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...
When Isaac Newton quantified gravity, his theory explained how everything in the world around us behaved in its presence. It opened a door to an understanding of something fundamental, yet elusive in explanation. Centuries later, Einstein came along and took a step back, finding a larger more comprehensive theory of gravity, one that explained the strange things that happen in the grand universe. His theory could even explain things that Newton’s theory of gravity could not, such as the odd orbit of Mercury around the Sun. But the greatest part of Einstein’s theory is that if you use it to...
The Milky Way is a decently big Galaxy. At 100,000 light years across, it is a full size barred spiral galaxy and distinctly different from what we would call ‘dwarf galaxies.’ But there are much larger galaxies in the universe. Most reside near the centre of a massive galaxy cluster and are the result of Billions of years of mergers and collisions. But some appear large because of their incredibly powerful release of energy. A new Galaxy discovered in the early universe by a team of astronomers from the National Centre for Radio Astrophysics is an incredible 4 million light years...
I went to the movies last night to see ‘The Martian,’ something I have been excited about for a long time. The theatre was packed, and the movie was amazing, both unsurprising facts. I had very few scientific issues with the film, even with low standards for a big screen pic, but mostly due to first thing the screen showed: ‘NASA was heavily consulted to ensure the science in this movie is accurate.’ Way to go Hollywood! My favourite parts of the movie employed some hilarious use of technical definitions. For example, when Mark Watney grows potatoes on Mars, he says...
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,...
One of the big questions in astrophysics is about variation of the laws of Physics. The laws we know and are familiar with; angular momentum, gravity, energy, are the same everywhere on Earth. But what about beyond Earth? The universe is so large and so vast, we may be in a local region where the laws of Physics are set, and our laws may be different from a distinct region somewhere else in the universe. The good news is that we can make predictions based on our understanding of physics. And with our powerful telescopes that allow us to view a variety of...
We are fairly confident about the idea that the Moon formed when a Mars sized object hit the young Earth over 4 Billion years ago. The resulting debris cloud condensed to form the Moon, giving the Earth a surprisingly large Moon for its size. Next to Charon and Pluto, the Earth’s Moon is the largest relative to the size of its planet. It’s also the third largest of all moons in the Solar System, next to Ganymede and Titan, #1 and #2 respectively. but there is one problem with this theory of the Moons formation: The Earth and Moon are...
Our entire universe, from the tiniest atoms, to the structure of our experiential world, to the most massive galaxy clusters and the cosmic web, is dependent on a set of single properties, where small changes to these fundamental numbers would lead to a state where none of it could exist. Understanding these fundamental numbers is the key to unlocking the deepest secrets of the universe and answering the biggest questions of our existence. One of these numbers is the tiny difference in the masses of the proton and neutron. If it varied even a little bit in either direction, we...
Have you ever heard of the Van Allen belts? If not you really should learn about them. After all, without them the majority of life on Earth could not survive. So what are they and how do they keep us alive? The Van Allen Belts are a collection of charged particles, held in place by the magnetic field of Earth, that act as a barrier to prevent the most harmful radiation from the Sun from reaching the surface of the Earth. They shift according to the incoming energy of the Sun, and if there is a large enough swell of...
