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# Category Archives: Physics

## The Simplex, the Cyclic polytope, the Positroidron, the Amplituhedron, and Beyond

A quick schematic road-map to these new geometric objects. The positroidron can be seen as a cellular structure on the nonnegative Grassmanian – the part of the real Grassmanian G(m,n) which corresponds to m by n matrices with all m by … Continue reading

## BosonSampling and (BKS) Noise Sensitivity

Update (Nov 2014): Noise sensitivity of BosonSampling and computational complexity of noisy BosonSampling are studied in this paper by Guy Kindler and me. Some of my predictions from this post turned out to be false. In particular the noisy BosonSampling … Continue reading

Posted in Computer Science and Optimization, Physics, Probability
Tagged BosonSampling, Noise, Noise-sensitivity, Quantum computation
4 Comments

## The Kadison-Singer Conjecture has beed Proved by Adam Marcus, Dan Spielman, and Nikhil Srivastava

…while we keep discussing why mathematics is possible… The news Adam Marcus, Dan Spielman, and Nikhil Srivastava posted a paper entitled “Interlacing Families II: Mixed Characteristic Polynomials and the Kadison-Singer Problem,” where they prove the 1959 Kadison-Singer conjecture. (We discussed part … Continue reading

## Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun

Yeshu Kolodni and Lord Kelvin The question In 1862, the physicist William Thomson (who later became Lord Kelvin) of Glasgow published calculations that fixed the age of Earth at between 20 million and 400 … Continue reading

Posted in Geology, Physics, Test your intuition
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## Test your Intuition/Knowledge: What was Lord Kelvin’s Main Mistake?

The age of the earth (Thanks to Yeshu Kolodny) We now know that the age of the earth is 4.54±1% Billion years. From Wikipedea: In 1862, the physicist William Thomson (who later became Lord Kelvin) of Glasgow published calculations that … Continue reading

Posted in Controversies and debates, Geology, Physics, Test your intuition
Tagged Earth, Geology, Lord Kelvin, Test your intuition
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## QSTART

Physics, Computer Science, Mathematics, and Foundations’ views on quantum information Inauguration conference for the Quantum Information Science Center (QISC), Hebrew university of Jerusalem Update: The news of our conference have made it to a big-league blog. Update (July 2013): QStart … Continue reading

## My Quantum Debate with Aram III

This is the third and last post giving a timeline and some non technical highlights from my debate with Aram Harrow. Where were we After Aram Harrow and I got in touch in June 2011, and decided to have … Continue reading

## My Quantum Debate with Aram II

This is the second of three posts giving few of the non-technical highlights of my debate with Aram Harrow. (part I) After Aram Harrow and I got in touch in June 2011, and decided to have a blog debate about … Continue reading

## My Quantum Debate with Aram Harrow: Timeline, Non-technical Highlights, and Flashbacks I

How the debate came about (Email from Aram Harrow, June 4, 2011) Dear Gil Kalai, I am a quantum computing researcher, and was wondering about a few points in your paper… (Aram’s email was detailed and thoughtful and at the … Continue reading