Have you ever heard that photons behave like both a particle and a wave and wondered what that meant? It's true. Sometimes light acts like a wave, and other times it behaves like a little particle. It's both. This week we discuss the experiments that demonstrate this, explain how scientists figured it all out in the first place. What does wave/particle duality have to do with astronomy? Well, everything, since light is the only way astronomers can see out into the Universe.
Southward looking oblique view of Mare Imbrium and Copernicus crater on the Moon. credit: NASA/Apollo 17
Pamela's attending the 39th Lunar and Planetary Sciences Conference, and you know what that means: the Moon… and planets! When you think of the Moon, you think of craters. In fact, that's a big theme this week at the conference, so Pamela took it as inspiration. Here you go, the week we drove the show into a crater. Wait… there's got to be a better way to describe this.
Gravity is always pulling you down, but there are places in the solar system where gravity balances out. These are called Lagrange points and space agencies use them as stable places to put spacecraft. Nature is on to them and has already been using them for billions of years.
ESA's Integral Space Observatory found a cloud of antimatter in the centre of our galaxy credit: NASA
Sometimes, we don’t get to decide what our show’s about. So many threads come together at the same time driving the decision for us. This is one of those situations. We’ve gotten so many questions from listeners in just the last week about antimatter that our show had just been chosen for it. You command, we obey. Let’s talk about antimatter.
We’ve been so crazy following our own whims through the universe that we’ve neglected your questions. That ends today. It’s time to dig deep into our overflowing email box to retrieve the puzzling questions our listeners have sent in.
This active galaxy (3C442A) is emitting high-energy particles through its poles, as you can see with the xray/radio composite. credit: X-ray: NASA/CXC/Univ. of Bristol/Worrall et al.; Radio: NRAO/AUI/NSF
We’re going to return back to a long series of episodes we like to call: Radiation that Will Turn You Into a Superhero. This time we’re going to look at cosmic rays, which everyone knows made the Fantastic Four. These high-energy particles are streaming from the Sun and even intergalactic space, and do a wonderful job of destroying our DNA, giving us radiation sickness, and maybe (hopefully!) turning us into superheroes.
Artist's conception depicting the decay of a Higgs particle following a collision of two protons in the CMS experiment. credit: CERN/LHC
When it was first developed, the standard model predicted a collection of particles, and thanks to more and more powerful colliders, physicsists have been able to find them all except one: the Higgs-Boson. It's an important one because it should explain how objects have mass. The European Large Hadron Collider should have the power and sensitivity to find the Higgs-Boson.
The gravity of the two colliding antennae galaxies creates the impressive tidal tails. credit: copyright Daniel Verschatse (Antilhue Observatory)
Last week we talked about tidal forces within our solar system. This week we're going to expand our view and encompass the entire universe. Some of the most dramatic events originate from tidal forces caused by gravity: other worlds, galaxies, black holes and even entire clusters of galaxies are under this influence.
The force of gravity can cause comets like Shoemaker-Levy 9 to rip apart credit: H. Weaver (JHU), T. Smith, NASA
Consider the following: we've got tides here on Earth, the Moon only shows one face to the Earth, we've got volcanoes on Io, and ice geysers on Enceladus. All these phenomena originate from a common cause: the force of gravity stretching across space to tug at another world.
This week we wanted to give you a basic physics lesson. This isn't easy physics, this is a lesson on the basic numbers of the Universe. Each of these numbers define a key aspect of our Universe. If they had different values, the Universe would be a changed place, and life here on Earth would never have arisen.