Some of these wonderful questions were answered by a group from eMIT, a blog written by MIT graduate students to explore how science and technology affect our daily lives.
Why Do Some People Have Allergies? (Aine Büchau, Age 12)
Our bodies have immune systems that search for harmful germs and destroy them. We need our immune systems to protect us. As people grow up, their immune systems get to know what is friendly (like food) and what isn’t (like the flu virus). What would happen if your body decided that your
food was an enemy? That is precisely what happens in people who have allergies: the immune system tries to fight off normally harmless things like pollen, cat fur, or peanuts. Allergies can be hereditary, meaning that they can be passed down to children from their parents. This explains why relatives sometimes have the same allergies. Now, scientists have found another cause of allergies in a theory they call the “hygiene hypothesis.” They found that children growing up in environments that are too sterile are more likely to develop allergies.
Would We Be Able to Live on the Moon, and if so, what would we need to bring with us? (Maya Ashour, Age 9)
We could definitely live on the Moon, but our lives there would be very different from our lives on Earth. We humans require oxygen, liquid water, and food, none of which the Moon currently offers (though we think there is ice in craters near the north and south poles of the Moon). Astronauts would either have to bring all of those things from Earth, or else would need to find a way to produce them on the Moon. For example, we could use a machine to melt ice, or bring materials to grow a garden for food. On Earth, plants recycle carbon dioxide into oxygen that we can breathe, so a large garden on the moon could provide breathable air as well. Because the Moon does not have an atmosphere, humans would have to live inside of a pressurized habitat or wear a pressurized space suit, which is like wearing a blown-up balloon. The Moon’s gravity is much weaker than Earth’s gravity – about one sixth as strong. This actually makes it harder to move around quickly, especially while wearing a balloon-like space suit. In order to explore the Moon and get between locations quickly, we would need to bring rovers to drive around in.
Why Are Fireworks So Loud? (Brave Arimah Sherab, Age 6)
Objects make sounds by causing vibrations in the air. These vibrations travel like waves. You can make your own waves in a jump-rope by waving one end while a friend holds the other end. The bigger the waves, the louder the sound. Before a firework is lit, it’s a solid object—a cardboard tube with some powder inside. When that powder is set on fire, it turns from a solid into a gas, and the gas expands very quickly. That fast expansion is what we call an explosion, and it causes a massive shockwave in the air. When that wave smacks into your eardrums, your eardrums get shaken very hard, and you hear a loud bang. You might also feel the vibration as wind. Rockets and thunder are very loud for the same reason.
Why Are Yawns Contagious? (Hope Bell, Age 13)
We don’t really know why yawns are contagious. In fact, scientists still haven’t agreed on the reason we yawn at all. One idea is that it causes us to breathe in more deeply, sending oxygen deep into our lungs. This can make our brains more active, keeping us alert when we are tired or bored. Another theory is that yawning helps cool our brains, either by changes in oxygen or by changes in brain pressure. Some scientists believe that yawns are related to emotions, since parts of the brain that control emotions also control yawns. The contagious nature of yawns may be a result of this, since empathy and emotional closeness with a “yawner” can predict whether someone will “catch” a yawn. For instance, you might yawn when your friend does, but not when a stranger yawns. Did reading this
paragraph make you yawn?
What is a Shooting Star? (Anda Gravlin, Age 12)
There is stuff floating around in space. Sometimes, it gets too close to Earth and falls down to the ground. A shooting star starts out with a “meteoroid”, a piece of rock or metal from space. It can be as small as a grain of sand or as big as a house. When a meteoroid falls down through the air, it is moving very fast - many miles every second - and it becomes very hot. Some of the heat is caused by friction as air rushes past, but most of the heat actually comes from squeezing the air in front of it, because it’s moving too fast for the air just to get pushed aside. It gets so hot that it glows like a lightbulb (the old kind with a wire, not the newer fluorescent or LED lights). A small meteoroid will completely burn away in the atmosphere, but the pieces of a larger one may survive the journey. That’s what happened with a gigantic meteoroid that hit Russia last year – it was 60 feet wide, and it
weighed more than the Eiffel Tower in Paris. The pieces that make it to the ground are called “meteorites” and often look like a mix of metal and rock.