Gravity and energy

rave77

I have the following question:

Let's suppose that I have a bucket filled with boiling water (metal bucket), and I intend to freeze the water by spaying liquid nitrogen to it.
Which of this two would be the most effective way to achieve my goal:
Placing it on the grass and spraying it from above? Or from below hanging and covering the bucket with a block of grass? (The exact same block of grass is used in both cases).

This is a different question; if you could help me answer it I would appreciate it.
A friend of mine asked me:
How fast does gravity travel.
I told him that gravity does not travel, all matter in this universe is connected, no matter how far apart they are from each other.
Then he asked me the following question:
If a particle starts traveling at a great velocity heading towards another. How fast would the attraction increase as they both shorten the distance among them?

K^2

Gravitational waves propagate at the speed of light. If an object you are gravitationally pulled to moves, there is a speed-of-light delay before gravitational pull changes.

Usually, cooling fluids from above is more efficient, as cooler fluid is more dense and will sink to the bottom, mixing the fluid you are cooling.

TheTechNoir

This response might be a bit misleading to the original poster, I just wanted to clarify a little bit (unless I am the one being misleading and am incorrect here) there is a difference between gravity itself as a force and gravitational waves.

Gravitational waves also travel at the speed of light, but they are an actual distorting of spacetime for example orbiting black holes creating gravity waves/gravity radiation.

Gravity itself as an attractive force or gravitons also travel at the speed of light though, and this is what is responsible for the pull of gravity. I do not believe it is gravitational waves that cause massive objects to be attractive.