• gedaliyah@lemmy.world
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      5 months ago

      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.

      • Flying Squid@lemmy.worldOP
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        5 months ago

        What they did was close to wizardry.

        With no way to fix the chip, the team instead split the code up so it could be stored elsewhere. Initially they focused on reacquiring the engineering data, sending an update to Voyager 1 on 18 April 2024.

        It takes 22.5 hours for a radio signal to travel the 24 billion kilometres (15 billion miles) out to Voyager 1, and the same back, meaning the spacecraft’s operations team didn’t receive a message back until 20 April.

        But when it arrived, they had usable data from Voyager 1 for the first time in five months.

        https://www.skyatnightmagazine.com/space-missions/how-fixed-voyager-1

        • Wogi@lemmy.world
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          5 months ago

          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.

          • Flying Squid@lemmy.worldOP
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            5 months ago

            The speed of light in a vacuum unaffected by external forces such as gravity should be the same no matter what direction it is in. I’m not sure why it wouldn’t be. That’s like saying a kilometer is longer if you go East than if you go West.

            However, it’s actually far more complicated than that, and much of it beyond my understanding.

            https://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/speed_of_light.html

            That said, direction should not matter.

          • vvv@programming.dev
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            5 months ago

            … 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!