Lawrence Krauss: Quantum Computing Explained | Big Think

Lawrence Krauss explains the basic concepts of quantum computing and the technical hurdles to building practical quantum computers.

Lawrence Krauss: Quantum Computing Explained Watch the newest video from Big Think: bigth.ink/NewVideo Join Big Think Edge for exclusive videos: bigth.ink/Edge ---------------------------------------------------------------------------------- Lawrence Krauss describes quantum computing and the technical obstacles we need to overcome to realize this Holy Grail of processing. ---------------------------------------------------------------------------------- LAWRENCE M. KRAUSS: Lawrence Maxwell Krauss is a Canadian-American theoretical physicist who is a professor of physics, and the author of several bestselling books, including The Physics of Star Trek and A Universe from Nothing. He is an advocate of scientific skepticism, science education, and the science of morality. Krauss is one of the few living physicists referred to by Scientific American as a "public intellectual", and he is the only physicist to have received awards from all three major U.S. physics societies: the American Physical Society, the American Association of Physics Teachers, and the American Institute of Physics. ---------------------------------------------------------------------------------- TRANSCRIPT: Lawrence Krauss: Let me briefly describe the difference between a quantum computer and a regular computer, at some level. In a regular computer, you've got ones and zeros, which you store in binary form and you manipulate them and they do calculations. You can store them, for example, in a way that at least I can argue simply. Let’s say you have an elementary particle that’s spinning. If it’s spinning, and we say it’s spinning, it’s pointing up or down depending upon whether it’s spinning this way or this way, pointing up or down. And so, I could store the information by having lots of particles and some of them spinning up and some of them spinning down. Right? One's and zero’s. But in the quantum world, it turns out that particles like electrons are actually spinning in all directions at the same time, one of the weird aspects of quantum mechanics. We may measure, by doing a measurement of an electron, find it’s spinning this way. But before we did the measurement, it was spinning this way and this way and that way and that way all at the same time. Sounds crazy, but true. Now that means, if the electron's spinning in many different directions at the same time, if we don’t actually measure it, it can be doing many computations at the same time. And so a quantum computer is based on manipulating the state of particles like electrons so that during the calculation, many different calculations are being performed at the same time, and only making a measurement at the end of the computation. So we exploit that fact of quantum mechanics that particles could do many things at the same time to do many computations at same time. And that’s what would make a quantum computer so powerful. One of the reasons it’s so difficult to make a quantu