection of these point images is a bright fringe corresponding to a path difference of m{\lambda }_{0} ((Figure)). When {\text{M}}_{1} is moved a distance \text{Δ}d={\lambda }_{0}\text{/}2, this path difference changes by {\lambda }_{0}, and each fringe moves to the position previously occupied by an adjacent fringe. Consequently, by counting the number of fringes m passing a given point as {\text{M}}_{1} is moved, an observer can measure minute displacements that are accurate to a fraction of a wavelength, as shown by the relation."
https://opentextbc.ca/universityphysicsv3openstax/chapter/the-michelson-interferometer/
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@stack
The instrument devised (interferometer) for the experiment was designed to measure very hyper-exacting distance
Wrong. Also, please provide some support for your claim that the interferometer was first made to measure distance. I'm waiting for it... If your reading comprehension is poor enough that you think that detail was included in the entry level article you posted - you have big problems to address before you can make any further progress learning from reading.
The michelson morely observation is not an experiment. Words have meanings.
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@stack
The instrument devised (interferometer) for the experiment was designed to measure very hyper-exacting distance
Wrong. Also, please provide some support for your claim that the interferometer was first made to measure distance. I'm waiting for it... If your reading comprehension is poor enough that you think that detail was included in the entry level article you posted - you have big problems to address before you can make any further progress learning from reading.
Interesting. You simply say, "Wrong," without providing any evidence other than you just saying, "Wrong." How is this not the detail required: "The path difference of the two beams when they recombine is 2{d}_{1}-2{d}_{2}, where {d}_{1} is the distance between M and {\text{M}}_{1}, and {d}_{2} is the distance between M and {\text{M}}_{2}.
As well we have:
A straightforward application for the Michelson interferometer is direct measurement of the wavelength of monochromatic light. By smooth changing of the distance d1(or d2) and counting the interference maxima, which comes as cosine function of the distance, eq. (2.13), one can determine the wave number as number of maxima per unit length,13 and the wavelength as inverse of the wave number.
A short list of the Michelson interferometer applications in the optical spectroscopy application includes:
- wavelength determination;
- measurements of the light coherence length (the interference pattern can be observed only for coherent beams I1 and I2);
- optics diagnostics (an optical component, e. g. a lens, can be inserted between mirrors M1 and M2 and any distortions of the wavefront will be seen in distortions of the interference pattern on the interferometer output);
- fine displacement measurements;
- optical correlators (ultra-short pulse width measurements, will be considered in Chapter 4.5.2);
- Fourier transform infrared spectroscopy;
https://www.sciencedirect.com/topics/physics-and-astronomy/michelson-interferometers
The michelson morely observation is not an experiment. Words have meanings.
Yes, words do have meaning. And I have no idea what you are getting at. The Michelson-Morley Experiment (MMX for short) is referred to in physics as the "The Michelson-Morley Experiment". Do you take issue with what it is called? If so, please explain.
I think the bigger problem you may have is that is seems you are one of the types of people who offers no evidence to support your claims and expects others to solely rely upon your wisdom which has yet to be revealed in any meaningful way. What sort of evidence do you have that refutes the evidence I have offered. If you could provide something then maybe we could have a conversation about reading comprehension. All we have so far from you is "Wrong."
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@stack
Thank you for your thoughtful reply. I may have been in a foul mood when I was a little harsh with the "reading comprehension bit". My apologies.
Interesting. You simply say, "Wrong,
I do it to save time. It is common knowledge, after all - and should hardly be surprising to you. The "mmx" (j*sus tap dancing chr*st) was not performed to measure distance. This is historical fact, and I am still waiting on you to provide support for your revisionist claim - assuming you have one. I've read your entry level article - it does not serve to rewrite history in the manner you require. If you don't have any support for your claim in historical/scientific text, then why are you so certain about it?
I find it perfectly conceivable that your claim could have some merit, though you have provided no evidence for it so far. It is widely taught and known that the "mmx" measures velocity (or acceleration, depending on if you were taught correctly or not), not distance. Great pains were taken to eliminate the noise caused by the "distance" the interferometer would change shape due to vibration. It is still used today for that same purpose and that is its most common use.
And I have no idea what you are getting at.
