I learned this today. Most TV remote controls operate by sending binary signals to the TV using infrared light. The remote controller in your house has an LED fitted to the end of it. This LED emits a wavelength of 940 nm, which is infrared. The human eye can only detect wavelengths between 380 and […]
#21 How do TV remote controllers work? Read More »
I learned this today. Canning preserves food by killing all of the bacteria present through heat and then keeping the food in a bacteria-free, airtight can. For food to rot, bacteria need water, oxygen, a neutral pH level, and a warm temperature. The different ways of preserving food each deal with one of these. Freezing
#15 How is food canned? Read More »
I learned this today. Leather is strong because the collagen fibers in the animal skin are strengthened and bolstered by other chemicals. It can take up to ten weeks to make leather. Making leather is a complicated process. The first thing is to remove the hide. The skin of any animal can be used to
#14 How is leather made? Why is it so strong? Read More »
I learned this today. A gun silencer works by reducing the speed of the gases that push the bullet out of the barrel, but it cannot silence the sound of the sonic boom from the bullet. A gun fires a bullet that comes from a cartridge. The cartridge that you load into a gun has
#13 How does a gun silencer work? Read More »
I learned this today. Alcohol gets people drunk because it is a depressant and slows down the speed at which the brain can send signals. Most alcoholic drinks contain ethanol which is produced when sugars are fermented. It naturally occurs in nature. Humans have drunk alcoholic drinks for thousands of years. They probably started by
#12 How does alcohol make us drunk? Read More »
I learned this today. Seasickness is caused because of a discrepancy between the vestibular system and the eyes. Just inside your head, you have your inner ear which is used for sound detection and for balance. The balance part is what causes seasickness. There are two parts: the cochlea and the vestibular system. The cochlea
#10 What causes seasickness? Read More »
I learned this today. An airbag can inflate so quickly because it contains sodium azide, which produces nitrogen gas when it ignites. When you are in a car crash, a series of steps happen to launch the airbags. An accelerometer measures that the car has rapidly decelerated. Impact sensors work out where the impact has
#9 How can an airbag inflate so quickly? Read More »
I learned this today. Vantablack is the blackest material ever made because it absorbs 99.965% of light. Anything that you have in front of you right now is reflecting light back into your eyes. For example, my phone case is red with a brown cat on it. It is night, so there is no sunlight.
#8 How can Vantablack be so black? Read More »
I learned this today. Salt preserves food by removing the water and vinegar preserves food by increasing its acidity. The refrigerator was invented in 1834. Before that, people used ice to keep food chilled. In the 1800s, Americans used over 5 million tons of ice annually. The ice was cut from northern countries (Scandinavian countries)
#7 How do salting and pickling preserve food? Read More »
I learned this today. Vultures can eat rotten meat that would make us very sick because their stomach acid is 100 times stronger than ours. If you or I were to go and find a dead animal by the side of the road and eat it, we would get very sick within a few hours.
#4 How can vultures eat rotten meat and not get sick? Read More »
