hello_world_len
points to the special st_shndx == SHN_ABS == 0xF1FF
.0xF1FF
is chosen so as to not conflict with other sections.st_value == 0xD == 13
which is the value we have stored there on the assembly: the length of the string Hello World!
.This means that relocation will not affect this value: it is a constant.
This is small optimization that our assembler does for us and which has ELF support.
If we had used the address of
hello_world_len
anywhere, the assembler would not have been able to mark it as SHN_ABS
, and the linker would have extra relocation work on it later.The "last" gene, and also an E. Coli K-12 MG1655 gene of unknown function.
A collection of closely related and curated C. elegans datasets.
____
The default isolation level for SQLite is SERIALIZABLE
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The default isolation level for SQLite is SERIALIZABLE
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It does not appear possible to achieve the other two levels besides SERIALIZABLE and READ UNCOMMITED
Envelope.
Has Serial wire debug debug. Why would you ever get one without unless you are a clueless newbie like Ciro Santilli?!?!
- symmetry in classical field theory
- from Lagrangian density we can algorithmically get equations of motion, but the Lagrangian density is a more compact way of representing the equations of motion
- definition of symmetry in context: keeps Lagrangian unchanged up to a total derivative
- Noether's theorem
- youtu.be/cj-QpsZsDDY?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=3062 Lagrangian and conservation example under translations
- youtu.be/cj-QpsZsDDY?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=3394 same but for Poincaré transformations But now things are harder, because it is harder to describe general infinitesimal Poincare transforms than it was to describe the translations. Using constraints/definition of Lorentz transforms, also constricts the allowed infinitesimal symmetries to 6 independent parameters
- youtu.be/cj-QpsZsDDY?list=PLDfPUNusx1EpRs-wku83aqYSKfR5fFmfS&t=4525 brings out Poisson brackets, and concludes that each conserved current maps to a generator of the Lie algebraThis allows you to build the symmetry back from the conserved charges, just as you can determine conserved charges starting from the symmetry.
Once upon a time, the British Government decided to invest some 80 million into quantum computing.
Jeremy O'Brien told his peers that he had the best tech, and that he should get it all.
Some well connected peers from well known universities did not agree however, and also bid for the money, and won.
Jeremy was defeated. And pissed.
So he moved to Palo Alto and raised a total of $665 million instead as of 2021. The end.
Makes for a reasonable the old man lost his horse.
www.ft.com/content/afc27836-9383-11e9-aea1-2b1d33ac3271 British quantum computing experts leave for Silicon Valley talks a little bit about them leaving, but nothing too juicy. They were called PsiQ previously apparently.More interestingly, the article mentions that this was party advised by early investor Hermann Hauser, who is known to be preoccupied about UK's ability to create companies. Of course, European Tower of Babel.
The departure of some of the UK’s leading experts in a potentially revolutionary new field of technology will raise fresh concerns over the country’s ability to develop industrial champions in the sector.
Ubuntu 21.10 has a certain default level of logging by default to:but it does not log everything, only/mostly errors it seems.
/var/log/postgresql/postgresql-13-main.log
Setting:under:and then restarting the server:just works.
log_statement = 'all'
/etc/postgresql/13/main/postgresql.conf
sudo service restart postgresql
Realtime monitoring for long queries instead: stackoverflow.com/questions/8597516/app-to-monitor-postgresql-queries-in-real-time
The breadboard of photonics!
For example, that is how most modern microscopes are prototyped, see for example Video "Two Photon Microscopy by Nemonic NeuroNex (2019)".
This is kind of why they are also sometimes called "optical breadboarbds", since breadboards are what we use for early prototyping in electronics. Wikipedia however says "optical breadboard" is a simpler and cheaper type of optical table with less/no stabilization.
There are unlisted articles, also show them or only show them.