That's fair - i did not explain. An experiment is not merely an observation. You must have at least one IV and DV and it must validate or invalidate the hypothesis by establishing a causal link between the two - it is not optional. The michaelson morely "experiment" is merely an observation - not an experiment. It may seem like a semantic quibble, but it is far more important than that.
What sort of evidence do you have that refutes the evidence I have offered
Roughly all of it. You are the only one who seems to have been taught the new history that michaelson morely invented the interferometer to measure distance first, and THEN used it to determine motion through space in the "mmx" (shudder...). I find this view interesting, and potentially plausible - but it has no historical support. Unless you have some?
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@stack
Thank you for your thoughtful reply. I may have been in a foul mood when I was a little harsh with the "reading comprehension bit". My apologies.
Interesting. You simply say, "Wrong,
I do it to save time.
You still have provided no evidence to the contrary, entry-level or otherwise. So in the interest of time, you are wrong.
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@stack
It isn't worth my time. Every source tells the same history as far as I am aware.
If you have any support for your view, I am intereted in it - however you are not obligated to share (it's just the right/best thing to do - for you and all of humanity)
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@stack
It isn't worth my time. Every source tells the same history as far as I am aware.
If you have any support for your view, I am intereted in it - however you are not obligated to share (it's just the right/best thing to do - for you and all of humanity)
From Michelson & Morley's original experiment paper, "On the Relative Motion of the Earth and the Luminiferous Ether":
"Let V= velocity of light.
v= velocity of the earth in its orbit,
D=distance ab or ac, fig. 1.
T=time light occupies to pass from a to c.
T =time light occupies to return from c to a/, (fig. 2.)
(https://i.imgur.com/LTrCwIv.png)
In the first experiment one of the principal difficulties encountered was that of revolving the apparatus without producing distortion; and another was its extreme sensitiveness to vibration. This was so great that it was impossible to see the interference fringes except at brief intervals when working in the city, even at two o'clock in the morning. Finally, as before remarked, the quantity to be observed, namely, a displacement of something less than a twentieth of the distance between the interference fringes may have been too small to be detected when masked by experimental errors."
Note the quantity to be observed by the apparatus. A byproduct of the distance measurement is motion or the lack thereof.
And note that Michelson & Morley refer to their effort throughout the original paper as an "experiment". What you consider it to be is neither here nor there.
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Cool, so we're all on the same page then.
The "mmx" (holy hell...) was for the measurement of velocity by using an interferometer, specifically designed, to measure it (not distance).
I'm glad we cleared that up!
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Cool, so we're all on the same page then.
The "mmx" (holy hell...) was for the measurement of velocity by using an interferometer, specifically designed, to measure it (not distance).
I'm glad we cleared that up!
The experiment was about motion The Interferometer itself was the tool devised to measure hyper-precise distance and as a byproduct motion or no motion.
Interferometers are widely used in science and industry for the measurement of small displacements, refractive index changes and surface irregularities. In most interferometers, light from a single source is split into two beams that travel in different optical paths, which are then combined again to produce interference; however, under some circumstances, two incoherent sources can also be made to interfere.[3] The resulting interference fringes give information about the difference in optical path lengths. In analytical science, interferometers are used to measure lengths and the shape of optical components with nanometer precision; they are the highest precision length measuring instruments in existence.
https://en.wikipedia.org/wiki/Interferometry
Yep, all cleared up: MMX was an experiment and Interferometers measure distance. Cool.
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The experiment was about motion The Interferometer itself was the tool devised to measure hyper-precise distance and as a byproduct motion or no motion.
No, no one thinks that except you. The interferometer was invented for the experiment, and it was designed to measure velocity. Obviously the measurement comes in the form of an infintessimal distance, don't be a pedant just for prides sake.
Even the page you linked to to support your baseless claim, says nothing about it. I know you are trying so very hard to avoid just saying - I was wrong. Pride is a disability and a liability. It's not hard. I say it ALL THE TIME. I make mistakes too!
Or you could provide any support for your claim... I think you just assumed it - didn't you...
As I said, it does SOUND plausible, however with just your assumption to support your claim...
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The experiment was about motion The Interferometer itself was the tool devised to measure hyper-precise distance and as a byproduct motion or no motion.
