## Here’s Why the Quantum World Is Just So Strange – Walter Bradley Center for Natural and Artificial Intelligence

Posted: November 28, 2020 at 4:57 pm

In this weeks podcast, Enrique Blair on quantum computing, Walter Bradley Center director Robert J. Marks talks with fellow computer engineer Enrique Blair about why Quantum mechanics pioneer Niels Bohr said, If quantum mechanics hasnt profoundly shocked you, you havent understood it yet. Lets look at some of the reasons he said that:

The Show Notes and transcript follow.

Enrique Blair: Its really quite different from our daily experience. Quantum mechanics really is a description of the world at the microscopic scale. And its really weird, because there are things that initially we thought maybe were particles but then we learned that they have wave-like behaviors. And there are other things that we thought were waves and then we discovered they have particle-like behaviors.

But thats hardly the strangest part. The strangest part is that a quantum particle does not actually have a position until we measure it, according to the generally accepted Copenhagen interpretation of quantum mechanics.

Robert J. Marks: Whats the Copenhagen interpretation?

Enrique Blair (pictured): Its that the quantum mechanical wave function describes measurement outcomes in probabilities. You cant predict with certainty the outcome of a measurement. Which is really shocking, because in the classical world, if you have a particle and you know its position and its velocity, you can predict where its going to be in the next second or minute or hour. Now in quantum mechanics, the really weird thing is, we say that a particle doesnt even have a position until you measure its position.

Robert J. Marks: It doesnt exist?

Enrique Blair: Not that it doesnt exist, but its position is not defined.

Dr. Marks compared quantum mechanics (QM) to one of the characters in a 1999 film, Mystery Men, featuring inept amateur superheroes, including one who says, Im invisible as long as nobodys looking at me. With QM, thats not a joke. The quantum particle doesnt have a position until we measure it. But how did we discover this? The story goes back to the early 1800s when British physicist Thomas Young (17731829) did a famous experiment with a card held up to a small window

Enrique Blair: Youngs double-slit experiment goes all the way back to 1801, where Young shot light at a couple of slits and then the light passing through the slits would show up on a screen behind them.

So light behaves like a wave, with interference patterns. But what happens when we try doing the same thing with a single particle of lighta photon? Thats something we can do nowadays.

Enrique Blair: We can reduce a beam of light so that its single photon. One photon is emitted at a time, and were shooting it at our double slit again.

What happens when each particle of light goes through these slits? Well, each particle splats up against this screen, and so you can know where the photon hits. But if you do this over a long period of time, the interference pattern shows up again. You have particles hitting the screen, so we see the particle behavior. But we also see the interference pattern which suggests that okay, weve got some wave interference going on here.

So the only way to explain both of these at the same time is that each photon, which is an indivisible packet of light, has to go through both slits at the same time and interfere with itself, and then the buildup of many, many photons gives you that interference pattern.

Robert J. Marks: A particle was hypothesized to go through both slits?

Enrique Blair: Yes, and thats the mind-blowing ramification of this thing.

Robert J. Marks: How do we decide which slit the particles go through? Suppose we went down and we tried to measure? We put out one photon and we put it through the double slit. Weve tried to measure which slit it went through. If its a particle, it can only go through one, right?

Enrique Blair: Right. That introduces this concept of measurement. Like you said, which slit does it go through? Now the interesting thing is, if we know which slit it goes through maybe we set up a detector and we say, Hey, did it go through Slit One or Slit Two? we detect that, we measure it and the interference pattern goes away because now its gone through one slit only, not both.

Robert J. Marks: Just by the act of observation, we are restricting that photon to go through one slit or the other. Observation really kind of screws things up.

Enrique Blair: Thats right. This is one of the things that is hard to understand about quantum mechanics. In the classical world that we deal with every day, we can just observe something and we dont have to interact with it. So we can measure somethings position or its velocity without altering it. But in quantum mechanics, observation or measurement inherently includes interacting with that thing, that particle.

Again, youve got this photon that goes through both slits, but then you measure it and it actually ends up going through oneonce you measure it.

Robert J. Marks: This reminds me again of Invisible Boy in Mystery Men. The photon goes through one of the two slits while youre looking at it. Unless you look away. Then it goes through both slits.

Enrique Blair: Right. Very tricky, those photons.

Next: How scientists have learned to work with the quantum world

Note: The illustration of the double-slit experiment in physics is courtesy NekoJaNekoJa and Johannes Kalliauer (CC BY-SA 4.0).

