this post was submitted on 15 Jun 2024
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It is just incredible to me that we have the ability and knowhow to send instructions to a 40 year old transistor computer to reprogram itself and get it working again with just radio signals.
What they did was close to wizardry.
https://www.skyatnightmagazine.com/space-missions/how-fixed-voyager-1
Here's a fun fact that I think of every time I read about light delay.
We assume the speed of light is the same in all directions but there's no way to prove that it is.
It could be light speed is instantaneous in one direction, and half the speed we think it is in the reverse. Any test we could devise depends on information traveling in two directions, nullifying any discrepancies in light speed.
... 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%E2%80%93Morley_experiment , and please consider a bit of caution before you refer to things as facts in the future!
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
How does the double slit experiment work into this?