The Swing of a Pendulum

[billvon]

Because the light sphere can tell if the acceleration is an increase in velocity or a decrease in velocity.

No, it can't; that experiment has been run thousands of times and it always shows zero velocity. Light always travels the same distance in one local second no matter what speed the measurement mechanism (sphere in your case) is moving.

So let's put this in real world terms. You run that experiment and it shows you at zero velocity no matter what speed you are traveling at. What is the speed of your reference frame?

 

[Motor Daddy]

No, it can't; that experiment has been run thousands of times and it always shows zero velocity. Light always travels the same distance in one local second no matter what speed the measurement mechanism (sphere in your case) is moving.

So let's put this in real world terms. You run that experiment and it shows you at zero velocity no matter what speed you are traveling at. What is the speed of your reference frame?

That is only a confusion on your part caused by bad theory. I am not confused. I showed you the geometry of the light sphere and gave you the times, velocities, accelerations, distances traveled, and light sphere radius at all times noted. When you can tell me where I made an error in the geometry and/or numbers, then I will have no choice but to acknowledge that my diagram is wrong, but until you do that all your arm waving about how you measured something in the universe is BS! You haven't measured anything until you've measured it using the light sphere! What you have on your hands is a great big pile of evidence that belongs in a dumpster!

 

[billvon]

When you can tell me where I made an error in the geometry and/or numbers

I pointed it out several times.

but until you do that all your arm waving about how you measured something in the universe is BS! You haven't measured anything until you've measured it using the light sphere!

That's what the Michelson/Morley experiment measures; it is your "light sphere" experiment. I didn't measure it, but here are a few organizations that did, listed by researcher/organization/date:

Michelson[4] Potsdam 1881
Michelson and Morley[1] Cleveland 1887
Morley and Miller[8][9] Cleveland 1902–1904
Miller[13] Mt. Wilson 1921
Miller[13] Cleveland 1923–1924
Miller (sunlight)[13] Cleveland 1924
Tomaschek (star light)[14] Heidelberg 1924
Miller[13][A 14] Mt. Wilson 1925–1926
Kennedy[10] Pasadena/Mt. Wilson 1926
Illingworth[11] Pasadena 1927
Piccard & Stahel[16] Brussels 1927
Piccard & Stahel[17] Rigi 1927
Michelson et al.[18] Mt. Wilson 1929
Joos[12] Jena 1930
Louis Essen[19] 1955
Cedarholm et al.[20][21] 1958
Mössbauer rotor experiments 1960–63
Jaseja et al.[22] 1964
Shamir and Fox[23] 1969
Trimmer et al.[24][25] 1973
Wolf et al.[28] 2003
Müller et al.[26] 2003
Wolf et al.[29] 2004
Wolf et al.[30] 2004
Antonini et al.[31] 2005
Stanwix et al.[32] 2005
Herrmann et al.[33] 2005
Stanwix et al.[34] 2006
Müller et al.[35] 2007
Herrmann et al. 2009

As time progressed they have shown with greater and greater accuracy that the measured speed of light is the same in every direction no matter how fast you are going, and can now do so down to one part in 10^17 (i.e. speed is the same down to less than a millimeter per second.) Your light pulse hits all parts of your sphere at the same time no matter what speed you're going. And this has nothing to do with math; this is actual experimental data.

No one has ever found what you claim. Ever.

What you have on your hands is a great big pile of evidence that belongs in a dumpster!

Ah, so your underlying argument is simply that you do not believe decades of verified experimental data.

 

[Motor Daddy]

Maybe you don't understand the situation, so let me make it much easier for you to understand.

If light travels for 1 second in a vacuum, the length of the path from the start point to the end point is 299,792,458 meters. PERIOD!!
If the source that emitted the light is a distance away from the light start point at t=1 when the light completed traveling the 299,792,458 meters, then distance and time are known for the absolute velocity of the source.

By definition that is indisputable!

 

[billvon]

Maybe you don't understand the situation, so let me make it much easier for you to understand. If light travels for 1 second in a vacuum, the length of the path from the start point to the end point is 299,792,458 meters. PERIOD!!

That is correct - no matter what speed the measuring apparatus is traveling at.

If the source that emitted the light is a distance away from the light start point at t=1 when the light completed traveling the 299,792,458 meters, then distance and time are known for the absolute velocity of the source. By definition that is indisputable!

Incorrect, because of your first sentence. Light always travels ~3x10^8 m/s, period. No clever tricks exist that let you see "slow light."

 

[Motor Daddy]

That is correct - no matter what speed the measuring apparatus is traveling at.



Incorrect, because of your first sentence. Light always travels ~3x10^8 m/s, period. No clever tricks exist that let you see "slow light."

The light traveled 299,792,458 meters in one second, and during that second the source moved away from the point in space that the light was emitted at t=0, where the source was at t=0.

 

[billvon]

The light traveled 299,792,458 meters in one second, and during that second the source moved away from the point in space that the light was emitted at t=0, where the source was at t=0.

