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 If Quantum Computers are not Possible Why are Classical Computers Possible?
 Sergiu Hart: TwoVote or not to Vote
 A toast to Alistair: Two Minutes on Two Great Professional Surprises
 TYI 31 – Rados Radoicic’s Rope Problem
 Eran Nevo: gconjecture part 4, Generalizations and Special Cases
 The World of Michael Burt: When Architecture, Mathematics, and Art meet.
 Layish
 Some Mathematical Puzzles that I encountered during my career
 Friendship and Sesame, Maryam and Marina, Israel and Iran
Top Posts & Pages
 If Quantum Computers are not Possible Why are Classical Computers Possible?
 Elchanan Mossel's Amazing Dice Paradox (your answers to TYI 30)
 TYI 30: Expected number of Dice throws
 Answer: Lord Kelvin, The Age of the Earth, and the Age of the Sun
 Sergiu Hart: TwoVote or not to Vote
 The Race to Quantum Technologies and Quantum Computers (Useful Links)
 Friendship and Sesame, Maryam and Marina, Israel and Iran
 A Breakthrough by Maryna Viazovska Leading to the Long Awaited Solutions for the Densest Packing Problem in Dimensions 8 and 24
 Believing that the Earth is Round When it Matters
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Author Archives: Gil Kalai
If Quantum Computers are not Possible Why are Classical Computers Possible?
As most of my readers know, I regard quantum computing as unrealistic. You can read more about it in my Notices AMS paper and its extended version (see also this post) and in the discussion of Puzzle 4 from my … Continue reading
Posted in Computer Science and Optimization, Physics, Quantum
Tagged Guy Kindler, Quantum computers
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Sergiu Hart: TwoVote or not to Vote
Sergiu Hart raises a very interesting idea regarding elections. Consider the Brexit referendum. Sergiu proposes to have two rounds two weeks apart. Every voter can vote in each, and the votes of both rounds add up! The outcomes of … Continue reading
A toast to Alistair: Two Minutes on Two Great Professional Surprises
Alistair and the Simons Institure friendly and helpful staff Luca Trevisan invited me to give a 3minute (vidotaped or live) toast for Alistair Sinclair to celebrate that Alistair much deservedly received the SIGACT service award and to mourn that he also … Continue reading
TYI 31 – Rados Radoicic’s Rope Problem
Ropemaker (source) Rados Radoicic wrote me: “Several years back, I heard the following puzzle that turns out to be rather ‘classical’: “There are N ropes in a bag. In each step, two rope ends are picked uniformly at random, tied … Continue reading
Posted in Combinatorics, Probability, Test your intuition
Tagged Rados Radoicic, Test your intuition
7 Comments
Eran Nevo: gconjecture part 4, Generalizations and Special Cases
This is the fourth in a series of posts by Eran Nevo on the gconjecture. Eran’s first post was devoted to the combinatorics of the gconjecture and was followed by a further post by me on the origin of the gconjecture. Eran’s second post was about … Continue reading
Posted in Combinatorics, Convex polytopes, Guest blogger, Open problems
Tagged Eran Nevo, gconjecture
2 Comments
The World of Michael Burt: When Architecture, Mathematics, and Art meet.
This remarkable 3D geometric object tiles space! It is related to a theory of “spacial networks” extensively studied by Michael Burt and a few of his students. The network associated to this object is described in the picture below. … Continue reading
Posted in Art, Combinatorics, Geometry
Tagged Architecture, Branko Grunbaum, Michael Burt
4 Comments
Some Mathematical Puzzles that I encountered during my career
Recently, I gave some lectures based on a generalaudience personal tour across four (plus one) mathematical puzzles that I encountered during my career. Here is a paper based on these lectures which is meant for a very wide audience (in … Continue reading
Friendship and Sesame, Maryam and Marina, Israel and Iran
Happy new (Jewish) year everybody. Amazing scientific partnership between Jordan, Cyprus, Egypt, Iran, Israel, Pakistan, the Palestinian Authority, and Turkey SESAME (Synchrotronlight for Experimental Science and Applications in the Middle East) is a “thirdgeneration” synchrotron light source that was officially opened in Allan (Jordan) on 16 May 2017. … Continue reading
Posted in Obituary, Updates, Women in science
Tagged Eliezer Rabinovici, IsraelIran relationship, Marina Ratner, Maryam Mirzakhani, Sesame
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Elchanan Mossel’s Amazing Dice Paradox (your answers to TYI 30)
TYI 30 asked Elchanan Mossel’s Amazing Dice Paradox (that I heard from Yuval Peres yesterday) You throw a die until you get 6. What is the expected number of throws (including the throw giving 6) conditioned on the event that all throws … Continue reading
Posted in Combinatorics, Probability, Test your intuition
Tagged condition probability, Elchanan Mossel
62 Comments