[chris (OP)]

If the Sun were to instantaneously disappear presumably we would still see its light for the 8 minutes it takes that light to reach us. But what about the gravitational effects of the Sun? Would the curvature of space-time induced by the Sun's mass instantly vanish and therefore the Earth would cease to feel a gravitational attraction? Or would be not feel that change in gravitation initially?

Chris

[Chemistry4me]

Previous threads: http://www.thenakedscientists.com/forum/index.php?topic=18297.0

http://www.thenakedscientists.com/forum/index.php?topic=2623.0

Also this: http://www.newscientist.com/article/dn3232

[ScientificBoysClub]

If the Sun were to instantaneously disappear presumably we would still see its light for the 8 minutes it takes that light to reach us. But what about the gravitational effects of the Sun? Would the curvature of space-time induced by the Sun's mass instantly vanish and therefore the Earth would cease to feel a gravitational attraction? Or would be not feel that change in gravitation initially?

Chris

Very good Question !!
Watch this what would happen .....

this vdo shows light from distant star ..

Well velocity of light and velocity of Gravitational Waves are same (constant )
so, after  Sun ceases to exist ...... the G waves would reach us (at same time as light ) I mean the distortion of space gets modified to no distortion state .. and after that planets revolving around the sun would loose there orbit .. and gets lost in space !!
 
This effect will be after 8 minutes 24 seconds !!!
 

[lyner]

We've been here before but how did you envisage taking the Sun away?

[lightarrow]

Very good Question !!
Watch this what would happen .....

this vdo shows light from distant star ..

Well velocity of light and velocity of Gravitational Waves are same (constant )
so, after  Sun ceases to exist ...... the G waves would reach us (at same time as light ) I mean the distortion of space gets modified to no distortion state .. and after that planets revolving around the sun would loose there orbit .. and gets lost in space !!
 
This effect will be after 8 minutes 24 seconds !!!
 

I would tend to agree with you, but the video seems instead to suggest that the planets escapes its orbit immediately after the Sun's disappearance.

[lyner]

Bearing in mind that the Sun would not "disappear", just like that, the question is meaningless unless the method and timescale are both considered. There are many better theoretical scenarios to consider which investigate the relative propagation of electromagnetic and gravitational effects.
I am not being grumpy - just realistic. It just isn't as simple as that.

[lightarrow]

Bearing in mind that the Sun would not "disappear", just like that, the question is meaningless unless the method and timescale are both considered. There are many better theoretical scenarios to consider which investigate the relative propagation of electromagnetic and gravitational effects.
I am not being grumpy - just realistic. It just isn't as simple as that.

What about a very small naked singularity in place of the Sun, which escapes in another dimension?  []
(I know, it's not exactly more realistic... [])

[lyner]

go on then. I'm convinced. []

[lightarrow]

go on then. I'm convinced. []

Ok: a collision of the massive particle with another negative-mass particle... []

[lyner]

Wouldn't that involve quite a lot of energy transfer - to disturb the 'simple' experiment?

[Bored chemist]

roughly 8 minutes after the sun disapeared people would be far too worried about the lack of light to care what the earth's orbit was doing.

[lightarrow]

Wouldn't that involve quite a lot of energy transfer - to disturb the 'simple' experiment?

positive mass + negative mass = positive energy + negative energy = zero energy.