In Sun-like stars, hydrogen gets fused into helium. In the Big Bang, hydrogen fusion also makes helium. But they aren’t close to the same. — In all the Universe, there’s arguably no reaction more important than nuclear fusion. Without it, hydrogen would be the only element in the Universe. Without it, there would be no shining stars throughout the Universe. Without it, planets wouldn’t be possible, and there would be no instances of life in…

Drop sodium in water, and a violent, even explosive reaction will occur. But quantum physics is needed to explain why. — It’s a little bit paradoxical: when we encounter something unexpected for the first time, we wonder why it happens that way. But if we encounter a phenomenon often enough, even if it ought to surprise us and cry out for an explanation, we simply accept that this is how the…

The Standard Model may or may not be in trouble, but particle physics definitely needs saving. Here’s what the new LHC can do. — Everyone in the physics community agrees: particle physics is in trouble. Yet, depending on whom you ask, you’re likely to hear that the root of the trouble originates in a few very different places. Particle physics is in trouble because there are now so many cracks in the Standard Model…

Everything that gets heated up has to, somehow, radiate that energy away. Here’s what we see when that happens in the Universe. — On average, today’s Universe is an extremely cold place.

For a thousand light-years in all directions, there’s a “bubble” that the Sun sits at the center of. Here’s the story behind it. — When we look out at the Universe, what we see is typically what we think of: the points of light. Depending on the scales we’re looking at, this can come in the form of stars, galaxies, or even clusters of galaxies, but it’s almost always information that comes to…

Probably not. Even though we’re still investigating the origin of life, the evidence suggests that cells only came much later. — When we look out at all the various forms of life that exist on planet Earth today, from the simplest bacteria to the largest, most complex and differentiated plants, animals, and fungi, we find that everything contains the same basic building block: the cell. As we go through the fossil…

Most potentially hazardous asteroids remain unidentified. NEO surveyor could change that, but only if it’s funded, and soon. — In all the world, there are few things more immediately dangerous to humanity than the potential for a large, massive object, like an asteroid or a comet, to collide with our planet. While our imaginations might immediately go to the devastating event 65 million years ago that led to our…

Was there ever life on Mars? Is there life on Mars now? Did it originate there or here, on Earth? All possibilities are fascinating. — For as long as humanity has been watching the skies, we’ve been fascinated with the possibility that other worlds — much like Earth — might contain living organisms. While our visits to the Moon taught us that it’s completely barren and uninhabited, other worlds within our Solar System remain full…

Look out at a distant object, and you’re not seeing it as it is today. It’s size, brightness, and actual distance are all different. — Take a look at any object, and what you see will be dependent on how far away it is from you. In reality, this object will have specific physical properties: size, color, brightness, etc., and will be located a particular distance from you. Typically, your way of detecting this object…