Gothic churches are known for having very large and extravagant flying buttresses which are really used to support the arches inside the cathedral. The spires on top of those buttresses are usually thought to be ornamental but they really have an important purpose. They add a great deal of weight to the buttress which adds to the support the buttresses supply the building.

(The Great Courses – Understanding the World’s Greatest Structures)

The Eiffel Tower has 2.5 million bolts. It is also so light that if it was melted down into a base the size of its base it would only be three inches thick.

(The Great Courses – Understanding the World’s Greatest Structures)

Rainbows are always seen at about a 42 degree angle from a line between you and the sun. The lower the sun on the horizon the higher the rainbow in the sky. Red reflects at about 42 degrees in a drop of rain and violet reflects at about 40 degrees with the other colors in between which is why you see the rainbow as a width of colors.

(The Great Courses – Physics in Your Life)

CD’s with data on them purchased in stores (like music) have physical ‘pits’ in them which holds the data. CD’s which you buy so that you can burn them a single time use dyes which are rearranged on the disk. CD’s which you buy to burn that are rewritable use crystals which can be rearranged for the rewrite.

(The Great Courses – Physics in Your Life)