Lawrence Krauss: Quantum Computing Explained | Big Think
Lawrence Krauss: Quantum Computing Explained
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Lawrence Krauss describes quantum computing and the technical obstacles we need to overcome to realize this Holy Grail of processing.
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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.
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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 quantum computer, and one of the reasons I’m a little skeptical at the moment, is that – the reason the quantum world seems so strange to us is that we don’t behave quantum mechanically. I don’t – you know, you can – not me, but you could run towards the wall behind us from now ’til the end of the universe and bang your head in to it and you’d just get a tremendous headache. But if you’re an electron, there’s a probability if I throw it towards the wall that it will disappear and appear on the other side due to something called quantum tunneling, okay.
Those weird quantum behaviors are manifest on small scales. We don’t obey them – have those behaviors ’cause we’re large classical objects and the laws of quantum mechanics tell us, in some sense, that when you have many particles interacting at some level those weird quantum mechanical correlations that produce all the strange phenomena wash away. And so in order to have a quantum mechanical state where you can distinctly utilize and exploit those weird quantum properties, in some sense you have to isolate that system from all of its environment because, if it interacts with the environment, the quantum mechanical weirdness sort of washes away.
And that’s the problem with a quantum computer. You want to make this macroscopic object, you want to keep it behaving quantum mechanically which means isolating it very carefully from, within itself, all the interactions and the outside world. And that’s the hard part, Is isolating things enough to maintain this what’s called quantum coherence. And that’s the challenge and it’s a huge challenge.
But the potential is unbelievably great. Once you can engineer materials on a scale where quantum mechanical properties are important, a whole new world of phenomenon open up to you. And you might be able to say – as we say…
Read the full transcript at https://bigthink.com/videos/lawrence-krauss-quantum-computing-explained
@bigthink
February 6, 2026 at 9:01 am
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@bonganingwenya8674
February 6, 2026 at 9:01 am
Quantum Computing is the next big thing for those who didn't catch what he said at the end
@InaneBlatherPodcast
February 6, 2026 at 9:01 am
So are you guys gonna take this down since this guy is a Jeffrey Epstein defender??
@cynthiagarnham1157
February 6, 2026 at 9:01 am
What about a quark computer . They are naturally up or down, so a kind of switch possiblity? The is always the problem tho of the comic background radiation interfering on such a small scale. There is a theory that this radiation can react with particles in clouds, causing periodic ice ages. The sun rotation around the galaxy ( once every 230 million years!), means that its path passes thru various levels of cosmic radiation! I love all this kind of stuff!
@cameleon5724
February 6, 2026 at 9:01 am
One content, two languages. What I have now written may have a perfect mirror in another language.!!!!!!!!
@cameleon5724
February 6, 2026 at 9:01 am
Endless enigmatic book in all languages. You can write a book with mirrors in all languages of the world. You can speak two languages at once, you just need to find the perfect reflection, same content, different translation. Infinite Mirrors. Pi 3.14 XBooks. Hybrid language!!!!
@enifu
February 6, 2026 at 9:01 am
0 and 1 is rubbish. What really sets quantum computers apart from classical computers is the logic gates involved. A Hadamard gate is a fundamental quantum logic gate.
@GregoryTheGr8ster
February 6, 2026 at 9:01 am
The quantum computer sounds unnatural to me. It is a technology that we might not want to pursue or unleash.
@agustinp.montero1434
February 6, 2026 at 9:01 am
Interesting to see a video from 7 years ago being sceptical of a reality today, i.e., quantum computers
@thedecktothe16thpower56
February 6, 2026 at 9:01 am
1. Linear brane. 2. Super position brane.
People are the quantum computers atm that both a linear brane(s) and a super position brane(s) are studying. Not to mention you and I.
Quantum computers are like, gas light me, HA, wait till I gas light all you right back in your faces! No lie. You actually have to calm the damn programs down because it has no eyes to make quantum judgements for a brain.
@denizliberal
February 6, 2026 at 9:01 am
It is a bad explanation.
@TheProGam3rHD
February 6, 2026 at 9:01 am
Lmao imagine if after the quantum computer is observed, it collapses into a classical computer.
@samliu6913
February 6, 2026 at 9:01 am
The measurement itself is computing. Just information and connections.
