if the Sun is gone

[sergebroom]

About 10 years ago, I asked a Caltech graduate this question.

If the Sun suddenly vanished, would the Earth keep orbiting along its normal path around something that's not there anymore until the absence of the Sun's mass is finally felt?

He never could answer that question. He was unable to go beyond the Sun's disappearance and what would cause that. That may be because he wasn't a reader of SF.

That being said, It'd take humans about 8 minutes to notice that something is awry, and then we'd freeze to death in a very dark night. I don't know how long it'd take before the absence of the Sun's gravitational is felt, but, until then, what would the Earth be doing?

Comments

[geekosaur]

Depends on whose theories you use. General relativity says gravitation is a bending of space-time, so it would be instantaneous if not for special relativity which limits it to speed of light. So, that for 8 minutes which is the speed-of-light "distance" between the Earth and the ex-Sun, everything is normal, then suddenly the sky goes dark and the Earth goes off at a tangent to its former orbit.

Thing is, not everyone's fully convinced of general relativity any more, so were this possible it would provide a quick test of GR vs. alternatives (ironically right when it would be completely useless...).

[serge-lj.livejournal.com]

it would provide a quick test of GR vs. alternatives

I find it hard to believe that nobody ever wrote a story about that. Of course, it may well be that somebody did.

[lunacy-gal.livejournal.com]

Funny, I was just wondering what would happen if the *moon* suddenly disappeared. Besides the boating industry going topsy-turvy...

[serge-lj.livejournal.com]

I think there was a science book that had a whole chapter that I read years ago. I can't remember the title, but I could dig it up when I get home.

The Moon poofing away means we'd have to get rid of Cher's movie Moonstruck.

[lunacy-gal.livejournal.com]

And a bunch of poor werewolves would be out of luck.

[serge-lj.livejournal.com]

Heh.

By the way, the book I was thinking of is Neil F Comins's What If The Moon Didn't Exist. It's not about Luna going away, but it was still quite interesting.

[lunacy-gal.livejournal.com]

Thanks! I shall look it up.

[serge-lj.livejournal.com]

You're welcome. It consists of various what-if essays, and the one that gave this 1995 book its title was my favorite.

[mjlayman.livejournal.com]

It depends how the sun disappears. The gravity may pull the inner planets with it.

[serge-lj.livejournal.com]

This assumes that the Sun just stopped existing. Maybe willed away by one of Star Trek's annoying godlike beings.

[mjlayman.livejournal.com]

Ah, in that case, we'd know pretty soon.

[serge-lj.livejournal.com]

Especially if it's Q or Trelayne. But what if it were done by a discrete godlike being? (Not many of those hanging around the Federation, I know.)

[mjlayman.livejournal.com]

The Earth would just go flying off (so would the other planets). Think about swinging a ball on a string around and around and the string breaks.

[serge-lj.livejournal.com]

That comparison was pretty much the only way I could get the guy to come even close to figuring it out, and still he didn't. Oh well.

[pedanther]

Yes, continuous godlike beings are so much more common. :D

[serge-lj.livejournal.com]

Curses! Misspelled again!