What time is it?

[Neddy Bate]

How do you "stamp" a signal if it's made of light, though? Have you thought this through?

I don't speak for Motor Daddy, (who has some serious misconceptions about the meaning of the constant c), but please note that whenever you look toward a clock, the clock is sending you a time "stamp" made of light.

The absolute velocity of the plane in space.

Are you aware that currently accepted physics does not support the concept of absolute velocity? Are you aware that absolute velocity has never been determined experimentally?

 

[Pete]

The switch closes a circuit that activates the timestamped light signals to be sent simultaneously from each end.

You realise that a signal has to travel from the switch through the circuit, and that this takes time, right?

Given the fact that light always travels at c, and the distance between the transmitters and receiver are equal, unchanging, and known, the variance in timers can be calculated and an absolute velocity of the plane can also be calculated. These are the facts of distance and time, and can't be disputed.

That's easy to say, MD, but have you tried it? Really, it's a worthwhile exercise. Give it a shot.

 

[Pete]

But the velocity of the frame of reference wouldn't change the speed of light, and both signals would have the same distance to travel.

Well, we can consider whatever clocks and rulers we like. We can even "mix frames", if we know what we're doing. I find that kind of thing interesting and useful to explore, especially when you're dealing with people who don't know what you mean by "frame of reference." You just focus directly on the clocks and rulers, and work from there.

What speed do you think you are measuring, the speed of the plane relative to the Earth? Or the speed of the Earth/plane combination relative to the solar system? Or the speed of the Earth/plane/solar system combination through the galaxy?

MD thinks he can measure an absolute speed. Michelson Morley be damned!

 

[arfa brane]

please note that whenever you look toward a clock, the clock is sending you a time "stamp" made of light.

Since it's a slow news day here at sciforums, please also note that it takes time for light to reach you from a clock when you look at it.

It takes time to do anything, actually. There's no free coffee with your free lunch, I'm afraid. Actually, there's no free lunch either.

 

[funkstar]

These are the facts of distance and time, and can't be disputed.

Oh, well, if they can't be disputed, then I guess that's that.

I wonder how people won arguments before you came along with you "can't be disputed" gambit. Why, they probably had to resort to silly stuff like 'reason' and 'arguments', poor fools.

 

[Neddy Bate]

Since it's a slow news day here at sciforums, please also note that it takes time for light to reach you from a clock when you look at it.

So light travels at c then? (in vacuo)

 

[Motor Daddy]

You realise that a signal has to travel from the switch through the circuit, and that this takes time, right?


That's easy to say, MD, but have you tried it? Really, it's a worthwhile exercise. Give it a shot.

The transmitters and receiver have built-in timers and a recording mechanism. When a signal is sent the time of transmission is recorded, ie, transmission 1 sent at 12:00:03. The receiver records the transmissions received the same way. The light itself doesn't need to carry the time, we only need to know what time the transmission was sent according to the transmitter, and what time the transmission was received according to the receiver. Like I said, knowing that light always travels at c, and the distance between the transmitters and receiver is equal, known, and unchanging makes this possible. It then becomes a math exercise of distance and time(s).

 

[Motor Daddy]

MD thinks he can measure an absolute speed. Michelson Morley be damned!

I don't have the precise equipment needed, but that doesn't make me wrong. It's a concept of distance and time, and it's how it works, and you know it.

 

[Pete]

The transmitters and receiver have built-in timers and a recording mechanism. When a signal is sent the time of transmission is recorded, ie, transmission 1 sent at 12:00:03. The receiver records the transmissions received the same way. The light itself doesn't need to carry the time, we only need to know what time the transmission was sent according to the transmitter, and what time the transmission was received according to the receiver. Like I said, knowing that light always travels at c, and the distance between the transmitters and receiver is equal, known, and unchanging makes this possible. It then becomes a math exercise of distance and time(s).

Yes, MD, I've done the math exercise. It was worthwhile, with interesting results that I suspect would surprise you.

You should try it yourself. Don't forget to include length contraction and time dilation in your calculations.

 

[Pete]

I don't have the precise equipment needed, but that doesn't make me wrong.

What makes you wrong, MD, is that people who do have the precise equipment needed have tried what you suggest, and found that you're wrong.

It's a concept of distance and time, and it's how it works, and you know it.

Yes, MD, I do know how distance and time seem to work.
Work through the exercises yourself, and you can learn too.

 

[Motor Daddy]

What makes you wrong, MD, is that people who do have the precise equipment needed have tried what you suggest, and found that you're wrong.

They're mistaking.

Distance and time have already been defined using the units of measure the meter and second. Light travels a specific distance in a specific amount of time, independent of the motion of the ruler.

 

[funkstar]

Look at him apply the "They're wrong" gambit. Such skill! Such panache!

Clearly, we are in the presence of a master.

 

[Motor Daddy]

Clearly, we are in the presence of a master.

Please keep the applause to a minimum, I'm a humble guy.

 

[Pete]

Yep. That sure settles it. They're just mistaking.

 

[Pete]

The transmitters and receiver have built-in timers and a recording mechanism. When a signal is sent the time of transmission is recorded, ie, transmission 1 sent at 12:00:03. The receiver records the transmissions received the same way. The light itself doesn't need to carry the time, we only need to know what time the transmission was sent according to the transmitter, and what time the transmission was received according to the receiver. Like I said, knowing that light always travels at c, and the distance between the transmitters and receiver is equal, known, and unchanging makes this possible. It then becomes a math exercise of distance and time(s).

Once again, MD:
Have you done this math exercise?

 

[Motor Daddy]

Yep. That sure settles it. They're just mistaking.

See my "A Train, Three Clocks, and an Observer" thread for a full understanding of distance and time.

 

[Motor Daddy]

Once again, MD:
Have you done this math exercise?

It's proprietary information.

 

[cosmictraveler]

It's proprietary information.

So is my party on the plane!

 

[Pete]

See my "A Train, Three Clocks, and an Observer" thread for a full understanding of distance and time.

Yes, you should try that.

It's proprietary information.

No, it's a simple exercise in arithmetic.
I can show it to you, but you would learn more by doing it yourself.
Don't forget to include time dilation and length contraction, and don't forget to include the times between when the switch is activated and when the transmitters send their signals (note that it could be different for each end).

 

[spidergoat]

The absolute velocity of the plane in space.

Both signals only travel the same distance if the plane has an absolute zero velocity. If the plane has a velocity the light signals will each travel a different distance, and hence the light travel time will be different.

There is no such thing as an absolute reference frame.