You may also enjoy: A materialist gives up on determinism. Evolutionary biologist Jerry Coyne undercuts his own argument against free will by admitting that quantum phenomena are real (Michael Egnor)

Quantum randomness gives nature free will. Whether or not quantum randomness explains how our brains work, it may help us create unbreakable encryption codes (Robert J. Marks)

Podcast Transcript Download

Read the original here:

- Bigger quantum computers, faster: This new idea could be the quickest route to real world apps - ZDNet - July 2nd, 2021
- Quantum computing just took on another big challenge, one that could be as tough as steel - ZDNet - July 2nd, 2021
- Missing Piece Discovered in the Puzzle of Optical Quantum Computing - SciTechDaily - July 2nd, 2021
- Rare Superconductor Discovered May Be Critical for the Future of Quantum Computing - SciTechDaily - July 2nd, 2021
- Quantum Computing Breakthrough: Unveiling Properties of New Superconductor - Analytics Insight - July 2nd, 2021
- This Startup Is Using Quantum Computing And AI To Cut Drug Discovery Time From 3 Years To 4 Months - Forbes - July 2nd, 2021
- Keynotes Announced for IEEE International Conference on Quantum Computing and Engineering - HPCwire - July 2nd, 2021
- The only answer to the quantum cybersecurity threat is quantum - Sifted - July 2nd, 2021
- NIST's Quantum Security Protocols Near the Finish Line The U.S. standards and technology authority is searching - IoT World Today - July 2nd, 2021
- #YouthMatters: IBM's Amira Abbas on quantum computing and AI - Bizcommunity.com - July 2nd, 2021
- CSRWire - Refusing Limits with Liz Ruetsch - CSRwire.com - July 2nd, 2021
- Quantum Computing Software Market Analytical Overview, Growth Factors, Demand and Trends Forecast to 2027 The Manomet Current - The Manomet Current - July 2nd, 2021
- People of Argonnes history: A look at leaders who made Argonne what it is today - Newswise - July 2nd, 2021
- Clearing the way toward robust quantum computing - MIT News - June 17th, 2021
- IBM's first quantum computer outside of the US has just gone live - ZDNet - June 17th, 2021
- Honeywell Does a Quantum Computing Deal. Is This the New Age of Computing? - Barron's - June 17th, 2021
- Hacking bitcoin wallets with quantum computers could happen but cryptographers are racing to build a workaround - CNBC - June 17th, 2021
- Honeywell joins hands with Cambridge Quantum Computing to form a new company - The Hindu - June 17th, 2021
- New quantum computing company will set the pace - Cambridge Network - June 17th, 2021
- Trinity College teams up with Microsoft on quantum computing programme - The Irish Times - June 17th, 2021
- Google wants to build a useful quantum computer by 2029 - The Verge - May 22nd, 2021
- 27 Milestones In The History Of Quantum Computing - Forbes - May 22nd, 2021
- Quantum Computing: The Chronicle of its Origin and Beyond - Analytics Insight - May 22nd, 2021
- Quantum computing is a concept we struggle to understand. - The Morning News - May 22nd, 2021
- Quantum computings imminent arrival in Cleveland could be a back-to-the-future moment: Thomas Bier - cleveland.com - May 22nd, 2021
- Quantum Computing Market 2021-Industry Demands, Size & Share, Covid-19 Impact Analysis, Recent Developments, Global Growth, Trends, Top Operating... - May 22nd, 2021
- Researchers design new experiments to map and test the quantum realm - Harvard Gazette - May 22nd, 2021
- France takes next step in quantum technology with Dutch processor - Innovation Origins - May 22nd, 2021
- The Worldwide Quantum Technology Industry will Reach $31.57 Billion by 2026 - North America to be the Biggest Region - PRNewswire - May 22nd, 2021
- Maryland Today | 'We Really Are Terrapin Strong' - Maryland Today - May 22nd, 2021
- Following Atoms in Real Time Could Lead to New Types of Materials and Quantum Technology Devices - SciTechDaily - May 22nd, 2021
- International Advanced Research Workshop on HPC Returns to Cetraro July 2021 - HPCwire - May 22nd, 2021
- IBM and MIT kickstarted the age of quantum computing in 1981 - Fast Company - May 9th, 2021
- Here's the lowdown on how quantum computing affects the Middle East - SCOOP EMPIRE - May 9th, 2021
- IBM Extends HBCU Initiatives Through New Industry Collaborations - PRNewswire - May 9th, 2021
- Here comes the worlds first ever multi-node quantum network - TelecomTV - May 9th, 2021
- Crystal Ball Gazing at Nvidia: R&D Chief Bill Dally Talks Targets and Approach - HPCwire - May 9th, 2021
- Cambridge named as world-leading centre of quantum computing research - Varsity Online - February 5th, 2021
- Quantum Computing Market 2018 Size, Application,Revenue, Types, Trends in Future, Scope to 2030 | D-Wave Systems Inc., QX Branch Co., IBM Co., Google... - February 5th, 2021