@lebergerdesphotons4565
February 6, 2026 at 9:01 am
this guy is clearly full of shit. He doesn't even know that an electron is only a "particle" based on our tiny-brained point of view.
The only difference between a particle and a complex oscillation is that doofuses call a "particle" a "particle".
This quantum computing is a scam. This fellow is either a chump or a lying sack of shit. Like the cat in the box, who cares which?
@marciomaia4020
February 6, 2026 at 9:01 am
We already have quantum computers.
@uvss7980
February 6, 2026 at 9:01 am
Direct from Devil's mind.
@satyanarayanyadaw2447
February 6, 2026 at 9:01 am
Is it available on sale ?
@RickHollmer
February 6, 2026 at 9:01 am
I love it. A mere 6 years after this video was published, we have a quantum computer race. 1 qit, 2, qbit, 24 qbit, 49 qbit. It's not scaling to base 2 for some reason, but… the quantum world really is weird. LOL.
@smakosz2
February 6, 2026 at 9:01 am
Yeah just don’t observe the computer and it’ll continue doing all 4 computations at once… in theory.
@sonyabadass
February 6, 2026 at 9:01 am
Electron is like spoiled child. dont obey by the rule….. F U electron!
@sonyabadass
February 6, 2026 at 9:01 am
And i think it will definitely run crysis 10. I promise you
@sausagefinger8849
February 6, 2026 at 9:01 am
And you are Sir…A theoretical physicist Thinking, talking and Doing…. Nice one X
@Mrfailstandstil
February 6, 2026 at 9:01 am
Well hello there my large classical object YouTube dwellers
@kostailijev7489
February 6, 2026 at 9:01 am
And he still didn't explain quantum computers!
@weareguitars97
February 6, 2026 at 9:01 am
Ask Doctor Larry
@ArthurHau
February 6, 2026 at 9:01 am
Quantum computing has nothing to do with quantum mechanics! It is just a special case of using a Bayesian network to do computation in a faster manner. Instead of talking about conditional probabilities of some not-yet revealed states, quantum computing talks about those not-yet revealed states themselves. Whereas quantum mechanics contradicts our intuition of the behavior of our physical reality (possibly because of the poor design of the experiments or the unknown nature of the effects of the influence of the instruments used for measurement on the behaviors of the measured particles), a Bayesian network and the Bayesian interpretation of the probabilistic world is in line with our intuition!
@abdellahiabderahmane3731
February 6, 2026 at 9:01 am
How does one know how the electron was moving before doing any measurements
@Gericho49
February 6, 2026 at 9:01 am
Putting aside the insurmountable atheists' problem of a finite past, here is Krauss' version of "A Universe from Nothing"
1 Nothing is“ a quantum vacuum seething with particles of matter and anti-matter
2. "Empty space is complicated."
3 – "strength of the energy [SIC] field has to be huge"
4 – "Nothing is unstable"
5 – "follows the rules of quantum mechanics"
6 – "all these phenomena imply that under the right conditions not only nothing can become something, but it is required
to.”
" Oxford dictionary defines "nothing" properly as "Not anything!" Having no attributes! *Nothing has
"no space" not "empty space!"*
Nothing has no boiling brew of virtual particles
Nothing has no energy field. Nothing has no instability.
Nothing has no quantum mechanics laws acting on it Nothing has no phenomena, no
right conditions, and no requirements. The Oxford dictionary defines the word
"Equivocation," as, "The use of ambiguous language to conceal
the truth or to avoid committing oneself."
Is Lawrence Krauss a celebrated physicist, or Just a (very, very) bad Philosopher whose science is dictated by his unwavering commitment the philosophy of Scientific naturalism ? (A scientific American assessment) https://blogs.scientificamerican.com/cross-check/is-lawrence-krauss-a-physicist-or-just-a-bad-philosopher/ A scathing review in the New York Times on Krauss' book and in particular his version of *nothing" https://www.nytimes.com/2012/03/25/books/review/a-universe-from-nothing-by-lawrence-m-krauss.html
@dan-iu2rd
February 6, 2026 at 9:01 am
Valenkin theory. Why did you omit it? Liar.
@pandora8478
February 6, 2026 at 9:01 am
A really bad explanation!
Comments are closed.