• In the recent film starting Tom Holland, Peter Parker cooks up his own webbing in his high-school chemistry class. Now, he could have made it out of anything, like fishing line or even steel, and yet he chooses to replicate spider silk. Spider silk. This kid is trusting his life to a flimsy-looking strand of arachnid goo. But it turns out, if Peter’s web is anything like real spider silk, then his web-slinging antics are more realistic than they might appear. Now, spider silk doesn’t look very durable. After all, a strand can be as little as 1/40 the thickness of a human hair, but, pound for pound, it’s stronger…

• Sometimes math and physics conspire in ways that feel too good to be true. Let’s play a strange sort of mathematical Croquet. We’ll have two sliding blocks and a wall. The first block starts by coming in at some velocity from the right, while the second starts out stationary. Being overly-idealistic physicists, let’s assume that there is no friction and that all collisions are perfectly elastic, which means no energy is lost. The astute among you might complain that such collisions would make now sound, but your goal will be to count how many collisions take place, so in slight conflict to the assumptions, I want to leave in a…

• An ion is a charged atom. Here we see two of them: a calcium and a strontium ion. They are superb controllable quantum systems, and we’ll see we can store information into either one. Suppose our strontium is initially in state zero. We can apply a pulse of energy to switch it to state one. Later, for readout, we can use a laser that would have no effect on state zero, but our ion in state one will absorb energy and then emit it back as a photon, a particle of light which we can detect. Let’s zoom out. We see gold strips below. These produce electric fields holding our…

• We’re suiting up to take you inside a clean room that’s building an engineering marvel that’ll push the entire electronics industry to the next frontier. They’re both amazing machines and scary machines. There’s an enormous amount of complexity with them. There’s an enormous number of things that can potentially go wrong. It’s something that you don’t necessarily sleep well at night, just having the machine on your floor. It’s about the size of a school bus, weighing over 180,000 kilograms, with over 100,000 parts, and 3,000 interlocking cables. Pop the hood and you’ll see lasers shooting tiny droplets of tin, generating plasma that’ll get collected and reflected by a series of mirrors,…

• There are many possible ways to build the hardware for a quantum computer, because there are many physical systems that can be used as qubits. But to give you a concrete example, I’m going to show you what it takes to build a quantum computer using the spin of single electrons inside a solid state semi-conductor chip. This is a pathway that is being pursued very actively partly because it may allow us to build quantum computers using the same fabrication methods used for classical computer chips. But the way the quantum chip is operated will be very different. First of all, we need to confine individual electrons within a…

• So physics is a huge subject that covers many different topics going from galaxies in the depths of space right down to subatomic particles. And if you don’t already know physics its difficult sometimes to see how all these different subjects are related to each other. So this is my attempt to show that in a map, so this is the map of physics. I hope you enjoy it. Physics can be broadly broken down in to three main parts: Classical Physics, Quantum Physics, and Relativity. We’ll start with classical physics and a good person to start with is Issac Newton. His laws of motion describe how everything made of…

• A quantum computer is a hypothetical machine that would exploit the principles of quantum mechanics that govern the subatomic world, in order to solve certain problems much faster than we know how to solve them with any computer today. Quantum mechanics has been the basic framework for almost all of physics for nearly a century. What is says is that if you don’t know what state a system is in – like you don’t know if an electron is in its ground state, its lowest energy or in the next higher energy – well the issue is in quantum mechanics the different places where the particle could be, or the…

• In this video I would like to explain how to amplify digital signals, so that you can control homebuilt peripherals by computers or microcontrollers. Furthermore simple input functionalities are treated. The control units I am using are an Arduino Uno microcontroller and a Raspberry Pi single board computer. Both computing machines have digital input/output pins that can be used to control peripherals. Before connecting a device to a pin you must consider the electrical properties of the ports! The Arduino Uno operates with a pin voltage of 5V, while the voltage at the pins of the Raspberry Pi must be kept below 3.3V. First let’s have a look at the…

• We’d like to thank Audible for supporting PBS. Quantum computing is cool, but you know what would be extra awesome – a quantum internet. In fact if we want the first we’ll need the latter. And the first step to the quantum internet is quantum cryptography. Quantum theory may seem like an obscure subject of questionable relevance to the average person. But in fact much of our technological world depends on our understanding of the quantum properties of the subatomic universe. And soon, perhaps very soon, we’ll be interacting with the weirdness of quantum mechanics even more directly – with the coming of quantum computing and the quantum internet. Today…