Many of the moons and planets across the Universe are in resonance with each other and their star. What causes this resonance, and how can it help us understand the history of planetary formation and migration? We usually record Astronomy Cast every Friday at 3:00 pm EST / 12:00 pm PST / 20:00 PM UTC. […]
For people living in oceanfront communities, the prospect of a tsunami is a frightening one. Much like earthquakes, volcanoes, hurricanes and tornadoes, tsunamis are one of the most destructive natural forces on the planet. And much like these other phenomena, they require the right conditions to happen and are more common in some areas of […]
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 […]
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.
It’s no surprise that Titan’s north polar region is covered with vast lakes and seas of liquid methane — these have been imaged many times by Cassini during its ten years in orbit around Saturn. What is surprising though is just how incredibly smooth the surfaces of these lakes have been found to be. One […]
Two white dwarfs similar to those in the system SDSS J065133.338+284423.37 spiral together in this illustration from NASA. Credit: D. Berry/NASA GSFC Locked in a spiraling orbital embrace, the super-dense remains of two dead stars are giving astronomers the evidence needed to confirm one of Einstein’s predictions about the Universe. A binary system located about […]
[/caption]Light and sound are both waves. However, the former can travel through a vacuum while the latter cannot. So what is sound and how does it propagate as a wave? Sound is actually a pressure wave. When an object vibrates, it creates a mechanical disturbance in the medium in which it is directly adjacent to. […]