Voyager 1 fires thrusters last used in 1980 – and they worked! NASA's announced that Voyager 1's already-amazingly-long mission will probably be extended for an extra two or three years, thanks to a successful attempt to use thrusters that haven't fired up since the year 1980. As NASA announced last Friday, Voyager 1's been using its “attitude control thrusters” (ACMs) for decades, to …
@Geniality "You need to be going very close to the speed of light (299,762 km/sec) for time dilation to become meaningful on a macroscopic scale. "
Tell that to the GPS satellite physicists. They'll set you straight^H^H^H^H^H^H freefall trajectory through curved spacetime.
http://physicscentral.com/explore/writers/will.cfm
" ... Both are needed ..."
This damned universe doesn't work right.
Between SR, GR and Quantum it's over-engineered and poorly put together. It's a lemon.
I want a better one. One with FTL Starships. And, perhaps, a full refund.
Of course, this one *does* have nice things, cats, my lady, rainbows and curries to name but a few but it needs to be far less complicated and a bit looser around the speed limitty bits. Now, where's the Complaints Department?
@Barley registers Satellites have to keep incredibly precise time, down to the picosecond (which isn't macroscopic). Voyager 1 doesn't. As I said, time dilation takes place at any relative velocity but it takes a long time to build up to something meaningful. Even for GPS satellites it takes months to go a few picoseconds out of sync with Earth-based stations.
@Geniality - you didn't read that link did you?
Money quote: "But at 38 microseconds per day, the relativistic offset in the rates of the satellite clocks is so large that, if left uncompensated, it would cause navigational errors that accumulate faster than 10 km per day!"
So - relativistically tiny speeds still causing 10km per day error.
Pretty meaningful in my book. Your mileage may vary. (Ha! see what I did there?)
You need to be going very close to the speed of light (299,762 km/sec) for time dilation to become meaningful on a macroscopic scale. It does happen at any speed though, Voyager's time travel relative to Earth would be a bit less than 2 seconds, accumulated over the last 40 years, if it travelled in empty space. Because of its tour of the outer planets, their gravitational wells actually sped up its relative time. It's hard to calculate how much dilation that caused though, since it depends on altitude and how many bodies (planets, moons and rings) had a meaningful impact.
Au contraire, it should be easy to calculate, just compare the onboard Real Time Clocks with identical models kept in a nice museum back home.
Assume any clock drift caused by the non-atomic nature of the clocks is roughly the same on all clocks from the same line and compare the local ones to U.T.C. or whatever NASA use as their standard. The difference between V'Ger and Local would be the accumulated relativistic weirdness.
Would V'Ger *have* R.T.C.'s that still work?
Well perhaps back in 1980 it was a cylinder and not a golden disk originally.
As Voyager approaches the speed of light, something called the Fitzgerald contraction becomes effective.
There once was a fencer named Fisk,
Whose speed was incredibly brisk.
So fast was his action,
The Fitzgerald contraction,
Foreshortended his foil to a disk.
17.46 km/s is not close enough to light speed for significant time dilation, but the fact that Voyager is so much further out of the Sun's gravity well, the on board clocks of Voyager would certainly be ticking faster than clocks on Earth. Gravitational time dilation even has to be accounted for on GPS satellites and they're much closer to Earth (and the Sun).
"When you're going that fast, doesn't time slow down or something"
yes but the amount is negliglble. you'd probably notice if you're receiving radio signals that are supposed to be xx.xxxx Mhz, but end up being xx.xxxy Mhz [that kind of difference].
As I recall, on one of the Apollo missions, they had an atomic clock or something similar on board the spacecraft, and they actually measured the time difference. Since they were moving at ~50k MPH for the trip to/from the moon, there would be a measurable effect, even though it was pretty tiny. But, the scientists involved in the experiment DID find "that difference" and announced that Einstein WAS right. It was definitely worth doing, yeah.
You can figure out the effect on time when you consider that if you're travellng at 1/2C, then [simplified] from YOUR perspective, light still moves at C, which means that for you, time effectively moves 1/2 as fast as it is for someone who's not moving at all. It's actually more complicated than that, but discussing all of the details in here would be TLDR and *yawn*. NOT mentioning that would invite the anal retentive howler monkey types to nit-pick every word.
anyway, ~18km/sec compared to ~300,000 km/sec is a pretty small change in the flow of time, but it's in the neighborhood of 1/10,000 [unless I made a math error] so radio frequencies would be shifted in a measurable way [as I already mentioned at the top] but that's about it. What's interesting, however, is that the shift would probably be TWICE what doppler alone would cause, because the relative time would affect the RF oscillators, which would put out a lower transmit frequency, which would then be further time-stretched by the doppler effect as the craft moves away from earth.
