I Learned This Today

#357 How are tower cranes assembled?

How are tower cranes assembled? By raising themselves up and adding in a piece at a time. There are many different types […]

Why does an elastic band stretch? Because it is made of long chains of polymers that would rather be tangled together than […]

How does antibiotic resistance happen? Bacteria develop the ability to survive an antibiotic, which is then passed on to future generations. The […]

How does a skeleton key work? By removing all of the parts that would get caught on the wards. Skeleton keys are […]

When did supermarkets start? The first supermarket was opened in 1916. Most of us don’t think twice about pushing a cart around […]

How do reflexes work? They work by using a reflex arc that bypasses the brain. There are many different types of reflex, […]

What is the Doppler effect? The Doppler effect is the change in frequency of a wave in relation to an observer who […]

How do amphibians breathe underwater? They breathe through their skin. The word “amphibian” comes from the Greek amphi, meaning both and bios, […]

When were credit cards invented? The first use of the phrase “credit card” was in 1887. A credit card is a system […]

What are the crown jewels? The crown jewels are a collection of 142 objects, many are used in ceremonies such as the […]