theothermkn

This very much depends on the model space in question. If our model space includes “climate continues normally” and “climate gets weird/warm over time” models, then an event that occurs that is an outlier for “normal,” but routine for “warm/weird,” does tip the odds toward “we are in the weird/warm regime, now.” In other words, future weather days, modeled as tokens being drawn from one of two climate bags, are not independent. Each draw of warm/weird makes it more likely that we have switched from the normal bag to the weird one.

As I read this, I ruminated on my travails at getting a standard USB mouse to work on Ubuntu 18.04. I didn’t ask any questions in forums, largely because all of my hours of searches revealed an entitled community responding to other questioners with NIH (It’s a hardware problem, even though your hardware works on other OSs.), instructions that demonstrably don’t work, or just not responding at all. I don’t mean to take anything away from the author’s fine article; it truly is good. But there can be toxic communities. There can be problems that are entirely opaque to the uninitiated. (Who configures mice in 2019?) And there can be problems for which Googling sends you down a maze of dismissive and entitled responses.

Also, if anyone here has gotten an Anker vertical USB mouse to stay awake, scroll smoothly, and click reliably on a clean install of 18.04, I’m all ears. :D

From the fine article:

> But a less chattered-about problem is the effect on the local environment: The primary byproduct of desal is brine, which facilities pump back out to sea. The stuff sinks to the seafloor and wreaks havoc on ecosystems, cratering oxygen levels and spiking salt content.

My problem with this article is the focus on the "startup" mythology of moving fast and breaking things. Break a Coulomb barrier, first, and then come talk to us.

I really liked https://www.youtube.com/watch?v=L0KuAx1COEk for a discussion of how to evaluate and understand fusion claims, as well as a discussion of the high-field REBCO tapes that seem poised to enable the ARC/SPARC reactors out of MIT. Another video I like is https://www.youtube.com/watch?v=SMxOvuSMAug , featuring Steven Cowley.

In short, newly commercially available high temperature superconductors in mass quantities seem poised to give us at least a doubling of available magnetic field strength, and all the figure of merit that improve only linearly with size improve to the 2nd, 3rd, or 4th power with magnetic field strength. This is what could lead to break-even before ITER, not the mythology of American entrepreneurial moxie.

In my opinion, the article author knows whom he's flattering.

Oh, dear. Here goes more karma.

The veneer of innovation over the monopolies of the FAANG companies is pretty thin on most days, but VR and AR are two things that cause my suspension of disbelief to collapse entirely. Can I get up to pee while "immersed" in VR? Can I find my popcorn? Does anybody realize that the AR demos online are showing phone screens, and not the reality that you will see without a screen in front of you? (On some level, on that last, they do. But the hype seems built upon an off-by-one error in representation.)

We are no longer in an age of innovation and disruption with regard to the Internet. It has been thoroughly colonized, and any innovation will be bought by one of the big fish, in order to prevent the disruption of fairly lucrative relative monopolies that face no, or only the most glacial, threats from commoditization. VR is not it. AR is not it. From here on out, it's ML to try to improve on k-nearest-neighbor with k==1 to drive recommendation engines.

Much like the Moon Program propaganda informs outmoded (what I regret to call) virtue signaling around STEM, propaganda from the era of the rise of the FAANG group drives the same among ink-spillers around The Next Big Disruptive Innovation.

Here's a hint: Whatever the next disruptive thing is, it's not going to come to you via TechCrunch relaying Andreesen's ravings about which thing is bigger than what. If it happens at all. It's entirely possible that nothing will rise from the ashes of Facebook, for example.

Slightly off topic, but I can't play first person shooters--or, heck, even Minecraft--because I get motion sick from simulated motion with no actual motion. It's so bad that when I used to try to play, I'd continue to be sick if I watched, after I'd get sick and stop, someone play from across the room.

The odd thing is that I don't get seasick, which is (mostly) from actual motion with little, no, or confused apparent motion. Go figure.

What's interesting to me about this is that no major airline wants to go supersonic, for two reasons. First, because of the cost of development, and, second, because you lose a significant fraction of business class revenue to your supersonic fleet, raising the costs of tickets for leisure travelers and affecting routing. However, you don't want to be subsonic if another carrier is supersonic, because then they get your business class revenue.

It'll be interesting to see what happens if they make it.

