1) The Beatles hold the record for the most number-one hits on the Billboard Hot 100 chart, with 20 songs reaching the top spot.

2) The shortest war in history lasted only 38 to 45 minutes between Britain and Zanzibar in 1896.

3) The oldest known musical instrument is a flute made from a bird bone, estimated to be around 43,000 years old.

4) The Earth's core is primarily composed of iron and nickel and is as hot as the surface of the sun.