[gravity wells, as mentioned earlier, notwithstanding]
17.46kps really isn't that fast when compared to light speed at 300,000kps, so any time dilation can safely be ignored. The dilation only becomes meaningful when you get up to higher fractions of light speed.
According to Relativity time will slow down even when you just walk to the corner store. Its all about how fast your moving relative to another point of reference.
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That's about Mach 49 (for reference Earth orbital velocity is about M23).
OTOH that's 0.0056% of the speed of light.
However in principal systems can be engineered (no breakthroughs in physics, including fusion, needed) that could get to 5% of the speed of light.
Mach number is relative to local speed of sound so a velocity doesn't correspond to any specific Mach number unless you know what the local speed of sound is. For ideal gas the local speed of sound is a function of temperature (and temperature only). As for the temperature of the so-close-to-vacuum-as-makes-no-difference environment of the Voyager probes (assuming analyzing it as ideal gas even makes sense)... I have no idea.
'... I have no idea.'
*Somebody* does. The Solar Wind has a huge region in which it moves "supersonically" but it drops to subsonic somewhere around the Heliopause. That being so, there must be some smart guys out there who know what speeds those two terms mean locally.
https://en.wikipedia.org/wiki/Solar_wind Okay. 250-750 km/s. That's a *lot* faster than any of Man's little robots so not one of them is supersonic. Indeed, none of the planets are, either.
Okay, technically, V'Ger 1 *is* now supersonic as she has reached the Heliopause and the Solar Wind's outwards speed is just about zero out there, but I'm not sure if that still counts as a Mach number?
Possibly why us runners tend to use minutes per mile or for the modern inclined minutes per km. I having grown up in metric NZ and being an SI unit using scientist (I have to think about what an Angstrom is) for some reason which is opaque to me still use minutes per mile. Though for a rough and ready 5min/km = 8min/mile.
I suspect it is because most road distance races are 5miles, 10miles, half marathon (13.1miles) or marathon (26.2miles) etc. 10km's (6.25miles) is an aberration in the system. I bow to the track system of course though I haven't run a track race in several decades. Cross country races tend to be approximate due to the nature of the beast, proper cross country races anyway, with sucking mud patches and fences you have to vault with cow pat hazards. Sheep droppings are a mere inconvenience.
In the last thirty seven years, Voyager 1 has 'lost' almost two whole seconds, compared to us on the earth due to relativistic velocity time dilation.
(not really 'lost time', more, 'experienced time at a rate very slightly slower than us')
(On the other hand, being in a smaller gravitational field, the Voyager probes will have 'gained' some time as well, but less than lost to velocity)
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"they could easily reach planets with megatons of the stuff" (re: recycling v-ger for its gold)
right, heavy elements (like gold) are quite possibly more common on inner planets, and if you mine stuff at night, and at the poles, not unreasonably hot either. If I had the tech available, I'd certainly give it a shot.
the basic logic: outer planets are nearly all 'gas giants', inner ones are rocky. It seems to me that heavier elements collect closer to a star than farther away from it. Conclusion: Mercury probably has more gold than Earth.
asteroid mining would give you easier physical access to "everything", too, but how much gold, platinum, and other 'rare earths' being present in asteroids is still completely unknown.
Anyway...
True, but all the platinum group metals mined in southern Africa are found in the remnants of two large meteor strikes which hit the planet after the crust was formed. Any gold, platinum, etc... present at the formation of the planet would have settled to the core before any crust formation.
Scroticus Canis, precisely the reason Mercury might be a good place to prospect if energy to change orbits was cheap enough. It seems to have lost its crust and maybe mantle due to the energy of impacts. NASA did well with Messenger.
On another suggestion, NASA have chosen an apparently metallic asteroid which may be a core remnant for a mission. Current energy technology makes space mining hopelessly uneconomic for the foreseeable future unless fusion reactors can use He3. Then it might be worth mining the Moon for helium, not metals.