No, no one thinks that except you. The interferometer was invented for the experiment, and it was designed to measure velocity. Obviously the measurement comes in the form of an infintessimal distance, don't be a pedant just for prides sake.
Even the page you linked to to support your baseless claim, says nothing about it. I know you are trying so very hard to avoid just saying - I was wrong. Pride is a disability and a liability. It's not hard. I say it ALL THE TIME. I make mistakes too!
Or you could provide any support for your claim... I think you just assumed it - didn't you...
As I said, it does SOUND plausible, however with just your assumption to support your claim...
"In analytical science, interferometers are used to measure lengths and the shape of optical components with nanometer precision; they are the highest precision length measuring instruments in existence."
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That's all well and good.
Where is the support for your claim that the interferometer was FIRST created to measure distance and then repurposed to be used to measure motion instead?
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If you measure the distance to something once, then you measure the distance to that same thing again after some amount of time, if theres a difference between those two measurements... you've measured motion.
Not rocket appliances
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That's all well and good.
Where is the support for your claim that the interferometer was FIRST created to measure distance and then repurposed to be used to measure motion instead?
What is the purpose of focusing on what interferometers were FIRST built to measure? Does it make any difference at all to what they CAN measure? You have admitted that they can measure distance, so what exactly would it prove one way or the other? It's like asking what the tape measure was invented for, to measure distance or to be easily portable? Doesn't matter, they still do both.
As I said, I've built an interferometer and used it before and can verify it can measure distances very precisely. I've used them to measure the shape of primary telescope mirrors and verify the curve and smoothness of ther optical coatings. And of course I experimented with it once I had it all set up. I can verify, personally that they do indeed measure distance, and they do work very well. There is no reason the LIGO interferometers would not work just as well as my home-brewed version.
LIGO uses interferometers to measure distance because they are extremely good at doing that. When gravitational waves pass through the two arms, the interferometers detect the change in distance and record the results. This is direct evidence of gravitational waves, they are literally measuring space stretching and compressing in real time.
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@JSS
What is the purpose of focusing on what interferometers were FIRST built to measure?
You might have arrived late to the party. Stack has made an assumption that they are attempting to disingenuously/erroneously pass off as historical fact without any support (even anecdotal / personal "reasoning"). I am endeavoring to help keep them honest with themselves and others (only if they wish it, however).
What the interferometer does, and how it works, is actually much more relevant to the shape of the world and the observation of various phenomena (several erroneously attributed to the earth's presumed rotation) than it appears at first glance!
I agree that it is a minor point, but if it weren't important to understand I would have dropped it long before now. The other reason I continue to focus on it is because I have made mistakes like this before, and I wish to help stack to do better - if I can and they will allow me.
Doesn't matter, they still do both.
In the case of the interferometer, that is completely correct. However what is key is HOW it is doing it. We might need another thread where all this jibber jabber can go and stop cluttering this one.
There is no reason the LIGO interferometers would not work just as well as my home-brewed version.
Definitely true! In fact, there is every reason to suspect that they would work much better! However, ligo's arms are of fixed length, calibrated, and insulated from local noise and vibration. Great pains are taken to avoid any path length deviation. It is true that a vibration could cause a mirror (or the arm itself) to move and cause fringe patterns - it's just that that is not what causes the fringe patterns in ligo - nor is that the source of the fringe patterns in stationary and uniformly moving FOG's/RLG's.
When gravitational waves pass through the two arms, the interferometers detect the change in distance and record the results.
That is their earnest belief/conviction, yes. However, it is not what is happening. The interferometer is measuring perturbation in the medium of which light is comprised and travels within. There is no "gravitational wave" - that is largely a made up term to mislead laypeople into thinking "gravity" has been found/detected.
This is direct evidence of gravitational waves,
It is direct measurement of the light waves traveling in each arm. From it we can infer about the media through which light travels and is comprised. The arms of the interferometer did not change length. Noise and vibration did not move the mirrors. The path lengths remain fixed as best as can be achieved by ungodly amounts of money being thrown at the problem.
they are literally measuring space stretching and compressing in real time.
This is essentially correct in my view, assuming the data is real - which is highly suspect.