this post was submitted on 15 Jun 2024
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[–] [email protected] 98 points 5 months ago (2 children)
[–] [email protected] 99 points 5 months ago (5 children)

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.

[–] [email protected] 85 points 5 months ago (1 children)

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

[–] [email protected] 20 points 5 months ago (4 children)

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.

[–] [email protected] 27 points 5 months ago* (last edited 5 months ago) (2 children)

... 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!

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[–] [email protected] 21 points 5 months ago (1 children)

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.

[–] [email protected] 16 points 5 months ago (1 children)

There's no reason it wouldn't be. The point is that it's impossible to prove that it is. There is no conceivable experiment that can be performed to prove the two-way speed of light is symmetric.

[–] [email protected] 7 points 5 months ago (26 children)

That's not how anything works. It's impossible to prove that the universe wasn't created last Thursday with everything in place as it is now. There's no point in assuming anything that can't be proven has validity.

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[–] [email protected] 6 points 5 months ago (1 children)

Another interesting way to conceptualize it is that the speed of light is infinite and it's causality/information that is limited to c. You shine a light at the moon and it takes 1.3 seconds for the "fact" that the light was turned on to propagate that far.

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[–] [email protected] 6 points 5 months ago (1 children)

Couldn't we send out two devices in different directions, wait a decade, have them shine light at eachother simultaneously, record when they receive the light, then send the times back to earth?

[–] [email protected] 8 points 5 months ago* (last edited 5 months ago)

Your question is good. You're missing understanding of time dilation and frame of reference. An explanation of the theory of relativity is at least pages long.

The first book I ever read on the subject, and IMO the best introductory text for any non-physiscist, is Stephen Hawking's "A Brief History of Time". But, any introduction to relativity should answer your question.

[–] [email protected] 50 points 5 months ago

...from 15.2 BILLION miles away.

And it can reply by basically shining a (very high-frequency) flashlight back at us.

[–] [email protected] 13 points 5 months ago* (last edited 5 months ago) (4 children)

Incredible is the right word, how does this still work after more than 47 years? How do they even still have energy to send and receive signals? That's one heck of a durable power source. How do the computers and sensors still work? The reliability and durability of these probes is amazing. NASA truly had some reality wizards doing what seems like magic to accomplish this.

Either that or, aliens have been helping out and repaired it from time to time.

[–] [email protected] 12 points 5 months ago* (last edited 5 months ago) (1 children)

How do they even still have energy to send and receive signals?

They're apparently on their last legs now in terms of being able to keep all the instruments running.

The Voyagers have enough electrical power and thruster fuel to keep its current suite of science instruments on until at least 2025.

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[–] [email protected] 12 points 5 months ago

Same. That was incredible.

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[–] [email protected] 84 points 5 months ago (1 children)

I'm constantly amazed at the longevity of this probe, so awesome!

[–] [email protected] 19 points 5 months ago (7 children)

it's too bad they don't make cellphones like this

[–] [email protected] 18 points 5 months ago* (last edited 5 months ago) (4 children)

Kinda goes against capitalism. Planned obsolescence has been around for a long time and if somebody goes against it, they will be removed by the big players.

[–] [email protected] 7 points 5 months ago

I'm not saying planned obsolescence isn't a thing (because it is), but that's not the only reason. Making phones smaller, lighter, faster, and more feature-dense all mean that the phone has to be built with tighter manufacturing and operating tolerances. Faster chips are more prone to heat and vibration damage. Higher power requirements means the battery has a larger charge/discharge cycle. And unfortunately, tighter operating tolerances mean that they can fall out of those tolerances much more easily.

They get dropped, shaken, exposed to large environmental temperature swings, charged in wonky ways, exposed to hand oils and other kinds of dirt, and a slew of other evils. Older phones that didn't have such tight tolerances could handle all that better. Old Nokia phones weren't built to be indestructible, they are just such simple phones that there isn't much to break; but there's a reason people don't use them much anymore. You can still get simple feature phones, but the fact remains that they don't sell well, so not many are made, and the ones that are made don't have a lot of time and money invested in them.

