How long would it take to get to Saturn at the light speed?

It takes over eight minutes

To reach Saturn, the next closest planet, would take another 36 minutes, and a further three hours or so to reach Pluto.

Explanation:

coil wire, increase current, put iron inside the coil

in simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or the density of the fluid multiplied by the submerged volume times the gravitational acceleration, g. this is also known as upthrust.