ArcaMax

Knowledge

on May 24, 2026

Chalcedony
Chrysoberyl
Chrysoprase
Corundum

Corundum. Ruby and sapphire are both forms of corundum, with a hardness rating just below a diamond.

Science Trivia / May 24, 2026

Electron Microscope. In 1928, the first electron microscope was able to magnify 17 times.

Science Trivia / May 23, 2026

A Tree. Kapok is used as filling for lifejackets, mattresses and pillows.

Science Trivia / May 23, 2026

1869. Alexander Buchan of the Scottish Meteorological Society charted climates in 1869.

Science Trivia / May 22, 2026

The Moon. With its transmission of pictures of the moon's surface, the Ranger VII mission was the first successful mission in the Ranger series.

Science Trivia / May 22, 2026

Stall. Stall occurs when an aircraft is flown at an angle of attack greater than the angle for maximum lift.

Science Trivia / May 21, 2026

Human. Metamorphosis is accompanied by a change in behavior or habitat.