lutorm

So, as I understand it, the wing is broken down in sections, each of which will use some tabulated lift and drag for that airfoil at the current velocity vector and dynamic pressure? That seems fine. But it doesn't talk about how it deals with the fuselage and how it calculates its lift/drag. Calculating pressure drag is complicated and depends on the details of the airflow around the fuselage, and there's intersection drag at the interfaces with the wings/empennage. A significant portion of the drag for piston airplanes is also the cooling drag of the air that's forced through the cowling and the engine baffles. Does anyone know to what extent this is taken into account?

I'm not understanding the situation. When I had RSUs as an employee, those grants were voided at separation. I only got to keep the RSUs that had vested before separation (which were then just common stock and that I had paid taxes on at vesting.)

Are you saying your former employer let you keep your unvested RSUs which subsequently vested at the IPO? (I've never heard of anyone getting to keep their unvested grants after separation.) Or were you still an employee during the IPO and left the company between then and now?

Did European hard drives run at 3000 rpm then?

I find it most annoying when moving your eyes. Anyone will notice the flicker if their eyes aren't stationary since then each "flick" will end up on a different part of the retina. So, instead of a normal motion blur you see a dashed line which is hard to ignore.

The US supreme court has not, at least so far, endowed computers with personhood...

... simply reprogramming the computer ...

So who makes the decision to do that?

I think most people are missing the point about accountability and thinks, in typical American fashion, about punishment. Accountability is about being responsible for outcomes. That may mean legally responsible, but I think far more important is the knowledge that "the buck stops with me", someone who is entrusted with a task and knows that it is their job to accomplish that task. Said person may decide to use a computer to accomplish it, but the computer is not responsible for the correct outcome.

Given that they were only authorized to fly in the "Bell X-1 supersonic corridor", I'd wager that sonic booms are fairly commonplace there. I doubt there are any residents around.

https://www.afmc.af.mil/News/Photos/igphoto/2003098938/

I really don't care for controlling lights or whatever, but I find it very nice as a common place to monitor all the different things we have in the home: heat pump, evse, humidity in rooms, power consumption, state of lawn mower bot, etc.

Even with a car's higher rolling resistance, most of the drag at cruising speed is aerodynamic, though.

But a commuter train, by definition, starts and stops a lot so it makes sense that a large fraction of the energy used would be for acceleration.

Although "Top-level vdevs can only be removed if the primary pool storage does not contain a top-level raidz vdev, all top-level vdevs have the same sector size, and the keys for all encrypted datasets are loaded."

Apart from just peace of mind from bitrot, I use it for the snapshotting capability which makes it super easy to do backups. You can snapshot and send the snapshots to other storage with e.g zfs-autobackup and it's trivial and you can't screw it up. If the snapshots exist on the other drive, you know you have a backup.

Given their development pace, they really must succeed if they want their "slowly and carefully" model to be competitive.

"Dark matter" is just a description that refers to matter which interacts gravitationally but not, or at least very weakly, in other ways. It doesn't imply anything about the nature of such matter. We know that there are several types of dark matter, specifically neutrinos and brown dwarfs, although it is now established that they don't make up anything near the density required by the cosmological models. Primordial black holes, which may exist, would be a dark matter. Some particle physics models, like supersymmetry, also naturally predict that there will be a massive particle that would behave like dark matter. So I don't think the analogy with the aether is very good, because that really was pulled out of thin air (pun intended). Given how successful general relativity is, it's perfectly rational to interpret the observations as probing mass distributions while assuming GR will continue to hold. There are of course people also assuming that GR is wrong and attempting to explain the observations without dark matter, but my impression is that they struggle to come up with self-consistent theories that fit all the data, although I'm not very familiar with that work.

What other people have been doing over the past 40 years is attempting to devise tests for these various dark matter candidates. We know, for example, through lensing observations, that MACHOs/brown dwarfs don't exist in the required numbers and that the neutrino mass seems too low. The problem, of course, is that there are only so many ways to try to observe matter that is truly dark.

I agree, though, that, in the end, it may be that dark matter will be an untestable hypothesis, just like quantum gravity or whatever.

Well, it's not like people pulled it out of thin air. Both inflation and the lambda-CDM models are solutions to the GR equations, so in that sense it's perfectly justifiable to see if general relativity can explain the data. I don't think it's fair to say that it "makes no logical sense".

