AC adapter Updated 2025-07-16
AKS primality test Updated 2025-07-16
Internet privacy organizations Updated 2025-07-16
Udacity Updated 2025-07-16
It is a shame that they refocused to more applied courses. This also highlights their highly "managed" approach to content creation. Their 2022 pitch on front page says it all:they are focused on the highly paid character of many software engineering jobs.
for as few as 10 hours a week, you can get the in-demand skills you need to help land a high-paying tech job
But one cool point of this website is how they hire tutors to help on the courses. This is a very good thing. It is a fair way of monetizing: e-learning websites must keep content free, only charge for certification.
x86 Paging Tutorial TLB replacement policy Updated 2025-07-16
When TLB is filled up, older addresses are overwritten. Just like CPU cache, the replacement policy is a potentially complex operation, but a simple and reasonable heuristic is to remove the least recently used entry (LRU).
With LRU, starting from state:adding
valid linear physical
----- ------ --------
> 1 00003 00005
1 00007 00009
1 00009 00001
1 0000B 000030000D -> 0000A would give: valid linear physical
----- ------ --------
1 0000D 0000A
> 1 00007 00009
1 00009 00001
1 0000B 00003 Allegory Updated 2025-07-16
Electrolysis Updated 2025-07-16
Open instant messaging protocols Updated 2025-07-16
Weekend Updated 2025-07-16
Academia is broken Updated 2025-07-16
Sometimes Ciro Santilli regrets not having done a PhD. But this section makes him feel better about himself. To be fair, part of the merit is on him, part of the reason he didn't move on was the strong odour of bullshit oozing down to Masters level. A good PhH might have opened interesting job opportunities however, given that you don't really learn anything useful before that point in your education.
Profzi scheme by PhD Comics
. A Ponzi scheme that trains people in new skills is not necessarily a terrible thing. It is a somewhat more useful version than standard exam based education.
Perhaps the problem is "forcing" 35 year olds to go down that path when they might also want to have boring stuff like families and security.
If people could get to the PhD level much, much sooner, it wouldn't be as obscene: Section "Students must be allowed to progress as fast as they want".
List of instant messaging software Updated 2025-07-16
Physics World Updated 2025-07-16
Robert Noyce Updated 2025-07-16
Academic publishing Updated 2025-07-16
AC Josephson effect Updated 2025-07-16
It is called "AC effect" because when we apply a DC voltage, it produces an alternating current on the device.
By looking at the Josephson equations, we see that a positive constant, then just increases linearly without bound.
Wikipedia mentions that this frequency is , so it is very very high, so we are not able to view individual points of the sine curve separately with our instruments.
Also it is likely not going to be very useful for many practical applications in this mode.
An I-V curve can also be seen at: Figure "Electron microscope image of a Josephson junction its I-V curve".
I-V curve of the AC Josephson effect
. Source. 
Voltage is horizontal, current vertical. The vertical bar in the middle is the effect of interest: the current is going up and down very quickly between , the Josephson current of the device. Because it is too quick for the oscilloscope, we just see a solid vertical bar.
Superconducting Transition of Josephson junction by Christina Wicker (2016)
Source. Amazing video that presumably shows the screen of a digital oscilloscope doing a voltage sweep as temperature is reduced and superconductivity is reached.
I-V curve of a superconducting tunnel junction
. So it appears that there is a zero current between and . Why doesn't it show up on the oscilloscope sweeps, e.g. Video 1. "Superconducting Transition of Josephson junction by Christina Wicker (2016)"? Animal intelligence Updated 2025-07-16
São Paulo (state) Updated 2025-07-16
activatedgeek/LeNet-5 Updated 2025-07-16
It trains the LeNet-5 neural network on the MNIST dataset from scratch, and afterwards you can give it newly hand-written digits 0 to 9 and it will hopefully recognize the digit for you.
Ciro Santilli created a small fork of this repo at lenet adding better automation for:
- extracting MNIST images as PNG
- ONNX CLI inference taking any image files as input
- a Python
tkinterGUI that lets you draw and see inference live - running on GPU
Install on Ubuntu 24.10 with:We use our own
sudo apt install protobuf-compiler
git clone https://github.com/activatedgeek/LeNet-5
cd LeNet-5
git checkout 95b55a838f9d90536fd3b303cede12cf8b5da47f
virtualenv -p python3 .venv
. .venv/bin/activate
pip install \
Pillow==6.2.0 \
numpy==1.24.2 \
onnx==1.13.1 \
torch==2.0.0 \
torchvision==0.15.1 \
visdom==0.2.4 \
;pip install because their requirements.txt uses >= instead of == making it random if things will work or not.On Ubuntu 22.10 it was instead:
pip install
Pillow==6.2.0 \
numpy==1.26.4 \
onnx==1.17.0 torch==2.6.0 \
torchvision==0.21.0 \
visdom==0.2.4 \
;Then run with:This script:
python run.pyIt throws a billion exceptions because we didn't start the Visdom server, but everything works nevertheless, we just don't get a visualization of the training.
The terminal outputs lines such as:
Train - Epoch 1, Batch: 0, Loss: 2.311587
Train - Epoch 1, Batch: 10, Loss: 2.067062
Train - Epoch 1, Batch: 20, Loss: 0.959845
...
Train - Epoch 1, Batch: 230, Loss: 0.071796
Test Avg. Loss: 0.000112, Accuracy: 0.967500
...
