Is a length contraction just a visual thing?

[danshawen]

Energy isn't an object. It's a property.

Philosophy isn't science. It's philosophy. If we can't agree on the terms we are discussing, the discussion is finished. I'm not interested in philosophy, or a discussion of philosophy.

"Property" is an eight letter word. You just wrote it. I'm talking about something else.

 

[Russ_Watters]

Yes the Jolly Roger has been raised on the lower deck Captain, it is only at half mast and needs an edit and completion, I know my science and I know your science, SR , GR, your very reality is going to be completely debunked by my axiom theory.

Hehe. I love an idea titled with a self contradiction: self debunking!

 

[origin]

If the events are separated by light travel time, they are not simultaneous.

And if the light travel time is the same between the 2 events for observers in the same RF the observers will agree the events are simultaneous, no entanglement necessary. I fail to see how entaglement enters the picture of simultaneity

 

[James R]

Philosophy isn't science. It's philosophy. If we can't agree on the terms we are discussing, the discussion is finished. I'm not interested in philosophy, or a discussion of philosophy.

I expected you would use a scientific definition of "energy" in a science thread. My mistake.

"Property" is an eight letter word. You just wrote it. I'm talking about something else.

Ok. I'll leave you to it. Obviously you have no real response to the many matters I raised in my previous post.

 

[PhysBang]

I fail to see how entaglement enters the picture of simultaneity

So does danshawen. Ask him how we can use entanglement to synchronize a clock.

Seriously, though, he put me on ignore because I asked direct questions about the relationship of his claims to actual scientific practice. It does not do good things for his mental health to actually hold his claims to the standards he espouses.

 

[PhysBang]

Simultanaeity does not exist in this universe, other than for events which are the same event viewed from different perspectives, or events which are entangled, WHICH AMOUNTS TO THE SAME THING. In a universe composed entirely of energy transfer events, it really makes no sense to speak of simultaneity in any other context.

Tell that to the next person who has to go to a job interview.

 

[Billy T]

If the events are separated by light travel time, they are not simultaneous. ...

They certainly can be. For example if at A & B, two separate digital clocks are both displaying 00:00 but they are not yet running as waiting in the dark to receive a "start" light flash.

Exactly half way between the clocks at A & B, both stationary in the same frame, there is a flash source. They start to run a short time after the flash happens (delay time of flash light transit to them). These clocks are synchronized and soon display 00:01 simultaneously, but if you are closer to the clock at A than the one a B, you will see A's 00:01 display before the clock at B is displaying that.

You need to distinguish between their true simultaneous switch to display of 00:01 from your perception of simultaneously.

If your perception is that they display 00:01 simultaneously they are not synchronized and further more, most observers will not see then as simultaneously displaying 00:01 as you do. Only those observers on a hyperbolic curve passing thru your point will agree with you that they simultaneously display the same time.

 

[rpenner]

I expected you would use a scientific definition of "energy" in a science thread. My mistake.

This is why danshawen gets reported for posting pseudoscience in science threads, he has no basis for his sense of entitlement to state his opinions as facts.

 

[danshawen]

They certainly can be. For example if at A & B, two separate digital clocks are both displaying 00:00 but they are not yet running as waiting in the dark to receive a "start" light flash.

Exactly half way between the clocks at A & B, both stationary in the same frame, there is a flash source. They start to run a short time after the flash happens (delay time of flash light transit to them). These clocks are synchronized and soon display 00:01 simultaneously, but if you are closer to the clock at A than the one a B, you will see A's 00:01 display before the clock at B is displaying that.

You need to distinguish between their true simultaneous switch to display of 00:01 from your perception of simultaneously.

If your perception is that they display 00:01 simultaneously they are not synchronized and further more, most observers will not see then as simultaneously displaying 00:01 as you do. Only those observers on a hyperbolic curve passing thru your point will agree with you that they simultaneously display the same time.

But you have specified a unique location as well as a frame of reference in an attempt to more precisely define simultenaeity. And you have still failed to do so in a manner that is physically meaningful.

Do you know what a "beat frequency" is? A "beat frequency" is what you get whenever you try to synchronize two free running oscillators. It is an indication that there is still a tiny error between them, and if they synchronize at all, it never happens for more than an instant, or in the case of "phase locked" oscillators, within a certain error amount over a given time interval, and only in a particular location at a particular time, to a single observer.

