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Big Bang Theory
There are only 3 populations of stars, but “generations” is a more complex question. When we look out at the stars in the Universe, we classify them into three different […]
If they have mass, then why don’t we see any slow-moving ones? For decades, the neutrino was among the most puzzling and elusive of cosmic particles. It took more than […]
NASA’s James Webb Space Telescope will truly usher in a new era of astronomy. If you want to find the very first galaxy of all, you have to understand not […]
The Big Bang started it all. And then we realized there was more. Of all the questions humanity has ever pondered, perhaps the most profound is, “where did all of this […]
As the Universe ages, will it eventually fade away entirely? The earliest signal we’ve ever directly detected from the Universe comes to us from shortly after the Big Bang: when […]
Some of them may have formed just 200 million years after the Big Bang. When we look out at the Universe, we’re not seeing objects as they are today, but rather […]
The history of the Universe is forever imprinted in our own bodies. We can learn a lot about the history of the Universe just by looking at each of our own […]
There’s a boundary to how far back we can observe everything that exists. Despite everything we’ve learned about our Universe, there are many existential questions that remain unanswered. We don’t know […]
How quickly is it expanding today, and how does that expansion rate change over time? What is the Universe made of? How quickly is it expanding today, and how does that […]
There’s a lot left to understand, ponder, and investigate. And there always will be. For hundreds of thousands of years — nearly all of human history — we had no definitive answers to some of […]
Without a little help from Einstein, we couldn’t have made this discovery. NASA’s Hubble Space Telescope, currently celebrating its 30th anniversary, still churns out novel discoveries. The Hubble eXtreme Deep […]
Nothing in the Universe can travel faster than the speed of light. So how does space itself do it? One of the fundamental rules we all learn in physics — set forth by […]
It happened 13.8 billion years ago, so why hasn’t the radiation all passed over us by now? For the past 13.8 billion years, our Universe has been expanding, cooling, and gravitating. […]
They said the “missing half” of the Universe’s matter was just found. But what they found barely makes a dent to the big picture. When we look up into the great […]
The origin of the 3rd element on the periodic table was one of the great cosmic mysteries. We just solved it. How did we form the elements that pervade the Universe […]
In order, they go: hydrogen, helium, oxygen, carbon, neon, nitrogen, magnesium, silicon, iron, sulfur. Here’s how we made them. Everything found on planet Earth is composed of the same ingredients: atoms. […]
If you traveled in a straight line for far enough, would you come back to where you started? If you were to set out on a journey from anywhere on Earth’s […]
There’s a million things we haven’t done. But just you wait. The Universe as we know it began some 13.8 billion years ago with the onset of the hot Big Bang. […]
All the things that surround us and make us up weren’t always here. But where did it all come from? The Universe, as we see it today, sure is full of […]
Today, our observable Universe extends for 46 billion light-years in all directions. But early on, things were much smaller. There are few things we can conceive of that are as mind-bogglingly […]
Sure, cosmic inflation has its detractors. But it also has something no alternative possesses: predictions and tests. Perhaps the most compelling part of any remarkable story is its origin: how it […]
It’s been called the biggest conundrum in all of cosmology, and recent measurements just add to the confusion. One of the most puzzling facts about the Universe is that different […]
For over 50 years, it’s been the scientifically accepted theory describing the origin of the Universe. It’s time we all learned its truths. The Universe we know today, filled with stars […]
In General Relativity, the fabric of space doesn’t remain static over time. Everything else depends on the details we measure. If there’s one thing we’ve experimentally determined to be a constant […]
The age of the Universe is only 13.8 billion years, but we know that protons survive much longer. Here’s how. Since the discovery of radioactivity in the 19th century, humanity has […]
Astronomy’s enduring quest is to go farther, fainter, and more detailed than ever before. Here’s the edge of the cosmic frontier. Astronomers have always sought to push back the viewable […]
The hot Big Bang occurred 13.8 billion years ago, and there’s no other possible answer consistent with what we know today. Conceptually, it might seem like the simplest idea in existence […]
We speak with cosmologist Dan Hooper, and ponder the literal edge of what we know about the Universe. Have you ever wondered what the first moments of our Universe were […]
How can physics on the smallest scales affect what the Universe does on its largest ones? Cosmic inflation holds the answer. On a macroscopic level, the Universe appears to be entirely […]
In science, breakthroughs don’t always begin with a ‘eureka’ moment. Sometimes, the true story is absolutely unbelievable. When it comes to our Universe’s origin story, many competing ideas once thrived. […]