That settling thingy would also happen on the real planets. The big ones, Jupiter and Saturn. Probably on Uranus and Neptune, too, though heavy metals would be rarer out there both because of the distance from the centre of the pile and because the real planets would scarf up much of everything around them.
Jupiter, far from having a core that is metallic hydrogen or a giant diamond [wouldn't it be some other allotrope of carbon at those temperatures and pressures?] might be a massive, bubbly fission reactor filled with all sorts of radioactive ickyness.
The Big Red Spot as a gigantic nuclear-powered hot-spot?
"Chris Jones said “The Voyager flight team dug up decades-old data and examined the software that was coded in an outdated assembler language, to make sure we could safely test the thrusters."
Have they done a Intel and changed the mnemonics for some reason? or were they expecting to find the CPU had been upgraded in the meantime
Why don't they just say the assembler was not what their programmers were used to but the process of getting back to fundamentals was a rewarding challenge for them.
The language is only outdated if it's been replaced by newer ones.
It's not like someone can nip out there and update the hardware. So for the CPU on Voyager 1, this assembler language is the latest and only language. It therefore cannot be outdated.
AFAIK, the Voyagers use old CPUs designs and thereby the related assembly code could look quite outdated compared to today standards - and probably the toolset to work with as well.
There's no a single "assembler", each assembly language is strictly tied to the CPU architecture it is designed for (being, after all, just a human representation of CPU opcodes), and they can be quite different from each other, although some basic instructions may be quite similar. If you learned assembly on an x86 today, and one day try to program a 6502, you'll find it outdated, and you'll have to learn not only the mnemonics, but how they need to be used on that particular architecture and hardware implementation.
And remember, they are not allowed a trial&error approach like most developers on Earth... sure, they can simulate, but once the instruction sequence is finalized, it has to work, and those old system have very few or none safety belts.
For some reason I am reminded of that old classic tune - RS232 Interface Lead.
https://www.youtube.com/watch?v=CDlj0jBtYmQ
My favourite lyrics being from the operatic version..
-Come here, my lovely Tosca, I have something that will forever solve your information transfer problems.
-Not so fast, Buster. I already have an R.S.232 Interface Lead, but it hasn't solved my local networking difficulties, so I'm going to kill myself.
The PIC assembler is fairly ancient (over 40 years old?), esp for 16x84 family. The the 8-bit PIC was developed in 1975 by GI. The later 16C84 (1985?) used essentially same Assembler, A version of the 16F84 (software compatible) is still sold.
I did SC/MP and then Z80 in 1980 and Intel 8051 in 1983. Also the NEC7800 (really primitive), I wrote a Forth like environment using MacroAssembler for the NEC7800. It was a shock trying the 16F8x family in 2003. I soon changed to C and then JAL for my PIC projects.
Compiler tech has improved so much that you don't need assembler for microcontrollers now, except the odd inline instruction to do something to a register not efficient in the language.
" x86 today, and one day try to program a 6502" If you mean an x86 in actual 8086 mode, no. Even the 286 just adds instructions so you can have flat memory model. The 386 a few more for virtual memory etc, basically based on 8080, which is same era as 6502 and maybe not as nice. The Acorn ARM team designing the new RISC cpu started with the 6502 as a sort of template!
ARM is MUCH nicer than evil x86.
Interestingly, all of the CPUs you mention are too new too have affected Voyager design. I just viewed a documentary titled "The Farthest: Voyager in Space" that included comments from some of the engineers and scientists involved with the Voyager program. One of the engineers commented that in the interest of stability, technology was locked in as of 1972. The 8080 (1974) and 6502 (1975) were too new to have qualified. Voyager used 3 different designs, but the Attitude and Articulation Control Subsystem used an updated version of that used on the Viking spacecraft, a General Electric 18-bit TTL design with 64 instructions that used plated-wire RAM. It is rocket science, after all. They couldn't afford to trust a commercial CPU that was never tested in a high radiation environment.
General Electric provided the CPU for Voyager, as they had for the earlier Viking system http://www.cpushack.com/space-craft-cpu.html
The RCA 1802 was launched barely a year before Voyager, so could never have been used. It did see use in NASA in the Magellan and Hubble projects over a decade later, which gives you an idea of how long these projects take to design and launch.
The CPUs in Voyager were 18-bit machines with 64 instructions. They seemed to be a one-off custom job for NASA, as GE never commercially offered a CPU, nor did any other GE minicomputer had such an odd word-length (although its 600-series was 36-bit). This would definitely confirm the "obsolete assembly language" part of the story.