Ah, so you "see light going slower" since you are moving the edge of the sphere away from it, and you are moving with the sphere! Move fast enough and it would take a lot longer for light to get there, and you've got your slow (from your perspective) light.

That's your fallacy; you will never see that. Scientists have looked for that phenomenon for decades. It does not happen. Light always hits all sides of the sphere at the same time. That's reality.

 

[Motor Daddy]

Ah, so you "see light going slower" since you are moving the edge of the sphere away from it, and you are moving with the sphere! Move fast enough and it would take a lot longer for light to get there, and you've got your slow (from your perspective) light.

That's your fallacy; you will never see that. Scientists have looked for that phenomenon for decades. It does not happen. Light always hits all sides of the sphere at the same time. That's reality.

By definition that is impossible. If that really happens then light can not travel at a constant speed. That can't happen because by definition when the clock ticks one the light has traveled 299,792,458 meters. So even if the speed of light was wishy washy and constantly changed motion, the speed of light would be a constant at 299,792,458 m/s. The end result is that you had a ruler that was wishy washy over a duration of time. But the speed of light is impossible to vary in a vacuum, by definition!!

 

[billvon]

By definition that is impossible.

That's what Michelson and Morley thought, and that's why they performed their experiment. It was not until Einstein formalized the theory of relativity that there was a good explanation for what they saw.

Being good scientists, they tested their theory - and discovered that their assumption (which is the same as your assumption) is wrong.

If that really happens then light can not travel at a constant speed. That can't happen because by definition when the clock ticks one the light has traveled 299,792,458 meters. So even if the speed of light was wishy washy and constantly changed motion, the speed of light would be a constant at 299,792,458 m/s.

Which it is, to every observer who observes it! Including the one on the moving sphere.

The end result is that you had a ruler that was wishy washy over a duration of time. But the speed of light is impossible to vary in a vacuum, by definition!!

Ah, but you keep using the term "meters per second." Seconds ARE variable, depending on your reference frame. Your second is not the same as the other guy's second, although the difference is very small until you approach the speed of light. There's your false assumption.

 

[kwhilborn]

@ OP,

The pendulums require gravity to work and so the planet would be the related motion, having a second car doing the same thing is simply repeating the same experiment. The cars have no relation to each other. Even from the perspective of a car you would see the pendulum shift backwards, but you would also see a planet standing still.

This seems like a gradeschool observation. I do not see the point the OP is trying to make?

 

[Motor Daddy]

That's what Michelson and Morley thought, and that's why they performed their experiment. It was not until Einstein formalized the theory of relativity that there was a good explanation for what they saw.

Being good scientists, they tested their theory - and discovered that their assumption (which is the same as your assumption) is wrong.

Maybe I wasn't clear enough? By definition that is impossible. If you say Einstein's was a good explanation then you are saying Einstein's method doesn't conform to the standard definition of the meter, nor the speed of light.

Ah, but you keep using the term "meters per second." Seconds ARE variable, depending on your reference frame. Your second is not the same as the other guy's second, although the difference is very small until you approach the speed of light. There's your false assumption.

Seconds are not variable! All times are according to the light sphere. You are chasing your tail in circles due to the fact that you don't know your absolute velocity, you don't know if when you are accelerating you are increasing or decreasing velocity, and you have no idea if you are traveling faster or slower than the vehicle you are using as your bases for all your relative velocity measurements. You're a blind man in a china shop!

 

[Motor Daddy]

@ OP,

The pendulums require gravity to work and so the planet would be the related motion, having a second car doing the same thing is simply repeating the same experiment. The cars have no relation to each other. Even from the perspective of a car you would see the pendulum shift backwards, but you would also see a planet standing still.

This seems like a gradeschool observation. I do not see the point the OP is trying to make?

Do you know what relative motion is? If so, then I am talking about the zero relative motion between two cars, and at the same time showing an acceleration in the absolute frame. Since the relative velocity between the cars doesn't change when the acceleration is occurring then the acceleration is not of the relative velocity. Acceleration is independent of the relative velocity.

 

[Aqueous Id]

The pendulum is indicating an acceleration.

It's indicating the presence of a force, which imparts an acceleration on the pendulum mass. This force is the net product of the torque on the drive wheels times the friction of the tires on the pavement. It's transmitted through the wheel bearings onto the hub, then through the frame to the place where the pendulum is attached to the car. From that point the force transmits through the frame of the pendulum to the string that holds the weight. The string will transmit the force as tension to the weight. This tension adds with the tension present from the gravitational force. The net tension thus changes whenever the car accelerates and decelerates. The drive force vector will be orthogonal to the gravity vector, illustrated by an inverted "L". The vector that spans the endpoints of the ell (forming the hypontenuse of a right triangle) is the net force transmitted as tension in the string.

You have no way of knowing if the velocity is increasing or decreasing.

