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Voyager 1 stops communicating with Earth

cnn.com

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Re: Voyager 1 stops communicating with Earth

#361

Post by ineptech »

RheingoldRiver wrote: post #309
japhyr wrote: post #235

Earlier quoted context omitted.

Assuming you're talking about the overall sharp drop-off and not the bounce-backs, this was my favorite way to explain it to students: We live near the ocean, and we have a rocky shoreline. We have a couple coves nearby. One cove is about the a half-mile across, but the opening to the larger bay nearby is just a couple hundred feet. On most days, the cove is really calm and the bay has roughly two foot waves. So, you…

That makes sense as far as explaining another situation where you would see a similar pattern, but it doesn't really explain why. What's the equivalent of the land surrounding the cove here? The sun's gravity well? But that's a gradual drop-off, are we looking at the distance where the gravitational pull on particles is canceled out by some other force?

AIUI, the solar wind does attenuate gradually; the relatively sharp drop-off is the transition from the "I feel the solar wind more than the interstellar medium" region to the "I feel the ISM more than solar wind" region.

Re: Voyager 1 stops communicating with Earth

#362

Post by lIl-IIIl »

kadoban wrote: post #312
jacquesm wrote: post #292

Earlier quoted context omitted.

If something like Voyager would arrive from outside our Solar system it would be the event of the millenium.

There's every possibility that neither Voyager will ever arrive anywhere ever again. If they do, it's going to be after our galaxy collides with another, and the place they arrive at may not even exist yet. https://www.space.com/predicting-voyager-golden-records-dist...

While the Milky Way galaxy is on course to collide with Andromeda galaxy in 4.5 billion years, that will not make Voyager's arrival anywhere more likely, since the stars are far enough apart that they will not be affected.

https://en.m.wikipedia.org/wiki/Andromeda%E2%80%93Milky_Way_...

Re: Voyager 1 stops communicating with Earth

#363

Post by murkt »

hunter2_ wrote: post #352
apitman wrote: post #308

One of my favorite tech legends is that apparently Voyager 1 launched with a Viterbi encoder, even though there was no computer on Earth at the time fast enough to decode it. After a number of years Moore's Law caught up and they remotely switched over to Viterbi for more efficient transmissions.

The notion that encoding/transmitting could be simpler than decoding/receiving is interesting. It reminds me of the way optical drives for many years could write at, say, 48x but read at 8x, such that the majority of time spent was the verification step (if enabled) rather than the burn step. Just speculating, I assume it's because of things like error correction, filtering out noise/degradation. Producing the extra…

CD drive speeds were written like 48/8/8, which stands for 48x for reading, 8x for writing CD-Rs, and 8x for re-writing CD-RWs.

Re: Voyager 1 stops communicating with Earth

#364

Post by tobyjsullivan »

AndrewKemendo wrote: post #330
dotnet00 wrote: post #275

Earlier quoted context omitted.

You could've said the same for air travel in the early days.

Well, we don’t have great figures on this but there are some estimates that only 20% of the human population has ever flown on an airplane. That seems like it’s a pretty heavily “gilded only” type of thing especially if you look at percentage distributions of flight frequency and by class.

Where are you setting the bar for something to be commonly accessible?

Only about 60% of the world’s population has reliable access to clean drinking water. 18% of people own a car.

Compared to those numbers, 20% of people flying seems downright common - especially considering many people likely never fly simply because they have nowhere worth going (relative to cost).

Re: Voyager 1 stops communicating with Earth

#366

Post by FredPret »

GeorgeTirebiter wrote: post #348
FredPret wrote: post #341

Is there any chance we can zap its general direction with a radio beam and then listen with a huge radio telescope to get an accurate radar fix on where it is?

No. It's simply too far away for that, because d*4 gets you. Now, if the zapper were Big Enough, when received it didn't destroy the probe, AND that there was a big enough receiver, they maybe...

According to [0] we can do 0.000012 arc seconds with interferometry.

At 22.5 light minutes, that works out to about half a meter (!) if my trig is correct.

We’d probably have to absolutely blast it with energy though.

[https://en.m.wikipedia.org/wiki/Angular_resolution#:~:text=T....]

Re: Voyager 1 stops communicating with Earth

#367

Post by dotnet00 »

Robotbeat wrote: post #344
dotnet00 wrote: post #331

Earlier quoted context omitted.

I tend to generally ignore Russia in the context of development nowadays in spaceflight because I don't see them having the spare resources or talent to do any meaningful new development. They're good at reusing and iterating what they inherited from the USSR, but they've promised so much new stuff over the years and have delivered on basically nothing. The countries I mentioned have all at least managed to bring onl…

China?

I did mention China as an example of humanity increasingly reaching for the stars :)

I don't like them politically, but they are clearly a very capable spacefaring nation, with the capability to develop new space-related technologies.

Re: Voyager 1 stops communicating with Earth

#368

Post by darig »

dylan604 wrote: post #269
luxuryballs wrote: post #256

Ok so it says online it’s going at almost 40,000 mph so what is stopping us from sending one at say 400,000 mph, then couldn’t we catch up with it eventually? and travel the same distance in like 5 years?

and do what? at that speed, all you'll be able to do is wave as it sails by. you're not stopping at anything at that speed. however, even at 400k mph, that will not reach the next anything of interest before humans are extinct. here's some logic on why even getting to the closest star isn't likely: https://space.stackexchange.com/questions/33274/how-long-cou...

[dead]

Re: Voyager 1 stops communicating with Earth

#369

Post by thrdbndndn »

gzer0 wrote: post #282

One of my favorite facts ever is that Voyager 1 contains something called the Voyager Golden Record [1]. It has the following quote written: This is a present from a small, distant world, a token of our sounds, our science, our images, our music, our thoughts and our feelings. We are attempting to survive our time so we may live into yours. I get chills everytime I think about this. I hope we can recover from this ev…

I think the golden record is even more famous than the Voyager(s) themselves.

At least I learned it in my childhood (together with Pioneer plaque -- I just noticed they're not the same thing!)

Re: Voyager 1 stops communicating with Earth

#370

Post by ineptech »

btach wrote: post #221
voytec wrote: post #70

I always have a sense of pride and a feeling of respect for us as a human race when reading about V'ger. It's astonishing that we were able to send a space probe, designed and built to be so robust that it's still doing its thing and sending us postcards after 46 years(!!!) of flying away from us in an extremely harmful environment, while we still fuck simple stuff up back home.

I appreciate the Star Trek reference (V'ger incase somebody doesn't know what I'm talking about - Star Trek, The Motion Picture). That movie awed me as a kid.

That's kind of a spoiler.
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