#928 How does a motion detector work?
How does a motion detector work? There are several different methods. They can use infrared light, microwave radiation, ultrasound, video, or electromagnetic radiation. There are many uses for motion detectors…
How does a motion detector work? There are several different methods. They can use infrared light, microwave radiation, ultrasound, video, or electromagnetic radiation. There are many uses for motion detectors…
Is there a planet beyond Neptune? It is possible, but there is no way to know for sure until telescope power increases. Neptune was discovered in 1846 and it was…
Why did the Chinese government move to Taiwan? The Republic of China’s government lost a war with the Chinese Communist Party in 1949 and fled to Taiwan. We have to…
How much oil is left? About 1.5 trillion barrels, which is enough oil for roughly 47 years. There are several problems with this question. The first problem is that there…
What are El Nino and La Nina? They are climate patterns that happen in the Pacific Ocean and affect weather all over the world. El Nino means “Little Boy” and…
How does an oil pipeline pump oil so far? They use centrifugal pumps to convert rotational energy into the energy that moves a fluid and there are more pumps every…
When does history start? This is a difficult question, but we have prehistory, protohistory, and then history. Protohistory is the point where prehistory becomes history and it is probably in…
How does a bicycle stay upright? It is a combination of things, but nobody seems to really know for definite. All of the reasons that a bicycle can stay upright…
Geoffrey Chaucer was known as the Father of English Literature. This is obviously a topic that is only important to English speaking countries, but he was a significant force in…
Why is a plane’s propeller at the front but a boat’s at the back? Because of how they move through the medium they travel in, the angle they need to…