Predicting the death of a star is easy. If we know how massive it is, and what stage of life it’s in, we know that it should explode eventually, within a set timeframe of many hundreds of thousands, or even millions of years. But on human timescales, that is just not good enough. What if we could predict a supernova explosion within a few months? For something that lives for so long, this would be a triumph in our understanding of the universe. Over the past couple of years, this is exactly what happened. Here’s how. A supernova is one of the most...
Beyond the atmosphere, past the stars we see, farther than the Milky Way, and continuing past Andromeda, we reach the real cosmic ocean. So called because like an ocean on Earth, it is vast, homogeneous, and impossible to navigate by common sense alone. In the cosmic ocean, an impossibly huge amount of space separates island galaxies, whose strong gravity binds them across incredible distances, dictating their course, and forming the largest and most massive structures in the universe: galaxy clusters. Because these immense structures are so vast and so distant, it requires the work of several telescopes to map out...
They may look like they are standing still, but galaxies are all spinning. Spiral galaxies have the lovely regular spin of a disk, while elliptical galaxies are all over the place, a buzzing hive of stars. We don’t see this rotation in real time because it takes millions of years for it to be noticeable. The Milky Way takes 250 Million years to spin just once around it’s axis. Looking at this rotation rate vs. distance from the galactic center was what originally led to the discovery of dark matter. Some galaxies do in fact spin slower than others, but how does...
Our planet orbits the Sun. 365.25 days to go full circle (ellipse actually) and bring the seasons to Earth. But the Sun is not really stationary, it’s actually moving through space. It’s orbiting the center of the Milky Way, along with the rest of the galaxy. It actually has a periodic motion as it moves around the Galaxy, slowly moving up above the galactic plane then being pulled back down below by the disk stars. Currently, the Sun is moving toward the constellation Hercules at a speed of around 72,000 Km/h. It is also moving up to the top of the...
Let me ask you, when you look at the stars on a cold, clear night, what do you see? Diamonds sparkling? Shapes? I do see those things, but I also see so much more. When I look at the stars, I see a thousand generations of humans looking up in wonder, writing shapes in the dirt and telling incredible stories of brave heroes, ferocious beasts, and important lessons. I see our common ancestors using the sky to predict the weather, the seasons, and even the coming of the end of the world. They were looking at a comet in the...
If you look up into the sky on a clear night, you would see thousands of stars. There are surely many more that you would need a telescope to see. But there are not stars everywhere. You can zoom in further and further with bigger and bigger telescopes, until eventually you find gaps where you simply don’t see stars. For a long time it was thought that the gaps were empty, until the Hubble telescope peered through the darkness by taking a 200 hour exposure of a supposedly empty patch of sky. What it revealed was a universe full of...
Data is beautiful. There is elegance in the artful manipulation of data to communicate information. I love to see new ways to communicate science to the layman and give an understanding of the collective human knowledge. So I had to post this timeline of the universe infographic, containing events from the beginning of the universe all the way up to the death of the Sun. This is obviously just the tip of the scientific iceberg so to speak, but some of the highlights chosen cross several disciplines of science and are truly significant events in history. Enjoy the truly beautiful...
The only reason we can see black holes in the universe is because some of them swallow up gas and dust. This heats up material that is spinning rapidly around the black hole as it falls in (called an accretion disk), and produces massive jets of material due to conservation of angular momentum that can be seen across the universe. The energy released in the jets and the energy given off in the accretion disk are proportional to how much gas and dust is being consumed by the black hole. More matter = more food = more energy released. But...
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...
Time is a very slow thing when we talk about the universe. Stars can live for many Billions of years, and over human timescales they seem stagnant and unchanging. So it’s no surprise that when we look at distant galaxies, they don’t appear to change at all over the course of centuries. But appearances can be deceiving. Galaxies do change, more quickly than you would imagine. M87, pictured above, is a monstrous Galaxy of nearly 1 Trillion stars, more than twice as populous as the Milky Way. It looks like a big fuzzy star, and it quite regular in appearance...