You can phase lock oscillators that are separated in time, and or space, but it is meaningless to specify simultanaeity without an acceptable amount of error and/ or a specified time interval (which, as I have explained, appears to be an instant with respect to a particular location, at a particular time).

The same mathematical bozos who would have us believe that an origin of a coordinate system is something that can be meaningfully specified at some precise location in inertialess relativistic space agreed upon by more than one frame of reference are the same people who think they understand what simultanaeity is. They don't. You can't do relativity with only one observer, or only a single mathematical expression to describe what is observed.

Simultanaeity always requires at least two observers, and there is no guarantee that time dilation is exactly the same at both locations. It almost certainly is not, for many reasons.

 

[paddoboy]

Yes the Jolly Roger has been raised on the lower deck Captain, it is only at half mast and needs an edit and completion, I know my science and I know your science, SR , GR, your very reality is going to be completely debunked by my axiom theory.

You do not have any axiom theory or any theory of any kind, you do not even have an hypothesis, a pseudoscientific or fairy tale interpretation yes.

 

[danshawen]

This is why danshawen gets reported for posting pseudoscience in science threads, he has no basis for his sense of entitlement to state his opinions as facts.

what is your definition of energy, rpenner?

Mine is mc^2 at rest and h * nu. You think that's pseudoscience? JamesR was behaving as if it was. Why was that?

 

[PhysBang]

what is your definition of energy, rpenner?

Mine is mc^2 at rest and h * nu. You think that's pseudoscience? JamesR was behaving as if it was. Why was that?

That is a really obvious lie about what James R wrote.

 

[Billy T]

But you have specified a unique location as well as a frame of reference in an attempt to more precisely define simultenaeity. And you have still failed to do so in a manner that is physically meaningful.

False. The method I described to get simultaneity of clock displays at A & B locations is very physically meaningful AND can be extended to make a clock at location C be synchronized with them both, where C is any location (in the universe) that is at rest with clocks at A & B - that is in their same inertial frame.

Do you know what a "beat frequency" is?

Certainly. I have known for 70 years. I was a young radio amateur using code (not voice as my radiated power was only about 40W) and set my local RF oscillator to differ from the RF signal I was receiving by an audio frequency difference, making a beat frequency tone I could hear. I suspect you were not yet born when I understood beat frequencies well.

Any two oscillators of nearly the same natural frequency will not make a beat frequency if there is even a small amount of energy exchanged between them. For example two electrical generators driven by steam turbines feeding a common power line (by which they can exchange) will lock together in the same frequency. This is why power in the US is so precisely 60hz even though at times some thousands of the steam turbines if decoupled would be spin to make 59hz and others 61hz.

Thus the following from you is also FALSE and nonsense. Most electric clocks use the 60Hz power line frequency to advance their displays and are perfectly synchronized California to Mane, as the tiny energy exchange that gets them locked in phase goes both ways.

You can phase lock oscillators that are separated in time, and or space, but it is meaningless to specify simultaneity without an acceptable amount of error and/ or a specified time interval (which, as I have explained, appears to be an instant with respect to a particular location, at a particular time).

There is no error when phase locked by energy exchange. Every where in the USA, the power line is with its 60hz cycles having its peak voltages at the same time. Admittedly that would not happen if one were the master and sending synchronization signals to all the others - Then their peak voltage would not be simultaneous.

So yes if you don't understand well (your problem) that they must be part of a network feeding small mounts of energy to each other to keep phase locked, the oscillators can not be synchronized. That is, yes you can do it wrong, but that does not mean you can not do the synchronization right!

The same mathematical bozos who would have us believe that an origin of a coordinate system is something that can be meaningfully specified at some precise location in inertialess relativistic space agreed upon by more than one frame of reference are the same people who think they understand what simultanaeity is. They don't. You can't do relativity with only one observer, or only a single mathematical expression to describe what is observed.

Simultanaeity always requires at least two observers, and there is no guarantee that time dilation is exactly the same at both locations.

All false and egotistical. No observers are required if a phase locked network is sharing energy (more to the oscillators that would run too slowly and fall out of phase and taking energy from others trying to run too fast). Clocks in different inertial frames can not be synchronized, even with a million observers! You have at least heard of time dilation, but don't seem to understand what that implies.

