Lyman Spitzer was a theoretical physicist and astronomer who worked on star formation and plasma physics. The scape telescope named after him is equipped with infrared imaging capability that enables the telescope to see through dust and gas clouds to reveal what lies underneath.
Spitzer is part of the 1970s idea NASA conceived for the Great Observatories. The idea was to have the Hubble Space Telescope operate in the visible range, Chandra which operates in the x-ray, and Spitzer which operates in the infrared. Here’s an informational video about Spitzer:
Subrahmanyan Chandrasekhar was one of the most careful, thorough, and impressive astronomers in the first part of the 20th century who worked in may different areas of astronomy, making great leaps with his discoveries. He won the Nobel prize for his ideas about when and how to get supernova, which he did while traveling on a boat at age 19! Chandra had a very elegant way of using mathematics to describe atmospheres of planets and stellar structures of galaxies. He was one of the few researchers that is able to teach as well as do his own research.
The Chandra X-Ray Observatory is the third of NASA’s Great Observatories. Chandra looks for high energy X-ray radiation, which appears near supernovae, supermassive black holes and neutron stars. Here’s an video about the telescope itself and how difficult it is to observe x-rays:
If you watch the moon, you’d notice that it rises in the east and sets in the west. This direction is called ‘prograde motion’. The stars, sun, and moon all follow the same prograde motion, meaning that they all move across the sky in the same direction.
This lecture series is from an astronomy course at Ohio State. It’s a 20-week college-level course, so don’t feel like you’ve got to do it all in one night! You’ll learn about the solar system, planets, and universe through a well-organized set of lectures that really brings astronomy, human history, and current technology together. This content is appropriate for advanced students and above.
Sound can change according to the speed at which it travels. Another word for sound speed is pitch. When the sound speed slows, the pitch lowers. With clarinet reeds, it’s high. Guitar strings can do both, as they are adjustable. If you look carefully, you can actually see the low pitch strings vibrate back and forth, but the high pitch strings move so quickly it’s hard to see. But you can detect the effects of both with your ears.
This is the experiment that all kids know about… if you haven’t done this one already, put it on your list of fun things to do. (See the tips & tricks at the bottom for further ideas!)
This experiment is just for advanced students. Ernst Florens Friedrich Chladni (1756-1827) is considered to be the ‘father of acoustics’. He was fascinated by vibrating things like plates and gases, and his experiments resulted in two new musical instruments to be developed.
Alexander Graham Bell developed the telegraph, microphone, and telephone back in the late 1800s. We'll be talking about electromagnetism in a later unit, but we're going to cover a few basics here so you can understand how loudspeakers transform an electrical signal into sound.
Have you ever torn apart something and then couldn’t figure out how to get it back together again so that it worked? Worse, you knew that if you had only taken a few moments to think about the problem or jot something down, you know it would have taken you far less time to figure it out?
This experiment is for Advanced Students. For ages, people have been hurling rocks, sticks, and other objects through the air. The trebuchet came around during the Middle Ages as a way to break through the massive defenses of castles and cities. It’s basically a gigantic sling that uses a lever arm to quickly speed up the rocks before letting go. A trebuchet is typically more accurate than a catapult, and won’t knock your kid’s teeth out while they try to load it.
When you warm up leftovers, have you ever wondered why the microwave heats the food and not the plate? (Well, some plates, anyway.) It has to do with the way microwaves work.
The atoms in a solid, as we mentioned before, are usually held close to one another and tightly together. Imagine a bunch of folks all stuck to one another with glue. Each person can wiggle and jiggle but they can’t really move anywhere.
Can we really make crystals out of soap? You bet! These crystals grow really fast, provided your solution is properly saturated. In only 12 hours, you should have sizable crystals sprouting up.
Density is basically how tightly packed atoms are. Mathematically, density is mass/volume. In other words, it is how heavy something is, divided by how much space it takes up. If you think about atoms as marbles (which we know they’re not from the last lessons but it’s a useful model), then something is more dense if its marbles are jammed close together.
This is a simple experiment that really shows the relationship of mass, volume, and density. You don't need anything fancy, just a piece of bread. If you do have a scale that can measure small masses (like a kitchen scale), bring it out, but it is not essential.
A gram of water (about a thimble of water) contains 1023 atoms. (That’s a ‘1’ with 23 zeros after it.) That means there are 1,000,000,000,000,000,000,000,000 atoms in a thimble of water! That’s more atoms than there are drops of water in all the lakes and rivers in the world.
