Sabine Hossenfelder: Backreaction

Recently, a pair of researchers made a massive breakthrough in the foundations of physics. In their paper, they describe how gravity is an emergent property. More specifically, they say that the origin of gravity is entropy. And not just any entropy, but the entropy of quantum fields. How big is this really? Let’s take a look.

One of the biggest limitations of quantum quantum computing is the “no cloning” theorem, which says you cannot copy a quantum state without destroying the original. If you could copy quantum states without harming the original, much of the error-correcting complications in quantum computing could be avoided. Luckily, in a recent paper, physicists have demonstrated that there’s a way around the “

You might think that black holes suck in light without letting it escape, but they actually concentrate light in the photon sphere which surrounds their horizon. In a recent paper, researchers created a new type of laser which concentrates light using a technique similar to those found in the photon sphere. Let’s take a look.

The electric car revolution was supposed to be inevitable. But over the past six months it's begun to look shaky. The clearest warning sign isn't sales figures, it's what carmakers are doing with their own money: writing off huge losses, scaling back their plans, and cancelling battery projects. So what's really happening to electric car demand, and is the slowdown temporary? Let's take a look.

A federal judge in the US has allowed a whistleblower lawsuit to go forward, in which a former official of the National Institutes of Health accuses a Harvard professor of repurposing research grants and falsely claiming he had met his objectives. The allegations are unproven. But the reason this case matters is that everyone in academia knows this kind of thing happens all the time, and until

A new, computer-based calculation shows that our solar system used to have 5 or 6, rather than 4 gas giants. It seems that, billions of years ago, we lost two planets due to an instability that probably also tilted Uranus’s axis and scrambled up its moons. Let’s have a look.

For over half a century, people taking the psychedelic drug DMT have reported meeting alien beings. Now a scientist says these aliens might be real, and that he has the mathematics to prove it. Forget string theory and extra dimensions; here come aliens and psychedelics. Let's take a look.

In Einstein's theory of general relativity, gravity is always attractive. But according to a new paper, quantum mechanics offers a loophole that can create antigravity. And not only this, if it was measurable that would prove that gravity has quantum properties. How does this work and how can repulsive gravity be compatible with the laws of physics that we know and like? Let's take a look.

About 25 years ago, astrophysicists noticed that the universe’s expansion is accelerating. To account for this observation, physicists came up with a new type of energy – called dark energy – which supposedly makes up more than 75% of the universe, and also has negative pressure. In a new paper, mathematicians claim that dark energy isn’t needed to explain that accelerating expansion, and

In today's video I talk about some commonly misunderstood points in the double slit experiment.

Last year, Microsoft announced its Majorana quantum computing chip, which supposedly used topological qubits to make calculations. The problem was that the paper published alongside the announcement didn’t show any evidence for those claims. Now they’ve announced a new quantum chip. Is it any better this time?. Let’s take a look.