You may be thinking of a "Boltzmann brain". It's not science fiction, but it's only a theoretical idea.
The Obama parade typically included around 40 floats.
It separates something that floats from something doesn't float.
something lighter than water
You put it in water and see if it floats.
"Throw me something, mister" is the typical solicitation chant for asking for throws from parade floats
rainbow
Put something in a glass of water, and see if it floats.
For making something that floats.
i fish alot of canals around Ireland and find waggler floats to be the best.
no it just floats around
buoyant means something floats on water.....
Put something that floats, for example an apple into water.