As I noted it earlier post, 247, in bold, it is you who don't even distinguish between true synchronization / simultaneous (in one frame) and your personal perception of synchronization / simultaneous of two (or more) events. With your degree of ignorance / mis understanding etc. you are in no position to call those who know the subject well: "bozos."

 

[danshawen]

False. The method I described to get simultaneity of clock displays at A & B locations is very physically meaningful AND can be extended to make a clock at location C be synchronized with them both, where C is any location (in the universe) that is at rest with clocks at A & B - that is in their same inertial frame.Certainly. I have known for 70 years. I was a young radio amateur using code (not voice as my radiated power was only about 40W) and set my local RF oscillator to differ from the RF signal I was receiving by an audio frequency difference, making a beat frequency tone I could hear. I suspect you were not yet born when I understood beat frequencies well.

Any two oscillators of nearly the same natural frequency will not make a beat frequency if there is even a small amount of energy exchanged between them. For example two electrical generators driven by steam turbines feeding a common power line (by which they can exchange) will lock together in the same frequency. This is why power in the US is so precisely 60hz even though at times some thousands of the steam turbines if decoupled would be spin to make 59hz and others 61hz.

Thus the following from you is also FALSE and nonsense. Most electric clocks use the 60Hz power line frequency to advance their displays and are perfectly synchronized California to Mane, as the tiny energy exchange that gets them locked in phase goes both ways. There is no error when phase locked by energy exchange. Every where in the USA, the power line is with its 60hz cycles having its peak voltages at the same time. Admittedly that would not happen if one were the master and sending synchronization signals to all the others - Then their peak voltage would not be simultaneous.

So yes if you don't understand well (your problem) that they must be part of a network feeding small mounts of energy to each other to keep phase locked, the oscillators can not be synchronized. That is, yes you can do it wrong, but that does not mean you can not do the synchronization right! All false and egotistical. No observers are required if a phase locked network is sharing energy (more to the oscillators that would run too slowly and fall out of phase and taking energy from others trying to run too fast). Clocks in different inertial frames can not be synchronized, even with a million observers! You have at least heard of time dilation, but don't seem to understand what that implies.

As I noted it earlier post, 247, in bold, it is you who don't even distinguish between true synchronization / simultaneous (in one frame) and your personal perception of synchronization / simultaneous of two (or more) events. With your degree of ignorance / mis understanding etc. you are in no position to call those who know the subject well: "bozos."

Nice try, BillyT, but clock synchronization only works within error limits also, just like phase locked loops.

It is chiefly the emerging science of quantum entanglement which means, among other things, that the science associated with simultanaeity needs an upgrade/update. Light in a vacuum is no longer the fastest process in the universe.

 

[Confused2]

There is no error when phase locked by energy exchange. Every where in the USA, the power line is with its 60hz cycles having its peak voltages at the same time. Admittedly that would not happen if one were the master and sending synchronization signals to all the others - Then their peak voltage would not be simultaneous.

I'm not sure this is quite that simple. The wavelength of light at 60Hz is about 3,100 miles, waves on cables travel a bit slower. So a load about 750 miles from your power station would be 90 degrees out of phase - a short circuit load would look like an open circuit and an open circuit load would look a short. I'm not sure you can just connect every power station in the US together and hope it settles down in a dignified manner. There is a large hydro power scheme which uses DC for transmission - I'm not sure but I suspect there might be a very good reason to use DC for long distance transmission even when 60Hz AC seems like the obvious answer. Your thoughts?

 

[Billy T]

... The wavelength of light at 60Hz is about 3,100 miles, waves on cables travel a bit slower. So a load about 750 miles from your power station would be 90 degrees out of phase ...

Yes that is correct if there is an AC source 750 miles from a passive load; but that was not the case I spoke of. If two essentially identical generators are 750 miles apart and both power line between them, the only stable condition is that the entire line reaches peak voltage at same time that the generators do. Any other condition is unstable and will settle down into that stable condition.

... I suspect there might be a very good reason to use DC for long distance transmission even when 60Hz AC seems like the obvious answer. Your thoughts?

Yes. The reason is that corona discharge effects* limit the peak voltage. If it is DC the transmission line can operate at that voltage all the time instead of only twice each AC cycle – I. e. a line can move more energy each hour between A & B if it is DC.

