Category Archives: Computer Science

Q: How do I encrypt/hide/protect my email?

Cryptographer: Lots of people have been asking “how do I encrypt my email” or “how can I hide from NSA surveillance”. It turns out that the answer to the first question is fairly straight forward, while the second is not, … Continue reading

Posted in -- Guest Author, Computer Science, Paranoia | 4 Comments

Q: What does it mean for light to be stopped or stored?

Physicist: We’ve gotten a handful of questions since this was published and led to articles like this, this, and, this.  In a nutshell, some dudes in Germany (Georg Heinze, Christian Hubrich, and Thomas Halfmann) have found a method to shoot … Continue reading

Posted in -- By the Physicist, Computer Science, Entropy/Information, Experiments, Physics, Quantum Theory | 11 Comments

Q: Since the real-world does all kinds of crazy calculations in no time, can we use physics to calculate stuff?

The original question was: I’ve heard somewhere that they’re also trying to build computers using molecules, like DNA. In general would it work to try and simulate a factoring algorithm using real world things, and then let the physics of … Continue reading

Posted in -- By the Physicist, Computer Science, Engineering, Entropy/Information, Physics | 6 Comments

Q: How do you write algorithms to enycrypt things?

Physicist: There are several algorithms, but almost all of them are all based on “trap-door encryption”.  The idea is that you find some kind of mathematical process that’s easy to run forward, but effectively impossible to run backward, unless you … Continue reading

Posted in -- By the Physicist, Computer Science, Math, Number Theory | 8 Comments

Video: Getting Computers to Learn

An introduction to machine learning (a form of artificial intelligence concerned with getting computers to learn from data), and a discussion of some of the mathematics underlying machine learning algorithms. Part 1 of 4: Part 2 of 4: Part 3 … Continue reading

Posted in -- By the Mathematician, Computer Science, Machine Learning & A.I., Videos | 4 Comments

Q: How can quantum computers break encryption?

Physicist: What follows is the famous Shor algorithm, which can break any RSA encryption key. The problem: RSA, the most common form of public key encryption, is based on the fact that large numbers are hard to factor.  Without going … Continue reading

Posted in -- By the Physicist, Computer Science, Equations, Math, Number Theory, Physics, Probability, Quantum Theory | 17 Comments