I Learned This Today

#1851 When did people discover that electrons carry electricity?

November 1, 2026 / Leave a Comment

When did people discover that electrons carry electricity? People generally discovered that electrons carried electricity at the very end of the nineteenth century and the start of the twentieth. Electricity is a collection of phenomena involving electric charges. One of these is electric current, which is the movement of electric charge through a material. There

#1851 When did people discover that electrons carry electricity? Read More »

#1850 Where did Halloween come from?

October 31, 2026 / Leave a Comment

Where did Halloween come from? Halloween is the shortened form of All Hallows’ Eve, and it probably originated with the Irish Gaelic harvest festival called Samhain. The traditions of Samhain and All Hallows Eve were carried across to the United States by Irish and Scottish immigrants. Modern Halloween probably has roots in the Irish harvest

#1850 Where did Halloween come from? Read More »

#1849 How did travelers exchange money before modern banks?

October 30, 2026 / Leave a Comment

How did travelers exchange money before modern banks? Before banks, travelers had different ways of getting money at their destination. They could carry gold and silver; they could sell goods; they could swap coins; they could use a letter of credit, or they could use an early form of a traveler’s check. These days, if

#1849 How did travelers exchange money before modern banks? Read More »

#1848 How deep could a space probe travel into Jupiter?

October 29, 2026 / Leave a Comment

How deep could a space probe travel into Jupiter? No one knows for sure, but a space probe using modern materials could possibly get several hundred kilometers into Jupiter’s atmosphere before being destroyed by the enormous pressure and heat. The only probe that has been launched into the atmosphere of Jupiter was the Galileo probe

#1848 How deep could a space probe travel into Jupiter? Read More »

#1847 What causes nuclear winter?

October 28, 2026 / Leave a Comment

What causes nuclear winter? A nuclear winter is caused by soot, ash, and other particles being kicked up into the atmosphere by a nuclear war. These particles block out sunlight, and the temperature on the surface of Earth would be drastically reduced. A nuclear winter caused by nuclear weapons has thankfully never happened. We have

#1847 What causes nuclear winter? Read More »

#1846 Did Wyatt Earp have the law on his side at the OK Corral?

October 27, 2026 / Leave a Comment

Did Wyatt Earp have the law on his side at the OK Corral? A lot of people at the time might have disagreed, but Wyatt Earp acted legally during the Gunfight at the OK Corral. The Gunfight at the O.K. Corral happened on October 26, 1881, in Tombstone, Arizona. Wyatt Earp, his brothers Virgil and

#1846 Did Wyatt Earp have the law on his side at the OK Corral? Read More »

#1845 Was the Iron Maiden ever actually used?

October 26, 2026 / Leave a Comment

Was the Iron Maiden ever actually used? Despite its terrifying reputation, there is no credible evidence that the iron maiden was used as a medieval torture device. The familiar spiked cabinet appears to have been invented much later, during the 19th century. The iron maiden is probably one of the most famous medieval torture devices

#1845 Was the Iron Maiden ever actually used? Read More »

#1844 Why do some chemical reactions give off heat and others don’t?

October 25, 2026 / Leave a Comment

Why do some chemical reactions give off heat and others don’t? The answer depends on the amount of energy absorbed when chemical bonds are broken compared with the amount released when new bonds are formed. There are two types of chemical reactions: endothermic and exothermic. Endothermic reactions are those that require energy, and exothermic reactions

#1844 Why do some chemical reactions give off heat and others don’t? Read More »

#1843 What is Göbekli Tepe?

October 24, 2026 / Leave a Comment

What is Göbekli Tepe? Göbekli Tepe is one of the world’s oldest temples and megalithic sites. It was built in roughly 9500 BC, over eleven thousand years ago. It is in the south of the modern country of Turkey, not far from the border with Syria. It is the first human-built holy place in the

#1843 What is Göbekli Tepe? Read More »

#1842 Why are lemons sour when other fruits are sweet?

October 23, 2026 / Leave a Comment

Why are lemons sour when other fruits are sweet? Lemons are sour because they contain a lot of citric acid. We also need to remember that there are a huge variety of lemons, some very sour and some not so much. We need to break this question down into a few parts. Why does citric

#1842 Why are lemons sour when other fruits are sweet? Read More »