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Voyager 1 stops communicating with Earth

cnn.com

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Re: Voyager 1 stops communicating with Earth

#641

Post by lazide »

pdonis wrote: post #639
lazide wrote: post #634

Earlier quoted context omitted.

If the intersteller medium is not a vacuum, what is? Last I checked, it was literally billions of times lower density than the hardest vacuum we’ve been able to produce on earth.

> If the intersteller medium is not a vacuum, what is? There is no threshold of low enough density at which there is suddenly "vacuum". If there are particles present, there are particles present, and they can have effects. > Last I checked, it was literally billions of times lower density than the hardest vacuum we’ve been able to produce on earth. [Edit--these numbers are off--see my post downthread] And the solar…

Cite? Everything I see indicates solar wind density is 10-100 times interstellar medium density.

I suspect you got your numbers reversed.

Re: Voyager 1 stops communicating with Earth

#642

Post by pdonis »

lazide wrote: post #641
pdonis wrote: post #639

Earlier quoted context omitted.

> If the intersteller medium is not a vacuum, what is? There is no threshold of low enough density at which there is suddenly "vacuum". If there are particles present, there are particles present, and they can have effects. > Last I checked, it was literally billions of times lower density than the hardest vacuum we’ve been able to produce on earth. [Edit--these numbers are off--see my post downthread] And the solar…

Cite? Everything I see indicates solar wind density is 10-100 times interstellar medium density. I suspect you got your numbers reversed.

> Cite?

You are correct that the numbers I cited were off, because I had neglected to check specifically for numbers at the heliopause. Here is a better set of numbers:

https://ui.adsabs.harvard.edu/abs/2019NatAs...3.1024G/abstra...

The plasma density in the outer heliosphere is typically about 0.002 cm-3. The first electron density measured by the Voyager 2 plasma wave instrument in the interstellar medium, 0.039 cm-3 ± 15%, was on 30 January 2019 at a heliocentric radial distance of 119.7 au. The density jump, about a factor of 20, confirms that Voyager 2 crossed the heliopause.

In other words, the density of the interstellar medium just outside the heliopause, as detected by Voyager 2, was about 20 times larger than the density of the plasma just inside the heliopause.

Re: Voyager 1 stops communicating with Earth

#643

Post by pdonis »

lazide wrote: post #633
adwn wrote: post #522

Earlier quoted context omitted.

They interact via the electromagnetic force.

So that graph showing no interactions is lying?

The graph is not a graph of interactions between solar wind particles and interstellar medium particles. It is a graph of solar wind particles detected by Voyager 1.

Re: Voyager 1 stops communicating with Earth

#644

Post by pdonis »

lazide wrote: post #632
pdonis wrote: post #561

Earlier quoted context omitted.

They are plenty dense enough to interact given that it's plasma.

You might want to re-read that graph. And conservation of momentum means the particles leaving the sun don’t stop rotating when they leave the sun - the sun is rotating.

> You might want to re-read that graph.

You might want to re-read the Wikipedia page. It explicitly says that Voyager 1 saw the density of plasma around it increase by a factor of 40 as it crossed the heliopause. (For Voyager 2, it was a factor of 20, as I have posted elsewhere in this discussion.) It also explicitly says that the solar wind is stopped at the heliopause due to the pressure of the interstellar medium, which, last I checked, means the interstellar medium is interacting with the solar wind.

> conservation of momentum means the particles leaving the sun don’t stop rotating when they leave the sun - the sun is rotating

Sure, with a period of about 27 days. Go do the math and compare the tangential velocity that equates to with the tangential velocity required to orbit the Sun just above the Sun's surface.

Re: Voyager 1 stops communicating with Earth

#645

Post by johnwalkr »

saalweachter wrote: post #590
johnwalkr wrote: post #236

Earlier quoted context omitted.