In Norway and Sweden the population centers are in the South, but much of the hydro power is far to the North of these demand centers, so even though there are small losses in converting the high voltage DC to AC there is significant gain with DC long distance transmission. I think it has been used for more than three decades now that efficient solid state devices can do the DC to AC conversion.

* You will often see even high voltage AC transmission lines with four closely spaced parallel conductors, This crudely simulates a single large diameter conductor of Radius R, not the tiny r of the wires. The electric field at the surface of a conductor of Radius R is less by far than if same voltage were applied to single conductor of radius r. The voltage at the surface must be kept less than one which makes a corona discharge.

 

[danshawen]

This is why danshawen gets reported for posting pseudoscience in science threads, he has no basis for his sense of entitlement to state his opinions as facts.

i freely admit that I have no more basis than anyone else has to state their opinions as facts. Check the profile logo.

Check also Stephen Hawking's numerous lost physics bets, Penrose Rings, Bicep2, superluminal neutrino fiasco. The list is long and gets longer every day. Some high ranking credentialed people in high profile science are just as cranky as I am.

The thread is: "is length contraction just a visual thing?" You know it isn't, and so do I. Neither is time dilation just a "visual thing". Any real issues with that opinion?

 

[danshawen]

Yes that is correct if there is an AC source 750 miles from a passive load; but that was not the case I spoke of. If two essentially identical generators are 750 miles apart and both power line between them, the only stable condition is that the entire line reaches peak voltage at same time that the generators do. Any other condition is unstable and will settle down into that stable condition.Yes. The reason is that corona discharge effects* limit the peak voltage. If it is DC the transmission line can operate at that voltage all the time instead of only twice each AC cycle – I. e. a line can move more energy each hour between A & B if it is DC.

In Norway and Sweden the population centers are in the South, but much of the hydro power is far to the North of these demand centers, so even though there are small losses in converting the high voltage DC to AC there is significant gain with DC long distance transmission. I think it has been used for more than three decades now that efficient solid state devices can do the DC to AC conversion.

* You will often see even high voltage AC transmission lines with four closely spaced parallel conductors, This crudely simulates a single large diameter conductor of Radius R, not the tiny r of the wires. The electric field at the surface of a conductor of Radius R is less by far than if same voltage were applied to single conductor of radius r. The voltage at the surface must be kept less than one which makes a corona discharge.

You understand that the rate at which time passes is affected by altitude, right? How frequently will you set all your clocks at different altitudes to keep them synchronized?

 

[Billy T]

Nice try, BillyT, but clock synchronization only works within error limits also, just like phase locked loops.

No there is no error in an interconnected set of generators in phase locked condition. If one has N cycles in 1000 years all the others will too. See my comment in first part of post 256 about what is the only stable condition.

It is chiefly the emerging science of quantum entanglement which means, among other things, that the science associated with simultanaeity needs an upgrade/update. Light in a vacuum is no longer the fastest process in the universe.

Yes it is. This comment only reflects your lack of understand of a quantum entangled system. When a measurement is made on part of it a 1000 miles from the farest part of this entangled system, no information is transferred from one end of the system to the other.

It is ONE quantum system with spins (for example) totaling zero, but at widely separated locations where measurement of spin can be made. That measurement of the spin state determines the results of a measurement (made or not) at the other distant site. This is because the QM system is in a mixed state, not pure eigen states. If I disturb this quantum state to force the observed part near me into a pure eigen state, say spin = -0.5, then that same disturbance on the one QM system will force the state (observed or not) at the other location into spin = 0.5; no signal was sent between. It is the forcing of the one mixed state QM system to be the sum of two pure eigen states (+0.5 & -0.5) that keep the total zero that makes it only appear that information has traveled faster than light.

Perhaps an analogy will help you understand: I know have exactly 100 dollars in two saving accounts, one in Boston and the other Oakland CA but I forget how much is in each. I can IMMEDIATELY learn how much is in the Boston one by checking the amount in the Oakland one.

 

[Billy T]

You understand that the rate at which time passes is affected by altitude, right? How frequently will you set all your clocks at different altitudes to keep them synchronized?

Yes but it is gravity, not altitude. To really be in the same inertial frame they must be in the same gravitational field. This requirement is not usually stated, so I did not.