2062: Barnard's Star

Explain xkcd: It's 'cause you're dumb.
Revision as of 18:09, 22 October 2018 by (talk) (Explanation)
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Barnard's Star
"Ok, team. We have a little under 10,000 years before closest approach to figure out how to destroy Barnard's Star." "Why, does it pose a threat to the Solar System?" "No. It's just an asshole."
Title text: "Ok, team. We have a little under 10,000 years before closest approach to figure out how to destroy Barnard's Star." "Why, does it pose a threat to the Solar System?" "No. It's just an asshole."


Ambox notice.png This explanation may be incomplete or incorrect: Please edit the explanation below and only mention here why it isn't complete. Do NOT delete this tag too soon.
If you can address this issue, please edit the page! Thanks.
Distances to the nearest stars from 20,000 years ago until 80,000 years in the future

Barnard's Star is a very-low-mass red dwarf about 6 light-years away from Earth in the constellation of Ophiuchus. It is the fourth-nearest known individual star to the Sun (after the three components of the Alpha Centauri system) and the closest star in the Northern Celestial Hemisphere. It is a Red dwarf with a mass of 0.144 Solar masses and it is 7–12 billion years old. Because of this low mass the gravitational force in the core is much lower and thus the fusion rate is far smaller than in the core of the Sun. In fact this star is so dim, even though it's one of the nearest, it can't be seen by the naked eye. The low fusion rate also means that the lifespan of small stars is much longer. While the Sun might last about 10 billion years and huge stars only a few hundred million years, a small Red dwarf has a lifespan of about a trillion years.

Barnard's Star is the star with the greatest apparent motion in the sky. Apparent motion is motion in the sky other than that caused by earth's rotation. Barnard's star is both very close to the sun (as these things go) and moving at a speed of more than 140 km/s toward the Sun. It will make its closest approach to the Sun in approximately 10,000 years, at a distance within about 3.75 light-years.

The image on the right shows different stars near the Sun over 100,000 years and it can be seen that none of them are getting closer than 3 light-years. This is a safe distance to our Solar System and the stars will not influence the orbits of the planets or smaller bodies. It's also obvious that much closer approaches never have happened since the Solar System formed 4.5 billion years ago because otherwise the nearly circular orbits of the planets in the same plane wouldn't be possible.

The title text emphasises that this close approach will not be any hazard to the Solar System, but someone is envious of the long lifetime of Barnard's Star and annoyed by its unpleasant behavior.


Ambox notice.png This transcript is incomplete. Please help editing it! Thanks.
[A black sky is shown with a yellow spot near the bottom, left from the center. Three smaller red spots at the diagonal from top left to bottom right indicate a moving star over time. Above these red spots lines are connected to a text which starts and ends with many A, first growing, and at the end getting smaller:]
...AAAAHHi Sun! I was here billions of years before you formed and will shine for trillions of years after you dieEEEEEAAA...

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Uh . . . I'm pretty sure that stars don't talk. (talk) (please sign your comments with ~~~~)

And squirrels don't ring. This comic can be absurd sometimes. 17:05, 22 October 2018 (UTC)
[citation needed] -- 18:05, 22 October 2018 (UTC)
Why are you so sure that stars don't talk? 18:23, 22 October 2018 (UTC)
I think it was a NOVA doco where they describe the inner workings of the sun and how hydrogen atoms, photons, plasma, and magnetic flux interact, and it sounded a heck of a lot like the function of neurons and signals in the brain. Maybe I was just high, but I got to thinking that, with photons from every star in the universe connecting to every other star, the stars are in constant communication with eachother in some sort of neural-like network with each star having it's own neural-like network complete with it's own sentient thoughts (albeit probably far outside the realm of our imagination). FORTY TWO! (talk) (please sign your comments with ~~~~)
Obviously, stars, being in vacuum, don't talk in classic acoustic way. But they emit lot of light, which includes radio emissions ... and remember that properly encrypted signal is hard to recognize from random noise. -- Hkmaly (talk) 23:05, 22 October 2018 (UTC)

Stars can talk but usually don't. Maybe because they are under a lot of pressure ? 08:45, 24 October 2018 (UTC) BadJokeNinja

Am I'm the only one, who is reminded by the beginning "...AAAA" and the ending "EEEEEAAA..." to the "The Man Who Fell Sideways" comic?-- 12:17, 24 October 2018 (UTC)

"a small Red dwarf has a lifespan of about a trillion years." A trillion years? Any source for this? The universe is around 14 billion years old. 13:32, 24 October 2018 (UTC)comicreader

That doesn't mean it's that old now. It means it will last that long, which means it's a relative youngster at this stage of its life. I'm sure a trillion years is a very general estimate for its lifespan, which is highly dependent on its mass. As for the source of this estimate, it's probably well-sourced on Wikipedia that serves as the source of much of the explanation's current content. Ianrbibtitlht (talk) 13:48, 24 October 2018 (UTC)
And click the Wiki link for Red dwarf in the explanation. You will read: "...Red dwarfs therefore develop very slowly, maintaining a constant luminosity and spectral type for trillions of years, until their fuel is depleted. Because of the comparatively short age of the universe, no red dwarfs exist at advanced stages of evolution." --Dgbrt (talk) 18:34, 24 October 2018 (UTC)

Faster comunication than photons could be possible with plasma entanglement but I'm still skeptical as to whether or not stars are big giant sentient brains. Why is it traveling so fast I wonder... a remnant of some previous galactic merger?