Have they done a Intel and changed the mnemonics for some reason? or were they expecting to find the CPU had been upgraded in the meantime
Why don't they just say the assembler was not what their programmers were used to but the process of getting back to fundamentals was a rewarding challenge for them.
There is a awful lot to a complete assembly language than the bare instruction set: red tape directives, psuedoinstructions, how variables are referenced (and possibly typed), macros, even fundamentals such as comments and default (or even acceptable) bases.
None of these affect the CPU in the slightest but make a big difference to how assembly programming feels. Older niche architectures typically had very bare bones assemblers. Nowadays even an experimental research architecture can easily have a full featured assembler in a couple of hours using a assembler development kit, so yes I certainly recognise the outdated label.
"The Voyager flight team dug up decades-old data and examined the software that was coded in an outdated assembler language, to make sure we could safely test the thrusters."
I expect they had useful comments and documentation too, which will never be outdated. In fact many companies haven't even heard of them yet.
My first computer in 1979 had a Z80, like an 8080 on sugar (steroids as a meme had not been invented yet). So, STOSB ? But I'm guessing that NASA preferred military-grade cosmic-ray hardened.... if the manufacturer was neither Intel nor Zilog but something like Fairchild, I wouldn't be surprised.
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"My MK14 from ~1980 still works. Never quite got round to fitting it with thrusters or it most certainly wouldnt."
Now that is an obsolete assembly language machine code. Well I hope it is obsolete. I used to write for it with a typewriter !
And, yes, I've also still got one
Let's be honest, if Voyager is ever intercepted by another spacecraft then that other craft is likely to contain... us! We know where it is, and the chances of anyone/anything else out there bumping into it must be tiny. Surely the chances are that we'll go and hunt it down for posterity once we've sussed proper interstellar travel?
(Aside from that: the sheer thought that the Voyagers still work, and are so far away, just boggles the mind. I can't comprehend either the distance or the coolness of the humans that made them and keep them going. Outstanding.).
"Surely the chances are that we'll go and hunt it down for posterity once we've sussed proper interstellar travel?"
And tonight on Antiques Roadshow we have Brian, who found something interesting passing through the Smaller Magellanic Cloud.
[ You do know that Antiques Roadshow will outlive Voyager? ]
Just imagine: After 37 years, the seals on those thruster valves still opened without damage, and held tight again. Wouldn't want to rely on that with a faucet that hadn't been used since 1980.
Just shows what you can do when there's no stupid oxygen or light around.
Wow. Just wow. So return signals/responses take about 2 days? I know relativity. I understand the principles. I'm fine with what ever bizarre reality is thrown at us (relativity and different reference frames from GR, QM giving interesting principles in possible outcomes and effects at a distance)... but I'm still boggled and amazed at the practical and real effect it has!
Beer, because that can also give you a looooong delay on getting work done.
Relativity has almost nothing to do with the fact that signals have a 38 hour there and back transit time. This time period is because the spacecraft is so far away, roughly 19 light-hours in distance, that radio signals take 19 hours to reach it and the reply takes 19 hours to return.
Technically the return time will, on average, be marginally longer than the out time but that's more because the spacecraft is slightly further away from Earth by then than any other effect. How much this matters compared to Earth's orbit is another matter. Earth's orbital speed is 30 km/s, roughly twice that of Voyager 1, this is in a roughly circular orbit therefore roughly half the time Earth's orbit will be increasing the distance and the other half it will be reducing the distance but there will only be short periods when the maximum relative differences in velocity come into play.
"After 37 years, the seals on those thruster valves still opened without damage,"
Indeed, though I do wonder why they used attitude control thrusters which are dependant on a limited fuel supply in the first place instead of reaction wheels which simply require electricity.
Reaction wheels and gyros only work to alter the orientation of a spacecraft while they are spinning. Slow them down to a stop to save electricity and wear and tear on the bearing etc. and the spacecraft settles back into its original orientation. They don't last forever -- the Hubble space telescope has/had multiple redundant sets of reaction wheels used for tracking during observations and most of them have stopped working IIRC.
Expend some mass through a thruster, the spacecraft will rotate. Fire off some more mass in the opposite direction, it will stop rotating and stay in its new orientation.
Reaction wheels and gyros only work to alter the orientation of a spacecraft while they are spinning. Slow them down to a stop to save electricity and wear and tear on the bearing etc. and the spacecraft settles back into its original orientation.
