Fraser Cain
Universe Today
Dr. Pamela Gay
CosmoQuest
The Universe was inaccessible for most of human history, but the first tentative steps to space in the 20th century made humanity realize that science fiction was becoming science reality. New rules would have to be written to govern how we used this limitless expanse. Today we’ll talk about the Outer Space Treaty of 1967.
It’s been over 20 years since astronomers first discovered that the expansion of the Universe is accelerating thanks to dark energy. And in these decades, astronomers still don’t have much evidence for what could be causing the increased expansion rate. Maybe there’s something else going on to explain it.
Astronomers have made extremely accurate measurements of the expansion rate of the Universe and come up with different results. And the error bars for the observations don’t overlap, so there’s something strange going on. What’s the answer and how can the Crisis in Cosmology be resolved?
Astronomers came together in January to present their newest research, and not surprisingly, the Winter AAS meeting was heavy on news from JWST. What were some of the new results that were announced?
Recent Episodes
The coldest possible theoretical temperature is Absolute Zero, this is the point at which no further energy can be extracted from a system. How are physicists working to get as close as possible to this extreme cold? Download the show [MP3] | Jump to Shownotes | Jump...
In some of the most extreme objects in the Universe, white dwarfs and neutron stars, matter gets strange, transforming into a material that physicists call “degenerate matter”. Let’s learn what it is, how it forms. Download the show [MP3] | Jump to Shownotes | Jump to...
When we finally make the jump to fully colonizing the Solar System, we're going to want to use asteroids as stepping stones. We can use them as way stations, research facilities, even as spacecraft to further explore the Solar System. Today we'll talk about the...
Astronomers rely on the optics of their instruments, and there are some basic limits that you just can't avoid. Whatever we look at is distorted by the optics, in fact, a basic property of light means that we'll never get perfect optics. Here's why we can't "magnify...
When he wasn't puzzling the mystery of alien civilizations, Enrico Fermi was splitting atoms. He realized that when atoms were split, the neutrons released could go on and split other atoms, creating a chain reaction - and the most powerful weapons ever devised....
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. Download the show [MP3] | Jump to Shownotes | Jump to...
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...
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. Download the show [MP3] |...
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. Download the show [MP3] |...
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...
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. Download the show [MP3] | Jump to Shownotes...
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. Download the show [MP3] | Jump to Shownotes | Jump to Transcript This episode is sponsored...
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...
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,...
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...
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,...
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...
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...
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...
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...