Physicists knew the interior of the atom contained protons, neutrons and electrons, but they didn’t understand exactly how they were organized. It took Ernest Rutherford to uncover our modern understanding.
AstronomyCast
Ep. 377: Thomson finds Electron
At the end of the 19th century, physicists were finally beginning to understand the nature of matter itself, including the discovery of electrons – tiny particles of negative charge that surround the nucleus. Here’s how J.J. Thompson separated the electrons from their atoms and uncovered their nature.
Ep. 376: The Miller-Urey Experiment
Evolution explains how life adapts and evolves over eons. But how did life originate? Chemists Miller and Urey put the raw chemicals of life into a solution, applied an electric charge, and created amino acids – the building blocks of life.
Ep. 375: The Search For Life in the Solar System
With the discovery of water ice in so many locations in the Solar System, scientists are hopeful in the search for life on other worlds. Guest Morgan Rehnberg returns to Astronomy Cast to explain the best places we should be looking for life.
Ep. 374: Stern-Gerlach Experiment
In the world of quantum mechanics, particles behave in discreet ways. One breakthrough experiment was the Stern-Gerlach Experiment, performed in 1922. They passed silver atoms through a magnetic field and watched how the spin of the atoms caused the particles to deflect in a very specific way.
Ep. 373: Becquerel Experiment (Radiation)
Antoine Henri Becquerel discovered radioactivity completely by accident when he exposed a chunk of uranium to a photographic plate. This opened up a whole new field of research to uncover the source of the mysterious energy.
Ep. 372: The Millikan Oil Drop
In 1909 Robert Millikan devised an ingenious experiment to figure out the charge of an electron using a drop of oil. Let’s talk about this Nobel Prize winning experiment.
Ep. 371: Eddington Eclipse Experiment
At the turn of the 20th Century, Einstein’s theory of relativity stunned the physics world, but the experimental evidence needed to be found. And so, in 1919, another respected astronomer, Arthur Eddington, observed the deflection of stars by the gravity of the Sun during a solar eclipse. Here’s the story of that famous experiment.
Ep. 370: The Kaufmann–Bucherer–Neumann Experiments
One of the most amazing implications of Einstein’s relativity is the fact that the inertial mass of an object depends on its velocity. That sounds like a difficult thing to test, but that’s exactly what happened through a series of experiments performed by Kaufmann, Bucherer, Neumann and others.
Ep. 369: The Fizeau Experiment
Light is tricky stuff, and it took scientists hundreds of years to puzzle out what this stuff is. But they poked and prodded at it with many clever experiments to try to measure its speed, motion and interaction with the rest of the Universe. For example, the Fizeau Experiment, which ran light through moving water to see if that caused a difference.
Ep. 368: Searching for the Aether Wind: the Michelson–Morley Experiment
Waves move through a medium, like water or air. So it seemed logical to search for a medium that light waves move through. The Michelson-Morley Experiment attempted to search for this medium, known as the “luminiferous aether”. The experiment gave a negative result, and helped set the stage for the theory of General Relativity.
Ep. 367: Spitzer does Exoplanets
We’ve spent the last few weeks talking about different ways astronomers are searching for exoplanets. But now we reach the most exciting part of this story: actually imaging these planets directly. Today we’re going to talk about the work NASA’s Spitzer Space Telescope has done viewing the atmospheres of distant planets.
Ep. 366: HARPS Spectrograph
Almost all the planet hunting has been done from space. But there’s a new instrument installed on the European Southern Observatory’s 3.6 meter telescope called the High Accuracy Radial velocity Planet Searcher which has already turned up 130 planets. Is this the future? Searching for planets from the ground?
Ep. 365: Gaia
The European Gaia spacecraft launched about a year ago with the ambitious goal of mapping one billion years in the Milky Way. That’s 1% of all the stars in our entire galaxy, which it will monitor about 70 times over its 5-year mission. If all goes well, we’ll learn an enormous amount about the structure, movements and evolution of the stars in our galaxy. It’ll even find half a million quasars.
Ep. 364: The COROT Mission
Before NASA’s Kepler mission searched for exoplanets using the transit method, there was the European COROT mission, launched in 2006. It was sent to search for planets with short orbital periods and find solar oscillations in stars. It was an incredibly productive mission, and the focus of today’s show.
Ep. 363: Where Did Earth's Water Come From?
Where on Earth did our water come from. Well, obviously not from Earth, of course, but from space. But did it come from comets, or did the water form naturally right here in the Solar System, and the Earth just scooped it up?
Ep. 362: Modern Women: Carolyn Porco
It hard to think of a more influential modern planetary scientist than Carolyn Porco, the leader of the imaging team for NASA’s Cassini mission exploring Saturn. But before Cassini, Porco was involved in Voyager missions, and she’ll be leading up the imaging team for New Horizons.
Ep. 361: Modern Women: Maria Zuber
Maria Zuber is one of the hardest working scientists in planetary science, being a part of six different space missions to explore the Solar System. Currently, she’s the lead investigator for NASA’s GRAIL mission.
Ep. 360: Modern Women: Jocelyn Bell Burnell
Jocelyn Bell Burnell is an Irish astronomer, best known for being part of the team that discovered pulsars, and the following controversy when she was excluded from the Nobel Prize winning team.
Ep. 359: Modern Women: Margaret Geller
Margaret Geller is best known for her work on the large scale structure of the Universe, helping us understand the large clusters, super clusters and cosmic filaments that matter clumps into.
Ep. 358: Modern Women: Sandra Faber
Our focus on female astronomers continues with Sandra Faber, and Professor of Astronomy at UC Santa Cruz. Faber was part of the team that turned up the Great Attractor, a mysterious mass hidden by the disk of the Milky Way.
Ep. 357: Modern Women: Vera Rubin
It’s time for another series. This time we’ll be talking about famous female astronomers. Starting with: Vera Rubin, who first identified the fact that galaxies rotate too quickly to hold themselves together, anticipating the discovery of dark matter.
Ep. 356: Rotational Inertia
An object at rest stays at rest, and object in motion tends to stay in motion. This is inertia, defined famously by Isaac Newton in his First Law of Motion.
Ep. 355: Maker Space: 3D Printing Exploration
Getting stuff into space is complicated and expensive. And what do you do when your fancy space gadget breaks. You print out a new one, of course, with your fancy space 3D printer. It turns out, space exploration is one of the best uses for this technology.
Ep. 354: Comet Siding Spring vs. Mars
We were witness to a once in a million year event. A close approach of Comet Siding Spring to the Planet Mars. And fortunately, humanity had a fleet of spacecraft orbiting the Red Planet, ready to capture this monumental event in real time. What did we see? What will we learn?