It seems like this comment was anticipated in the article:

> One of the constant themes is the silent sucker—the person who was taken in but doesn’t want anyone to know,” Balleisen told me. Today’s America is very pro-entrepreneur, anti–big government; many Americans don’t have sympathy for people who lose their money to these kinds of schemes, he said. We celebrate the self-made man who starts a successful business from scratch, but mock the people who get duped trying to do the same thing. No one wants to admit that they’re the only one who can’t make it work.

> "..., there’s got to be a future in suborbital space,” Bennis said. “I want it to come in my lifetime.”

But, why? What possible benefit is there from a suborbital vomit ride? They're probably not even high enough to get the overview effect.

This is going to be the day of downvotes for me, but I can't see what good comes from strapping people in to a vehicle that gets less than 3% of the energy needed to get to orbit for a ticket price of $100k. None of the technical problems you'd have to solve would advance real spaceflight. It cannot be the space frontier dream of humankind to lob themselves briefly to 8 times the altitude of an airliner and then flop back down.

I'd have been embarrassed to have gone on that trip for that price, to the point that I'd have turned down a free ticket for fear of having given the impression that I'd paid.

In The Dictator's Handbook, by Bruce bueno de Mesquita and Alastair Smith, the authors outline why those who live in an extraction economy often do so under what we term dictatorships. Briefly, the supporters that are needed to maintain that extraction economy are a very small subset of the population and, from a government perspective, are not essential. The supporters you end up needing are the portion of the working class needed to run the extraction operation and a police force to keep the rest of the population in check. (Well, and a treasurer and some other bureaucrats, but the application here is to Texas in the U.S., where those services, and an army to defend your territory, are provided by the federal government.) In banana and oil republics, it's actually beneficial for the ruling class if most of the population is weakened and starving, as they are less able to organize.

Contrast this with a classical democracy, where the support base is the general population, and the treasury is made possible by the increased productivity of an educated populace who have access to infrastructure that supports their economic activity. In that instance, it is, broadly speaking, the health of the populace that feeds the health of the state.

I bring this contrast up at this time for two reasons. First, in the present case of an extraction colony existing inside a U.S. state, we can find a coherent theory of the difference between Republican/Conservative policies, such as states rights, authoritarianism, veneration of the mythology of the (by definition unempowered) individual, and left policies (I leave out Democrats, our centrist party): The former policies are tailored to preserve capital concentrations, favor extractive economic activity, curb controls on pollution, and suppress unions, all with the all-too-easy resort to violence (or it's equivalent, the all-too-common occurrence of looking the other way). The latter policies, from the left, are the opposite, intended to protect the (in fact) powerless and to broaden economic benefit, often through redistribution. Republicanism in this country, allied with business, exists in order to set up and protect banana republics at the state level.

Second, we can point to other trends that are worrying in the U.S. For example, infrastructure decay should be seen as a lagging indicator of the economic vitality of a democratic nation; if the benefit of infrastructure accrues indirectly to the ruling class through the productivity of the working classes, then it (infrastructure) will be maintained. After that benefit has gone away (say after manufacturing, technology, and information jobs have moved overseas) the infrastructure can be allowed to decay, as other economic systems arise to extract what's left. Unfortunately, what's left is the remaining savings of the working classes. Think ad revenue for eyeballs, opaque healthcare markets and lack of medical accountability to generate and capitalize on health calamity, cornered apartment markets to extract rent, isolated extraction economies like Dakota shale and the Permian basin, farmland, and so on. No longer relevant to the productivity of a nation, the citizen becomes, at best, a resource; at worst, a burden.

Anyhow, for the reasons above, I find the presence of these extractive economies inside the U.S. worrying, more so if they are increasing. The dynamics of power, namely wealth extraction in order to pay supporters, do not bode well if it really has come to this.

The critique of the propulsion scheme was laid out in the video. It was just framed in a way that tried to dodge the reality that this system cannot scale. For example, rather than presenting the thrust densities in a table for easy comparison, they were presented serially, so that the viewer might miss their relative scales. Quickly: What is the ratio of the thrust density of a jet engine to the thrust density of this ion propulsion scheme?[1]

Near the end, during the segue to the sponsorship at the end, he says, "This technology is in its infancy," alluding to his opening comparison to the Wright brothers. This is ridiculous. Not all weak or underpowered novel things are "in their infancy," awaiting further development into enabling technologies for our Glorious Future. This one, for example, has all the problems of battery energy density plus the problems of dragging, for example, tens of kilometers of wires through the atmosphere at passenger-jet speeds.

