I had the same experience as the root commenter. Sometimes ChatGPT seems to generate invalid typst code that doesn’t even compile. Maybe the syntax changed and it did work at some point but some stuff looked so wrong that I would guess it just doesn’t have enough training data for proper typst generation without feeding examples into the context first.
Is there a danger of overfitting if you train something on a physics sim? How do you prevent the model to exploit the differences to real life? Surely there are some numerical errors and other idealizations that result in some stuff being a good solution but not working in real life, or is the sim that accurate?
This is an active area of research (look up papers that mention the "sim2real gap"). It is indeed a problem, but there are known strategies to deal with it.
> And yes, it's a well-known trick for all major relational databases (not just Postgres) that if you want to delete 90% of rows from a large a table, it's much faster to just copy the rows you want to keep to a new table, run DROP TABLE on the old table, and rename the new table to the old table.
Dumb question but why does the optimizer not just do that in secret then? Seems like something that should be detectable with some heuristics.
Because what do you do if rows are being inserted in the original table, while the new table is having rows copied over? You'll get missing rows.
You can only do the DROP TABLE trick if you know nothing else is writing to the table at the same time. You know if that's the case, according to your business logic. The database has no idea.
The DROP TABLE trick effectively bypasses all the normal guarantees of data consistency. This is why it's so fast. But you have to know that that's a safe thing to do for your data.
There are ways the DB could recover the data consistency guarantees, eg. keeping a log of operations that came in while the table was being copied over and then applying the relevant ones afterwards.
The tricky part is that the latency characteristics of these operations would be pretty surprising and unintuitive. It has the same problems as virtual memory and mark/sweep GC; sometimes, depending on system state and things that other threads are doing, an unrelated operation might block for very long time periods and give you huge user-visible pauses. It's often better to force these expensive operations to be explicit so that the developer has to think through the latency & consistency implications and make the tradeoffs they want.
except in this particular case, as long as you don't exhaust resources, mvcc kind of lets you get away with making a transactionally consistent copy under the covers without blocking anyone, since its a big-ol read.
I assume partly because that would be extremely surprising behavior, and depending on the RDBMS and version, could introduce unexpected stalls. For example, MySQL < 8.0.23 scans the entire buffer pool to clear pages that were dropped, which can take a long time on large instances. There is / was a similar issue with its adaptive hash index, which AFAIK wasn’t ever fixed, though AHI’s default being shifted to OFF in 8.4 is a workaround, in a very hacky way.
Maintaining the expected observable behaviours would get complicated if queries (especially other updates) against the same table are happening concurrently.
Maybe the politicians position is that the whole system is based on cheating and everyone who partakes is acting immorally?
Is it fair that the founder got education and some money to start his company while other people are living on the street or have to care for relatives? If they come from a relatively privileged position and manage to build a company that ends up being successful, did they earn that money?
I don’t think the cheating people criticize is necessarily criminal fraud.
Edit: and the second thing people seem to criticize is that just keeping your company growing often seems to involve some unethical things. Basically every company that’s manufacturing hardware is doing that in Asia under inhumane conditions, so they probably can’t really claim they earned their money and it’s just maths.
I mean there's also just sheer luck. Getting billions is probably more about luck than hard work OR corruption, even if those two things can increase your chances.
But luck is also not "earning" in most senses of the word.
If the only viable alternative is that nobody gets to start their business rather than some idealized best case of everyone getting a chance of it, then yes, it's probably fair.
I don’t think the only options are the current way or that nobody is allowed to start companies.
Im not from the US so I’m probably not doing a good job at the devils advocate thing but I could imagine that you just tax the people that start the business so they still get some healthy personal wealth by redistributing the truly extreme wealth back to the workers/society.
There’s probably some motivation problem to grow the company further at some point but maybe you could limit the percentage any individual can earn by holding the company or something like that?
There are models of business which don't assume a handful of people - some of whom don't even do the work - get to keep the profits, and the rest are disposable.
But then you would have to redo the whole layout and design of the chip right? Surely you can’t just scale the mask and manufacture the same chip at different scales and everything still works?
Check out the Intel Quark, it was a <50mhz x86 that was resized and re-done on a smaller feature fab and runs on a watch battery (its a bios battery), a full x86 SOC!
I dont know what feats of engineering went into it, it is discontinued, but it is a very tiny x86
I still don’t see what the advantage is. Of course it’s physically possible to build a datacenter in space, but I can’t imagine land prices being that high that the same data center on earth wouldn’t be cheaper. Even just due to launch costs and the more sophisticated equipment needed for space.
The real issue is that the power situation in LEO is still actually terrible! Your solar is a little more performant, but you're plunged into hard shade every 45 minutes.
There exist the so-called Sun-synchronous orbits, which exploit the precession effect caused by the fact that the Earth is not a sphere, to pass over the same point of the Earth at the same local hour. On a small subset of these Sun-synchronous orbits the Sun is always visible from the satellite (i.e. on the subset of orbits whose plane is approximately perpendicular on the radius that connects the Sun to the Earth). Without the precession effect, a satellite that sees the Sun for an entire day would lose this property after a few days, because of the rotation of the Earth around the Sun, which alters the direction in space of the radius from the Sun to the Earth.
However, the number of slots that are available in Sun-synchronous orbits with permanent view of the Sun is limited, and many potential users want them. So those who desire to build datacenters would have to compete for such orbital slots. There are much less such slots than for geosynchronous orbits. Other countries would certainly be outraged if USA occupied all the available slots with datacenters.