The trajectory was a once-in-a-lifetime opportunity based on the dynamics of our solar system, and surely the relevant experts will take advantage of the next similar opportunities. It's also almost a miracle that the probes have lasted this long. They used analogue electronics and if they launched ten years later, they would have more modern electronics and would probably have failed by now. And it's not possible to…

> And it's not possible to simply argue to use older designs to last longer in a new mission, because you would give up multiple orders of magnitude of data collection. Why not both? The heavy parts of the probe, then or now, were presumably not the electronics themselves so much as the physical structure, the power system, etc etc. If you were designing a probe to last fifty, a hundred years, why not include series…

This is like asking why a Tesla model S can't revert to a Ford model T and keep functioning for decades (without a technician allowed to touch the car).

Re: Voyager 1 stops communicating with Earth

#646

Post by LegionMammal978 »

seeknotfind wrote: post #393
LegionMammal978 wrote: post #356

Earlier quoted context omitted.

> This equation has solutions for given X where X is an improvement, so as long as there is any improvement, it's always true waiting to start large enough computations will be faster. Though this does assume that X is a constant, or at least bounded below by a constant. If hardware performance improved up to an asymptote, then there would still be nonzero improvement, but it might not be enough for waiting to ever b…

As "If hardware next year is X times better (e.g. even 1.01 or 1% better) than this year" highlights X is a constant as a simplifying assumption, I'd have expected you to say "As this assumes that X is a constant" not "Though this does assume that X is a constant". So, I'm not sure what your disagreement is. If your disagreement is that a constant is not appropriate here, consider the interpretation in this compariso…

My apologies, I misinterpreted you as talking about waiting for many years (given a sufficiently large task) for performance to continue increasing, since this thread started talking about Moore's Law. I have no disagreement in the single-year case you were actually talking about.

Re: Voyager 1 stops communicating with Earth

#647

Post by hughesjj »

slimginz wrote: post #510
sgt wrote: post #479

Earlier quoted context omitted.

Port cloud? I think you've been working in IT for too long.

Probably just an autocorrect slip

^

...my fingers are fat and 99% of my posts are from a cell phone. I should proof read more but I'm a lazy piece of shit who shits out shit opinions in between compilations/cicd tests, as my comment history can attest to.

I should probably be a better netizen, along with many other aspects I should improve on (of which man, I'm trying to improve a bunch, I freely admit I as a human need some work)

(Also lol my phone initially auto corrected or more likely my fingers originally typed fat ->far)

Re: Voyager 1 stops communicating with Earth

#648

Post by phatskat »

mlrtime wrote: post #515
preisschild wrote: post #483

Earlier quoted context omitted.

That one guy also took money from his space exploration company to buy a social media site so that he can be even more of an online edgelord. Not really trustworthy...

But why do YOU need to trust him? Someone can be crazy on twitter AND be the the first (possible) person to get a man on Mars.

Musk has stated that his goals for space colonization are for his children’s children and his friend’s grandchildren to be the ones doing all the colonizing, and that earth is just a resource (people included) to burn up in pursuit of that goal. Any scientific advancements in his eyes are for the sole purpose of getting the ultra wealthy into space, with zero concern for the impact that has on the rest of us.

Re: Voyager 1 stops communicating with Earth

#649

Post by [deleted] »

fasterik wrote: post #588
kjkjadksj wrote: post #556

Earlier quoted context omitted.

Why do you even want to put a human on mars? What would you have them do that you can’t do with a probe or robot?. Its extremely risky to put people in space with our present technology. Even if nothing goes “wrong” they are dealing with microgravity and radiation. We aren’t adapted for it at all.

There are a few reasons. You could say that putting humans on Mars has intrinsic value. In other words, "because it's cool". The other main argument for putting humans on Mars is that the grand projects of humanity push our technology forward. Putting humans on Mars requires solving a larger class of problems than sending probes does. The first space race accelerated the development of rocketry, integrated circuits,…

[deleted]
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