But it seems that the principal objection to these counts is that birds don't necessarily die on impact but may travel quite far before succumbing to their injuries, so the counts necessarily result in an underestimate of the true effect. Are you saying the area that's surveyed is large enough that this isn't true?

This approach seemed super interesting and we attempted to use it for modeling a fairly complicated fluid system (pipes, valves, tanks, etc). However, in the end the equations that fell out made the solver choke. We abandoned the effort since it seemed like an undebuggable black box. It's unclear to me whether we just didn't do it right or if the open source alternatives just aren't capable.

IIRC the current Starlink beams are of order 10 miles on the ground. So much narrower than you guess.

Swarm wasn't a competitor to SpaceX at the time, Swarm and Starlink wasn't aiming at the same market at all. And they didn't exactly kill Swarm. They launched Swarm satellites for a while and there was talk of integrating Swarm transceivers on Starlink satellites. I think once direct-to-cell became a reality, the idea of Swarm was subsumed into that project since it should do everything Swarm did but better. It's worth noting that the Swarm founders are now working on the direct-to-cell project.

It's worth noting that cash held in a Fidelity brokerage account is handled the same way, by being "swept" into a bank account held by Fidelity at an actual bank so Fidelity can claim it's FDIC insured. I guess if Fidelity folds there would be bigger problems than where the cash balance is, though...

The booster is already strong enough to support itself in compression, because that's what it does during ascent and the landing burn. The entire bottom structure of a rocket (the "octaweb" for F9) is basically made to transfer the thrust compression loads of the engines into the tanks.

That will have to happen through in-situ resource utilization. aka making the fuel on Mars.

Every time you throw a rock, it ends up on a trajectory that "would have orbited if the earth was a point mass". That's just not a very useful definition of "being in orbit".

My experience (being fully remote for over a decade) is that it's extremely distracting to have all discussions public. It creates a lot of noise and it's very hard for people to not get drawn into conversations that doesn't directly affect them. It's definitely good to have finished conclusions available for everyone, but the "sausage making" is more distracting than useful.

Of course it depends on the size of the team we're talking about.

At least on our PHEV, when you read out the battery module state with an OBDII reader, you get to know not only the current estimated capacity but also how much time it's spent at various states of charge, how much time it's spent being charged and discharged at different currents, how much time it's spent at different temperatures, and a completely absurd amount of other diagnostics.

I'd feel a lot better about the state of the battery if I bought one used, rather than the state of the ICE. It's possible to borescope it, but you have no way of telling how long the previous owner went between oil changes, if they flogged it out to redline regularly, etc.

I mean, what choice, besides averaging, would make sense? Completely disregarding one pilots input seems worse, and averaging is what happens in a mechanically connected system. The crucial difference is that in that case the pilots can feel that this is happening. I don't know what sort of force feedback the Airbus sidesticks provide, but this lack of feedback seems to me to be the real root of the problem, not the averaging itself.

Thanks for the informative post. It pretty much backs up what I've already learned. However, the "complications are beyond rare" doesn't seem to be the case for myopic people doing RLE. In particular, the risks of retinal detachment seem to be around 1%, according to e.g. https://crstodayeurope.com/articles/2017-apr/long-term-compl... (see below) and other sources I've found. Maybe the state of the art has improved since 2017, but 1% is an uncomfortable gamble with something that will at the very least make you unable to read and drive.

The mean incidence of retinal detachment and cystoid macular edema (CME) after RLE are 1% and 0.1%, respectively. The risk of retinal detachment after RLE is increased with young age, male sex, degree of myopia, and axial length exceeding 27 mm

I'm considering RLE (which apparently can at least correct spherical aberration), they apparently don't really do laser treatments on people my age (50+). However, I'm not sold on the risk vs reward proposition of surgically altering my eyes so if I could get superhuman vision with contacts that would be attractive.

It's actually impossible to focus on an image within the lens, sort of by definition. It said the display is holographic, which I guess means that it will diffract light to create the appearance of an image at infinity, while not actually making an image in the traditional optics sense.

That's cool and all but I'd settle for the long-promised customized contact lenses that take out the particular high-order aberrations of my eyes.

The warranty is for the lifetime of the product. If it breaks, obviously its lifetime has ended so the warranty is no longer in effect...