Reaction wheels will set a fixed orientation: assuming the probe is in a stable orientation spin up the wheels and the probe will begin rotating in response. Stop the wheels and that reaction is reversed stopping the rotation, in general in a new orientation.
What reaction wheels can't do in a sustainable manner is compensate for an externally induced pre-existing rotation, in the long term inevitable even in deep space, especially when slingshotting around. To correct that you need to eject mass, i.e. thrusters.
This has to be one of my favourite pieces of science/technology. The imagination to conceive the mission. Professionals dedicating their entire careers to an (by today's standards) unimaginably long payback period. The ingenious solutions to hiccups along the way. The brilliant revelations on the outer planets and their moons. It just goes on....
Here's to Voyager, and the other deep, deep space probes. All alone in the night...
Maybe the local cluster or the Galaxy. Search "Escape velocity". You don't need continued thrust to escape a "gravity well" once you are going fast enough from the start. I think the gas giants were used to speed up Voyagers and Horizon by "sling shot" effect.
The recent interstellar rock that passed relatively close to the Sun has no fuel and isn't in a Solar orbit.
Good? Amazing show. Never realised how central a role was played by Carl Sagan, for example in getting it to take a shot of earth as it flew out to interstellar space.
My take away from the show was that Voyager will be still flying onwards long after our sun expands and wipes us off the map. We will be outlived by a machine we made back in the 70s.
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Testing that hypothesis was a job for software developers, as Jet Propulsion Laboratory chief engineer Chris Jones said “The Voyager flight team dug up decades-old data and examined the software that was coded in an outdated assembler language, to make sure we could safely test the thrusters."
Shurely assembler languages never become "outdated". They are just mnemonics for machine instructions and don't need to carry around the whole "ecosystem" of compilers, optimizers, frameworks, deployment infrastructure and consultants.
Well, ok, now we have typed assembly language, and about time too. But still.
And how do you turn those mnemonics into machine code? Sure, you can do it by hand, but to avoid mistakes you usually use a compiler... I don't believe they sent Voyager the assembly code and it compiled it before executing it...
>and don't need to carry around the whole "ecosystem" of compilers, optimizers, frameworks, deployment infrastructure and consultants.
But when working on bespoke hardware, it is useful to have a precision ruler: Even with the clock speeds being used back in the early 80's, I encountered timing problems where the outermost parts of a circuit board where operating several clock cycles behind the CPU. The ruler helped me to identify which components were affected.
Knowledge is always relevant. Imagine if Voyager had hit the heliopause and just blipped out of existence because its location variable was trying to access memory in the UniverSim that was dedicated to another process. Would that have been wasted money?
It didn't happen but it could have; that would have told us all manner of interesting things.
Shockingly, I do not accept low-grade science fiction speculation as justification for spending taxpayers' money.
Nor should any other taxpayers accept this blatant theft of their hard-earned money.
Since you seem to find it worthy of your rather poor attempt at being 'clever', I can only assume that you do not pay tax.
You must a Repugnican;anything you personally can't make a buck on is useless. Luckily, your kind lost at the end of the dark ages, or the renaissance would never have occurred. Although, since that would mean the western hemisphere would never have been "discovered" by Europeans I suppose the Native Americans would have been happier.
I seem to have struck a nerve. If NASA wish to replace the ageing RTG design with a commentard with steam coming out of its ears as a power source, do give me a shout. Just think of me as that neutron that pushes the reaction to criticality...
Oh dear your physics is really not good, it and nothing cannot rust, no oxygen, no water, and very very cold. Slow down, it cannot, it is not driven, it is now a celestial unit just going at its current speed, direction etc unless it is affected by something else eg smashing into something or being pulled by say a planet.
There is a caveat, perhaps you also think the moon is driven by gasoline, and that it has its steering set on going around a bend! Look out folks the earth is running out of gasoline! Duh!
Yes modern solder is absolute manure, most electronic failures today are apparently due to crap unleaded solder. Now here is a thought, is it better to have an item last for 30 years, or have a one fail every year or so and be thrown away. To me even though the lead is a bit more harmful over all surely 10 or 20 times more rubbish is worse.
