To build a scale model of the solar system outdoors:
· Use a basketball for the sun (9.5″ diameter)
· 86′ away from the sun is the earth at ~1/11 inch diameter …

Matthias Rillig, a soil ecologist at the Free University of Berlin

A beautiful book
· how to add a column of numbers

I have grave concerns about science activities.

I like the tightrope demo; that’s out of the box.

Do gaps form between the photons?

What is the English translation of Palomar (hint: not what I thought)?