The square brackets are for a closed interval wherein endpoints are included.
The round brackets are for an open interval wherein endpoints are excluded.
Notation for ranges with included or excluded extremes
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Category Archives: Mathematics
Golden Ratio
ChatGPT explains the golden ratio.
In The Lab With Jay Jay – July 28, 2023 – Testing Riden RD6006 with 19.5V power supply
This post is part of my video blog: In The Lab With Jay Jay.
Today I confirmed I can successfully power my Riden RD6006 power supply with this 19.5V AC adapter I picked up from Amazon. Big thanks to my mate Rick over on the EEVBlog forum for his help with this one.
In this video I use a 100W 6Ω resistor to test my Riden RD6006 power supply at various voltages from 1V to 18V up to a maximum power of 54W.
I should note that in this video I tried to draw 54W of power from the power supply, but the power supply is only rated up to 45W so I probably shouldn’t have done that, and won’t have any reason to ever do that again, I was just testing the maximum. So maybe don’t do that at home. :)
Lex Fridman interviews Andrew Strominger
Infinity
There’s infinity, right there:
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.