- Quantum computing breakthrough uses cryogenics to scale machines to thousands of times their current size - The Independent - February 3rd, 2021
- Quantum Computing Market worth $1,765 million by 2026 - Exclusive Report by MarketsandMarkets - PRNewswire - February 3rd, 2021
- IBM's Goldeneye: Behind the scenes at the world's largest dilution refrigerator - ZDNet - February 3rd, 2021
- Establishing a Women Inclusive Future in Quantum Computing - Analytics Insight - February 3rd, 2021
- The risk of giving in to quantum progress - ComputerWeekly.com - February 3rd, 2021
- Quantum Computing 101 -What it is, how is it different and why it matters - The Jerusalem Post - February 3rd, 2021
- Here's Why Quantum Computing Will Not Break Cryptocurrencies - Forbes - December 24th, 2020
- Global Quantum Computing Market Predicted to Garner $667.3 Million by 2027, Growing at 30.0% CAGR from 2020 to 2027 - [193 pages] Informative Report... - December 24th, 2020
- Quantum Computer Completed A 2.5-Billion-Year Task In 200 Seconds - Intelligent Living - December 24th, 2020
- University collaboration gives Scotland the edge in global quantum computing race - HeraldScotland - December 24th, 2020
- Scaling the heights of quantum computing to deliver real results - Chinadaily.com.cn - China Daily - December 24th, 2020
- Bitcoin is quantum computing resistant regardless of rising fears among investors - FXStreet - December 24th, 2020
- This Incredible Particle Only Arises in Two Dimensions - Popular Mechanics - December 24th, 2020
- Two Years into the Government's National Quantum Initiative - Nextgov - December 24th, 2020
- Atos Delivers Its First GPU-Accelerated Quantum Learning Machine to the Irish Centre for High-End Computing - HPCwire - December 24th, 2020
- With Next Cryo, a startup that's really cooling its jets - Innovate Long Island - Innovate Long Island - December 24th, 2020
- Chip-Based Photon Source Is 100X More Efficient than Previous, Bringing Quantum Integration Within Reach - HPCwire - December 24th, 2020
- Quantum computing - Wikipedia - December 17th, 2020
- What is quantum computing? - December 17th, 2020
- Explainer: What is a quantum computer? | MIT Technology Review - December 17th, 2020
- Eight leading quantum computing companies in 2020 | ZDNet - December 17th, 2020
- Wall Streets latest shiny new thing: quantum computing - The Economist - December 17th, 2020
- Quantum computing: Strings of ultracold atoms reveal the surprising behavior of quantum particles - ZDNet - December 17th, 2020
- Anyon Systems to Deliver a Quantum Computer to the Canadian Department of National Defense - GlobeNewswire - December 17th, 2020
- Chinese quantum computer may be the most powerful ever seen - Siliconrepublic.com - December 17th, 2020
- 'Magic' angle graphene and the creation of unexpected topological quantum states - Princeton University - December 17th, 2020
- This breakthrough could unlock the true power of quantum - Wired.co.uk - December 17th, 2020
- ASC20-21 Student Supercomputer Challenge Kickoff: Quantum Computing Simulations, AI Language Exam and Pulsar Searching with FAST - Business Wire - November 28th, 2020
- Imperfections Lower the Simulation Cost of Quantum Computers - Physics - November 28th, 2020
- Quantum Computing Market : Analysis and In-depth Study on Size Trends, and Regional Forecast - Cheshire Media - November 28th, 2020
- Global Quantum Computing Market 2020 Recovering From Covid-19 Outbreak | Know About Brand Players: D-Wave Systems, 1QB Information Technologies,... - November 28th, 2020
- Is the blockchain vulnerable to hacking by quantum computers? - Moneyweb.co.za - November 28th, 2020
- Cracking the Secrets of an Emerging Branch of Physics: Exotic Properties to Power Real-World Applications - SciTechDaily - November 28th, 2020
- Quantum Computing Market Detailed Analysis of Current and Future Industry Figures 2020-2026 | Leading Players StationQ- Microsoft, Google, 1QB... - November 16th, 2020
- Quantum Computing in the CloudCan It Live Up to the Hype? - Electronic Design - November 16th, 2020
- Supply Chain: The Quantum Computing Conundrum | Logistics - Supply Chain Digital - The Procurement & Supply Chain Platform - November 16th, 2020
- CCNY & partners in quantum algorithm breakthrough | The City College of New York - The City College of New York News - November 16th, 2020
- Hybrid cloud and quantum computing to shape IT: IBM chief - Nikkei Asian Review - November 16th, 2020
- NTTs Kazuhiro Gomi says Bio Digital Twin, quantum computing the next-gen tech - Backend News - November 16th, 2020
- A Scoville Heat Scale For Measuring The Progress Of Emerging Technologies In 2021 - Forbes - November 16th, 2020
- How quantum computing could drive the future auto industry - TechHQ - September 17th, 2020