[DejaJude]

It's meant to represent rational thought as opposed to faith in a deity. Science is supposed to be the epitome of rational thought, and an atom is a good symbol of science.

Seems to me that "science" has been incorrect about many things. It's constantly changing. I don't think it's rational to build a house on shifting sand.

[fromscratchmom]

"I don't think it's rational to build a house on shifting sand."

Bears repeating.

[antiRepublicrat]

Seems to me that "science" has been incorrect about many things. It's constantly changing.

That's the point, always using rational thinking and processes to further knowledge. It wouldn't be rational if it never changed -- it would be dogmatic.