Improved control of the satellites for collision avoidance could allow smaller slots, but maneuvering heavy datacenters would require a lot of fuel, so they might require periodic refueling, greatly increasing the costs.
I think calling solar a little more performant is underselling it. Once you have LEO getting to a better orbit costs relatively little. Getting from LEO to the moon is only like 30% more than getting from ground to LEO.
They are mostly planning sun synchronous orbits afaik. That means the orbit is tilted so the earth’s deformed shape continually moves the orbital plane so the satellite is always in the sun (or generally the plane has the same angle to the sun).
Sure: which is a higher and less accessible orbit. The relative fuel cost might be small, but in absolute terms the ship carrying payload is carrying a lot more to do it - see the number of Starships to refuel a Starship in LEO.
And here's the thing: all of this is competing with solar+batteries cost on Earth. The power situation is the only advantage here.
Like why not put a datacenter on a barge and run an HVDC line out to it far offshore? That would be expensive...but more expensive then space? It's not even outside of the capability set of SpaceX, who already run drone ships to facilitate Falcon 9 landings.
> Sure: which is a higher and less accessible orbit. The relative fuel cost might be small, but in absolute terms the ship carrying payload is carrying a lot more to do it - see the number of Starships to refuel a Starship in LEO.
No it’s not, it’s not either SSO or LEO. You can have SSO at 600km which is lower than the normal LEO satellite.
I agree that it doesn’t make a lot of sense (look at the root comment of this thread), but you absolutely can make a LEO datacenter with 100% sun coverage if you want to.
I doubt it'll make sense any time soon, but some arguments I can think of are that solar in space can easily be ~50% more efficient at any moment while also being continuous (enough) in the right orbit.
An even more radical idea is to put nuclear in space which would sidestep all the earthly hurdles (beyond the launch).
Right, but even if you get 100% solar time in orbit and maybe 20% on the ground, I still don’t see it. Just from a procurement cost and maintenance standpoint. I think spreading a few datacenters around the world to have quasi continuous availability is easier than launching them on satellites.
> An even more radical idea is to put nuclear in space which would sidestep all the earthly hurdles (beyond the launch).
That makes even less sense to me. Why would you launch then and not just stay on the ground? Do you think a country would allow you to launch a rocket with a nuclear reactor from their land but the reactor is so unsafe that you’re not allowed to operate it on the ground?
Then I would just say put it on a boat and park it in international waters, that’s surely cheaper than orbit, right?
Nuclear is used in space, but my understanding is that it is too low power and not really scalable to computing needs for this use case. Bonus side really is that nuclear power can provide power for very long time.
Until now only energy sources based on radioactive decay have been used in space, which have very low power, but they can provide it for many decades.
Nuclear fission reactors, similar to those used on submarines or ships, would enable very different applications.
Until now, they have not been used for fear of what would happen after a failed rocket launch, when the reactor would fall back on Earth.
This could be mitigated by sending only components of the reactor and assembling it in space.
I do not think that routine exploration of the Solar System beyond Mars will ever be possible without using at least nuclear fission reactors, because it is too slow with chemical sources of energy.
> This could be mitigated by sending only components of the reactor and assembling it in space.
How would that help? The main problem if the launch fails is that the radioactive material will spread around (in the worst case, they are encased so exactly that doesn’t happen).
You could maybe spread out the nuclear material in multiple launches but you would just increase the risk of a small contamination in exchange for a smaller risk of a large contamination.
I don’t think the individual parts of the reactor are intrinsically safer than the reactor, it’s not like it’s going to become an atomic explosion during launch.
One advantage that does come to mind in light of the Iran war (and the loss of an AWS DC) is difficulty in attacking it, even when it’s directly above foreign territory. I wonder if one of the intended customers will be gov/military? Conjoined spy satellite/DC for some function maybe?
I don’t know what the end game of the US looks like but surely you’ll always find some territory around the world to relatively safely put datacenters? And if your opponent isn’t Iran but something like russia or china, they’ll just blow up your datacenter in orbit, too.
I see the point to maybe do some onboard data processing on spy satellites etc, but on the other hand, downlink bandwidth seems to be become less of an issue over time, so it doesn’t seem that important to me compared to just sending down the raw data over star link or the military equivalent.
So if you get stopped by the police in a bribe-affine country and they make clear you can either pay some money or they will take you to jail even though you did nothing wrong, is that a tax or a bribe?
It's blackmail/extortion. The act of paying the money is the bribe. Here is the Wikipedia definition.
> Bribery is the corrupt solicitation, payment, or acceptance of a private favor (a bribe) in exchange for official action.[1][2] The purpose of a bribe is to influence the actions of the recipient, a person in charge of an official duty, to act contrary to their duty and the known rules of honesty and integrity.
This QR code fear mongering is one of the most annoying internet memes to me.
> Almost three-quarters of Americans (73%) scan QR codes without verification, and more than 26 million have already been directed to malicious sites, according to NordVPN.
Obviously, since the only way to verify a QR code before scanning is to decode it manually…
Just treat every QR code like an unknown URL and you’re fine.
In other words: it rusts, but it doesn't rust like iron. It rusts in a much less destructive way because the aluminum oxide protects the rest of the aluminum from oxygen
It is really called low energy, it refers to the low attractive force of the surface, liquids bead up and do not wetten, in epoxy that results in small contact area and a weak bond, on a high surface energy material it flows into all the crannies and has enormous contact area and a strong bond.
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