Finding One-Way Speed of Light: Use One Clock

[TylerSmith]

First off, I'm probably totally incorrect on all of this, so feel free to correct me.
Second, I'm only 15, so please just be gentle and helpful when I'm totally off.

Now for my idea:
Have a huge vacuum and put lasers on the inside with hundreds of different lasers at different angles equally distance from each other, then put highly precise sensors on the opposite side of each laser.

Measure the light speed in one direction and then you can put a laser the opposite way as well. You can do this with any of the lasers and sensors opposite to each other.

To get around the clock synchronization issues, the whole building is one clock that is relative to only itself. There may be issues with wires traveling to different places at different speed due to light bring potentially different in different directions. We could avoid this by not using wires and by using sound from one large speaker instead. When the sensors and lasers get the input of the sound/frequency, they would calculate the time it would take for the sound to travel to the microphone. Then they would both sync to the single clock and be able to calculate the one way speed of light with a single clock in multiple directions.I'd love to learn more so feel free to correct anything, but be nice about it, thanks!

 

[phinds]

"One way speed of light" has been debunked dozens of times on this forum. I suggest a forum search.

 

[PeterDonis]

To get around the clock synchronization issues, the whole building is one clock that is relative to only itself.

This is not possible. If you want to measure the one-way speed of light, you have to treat the building as having spatial extension. But "one clock" cannot be true of anything that has spatial extension. If you have multiple different points of space inside your apparatus, you have to have multiple clocks.

 

[TylerSmith]

Yes that makes sense but I think I still worded it wrong. The sensors and lasers would have clocks too but they wouldn't work by themselves, they would have to synced with the main clock. I'm quite possibly still wrong though and that is OK.

 

[PeterDonis]

The sensors and lasers would have clocks too but they wouldn't work by themselves, they would have to synced with the main clock.

Yes, they would, and whatever process of clock synchronization you use will affect the one-way speed of light that you measure. In other words, you're not actually measuring any property of light; you're measuring a property of whatever process of clock synchronization you are using. By choosing an appropriate clock synchronization process, you can make the one-way speed of light be anything you like. If you search the forum for previous threads on this topic, you will find plenty of discussions that end up at that same point.

 

[TylerSmith]

"One way speed of light" has been debunked dozens of times on this forum. I suggest a forum search.

Did you even read my message? Lol I doubt I have the exact same idea as somebody on here plus how would I search for the same idea anyways?

 

[PeterDonis]

I doubt I have the exact same idea as somebody on here

Your doubt is misplaced. Plenty of previous posters have come up with the same basic idea you have, the fundamental error of which is to fail to recognize the role that clock synchronization plays. Perhaps nobody has phrased things in exactly the same way you did, but that doesn't mean your idea is actually unique.

 

[PeterDonis]

how would I search for the same idea anyways?

You don't have to search for "the same idea". Just search for discussions of measuring the one-way speed of light. You will find what I described in post #5.

 

[TylerSmith]

Your doubt is misplaced. Plenty of previous posters have come up with the same basic idea you have, whose fundamental error is to fail to recognize the role that clock synchronization plays. Perhaps nobody has phrased things in exactly the same way you did, but that doesn't mean your idea is actually unique.

OK! Thanks for clarifying that.

 

[PeroK]

First off, I'm probably totally incorrect on all of this, so feel free to correct me.
Second, I'm only 15, so please just be gentle and helpful when I'm totally off.

Measuring the one-way speed of light is not an engineering or logical challenge. It's an impossibility due to the nature of spacetime. There is no universal "now" that applies unambiguously to all points in space. This, in itself, is quite an interesting topic and worth taking a look at. You can never say unambiguously that something that happened at point X and something that happened at point Y happened at the same time.

You can, however, say unambiguously how much time elasped on a given clock between two events local to that clock. If a clock starts when it emits a pulse of light and stops when it receives the pulse of light after some round trip, then the difference in clock readings between those two events is definite and unambiguous.

It would be more profitable, I suggest, to look at the foundations of the special theory of relativity and the relativity of simultaneity in particular.

 

[Dale]

To get around the clock synchronization issues

You cannot "get around" clock synchronization issues. It is part of the definition of a one way speed. A one way speed is DEFINED as the distance between start and finish divided by the difference in time between a pair of synchronized clocks, one at the start and the other at the finish. If you manage to make an experiment where you do avoid clock synchronization issues then what you have measured is not a one way speed. It is impossible to measure a one way speed without a clock synchronization since it is part of the definition.

 

[phinds]

Did you even read my message?

No, I did not. I didn't need to. As has been explained by now, and as you would have found out had your done a forum search as I suggested, it just won't work no matter WHAT your setup is.

 

[Grinkle]

Did you even read my message?

The first sentence below might sound harsh, I don't mean it harshly.

He only needed to read your thread title. His response is motivated from the same thinking as the US Patent Office declining to consider a patent they recognize to be a perpetual motion machine.

Its a helpful response because discussing the details of your proposal is not nearly so potentially illuminating for you as you working to understand why no scheme can work. Its not a simple thing to understand - it may take you some time and a lot of reading and discussion with others to get your head around what is being summarized in posts 10 and 11.

 

[cianfa72]

It is impossible to measure a one way speed without a clock synchronization since it is part of the definition.

For instance Einstein synchronization procedure is just one of the infinite possibile conventions to employ to define accordingly the one-way speed of "anything". In particular in any inertial coordinate system the one-way speed of light is the invariant (isotropic) universal constant c.

 

[Sagittarius A-Star]

There may be issues with wires traveling to different places at different speed due to light bring potentially different in different directions. We could avoid this by not using wires and by using sound from one large speaker instead.

That does not help. If you define the time-axis of your coordinate system in such a way, that the one-way speed of light is not the same in each direction, then also the speed of sound is not the same in each direction.