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bbojan commented on Why are 2025/05/28 and 2025-05-28 different days in JavaScript?   brandondong.github.io/blo... · Posted by u/brandon_bot
hughw · 9 months ago
Some use cases really do require the local TZ offset be saved. Transforming everything to UTC wipes out that information.

An engineer in the US reviewing industrial measurements logged in a plant in Asia from a variety of sources is definitely going to encounter lots of events recorded in local time. It would be maddening for that engineer to have to review and resolve events from different time coordinates, especially if they are doing the review months or years later. It's best to accept that reality and adopt local time as the standard. Then you must record the TZ offset per UTC in any new system you create.

bbojan · 9 months ago
You mean you must record the timezone? Because the TZ offset can change throughout the year (e.g. due to daylight saving time).
bbojan commented on Healthy soil is the hidden ingredient   nature.com/articles/d4158... · Posted by u/gnabgib
fsckboy · a year ago
copper kills invertebrates (it's in a range of fishtank infection treatments, doesn't kill fish but will kill snails and crabs)
bbojan · a year ago
Copper kills funghi too, and that's a problem as funghi are important element of healthy soil.
bbojan commented on Singapore OKs 4,300km subsea cable for importing electricity from Australia   mothership.sg/2024/10/ema... · Posted by u/wmstack
torginus · a year ago
I wonder if anyone other than the Russians makes one of those floating nuclear power plants that can be moored at sea?
bbojan · a year ago
Thorcon [https://thorconpower.com/] has a plan for this, but they're still years away.
bbojan commented on Build systems, not heroes   vitonsky.net/blog/2024/10... · Posted by u/thunderbong
bbojan · a year ago
Ralph Waldo Emerson is as relevant as always: "A foolish consistency is the hobgoblin of little minds, adored by little statesmen and philosophers and divines."
bbojan commented on Jazz – Apps with Distributed State   jazz.tools/... · Posted by u/gjvc
bbojan · a year ago
How does this compare to Instant (https://www.instantdb.com/)?
bbojan commented on A Taxonomy of Tech Debt (2018)   technology.riotgames.com/... · Posted by u/jakey_bakey
APublicMan · a year ago
My experience at big corporate is that (edit: unmanageable) tech debt is caused by undisciplined and unorganized scrum team.

When you have a proper backlog of tickets, including tech debt tickets, the team will eventually fix the tech debt when there are not enough feature tickets to exhaust capacity.

bbojan · a year ago
> the team will eventually fix the tech debt when there are not enough feature tickets to exhaust capacity

I have yet to visit this misterious universe you describe.

bbojan commented on EVinci nuclear microreactor moves towards commercialization   newatlas.com/energy/evinc... · Posted by u/peutetre
credit_guy · a year ago
This particular design has a very low burn-up indeed, but that's not because of the TRISO fuel. The Chinese HTR-PM helium cooled reactor, that went live 2 years ago, has a burnup of 90 GWd/ton of uranium, which is enriched at 8.5% U-235 [1]. That is an exceptionally high burn-up rate.

The eVinci reactor has an exceptionally low burn-up rate: about 4 GWd/ton, despite using a much more enriched fuel,at 19.75% ([2], but note that this is just an estimate, Westinghouse did not disclose the actual burnup). Why? That's the price you have to pay to have a micro-reactor. The square-cube law says that for such a reactor the surface of the core is very high compared to its volume, so the neutron economy is extremely poor. The only way to make it work is to use highly enriched uranium. Uranium enriched to more than 20% is considered weapons grade, so commercial reactors need to use fuel below that limit, and 19.75 is basically as high as you can go.

TRISO fuel is actually a miracle of science. It addresses many problems of the current generation reactor fuels. Fission results in transmutation. By the very nature of the fission process, you end up with fission products in burned fuel. Some of these products are gases (like Xeon) and they create pressure, and when you have hundreds of thousands of fuel elements some will burst, resulting in fission product discharge in the cooling water. Nasty stuff. The fuel in TRISO is encapsulated in some poppy-seed-sized granules, and it can withstand immense pressures, so this bursting scenario just does not happen. In addition to that, they can withstand immense temperatures as well, and they are surrounded by graphite that has an exceptional heat conductivity, and is also a very good moderator. From the point of view of reactivity control, graphite is actually the best moderator out there, ahead of hydrogen, deuterium and beryllium.

> is difficult to re-process

That's not a problem. You just don't reprocess it.

> it has quite low utilization of enriched uranium

This reactor will have low utilization, as discussed, but not because of the TRISO fuel.

[1]https://aris.iaea.org/PDF/HTR-PM.pdf

[2] https://www.osti.gov/servlets/purl/1501599

bbojan · a year ago
Thanks for the detailed info, this was the stuff I was looking for but couldn't find quickly.

>> is difficult to re-process

> That's not a problem. You just don't reprocess it.

There's not enough uranium in the world to last us more then a few decades if we leave 60-80 percent of it unreacted in spent fuel.

bbojan commented on EVinci nuclear microreactor moves towards commercialization   newatlas.com/energy/evinc... · Posted by u/peutetre
bbojan · a year ago
In my opinion TRISO fuel is bad because it has very low burn-up and is difficult to re-process.

These things together mean it has quite low utilization of enriched uranium.

bbojan commented on NASA announces Boeing Starliner crew will return on SpaceX Crew-9   twitter.com/NASA/status/1... · Posted by u/ripjaygn
bbojan · 2 years ago
Since then 500 million people or more have been taken out of poverty. They are competing with you for resources. That's why what was going on in the US in the 50s is no longer possible.
bbojan commented on Time is an illusion, and these physicists say they know how it works [video]   youtube.com/watch?v=uYOF-... · Posted by u/lisper
programjames · 2 years ago
Something I've heard physicists say but doesn't make sense to me is, "gravity is a just a distortion in space-time, it's not like the other forces." Can someone with more knowledge than me explain this? As far as I can tell:

1) General relativity is just a model.

2) The force that was observed as gravity can be modeled as a a distortion in space-time.

3) Thus (circular logic incoming), gravity is not actually a force, it's just a distortion in space-time, and that why it looks like a force.

This is just begging the question. I could say the exact same thing about any of the other forces between particles, just instead of using the permanent[0], I'd use the determinant[1] for fermions or the immanant[2] for anyons.

I remember in my electrodynamics class applying relativity to Coulomb's law, and seeing the magnetic force just pop out in the Taylor expansion (and I just learned the Feynman lectures does this too: II_13-6[3]). So what do physicists mean when they say gravity is special, or general relativity doesn't play well with quantum dynamics?

[0]: https://en.wikipedia.org/wiki/Permanent_(mathematics)

[1]: https://en.wikipedia.org/wiki/Determinant

[2]: https://en.wikipedia.org/wiki/Immanant

[3]: https://www.feynmanlectures.caltech.edu/II_13.html

bbojan · 2 years ago
Because all masses accelerate at equal rates in a gravitational field either:

1) Inertial mass and gravitational mass are exactly equal without an explanation why

or

2) The acceleration is just an effect of a curvature of space.

Imagine two bodies thrown exactly Northward on a sphere. Although their paths are parallel they would approach each other, as if there was an acceleration. This acceleration would be the same whatever their mass is.

u/bbojan

KarmaCake day671August 8, 2017View Original