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.
Ep. 301: Planetary Migration
We’re so familiar with the current configuration of the planets in the Solar System, but did the planets always orbit in this way? Did they form further out and then migrate inward to their current positions? And what about other star systems out there?
Ep. 295: The Observable Universe
We understand our place in the Universe because of our direct observations. We can see the light that travelled billions of light years across space to reach us. This sphere of space is the observable universe; everything we can detect. But it’s really just a fraction of the larger, unobservable universe. Today, we’ll talk about both.
Ep. 294: The Arecibo Observatory
The mighty Arecibo Radio Observatory is one of the most powerful radio telescopes ever built – it’s certainly the larger single aperture radio telescope on Earth, nestled into a natural sinkhole in Puerto Rico. We’re celebrating the 50th anniversary of the construction of the observatory with a special episode of Astronomy Cast.
Ep. 293: Earthquakes
We always say that the Universe is trying to kill you, but actually, the Earth isn’t so fond of you either. Certain parts of planet Earth are prone to earthquakes, where the planet’s shifting plates can cause the ground to shake violently. We’ve had a few devastating earthquakes in recent years, but do they also happen on other worlds?
Ep. 292: The Oort Cloud
The very outer reaches of the Solar System is a region of space known as the Oort Cloud, which may extend as far as a light-year from the Sun. We only know about the Oort Cloud because that’s where long-period comets come from, randomly falling into the inner Solar System from time to time.
Ep. 291: Shockwaves
As a meteor crashed into the atmosphere above Russia, the world discovered the importance of shock waves; how they’re caused and how they propagate through the atmosphere. Today we’ll discuss the topic in general and find many examples where shock waves can be created, here on Earth, and out in space.
Ep: 290 Failed Stars
If you get enough hydrogen together in one place, gravity pulls it together to the point that the temperature and pressures are enough for fusion to occur. This is a star. But what happens when you don’t have quite enough hydrogen? Then you get a failed star, like a gas giant planet or a brown dwarf.
Ep. 289 Cherenkov Radiation
Sure, our atmosphere protects us from a horrible Universe that’s trying to kill us, but sometimes it prevents us from learning stuff too. Case in point, the atmosphere blocks highly energetic particles from reaching our detectors. But there’s a way astronomers can still detect their influence: Cherenkov Radiation; the cascade of radiation that blasts out as a high-energy particle makes its way through the atmosphere, like a radioactive rainshower.
Ep. 288 Phases of Matter
As we quickly learn with water, matter can be in distinct phases: solid, liquid, gas and plasma; it all depends on temperature. But why do different materials require different temperatures? And what’s actually happening to the atoms themselves as the material switches phases?
Ep. 287 E=mc^2
It’s mind bending to think about this, but the light in your house, and the house itself are really the same thing. Matter and energy are interchangeable. This was the amazing revelation made by Albert Einstein, with his famous formula: E=mc^2. This is the process that the Sun uses to turn hydrogen into radiation through fusion, and the terrible damage from a nuclear weapon.
Ep. 286 How to Debunk an End-of-the-World Myth
Everyone is always predicting the end of the world. Someone’s going to tell you that this the year that it’s all going to end… the end of planet Earth… and they’re always wrong. But, someone will eventually be right. Planet Earth is doomed, lets figure out how.
Ep. 285 How the World Will Really End
Have you checked out the internet lately? Apparently there is some kind of rogue planet causing pole alignment and a killer solar flare that will set off a chain reaction turning the whole universe into strange-matter…. after an alien invasion.