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General Relativity
There are three factors all competing to determine the fate of the Earth, and the one that’s winning now won’t win in the end. If you could measure the average distance […]
When you look at the Universe in an entirely new way, you sometimes find what you could never have anticipated. Almost exactly one year ago today, the Event Horizon Telescope […]
Astrophysics has probed a test of a fundamental law, ‘Lorentz invariance,’ well beyond the LHC’s limits. Einstein is still right. The greatest scientific legacy that Albert Einstein left us is this: […]
The combination of charge conjugation, parity, and time-reversal symmetry is known as CPT. And it must never be broken. Ever. The ultimate goal of physics is to accurately describe, as precisely […]
Hawking radiation should really be happening, but black holes are farther from decaying than ever before. Black holes are, in many ways, the most extreme objects that will ever exist in […]
It isn’t just that mass and energy are equivalent and interchangeable. It tells us something fundamental about mass itself. Of all the equations that we use to describe the Universe, perhaps […]
Few scientific ideas have been as polarizing as string theory. There are good reasons to both love it and hate it. String theory is perhaps the most controversial big idea in […]
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 […]
Just because an idea is fashionable doesn’t mean it’s relevant for our Universe. One of the greatest unsolved puzzles in all of science is dark energy. The Universe isn’t just […]
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 […]
From outside a black hole, all masses take an infinite amount of time to cross the event horizon. How, then, can black holes grow? Every Milky Way-sized galaxy should contain hundreds […]
A black hole’s event horizon is thought of as the point of no return. But perhaps there are ways back out, after all. Black holes just might be the most extreme […]
Even extremely simple configurations in General Relativity cannot be solved exactly. Here’s the science of why. It’s difficult to appreciate how revolutionary of a transformation it is to consider the Universe […]
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. […]
The shape of our Universe has long been recognized to be flat. But that isn’t the only possibility. The Universe is expanding, and goes on for farther than even our […]
And if the data is good enough, we can determine that it’s accelerating directly, too, silencing the last remaining doubters. If you want to understand what the Universe is made […]
When you hear ‘quantum,’ you probably think of splitting everything into discrete, indivisible chunks. That’s not necessarily right. If you want to learn what the Universe is made out of […]
It might seem puzzling, in a Universe bound by the speed of light, that this could be true. Here’s the science behind it. If you look out into the distant Universe, […]
There are a lot of unsolved mysteries in the Universe, but dark energy is the most confusing. Here’s why. The majority of the energy in our Universe went completely undiscovered until […]
If you think about the way a gravitational wave detector works, you might encounter a paradox. Here’s the solution. One of the greatest scientific achievements in all of human history […]
100+ years ago, General Relativity came along, and Einstein gave the Universe a cosmological constant. Here’s why that was a mistake. Back in the 17th century, Isaac Newton put forth the […]
It’s been spectacularly confirmed by observation, but theoretically, it couldn’t have been any other way. If the Sun were to spontaneously cease emitting light, we wouldn’t know about it for about […]
The origin story for our Universe got a major revision nearly 40 years ago. Time to catch up. 13.8 billion years ago, all the matter and energy contained within our Universe […]
Traveling interstellar distances in human lifetimes is an amazing dream, but it won’t ever be achieved like this. For centuries, ever since we realized that every star we can see in […]
In the mid-20th century, ‘physical cosmology’ was considered an oxymoronic joke. Today, it’s Nobel-winning science. Imagine you wanted to know everything you could about the Universe. You’d want to find […]
It’s much more complex a question than dividing its mass by the volume of the event horizon. If you want to get a meaningful answer, you have to go deep. If […]
Or, quite possibly, is it more complex than either one of those scenarios? If there’s one lesson that humanity should have learned from the 20th century, it’s this: the Universe […]
A recent headline claimed they could. But if gamma-rays are just a form of light, don’t they have to travel at light-speed? There’s an ultimate speed limit in the Universe: […]
Even though it was the crowning achievement of Einstein’s career, he was only a small part of the full story. If you were a physicist in the early 20th century, there […]
As soon as you start thinking about energy and gravity, you’ll realize the need to go beyond it. When it comes to a science like physics, theoretical expectations must always be […]