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Spacetime Physics
We live in a four-dimensional Universe, where matter and energy curve the fabric of spacetime. But time sure is different from space!
There's a speed limit to the Universe: the speed of light in a vacuum. Want to beat the speed of light? Try going through a medium!
Extremely precise atomic clocks are not just of theoretical interest; they could help detect impending volcanic eruptions or melting glaciers.
There are a few possible solutions to the problem of interstellar travel, but they largely remain within the realm of science fiction.
The latest gravitational wave data from LIGO and Virgo finally shows us the truth: there are no "gaps" in the masses of black holes.
Or is ‘new space’ created in between the gaps of the ‘old’ space? It’s been almost 100 years since humanity first reached a revolutionary conclusion about our Universe: space itself doesn’t […]
Are space and time real like atoms are, or is spacetime just a calculational tool? When most of us think about the Universe, we think about the material objects that […]
Two stellar mass black holes, if they merge in the vicinity of a supermassive black hole, could have their gravitational wave signal affected by the strongly curved space around them. […]
It doesn’t propagate at infinite speeds, and that’s a problem for Newton. When you look at the Sun, the light you’re seeing isn’t the light that’s being emitted right now. Instead, […]
Are atoms, humans, planets, and galaxies destined to expand, too? One of the most revolutionary discoveries of the past century was the fact that the Universe is not eternally static and […]
We still don’t know how the information encoded onto it gets out. No matter what you do in the Universe, its overall entropy always increases. Even when we put things in […]
Yes, we’d all die. But for 21 minutes, we’d have the ride of a lifetime. One of the most remarkable facts about the Universe is this: in the absence of […]
Congratulations to Penrose, Ghez and Genzel, and to black hole enthusiasts everywhere. On October 6, 2020, the Nobel Prize in Physics was awarded towards research in black holes. 50% of […]
Why does dark matter, if it doesn’t dissipate energy, become gravitationally bound at all? One of the most puzzling components of the Universe has to be dark matter. Although we have […]
If there are cracks in Einstein’s theory, this is how to find them. Is Einstein’s most powerful theory, General Relativity, always correct? Or will there come a point where it breaks […]
It’s fundamentally different from space. Here’s how. Here’s a question that most of us have been asked at some point in our lives, “what’s the shortest distance between two points?” By […]
The view from beyond Pluto is far enough from Earth that we can see the stars shift. NASA’s New Horizons, humanity’s first spacecraft to encounter Pluto, is more than 4.3 billion […]
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: […]
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 […]
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 […]
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, […]
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 […]
You might think that we live in a three dimensional Universe based on space alone. But you cannot leave time out of it. If you were asked to describe how you […]
A star orbiting past our galaxy’s supermassive black hole offered a chance to test relativity as never before. The supermassive black hole at the center of the Milky Way is the […]
The Planck length is a lot smaller than anything we’ve ever accessed. But is it a true limit? If you wanted to understand how our Universe operates, you’d have to examine […]
If a star spins and then collapses, what happens to its angular momentum? The most common way to form a black hole in the Universe is to have a massive […]
Red, green, and blue? What we call ‘color charge’ is far more interesting than that. At a fundamental level, reality is determined by only two properties of our Universe: the quanta […]
It’s been over 100 years since Einstein, and over 300 since Newton. We’ve still got a long way to go. From measuring how objects fall on Earth to observing the motion […]