Science theme cakes

After ideas for DS 5th birthday which is science themed. We have a 'mad scientist' coming along to do experiments with the guests + face painting and balloon twisting.

And if you have pics of cakes you have made, I'd love to see them too!!

A volcano cake that erupts?

Planets or a specific planet.
Chemistry set
Periodic table cupcakes
A volcano cake!
A brain cake Or a round cake decorated with scientific symbols and then topped with a brain.

Albert eintsteins face
Molecule composition for air?
Bunsen burner with test tubes
Green goo inbetween the cake so when cake is cut its oozing with goo?

Periodic table would be dead easy. Just a slab cake with squares and letters piped on it. Even easier if you used fondant and those cake decorating pens.
Planet cake pops
A rainbow cake but with brown and white etc layers like the earth (could even pop a few 'fossils' in it).

A minecraft cake would be kinda cool too and fits within the theme I think.

I just googled and there was a pic of a heap of cup cakes in the shape of the periodic table with each cup cake having it's own element written on it. There were also a dissected frog, a DNA strand, and some petrie dish biscuits, with their own different growths on them.
What about a spacey- themed cake, like a rocket ship. It's scientific, lol!