I have a vintage Land rover, she smokes a bit however how much pollution is created for making a new car. say a modern car lasts 15 years, then there is likely to have been about 4 new cars and the scrapping thereof just to equate to my Land Rover that incidentally is easier to maintain, does not have technical bits that go wrong (poor solder) and just keeps going.
I know it's meant to help any alien civ that finds it learn about us humans and all that. But how would such a record actually be played? I mean, if it was a "typical" LP, the receiving civ has to understand how mechanics, electrics and sound well enough to build a record player, and if they understand all that, they surely know enough about electricity and magnetism to know that there is a boatload of radio signal noise coming from a small blue dot over yonder? Those signals would have arrived well before the Voyager probe showed up.
So maybe the record is sort of an apology for the noise that has been seeping into the ether? A kind of "yeah , sorry about those Alvin Stardust radio broadcasts. Here's a Chuck Berry record. This should be better."
I know it's meant to help any alien civ that finds it learn about us humans and all that. But how would such a record actually be played? I mean, if it was a "typical" LP, the receiving civ has to understand how mechanics, electrics and sound well enough to build a record player, and if they understand all that, they surely know enough about electricity and magnetism to know that there is a boatload of radio signal noise coming from a small blue dot over yonder? Those signals would have arrived well before the Voyager probe showed up.
There are instructions for decoding the record on the case, although expecting an alien race to be able to decipher them struck me as ambitious at best.
As for radio emissions I suspect you are thinking in terms of the wrong timescale: there is a small radioactive sample on board to allow the probe's age to be determined from its decay. It is designed to be readable for billions of years. I doubt we'll still be around, yet alone transmitting radio.
If code was error free decades ago, it is still error free. If there are bugs in there they were there in 1980. However, NASA spends a lot of time and money on testing – the kind of time and money most projects don't have.
So it is not surprising that code written and working in 1980 still works today. Hardware deteriorates, so that is the miracle that the hardware still worked.
This illustrates a difference between software and hardware. But bespoke hardware built and thoroughly tested for NASA at great expense would be much more rugged than modern off-the-shelf hardware that most of us use and can afford.
Ian, true, but 40 years in a vacuum is not a gentle environment. That the hardware worked, valves opened and closed properly suggests really tested and well built hardware that only we of many years can remember. The hardware makers get my upvote. Bit rot might be a fiction but hardware degradation is all too familiar.
Really?? Who uses THAT old shit? That's unreadable, unmaintainable, and not NEARLY the correct monthly flavor.
They should have used Java. Programmers are much more common, and so what if it's big and slow? That's what the swap area is for. But it's READABLE. MAINTAINABLE. And when it throws a traceback error, you know exactly where the problem is. Or use Docker and multi-thread it, so that one process does not kill the entire machine.
Besides, you have the Java/Docker automatic update feature, so you can make sure not bugs appear in the supporting language. Jeesh, it's like you guys never learned anything from a guy at home sitting in his underwear who knows much more than the PhDs that have supported this over the decodes.
Assembly? Sheesh, it's like you're LOOKING for an excuse to stay employed.
I suppose NEXT you'll tell me it's untouchable, so in a pinch I can't attach an RS-232 adapter for emergency debugging. Just what kind of supposed Microsoft graduate engineers ARE you, anyway?
Saturday Night Live back in the 70's announced that they had received a message from someone who intercepted the Voyager probe. They held up a card that said:
SEND MORE CHUCK BERRY
Oh, and he was a guest of JPL at the "finish" party after the Neptune encounter.
Question and one that used to wind my physics teachers up. What pray is the speed relative to. To have a given speed then it must be able to be compared with something that relative to the moving object is stationary. So please pray tell me in the universe which object is stationary. For example, if a gun on the satellite was fired say in the direction of travel at 700mph, is the bullet going at the speed of the satellite +700 or is the bullet going to come out of the back of the rifle. it cannot go backwards it must go forwards so if light was projected back to earth would it be at what speed.
You see the radio waves which travel at the speed of light get to the unit and come back, therefore in space there must be a "stationary" whatever that may be. A point in time, a geographic point. There now some body explain that. No person not even serious boffins have been able to explain it.
BTW, It is not well known that the "golden disk" aboard Voyager actually started out in 1980 as a cylinder! (as did most record disks in the early 1900s)
But the Fitzgerald Contraction is now starting to have its way. -
There once was a fencer named Fisk,
Whose speed was incredibly brisk.
So fast was his action,
The Fitzgerald contraction,
Foreshortended his foil to a disk.
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