If the sun disappeared now , how long would it take for all planets to fall out of orbit??

Question

If the sun disappeared now , how long would it take for all planets to fall out of orbit??

Answer 1

I just want to back up the answers that understand the effect is not instantaneous.

Check out:

http://en.wikipedia.org/wiki/Speed_of_gr...

and here is a link to an experiment to measure the spped of gravity:

http://web.missouri.edu/~news/releases/d...

(Sergei Kopeikin, the person who did this, has a wikipedia page too)

So as has been stated, gravity moves at the speed of light, so Mercury would head off in a straight line at a tangent to its orbit about 2.5 minutes after the sun vanished, venus would be next and so on...

Answer 2

Instantly

Answer 3

there actually wouldn't be any delay if you just made the sun disappear... technically withina one millionth of a second the planets will have already been moving out of orbit... because it started the exact moment in time the sun disappeared....

if the sun just disappeared, so would the orbits.

Answer 4

as fast as the speed of light from where they are, as they have nothing to orbit around.

We would stop being influenced by the sun's gravity in 8 minutes. It would be the same time it all went dark.

Answer 5

I would say very, very quickly. In seconds.

Why - what are you planning to do ?

Answer 6

Many posters here believe that gravity is instantaneous, which would mean it operates faster than light. This is impossible. Newton believed gravity was instantaneous, but Einstein showed conclusively that it moves at the speed of light (same as electromagnetism, and any other force).

Answer 7

Despite everyone's apparent confidence, we actually don't know because we don't really know what gravity is, we only know what it does.

If gravity is, in fact, a curvature of spacetime, then it would happen instantly.  If Gravity is a regular force who's energy is carried by a particle(graviton), then it would happen at the speed of light.

Answer 8

Mr Genius and the Drunken Fool (don't you love those avatars? :-) have the right answers. Now, people sometimes fail to understand the limitation of the speed of light.

That is very understandable because if you move on earth, you can't imagine something preventing you from moving slightly faster. But imagine that I ask you to stop moving then ... move even slower! Impossible, right? Well, it is the same with the speed of light that is a constant and the relation between space and time.

So, yes the earth will change its orbit 8 minutes after the disappearance of the sun, exactly at the moment we will observe darkness. But then ... there is no simultaneity nor absolute frame of reference in the universe so .. the 8 minutes is only a theoretical value because the sun disappearance and the earth plunge in darkness will be observed in two different spacetime frame of observation. Isn't Relativity fun, or what? :-)

Answer 9

They would start to go out of orbit immediately

Answer 10

Information can't travel faster than the speed of light, which includes gravity.  So that means it would take the same amount of time it takes light to reach us, 8 1/2 minutes.

Answer 11

Zero moments.

Answer 12

From what I've learned, gravity can't travel faster than the speed of light (I think it travels the same speed), therefore, if the sun was to dissapear, it would take somewhere around 8-15 minutes before we would witness it vanish, and 8-15 minutes for us to fall out of orbit.

So our sun could have dissapeared right now, we just won't know until about another 8-15 minutes

Answer 13

Mercury would be first after about 2.5 minutes, on out to Pluto, witch would fall away after about 4 hours. Earth would take about eight minutes because gravity travels at the same speed as light. We would leave orbit as soon as we actually SAW  the sun disappear, but we wouldn't see that it was gone until the light stopped coming to is. Eight minutes.

Answer 14

It would depend on their distance from the sun.

  In 8 minutes the earth would fly off at a tangent.

Answer 15

it would start quickly (as soon as the centrifugal force of spin ran down)

Answer 16

Most likely right away, but since we get sunlight that is 8 minutes old, we would fall out of orbit but not know that the sun was gone for 8 minutes. It would be disastrous. Plus it would then get very cold and all the plants would start to die from lack of sunlight, oh it would never rain again and we would all just eventually die.

Answer 17

in a matter of nano seconds because as there is no gravity, there is no centripetal force to cause the planets to orbit around the sun the sun

Answer 18

If my son disappeared now, it'd be catastrophic, but i doubt that the planets would fall out of orbit because of it.

Oh.  You mean the Sun, with an UPPER CASE 's'.  You threw me off the track for a second.  And here i was about to call the police.

Gravity propagates about at the speed of light. This has been measured.  It probably moves at exactly the speed of light.  Light and gravity are likely aspects of some single phenomenon which makes the whole Universe work the way it does.  But it hasn't been proven yet.  Prove this, and you'll likely get a Nobel Prize.  But don't wait too long.  The Nobel committee isn't known for awarding prizes promptly, and they don't award them at all to dead people.