When did telephone operators become obsolete? The tools to make them unnecessary were invented in 1888, but telephone operators kept working, in one form or another, well into the late 20th century – and the job has still not completely disappeared. Alexander Graham Bell is usually named as the inventor of the telephone, but he […]
#1530 When did telephone operators become obsolete? Read More »
What is a whale fall? A whale fall is when a whale dies and falls to the bottom of the ocean, providing a sudden food source. A whale fall has different stages that can last for several years. A dead whale can provide an enormous amount of food for other sea life. It is difficult
#1529 What is a whale fall? Read More »
What is a fog net? A fog net is a very fine mesh used for pulling fresh water out of fog. People get their water from a whole range of sources. They could be reservoirs, aquifers, rivers, desalination plants, or, sometimes, having it shipped in by truck. A lot of places are experiencing water shortages,
#1528 What is a fog net? Read More »
How do green roofs help? Green roofs help by cooling cities and by insulating houses. They absorb heat, absorb rainwater, cool the air around the building, and act as insulation as well. I suppose the first thing to look at is the fact that the plural of roof is roofs, not rooves. Apparently, rooves is
#1527 How do green roofs help? Read More »
How do airports sort bags? At its simplest, airports sort bags by scanning a ten-digit barcode on each bag and automatically controlling which conveyor belt the bag travels on to get to the plane it needs to be loaded on. If you have ever had a piece of luggage go missing, you may have gone
#1526 How do airports sort bags? Read More »
How do homing pigeons know where home is? Homing pigeons know where home is because of their natural GPS system. They also use scents, landmarks, and sounds. Homing pigeons have been used by people since before we had a regular postal service. The first recorded homing pigeon was used in 1350 BC, over 3,000 years
#1525 How do homing pigeons know where home is? Read More »
How does a high-speed camera work? This might sound rather obvious, but a high-speed camera works by taking a lot of images very very quickly. High-speed cameras don’t just take more frames per second; they also give each frame a much shorter exposure time, so fast things aren’t blurred. There are obviously different standards, but
#1524 How does a high-speed camera work? Read More »
What is a submarine escape system? A submarine escape system is basically a modified deep-sea diving suit with an air supply and a life raft attached. There are also diving bells that can be lowered from the surface to rescue trapped sailors. The problem with any kind of submarine escape system is that it
#1523 What is a submarine escape system? Read More »
How does a teleprompter work? A teleprompter works by projecting a script onto a mirrored glass panel. This allows the speaker to read the script and maintain eye contact with a camera or an audience, and it prevents the camera or audience from being able to see the script. A teleprompter works because light always
#1522 How does a teleprompter work? Read More »
Why do termites eat wood? Termites eat wood to get its cellulose. Termites are small insects that tend to live in nests. They look like ants and are often called “white ants”, but they are more closely related to cockroaches than ants. Termites are also not all the same. There are 3,000 different species of
#1521 Why do termites eat wood? Read More »
