There’s a lot you can learn by just staring at an object, watching how it changes in brightness. This is the technique of photometry, and it has helped astronomers discover variable stars, extra-solar planets, minor planets, supernovae, and much more.
Ep. 336: Units of Measure
How heavy is a kilogram, how long is a second? How warm is a degree? We measure our Universe is so many different ways, using different units of measurement. But how do scientists come up with measurement tools which are purely objective?
Ep. 335: Photoelectric Effect
Pop quiz. How did Einstein win his Nobel prize? Was it for relativity? Nope, Einstein won the Nobel Prize in 1921 for the discovery of the photoelectric effect; how electrons are emitted from atoms when they absorb photons of light. But what is it? Let’s find out.
Ep. 334: Chelyabinsk
Around this time last year a space rock crashed into the Earth above Chelyabinsk, Russia. It brightened the skies for hundreds of kilometers, broke windows and injured many people. Let’s look back at the event. What happened, and what did we learn?
Ep. 327: Telescope Making, Part 1: Toys and Kits
Why pick up a low quality, wobbly telescope from the department store when you can craft your own – just like Galileo, and all the great astronomers from history. For a minor investment, you can build a worthy telescope out of spare parts and high quality kits.
Ep. 326: Atmospheric Dust
When you consider the hazards of spaceflight, it’s hard to get worked up about dust bunnies. And yet, atmospheric dust is going to be one of the biggest problems astronauts will face when they reach the surface of other worlds. Where does this dust come from, and what does it tell us about the history of other worlds, and what can we do to mitigate the health risks?
Ep. 324: Sun Grazers
Comets can spend billions of years out in the Oort Cloud, and then a few brief moments of terror orbiting the Sun. These are the sun grazers. Some survive their journey, and flare up to become the brightest comets in history. Others won’t survive their first, and only encounter with the Sun.
Ep. 323: Isotopes
The number of protons defines an element, but the number of neutrons can vary. We call these different flavors of an element isotopes, and use these isotopes to solve some challenging mysteries in physics and astronomy. Some isotopes occur naturally, and others need to be made in nuclear reactors and particle accelerators.
Ep. 321: Solar Flares
Sometimes the Sun is quiet, and other times the Sun gets downright unruly. During the peak of its 11-year cycle, the surface of the Sun is littered with darker sunspots. And its from these sunspots that the Sun generates massive solar flares, which can spew radiation and material in our direction. What causes these flares, and how worried should we be about them in our modern age of fragile technology?
Ep. 320: Layers of the Sun
Our Sun isn’t just a terrifying ball of white hot plasma, it’s actually a lot more complex. It’s got layers. And today, we’re going to peel back those layers and learn about the Sun – from the inside out.
Ep. 319: The Zodiac
Although the Zodiac is best known for astrology nonsense, it has a purpose in astronomy too. The constellations of the Zodiac define the plane of the ecliptic: the region where the Sun, Moon and planets appear to travel through the sky. What are the constellations of the Zodiac, and how do astronomers use them as way-points?
Ep. 317: Observatories
Have you ever wondered what it’s like to visit one of the big research observatories, like Keck, Gemini, or the European Southern Observatory? What’s it like to use gear that powerful? What’s the facility like? What precautions do you need to take when observing at such a high altitude?
Ep. 316: Observational vs. Experimental Science
Sometimes you can do science by watching patiently, and sometimes you’ve just got to get your hands dirty with an experiment or two. These two methods have their advantages and disadvantages for revealing Nature’s secrets. Let’s talk about how and why scientists choose which path to go down.
Ep. 315: Particle Accelerators
Who knew that destruction could be so informative? Only by smashing particles together with more and more energy, can we truly tease out the fundamental forces of nature. Join us to discover the different kinds of accelerators (both natural and artificial) and why questions they can help us answer.
Ep. 314: Acceleration
Put that pedal to the metal and accelerate! It’s not just velocity, but a change in velocity. Let’s take a look at acceleration, how you measure it, and how Einstein changed our understanding of this exciting activity.
Ep. 313: Precession
The Earth is wobbling on its axis like a top. You can’t feel it, but it’s happening. And over long periods of time, these wobbles shift our calendars around, move the stars from where they’re supposed to be, and maybe even mess with our climate. Thank you very much Precession.
Ep. 312: The Inverse-Square Law and Other Strangeness
Why don’t we have insects the size of horses? Why do bubbles form spheres? Why does it take so much energy to broadcast to every star? Let’s take a look at some non-linear mathematical relationships and see how they impact your day-to-day life.
Ep. 311: Sound
Shhhh, shhh. You can stop screaming. That’s because nobody can hear you … in space. But why not? How does sound work here on Earth, and what would it sound like on other planets?
Ep. 309: Creating a Scienc-y Society
Our modern society depends on science. It impacts the way we eat, work, communicate and play. And yet, most people take our amazing scientific advancement for granted, and some are even hostile to it. What can we do to spread the love of science through education, outreach and media?
Ep. 308: Climate Change
When it comes to carbon dioxide, just a little goes a long way to warming the planet. Unfortunately, we’ve been dumping vast amounts into the atmosphere, recently passing 400 parts per million. Let’s look at the science of the greenhouse effect, and how it’s impacting our global climate.
Ep. 307: The Pacific Ring of Fire
The Pacific Ring of Fire wraps around the Pacific Ocean, including countries like Japan, Canada, New Zealand and Chile. And the inhabitants within those countries are prone to… oh… killer earthquakes, volcanoes and tsunamis. Let’s chat about the history of this region and the kinds of risks they face.
Ep. 306: Accretion Discs
When too much material tries to come together, everything starts to spin and flatten out. You get an accretion disc. Astronomers find them around newly forming stars, supermassive black holes and many other places in the Universe. Today we’ll talk about what it takes to get an accretion disc, and how they help us understand the objects inside.
Ep. 304: Death of a Spacecraft
In the end, everything dies, even plucky space robots. Today we examine the last days of a series of missions. How do spacecraft tend to die, and what did in such heroes as Kepler, Spirit, and Galileo (the missions… not the people).
Ep. 303: Equilibrium
So many of the forces in space depend on equilibrium, that point where forces perfectly balance out. It defines the shape of stars, the orbits of planets, even the forces at the cores of galaxies. Let’s take a look at how parts of the Universe are in perfect balance.
Ep. 302: Planetary Motion in the Sky
Even the ancient astronomers knew there was something different about the planets. Unlike the rest of the stars, the planets move across the sky, backwards and forwards, round and round. It wasn’t until Copernicus that we finally had a modern notion of what exactly is going on.