As humanity’s furthest reach into the Universe so far, the two Voyager spacecraft’s well-being is of utmost importance to many. Although we know that there will be an end to any science…
One of the more memorable physics classes I’ve had went into the history of discoveries that led to our understanding of relativity. The relevant story here, starts with how sound travels though air.
Let’s say you’re standing at the bottom of a building shouting to your friend peeking out a window on the 5th floor. On a calm day, that friend will hear you at pretty much the same time as someone standing the same distance away, but on the street. However, if it’s windy, the wind pushes around the air through which the sound of your voice is traveling, the friend up in the window will have a slight delay in receiving that sound. This can of course be verified with more scientific rigor, like a sound sent in two perpendicular directions activating a light.
Scientist at the time thought that light, like sound, must travel though some medium, and they called this theoretical medium the Aether. Since this medium is not locked to Earth, they figured they must be capable of detecting movement of this medium, an Aether wind, if you will. If somehow the movement of this medium caused the speed of light in one direction to be faster than another due to the movement of this medium, measuring the speed in two directions perpendicular to each other would reveal that difference. After a series of experiments of increasing distances and measurement sensitivities (think mirrors on mountain tops to measure the time for a laser beam to reflect), no change in the speed of light based on direction was found.
As far as I’m aware, what you cited only proves that there is no ether that acts on light in a way such that the round trip time in the direction of ether travel is different from the round trip time in the direction perpendicular to ether travel.
It’s not merely that:
somehow the movement of this medium caused the speed of light in one direction to be faster than another due to the movement of this medium, measuring the speed in two directions perpendicular to each other would reveal that difference.
Instead, it’s that the speed of light must be different in the two directions in a way such that their round trip times don’t average out to the same average as in the other direction.
The theories of ether at the time predicted such a round trip difference because of the wind like interactions that you say.
I believe that this in no way proves anything about the one way speed of light. The Michaelson Morley inteferometer only measures difference in round trip time.
… but there is a way, and it has been proven.
One of the more memorable physics classes I’ve had went into the history of discoveries that led to our understanding of relativity. The relevant story here, starts with how sound travels though air.
Let’s say you’re standing at the bottom of a building shouting to your friend peeking out a window on the 5th floor. On a calm day, that friend will hear you at pretty much the same time as someone standing the same distance away, but on the street. However, if it’s windy, the wind pushes around the air through which the sound of your voice is traveling, the friend up in the window will have a slight delay in receiving that sound. This can of course be verified with more scientific rigor, like a sound sent in two perpendicular directions activating a light.
Scientist at the time thought that light, like sound, must travel though some medium, and they called this theoretical medium the Aether. Since this medium is not locked to Earth, they figured they must be capable of detecting movement of this medium, an Aether wind, if you will. If somehow the movement of this medium caused the speed of light in one direction to be faster than another due to the movement of this medium, measuring the speed in two directions perpendicular to each other would reveal that difference. After a series of experiments of increasing distances and measurement sensitivities (think mirrors on mountain tops to measure the time for a laser beam to reflect), no change in the speed of light based on direction was found.
Please enjoy this wikipedia hole: https://en.m.wikipedia.org/wiki/Michelson–Morley_experiment , and please consider a bit of caution before you refer to things as facts in the future!
How does the double slit experiment work into this?
As far as I’m aware, what you cited only proves that there is no ether that acts on light in a way such that the round trip time in the direction of ether travel is different from the round trip time in the direction perpendicular to ether travel.
It’s not merely that:
Instead, it’s that the speed of light must be different in the two directions in a way such that their round trip times don’t average out to the same average as in the other direction.
The theories of ether at the time predicted such a round trip difference because of the wind like interactions that you say.
I believe that this in no way proves anything about the one way speed of light. The Michaelson Morley inteferometer only measures difference in round trip time.
(Insert comment about the irony of your last statement). See https://en.m.wikipedia.org/wiki/One-way_speed_of_light