Now Voyager is an extremely simple computer, made with technology that has huge tolerances, in an environment that is mostly consistent and known ahead of time so the design can deliberately account for it, had lots of testing, didn't have to take mass production into its design consideration, didn't have to make cost trade-offs, and has a dedicated engineering team to keep it going. It is still impressive that it has lasted this long, but that is more a testament to the incredible work that was and is being put into it than to the technology behind it.

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[–] [email protected] 16 points 5 months ago (4 children)

Yeah. I'd totally buy an $800 million phone.

Realistically you can buy something like a Fairphone that lets you replace most parts that wear out or get damaged, which definitely increases the overall longevity of your phone. Or that CAT phone that's supposed to be super durable if you're prone to breaking your phone. Or if smart phones aren't your deal you can maybe find the old reliable Nokia 3210, that phone does not break and the battery can be replaced.

If you have phone longevity issues then stop buying phones that are not designed to be used for a long time.

[–] [email protected] 8 points 5 months ago (3 children)

How much does the plutonium battery fairphone cost these days?

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[–] [email protected] 45 points 5 months ago (1 children)

It's like the Jason Vorhees of spacecraft

[–] [email protected] 11 points 5 months ago (1 children)
[–] [email protected] 9 points 5 months ago

I'd pay to see Voyager beat a teenager to death with another one in a sleeping bag. Sounds compelling.

[–] [email protected] 35 points 5 months ago (2 children)
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[–] [email protected] 32 points 5 months ago (2 children)

Anyone ever sometimes think, that there's an alien species that kinda feels a little paternal towards us and keeps fixing out Tonka Toys because it makes us happy?

[–] [email protected] 72 points 5 months ago (4 children)

Screw thanking aliens, it's an incredible team of engineers that have the skills and dedication to do what seems impossible. This was 100% humanity at its best.

They rebuilt the most critical core code on a near antique spacecraft that has effectively left the solar system over an equally ancient radio link. They had 1 shot, and nailed it.

[–] [email protected] 25 points 5 months ago (1 children)

Exactly. If there's anything that we can point to and say "humanity, fuck yeah" this is it. Giving thanks to aliens or to gods is an insult to the hard work of the HUMANS that accomplished this.

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[–] [email protected] 21 points 5 months ago (1 children)

This is disrespectful towards the achievements of the human race. My father kept attributing all of our recent technology to "the findings at roswell" and i have very strong feelings towards this position.

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[–] [email protected] 24 points 5 months ago (1 children)

Provided we engineer them well, this is good news for truly deep space operations. Cosmic radiation and interplanetary gasses could (and probably do) wreak havoc on various materials, but apparently technology from the 70s is capable of handling it very long term.

Now if we could just get out of these squishy meat suits we'd be in business.

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[–] [email protected] 20 points 5 months ago

I try to diagnose the carburetor in my 50 year old Jeep sitting right in front of me, and I still can't get it running right.

These people are amazing, and the people that built that so it can still be fixed out in the Oort Cloud were even better.

[–] [email protected] 14 points 5 months ago (1 children)

What's the baud rate and have they needed to adjust it over time?

[–] [email protected] 24 points 5 months ago (2 children)

Not baud, but actual data rate returned:

https://voyager.jpl.nasa.gov/mission/science/

Science data are returned to earth in real time at 160 bps

[–] [email protected] 13 points 5 months ago (1 children)

That "real time" on out of earth scale always boggles my mind. Technically it is as fast as it possibly could, knowing that radio waves travels at the speed of light. But damn, that light has to travel for a long time before arriving so "real time" data that arrives is technically "quite old" data.

[–] [email protected] 9 points 5 months ago

As far as it is, it's still just under one day at light speed.

[–] [email protected] 7 points 5 months ago (2 children)

Imagine the ping & jitter.....oh...god......

[–] [email protected] 7 points 5 months ago* (last edited 5 months ago) (3 children)

The latency to Voyager 1 is apparently a bit under 23 hours, so yeah, that's gonna be painful.

I'd guess that the jitter is probably zero.

Like, if they can pull data in realtime, I assume that they've chosen an encoding with enough redundancy that data can get through reliably at that rate. Because of the latency, they'd have to have a huge buffer if they wanted to have some protocol that required frequently requesting retransmits.

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[–] [email protected] 13 points 5 months ago

Absolute Chad.

[–] [email protected] 12 points 5 months ago
[–] [email protected] 9 points 5 months ago
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