Sabine Hossenfelder: Backreaction

People clicking on things is the most basic building block of the internet. But as we rely on AI more and more, fewer people are actually clicking things, and soon the only thing we might be interacting with are AI agents who do the rest for us. This isn’t a good development. Let’s take a look at how AI is reshaping the internet, and what that means for the future of information sharing.

Photonic computers are processors that use light – not electricity – to complete their calculations. In theory, photonic computers are both faster and more efficient than today’s silicon chips, and – according to the headlines – the technology is making serious progress. Does the technology live up to the hype? Let’s take a look at the current state of photonic computing.

The universe is full of an unending number of different things, from plants and animals to gas giants and supernovae. But where did all of this stuff (for lack of a better word) come from? Let’s take a look.

Data centers are all the rage right now thanks to AI, and SIlicon Valley is looking to push the concept of data centers to the extreme. Across tech, executives now say they want to build data centers in space, claiming putting computers into Earth’s orbit is both efficient and necessary. Is this true or have these guys gone mad? Let’s take a look.

In quantum physics, a wave function is a mathematical way to describe everything in the universe. But since quantum physics emerged, physicists have argued about whether or not the wave function is real. A group of physicists recently conducted a test of a theorem that describes the mechanics of the wave function, and they’ve told the press that they’ve settled the question: Yes, the wave-function is real. Let’s take a look.

A group of scientists suggests that the origin of life for complex organisms on Earth might have occurred not once, but twice. This challenges our current understanding of early evolution and the biological history of our planet. However, their findings have been rather controversial. Let's have a look at the evidence.

Spintronics is short for “spin electronics,” and refers to the study of the spin of the electron. In electronic devices, spintronics leverages the spin of electrons to process and store data with extreme efficiency – this technology is just a few years from reaching the consumer market, and will make your devices faster and more efficient. For a price, of course. Let’s take a look at how spintronics got here and where it’s going.

Complex numbers are created when you add a real number and an imaginary number (like “i”). These numbers are used throughout math and physics, notably in the Schrödinger equation, which is the key to quantum physics. In 2021, physicists published a paper claiming that you can’t entirely get rid of complex numbers in quantum physics, but two teams of physicists recently published papers disputing that claim. Let’s take a look.

Solar power is one of the most popular sources of renewable energy, due to both its cost-effectiveness and the fact that solar panels emit zero greenhouse gases. But according to new analyses, solar isn’t as cheap as we’ve been led to believe. Let’s take a look at the real cost of solar power and other problems with the technology.

A 15-year-old Belgian boy just finished his PhD in quantum physics, publishing a thesis focused on Bose-Einstein condensates. First, let’s take a look at his PhD thesis and then discuss the reality of going for a physics PhD in 2025.

According to new data analysis, our solar system is traveling through the universe roughly 3 times faster than our current models predict it should be moving. Why is this, and why does it matter? Let’s take a look.

Small modular nuclear reactors are supposed to fix the problem of conventional nuclear reactors being too expensive and time-consuming to build. But we’ve been hearing about how promising they are for 15 years now. So where are they? A report that just appeared sheds light on what happened.

AI is changing the world – how we work, how we write, and how we consume media. But it doesn’t seem like many people are interested in how AI is learning to think about itself. I am convinced that eventually AI will become conscious and I am beginning to worry that we simply wouldn’t notice because no one is watching out for it.

In today's video I want to talk about why I am optimistic about the future and why I think that some major technological breakthroughs in nuclear fusion, artificial intelligence, and genetic engineering are just around to corner.

A physicist from Japan claims that he has found the first direct evidence for dark matter in very highly energetic gamma-ray emissions from the centre of our galaxy. Let’s have a look at the paper.

Scientists just found a massive 7,000 kilometer-long gravitational anomaly off the coast of Africa in data from a NASA satellite. The anomaly occurred from 2006 to 2008 and has now disappeared. What caused it? Let’s have a look.

Physics has 7 base units: seconds, metres, kilograms, amperes, kelvins, moles, and candela. Of those, we technically only need the first three to calculate the latter four. But according to a new paper, we can actually calculate the first three as well – from a single constant. Let’s take a look.

Why haven’t we heard from aliens? That’s a question that sounds simple but turns into a mess the moment you try to answer it. Recently, a mathematician tried to simplify the equation by trying to calculate the odds that we’re the only intelligent life in the universe – according to his math, we shouldn’t be. Let’s take a look.

Over a century ago, Einstein wrote his theories of special relativity and general relativity. Within those theories, he predicted that, as an object moves faster, it slightly contracts in length. However, 50 years later Penrose and Terrell predicted that what one would see is instead that the object is rotated. In a recent experiment, physicists proved that this Penrose-Terrell effect is actually real. Let’s take a look.

I’d much rather only bring you good news, but I feel like I can’t just be quiet about this unfolding climate disaster. I no longer believe that we are able to keep the damage manageable by reducing emissions, and so all signs point to geoengineering. Remarkably enough, most climate scientists now think the same. Let’s have a look.