We know that galaxies like our Milky Way are far more massive than we can see. The dark matter in the Milky Way makes up 90% of it’s total mass. Another way of saying this is the Mass to Light ratio, comparing the total mass inferred by the rotation speed of the galaxy to the total mass of stars in the galaxy. This ratio, M/L, for the Milky Way, is about 10. But for a galaxy cluster, the M/L ratio is more like 100. Galaxy clusters are not just dense collections of stars and massive galaxies, they are also immense...
What do other planetary systems look like? We have seen some where massive Jupiter-sized worlds orbit closer to their star than Mercury does to the Sun, baking them with radiation. Others have had multiple rocky planets within the Earth’s orbit distance. Some have planets similar to Earth in a variety of locations. But what about far away from the star? We never expected to find gas giants like Uranus and Neptune in the far reaches of our solar system. Are there planetary systems where planets live even farther away? Maybe there are planets that live in the empty darkness between stars,...
Dark matter is everywhere. There is way more of it in the universe than the matter we are made of and interact with. Yet for the sheer amount of it, we have no way of determining what exactly it is. It’s as if we didn’t know what air was, and even though we could see it and breathe it, we couldn’t measure it. The most tantalizing part about dark matter is that we can see the gravitational effect it has, and so we can determine how much of it there has to be. Some places in the universe have more dark matter than...
Out of the over 2000 confirmed exoplanets, not one has been seen in the conventional sense, where we would see it’s surface, map out features and colours, and understand it’s atmosphere or surface from what we saw. Instead all the knowledge we have of exoplanets is based on the light we see. How big is the dip in the Kepler Telescope’s light curve? What absorption features do the reflected light of this planet show? This information is the result of careful analysis and brilliant inference, since the planets themselves are immeasurably tiny and hard to spot next to their giant...
It always fascinates me to see videos and photographs from the International Space Station (ISS), how simple day to day activities are so altered because of the altered Physics of constant free fall in orbit around the Earth. Many of the videos are showing what people call the ‘effects of zero gravity.’ This is actually not the case. There is gravity in space. Let’s take a closer look at the situation of an ISS astronaut. If we do the math (I do realize the term ‘do the math’ turns away a lot of people, so I will keep it short),...
It’s hard to do experiments in space. It costs a boatload of money, takes years of preparation, and even then we can’t get much further than low-Earth orbit. But there is a cheaper alternative to understanding the universe. We can perform experiments on Earth to simulate what happens far beyond our own planet. That’s just what scientists did at the Vertical Gun Range at NASA’s Ames Research Center in California. They found that Ceres is likely a mish-mash of celestial bodies from several billion years of bombardment. Until March of this year, when the Dawn spacecraft entered orbit of the...
When the launch of the James Webb Space Telescope comes a few years from now, we will have then opportunity to probe deeper into the cosmos than ever before, to see things we had only dreamed of seeing previously. Among the prime targets for this modern marvel of human ingenuity are potentially habitable exoplanets, where future humans could live, provided there isn’t already life occupying the real estate. To help astronomers assign importance to the growing number of exoplanets, researchers at the University of Washington’s Virtual Planetary Laboratory have devised an index to represent the habitability of worlds, near and...
And the 2015 Nobel Prize in Physics goes to….. Arthur B. McDonald and Takaaki Kajita for the discovery of neutrino oscillations, which show that neutrinos have mass. It fills me with pride to see that a Canadian scientist can win the most distinguished award for Physics in the world, and proves that cutting edge research is done by Canadian Universities. We are an important part of the global machine that is advancing humanity’s understanding of science. So what did this East-West collaboration discover? A long Standing Problem in particle Physics, called the ‘solar neutrino problem,’ developed back in the 1960s....
Are equations beautiful? Does a mathematician see the machine code of the universe in the complex language they use? Does a Chemist see the flow of matter? Does a Biologist see the evolution of life? Does a physicist see the probabilistic nature of electrons? Many scientists would affirm their view that the equations that dictate their respective fields are artistic, in addition to logical. So if equations can be beautiful, what is the most beautiful equation? Naturally, the most beautiful equation should be simple. It should be somewhat intuitive, yet surprising in it’s result. It should explain something fundamental about the universe,...
How do we determine the size of the Universe? How do we know how far away the planets and stars are? How can we measure it without ever being there? The answer, as it always is in Astronomy, is light! More Photons = More Science! Here’s my video explaining the concepts of Parallax, spectroscopic parallax, and type 1a supernovae! Space is big, and although we can figure out how big it is, its another challenge all together to understand and comprehend its sheer size.
