Favorite Science Effect

[Apathy Reactor]

i still think mixing alkali metals with water is more fun, personal preference i guess :/
hey kids! dont drink the koolaid!

[Vileo]

Does Mass Effect count?

[Langku]

Elmer's glue and liquid starch.

[rarehuntertay]

Either entanglement, because it breaks the speed of light barrier, or superfluidity (have you ever seen liquid helium? It is freakin' phenomenal!!)

[PapaBudz]

I like messing with polarity to make water marbles.

[particle]

can't remember name but the sound created when cars pass each other at different speeds.

[xStrayKnightx]

Isn't that the Doppler Effect?

My favourite is ignition source + magnesium. Awesome light show.