Category Archives: Mathematics
Lorentz Factor
ChatGPT tells me about the Lorentz Factor.
CRC
I watched Ben Eater’s videos How do CRCs work? and Checksums and Hamming distance (the full course is Learn about error detection) then found the Wikipedia page: Cyclic redundancy check.
Also of interest:
Keyspace on the back of an envelope
One question that always plagues me: should I use 32-bit or 64-bit keys. I can never make a firm decision on this point. But I’ve just done some back of the envelope calculations in thinking about it.
If you issued one identity per second, every second of every day, it would take 136 years to exhaust the keyspace.
If you issued one thousand identities per second, it would take 50 days to exhaust the keyspace.
HP-16C
I was watching Ben Eater’s video Build an 8-bit decimal display for our 8-bit computer and I was interested in what calculator he was using. Seems to be an HP-16C.
Blowfish
I found myself reminiscing about my implementation of Blowfish today. It earned me the great honour of being listed on Bruce Schneier’s web page. My implementation made Blowfish compatible across 32-bit signed ints, 64-bit signed ints, and 64-bit floats. I wrote this code coming up on 12 years ago… how time flies.
Intuitionism
Recently I read about Intuitionism and I can tell you unreservedly that I do not believe in it. I believe that objective things can exist independent of human minds and the most salient example I could give is in your computers. In your computer you can calculate 1 + 1 = 2 and you can do so quite independently of a human mind. 1 + 1 = 2 is an objective truth which can easily be modelled in a machine. Certainly mathematics can *also* be the result of constructive mental activity in human minds, but it is not limited to that. Also it might be interesting to note that machines will be able to find objective mathematical truths which are beyond the capacity of a human mind alone, in fact I’m quite sure that will have been done already (if you can think of an example feel free to let me know!).
Curry–Howard correspondence
Some light reading. /s
Humble Pi: A Comedy of Maths Errors
On my list of books to buy (and read!) is Humble Pi: A Comedy of Maths Errors by Matt Parker.
Strange Loop videos by Philip Wadler
Two presentations given at Strange Loop by Philip Wadler.