If you mean the pendulum doesn't behave differently, then see above. The tension force vector on the string reverses, the net force vector flips 180° about the vertical axis. At the moment the car begins to accelerate, the bob will be deflected in the opposite direction by a large angle. At the moment the car begins to decelerate, the opposite occurs. Measure this, and you have the direction of the car's acceleration, that is, whether it's acclerating or decelerating.

Here's a simulation to illustrate further the effect you're speaking about. Suggested settings:
First hit reset.
cart mass: 9999
pendulum mass: 0.1
pendulum length: 1.5
spring stiffness: 9999
gravity:9. 8
cart damping: 0.0
pendulum damping: 0.0

Grag the bob and set it swinging. Then grab the box and drag it to the left of the screen and let go. Observe the changes in bob angle as the box accelerates, decelerates, and turns around.

http://www.myphysicslab.com/pendulum_cart.html

 

[Motor Daddy]

It's indicating the presence of a force, which imparts an acceleration on the pendulum mass. This force is the net product of the torque on the drive wheels times the friction of the tires on the pavement. It's transmitted through the wheel bearings onto the hub, then through the frame to the place where the pendulum is attached to the car. From that point the force transmits through the frame of the pendulum to the string that holds the weight. The string will transmit the force as tension to the weight. This tension adds with the tension present from the gravitational force. The net tension thus changes whenever the car accelerates and decelerates. The drive force vector will be orthogonal to the gravity vector, illustrated by an inverted "L". The vector that spans the endpoints of the ell (forming the hypontenuse of a right triangle) is the net force transmitted as tension in the string.

A lot of unneeded words. When the pendulum swings it indicates an acceleration. That's all you need to know.

 

[billvon]

Maybe I wasn't clear enough? By definition that is impossible.

Again, that has been proven possible by experimental result. Reality disagrees with your assertion. When one is trying to decide whether to go with reality or someone's math that disagrees with reality - reality wins every time.

Seconds are not variable!

That is where you make your primary mistake.

You're a blind man in a china shop!

Again, unfortunate that you cannot make rational arguments without all the anger and bitterness.

 

[Motor Daddy]

Again, that has been proven possible by experimental result. Reality disagrees with your assertion. When one is trying to decide whether to go with reality or someone's math that disagrees with reality - reality wins every time.

You have no business talking about reality, since you can't even tell me if two rockets inside a sphere with the distance between them changing while they travel along the same axis, will exit the sphere at the same point or at opposite points of the sphere.. You have a relative velocity but you have no idea which direction the rockets are traveling along that axis.

 

[origin]

Again, unfortunate that you cannot make rational arguments without all the anger and bitterness.

Poor MD is bitter because it is starting to becoming clear even to him(!) that he is wrong and I think he is getting a little desperate.

 

[Motor Daddy]

Poor MD is bitter because it is starting to becoming clear even to him(!) that he is wrong and I think he is getting a little desperate.

See, every time you have a thought it turns out to be false. Just wondering what your overall correct statement percentage is? 15%? 20% max? Can't be any higher than that.

 

[Lakon]

I'm not "screaming", just suggesting. And if you think Motor Daddy has anything here that interesting, you are just as ignorant as he is. He doesn't understand even the most basic things about physics taught to school children and neither does he understand how to use simple math - he just ignores it every time it's mentioned.

All you've accomplished in this thread is showing that your education - if you had one - has failed you also.

I had no such education in the terms you mean it my friend, but have nonetheless learnt that no education fails - all things experienced are of some value.

Edit; thinks >things

 

[Lakon]

MD - in another post you summed up your OP nicely, thus ..

Do you know what relative motion is? If so, then I am talking about the zero relative motion between two cars, and at the same time showing an acceleration in the absolute frame. Since the relative velocity between the cars doesn't change when the acceleration is occurring then the acceleration is not of the relative velocity.

I still have issues with this. There is no relative motion between the two vehicles because you have, in your thought experiment, PRESCRIBED that there be none.

You can't say that the two vehicles must move as one, and then say, 'hey look, those two vehicles move as one, therefore .."

That's why on a couple of occasions I have said that they may as well be one .. or two .. or 57, or 2,000 ..

If you make it a condition precedent that they move as one, then of course there is no relative motion between them, just as there is no relative motion between the cars front and rear bumper bar, or the rockets nose and tail.

So you have a 'phenomenon' that moves as one, with a pendulum (or two or 57 or 2,000) inside it/them. That pendulum accelerates in different directions and degrees, depending on the differing acceleration and direction of the vehicle, as others have explained here. Surely you accept that the pendulum's movement will vary in accordance with the acceleration / direction of the vehicle ?

There is in fact, probably the most wonderful example you can think of of this - the balance mechanism in the human ear. It relies on no light, no sound, is in a perfectly enclosed space .. and relies on acceleration / inertia only. And it's been keeping you upright quite admirably all your life (presumably).

I still can’t see what your point is. You seem to be quite good at reducing an issue to simple, clear points so what is yours here ?

BTW, thank you for persisting with this most interesting and informative thread.