Train - Epoch 15, Batch: 230, Loss: 0.010040
Test Avg. Loss: 0.000038, Accuracy: 0.989300One of the benefits of the ONNX output is that we can nicely visualize the neural network on Netron:
Netron visualization of the activatedgeek/LeNet-5 ONNX output
. From this we can see the bifurcation on the computational graph as done in the code at:output = self.c1(img)
x = self.c2_1(output)
output = self.c2_2(output)
output += x
output = self.c3(output) Amazon Web Services Updated 2025-07-16
Cool data embedded in the Bitcoin blockchain Early AtomSea & EMBII uploads Updated 2025-07-16
These are of course likely all made by AtomSea & EMBII themselves while developing/testing their upload system.
They are also artsy peoeple themselves, and as pointed at twitter.com/AllenVandever/status/1563964396656812034 what they were doing was basicaly non-fungible token art, which became much much more popular a few years later around 2021.
The first upload that we could find at github.com/cirosantilli/bitcoin-inscription-indexer/tree/3f53e152ec9bb0d070dbcb8f9249d92f89effa70#atomsea-index was tx 44e80475dc363de2c7ee17b286f8cd49eb146165a79968a62c1c2c4cf80772c9 on block 272573 (2013-12-01) but it does not show on Bitfossil: bitfossil.org/44e80475dc363de2c7ee17b286f8cd49eb146165a79968a62c1c2c4cf80772c9/. This is was due to an upload bug explained by the following entry. By looking at the ASCII data at github.com/cirosantilli/bitcoin-inscription-indexer/blob/master/data/out/0272.txt#L449 that this is meant to contain the same content as the following message: a quote from the Bhagavad Gita, so this is definitely a bugged version of the following one.
The next one is tx c9d1363ea517cd463950f83168ce8242ef917d99cd6518995bd1af927d335828 block 272577 (2013-12-02). It actually shows on bifossil and it reads:followed by:The bug message is definitely a reference to the previous non-visible bugged upload bitfossil.org/4b72a223007eab8a951d43edc171befeabc7b5dca4213770c88e09ba5b936e17/, TODO understand exactly how they fucked up. This illustrates the beauty of the blockchain very well: unlike with version control, you don't just see selected snapshots: you see actual debug logs!!!
He who regards
With an eye that is equal
Friends and comrades,
The foe and the kinsman,
The vile, the wicked,
The men who judge him,
And those who belong
To neither faction:
He is the greatest.
WeAreStarStuff.jpgThe filename is of course a reference to the quote/idea: We Are Made of Star-Stuff that was much popularized by Carl Sagan.
bitfossil.org/fac0b9a4f90414710b806fd286e020aea2404498946845ef3783f305dd4cd3a7 (2024-01-13) contains a cropped version with only AtomSea persent.
HugPuddle.jpgThe fourth AtomSea & EMBII upload, and the second image. Message:
HugPuddle Testing Apertus Disk Drive
And then finally we meet Chiharu, EMBII's partner, with her hair painted blond (she's Japanese): ILoveYouMore.jpg.
Then there are two undecoded ones TODO investigate:
Then Nelson-Mandela.jpg.
Then there's an approximation of pi as ASCII decimal fraction on tx 70fd289901bae0409f27237506c330588d917716944c6359a8711b0ad6b4ce76 from block 273522 (2013-12-07):
3.1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865132823066470938446095505822317253594081284811174502841027019385211055596446229489549303819644288109756659334461284756482337867831652712019091456485669234603486104543266482133936072602491412737245870066063155881748815209209628292540917153643678925903600113305305488204665213841469519415116094330572703657595919530921861173819326117931051185480744623799627495673518857527248912279381830119491298336733624406566430860213949463952247371907021798609437027705392171762931767523846748184676694051320005681271452635608277857713427577896091736371787214684409012249534301465495853710507922796892589235420199561121290219608640344181598136297747713099605187072113499999983729780499510597317328160963185950244594553469083026425223082533446850352619311881710100031378387528865875332083814206171776691473035982534904287554687311595628638823537875937519577818577805321712268066130019278766111959092164201989
tx b8b9f50a354166c46b69ecd47a0fbd20ee78c3471d2557bf275aff1b4cf4752d (2013-12-07) on bitfossil.org) contains Where the Sidewalk Ends by Shel Silverstein:
There is a place where the sidewalk ends
And before the street begins,
And there the grass grows soft and white,
And there the sun burns crimson bright,
And there the moon-bird rests from his flight
To cool in the peppermint wind.
tx 56768b30dec33bd284223d85c23087975e2360b3391d20d505aa59a5675e5379 (2013-12-13, on bitfossil.org):
Dear Aliens,Hey.Sincerely,
EMBII & AtomSea
tx 415c702759893c63b3a57a7d196b014e51b2a33d2396c74b8e71acfaff6b9360 (2013-12-14) contains a poem by 13th century Persian poet Rumi (TODO find bitfossil.org toplevel), starting with:Reproduced e.g. at: www.abuddhistlibrary.com/Buddhism/H%20-%20World%20Religions%20and%20Poetry/World%20Religions/Islam/Teachers/Rumi/My%20dear%20friend/Rumi%20-%20my%20dear%20friend.htm
My dear friend
never lose hope
when the Beloved
sends you away.
bitfossil.org/73ca50321147bac9010bec43d63f7f76857fe9ede240cc89710e28723fdb242f/ (2013-12-14) has message:and links to 3 .txt files
MULTIFILE SUPPORT TEST
1.txt, 2.txt, 3.txt containing single characters 1, 2, and 3.
CompressedLogo.png
. Source. 2013-12-20. Message:Possibly www.linkedin.com/in/colby-nelson-59b538207/.
Colby Nelson and myself burnt the midnight oils designing the APERTUS imagery last night....Thanks Colby for all your help.
Contains an Apertus logo which is used on bitfossil.org/ itself, presumably they were designing that logo.
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