But, as I said at the beginning, that critique is contained in the video, just framed positively and obscured by weasel tactics. [2]

[1] Roughly 3300 to 1. An airliner using this scheme would need engines with a frontal area equal to 6600 high-bypass turbofan engines.

[2] Brought to you by Carl's Jr.

The Real Engineering channel has deteriorated into drivel. He spent half the video discussing ion engines for spacecraft, presumably in a bid to drive up enthusiasm around efficiency and top speed, before embarrassing himself with his discussion of the ion plane experiment. This technology is stillborn for the reasons he himself gives, though he dances around that, hoping against hope that few enough users will understand that the video is a flimsy excuse for a SkillShare ad, so that he can continue wringing sponsorship dollars from his increasingly pathetic offerings.

> The Sun is huge, so overall the amount of generated energy is huge, but on Earth a power plant that has the same power density as the Sun would need to have a volume of 4 billion m3 to be similar to a typical fission power plant (1GW). That's 4 cubes of 1 square kilometers each.

The density, in terms of fusion events per m^3 per second, is orders of magnitude higher for a tokamak than in the Sun. Stars are very inefficient at fusion, as you point out, because the cross section oh H-H fusion is so low. Deuterium-Tritium fusion has a higher cross section, and the conditions we can reach realize a much higher rate of fusion.

I built a paper and drinking straw canard glider in the 7th grade for a class project. I took Flight Dynamics and Control in college, while obtaining my degree in aerospace engineering. Your misapplied intuition about arrows is not at all convincing. Simply, you do not know anything about the stability of aircraft.

EDIT: WalterBright edited his comment to add examples and commentary after the arrow example. IOW, he added:

> Or make a paper airplane and toss it backwards.

> Or buy a toy glider and launch it backwards.

> They are unstable.

after I replied. His original comment was just:

> Try shooting an arrow with the feathers in the front :-)

A shitty move. I'll only address the "launch it backwards" comment, as the remaining bits are even more idiotic.

A canard airplane is not simply a backwards airplane. The criterion for stable forward motion, in pitch, is that dCm/d_alpha is negative, where Cm is the moment coefficient, and alpha is the angle of attack, and that the center of gravity be ahead of the center of lift. A "reversed" airplane, in either conventional or canard configuration, would have the center of gravity behind (in the new direction of travel) the center of lift, and would therefore be unstable.

Yaw stability is obtained by the vertical stabilizer exerting a moment opposite to the current yaw, by virtue of being behind the center of gravity and center of lift and, when yawed, being angled toward the midline of the aircraft. This is why, on a canard craft, the vertical stabilizer(s) are at the wing tips, or behind the center of lift and center of mass. A reversed aircraft, in WalterBright's imagination, or at his desk--It is difficult to trust anything he says, at this point.-- would have its vertical stabilizer ahead of the centers of lift and mass, and therefore destabilize the aircraft.

These two, that the center of mass is behind of the center of lift in the reversed configuration, and that the vertical stabilizer are ahead of it, are the actual reasons that WalterBright's toy glider, surprise, prefers to fly in the direction for which it was designed.

(He mentions the glider at his desk in his reply to this comment, which I will reproduce here, in case he deletes it: "I have a glider in my office. I launched it backwards. It promptly flipped over and proceeded in the normal direction.")

It would be interesting if, for example, WalterBright could produce a discussion from, say, Aerodynamics, Aeronautics, and Flight Mechanics, by Barnes W. McCormick, for example, warning the unawares aeronautical engineer in training of the dangers of the supposedly unstable canard aircraft.

The discussion above is all elementary flight mechanics, of which WalterBright would be aware if he'd had any training, or any expertise. Contrary to his repetition, his intuition does not suffice, and will not overturn these facts.

From the researchgate paper:

> Thus, it did not exceed the stick free neutral point and it is static stable for the entire operating envelope of the aircraft.

It looks like the canard design in the paper is stable, and the blanket statement that canards are unstable is, as yet, unsupported.

Whether one is able to settle on a working solution involves luck. The article says they "noticed" that birds warp their wings. They were unlucky, for a time, in that they experienced adverse yaw. Then they were unlucky, for a time, when a fixed tail arrangement did not work. Then they made the tail assembly steerable.

They were also unlucky in that they killed a passenger, but lucky that it wasn't rather than one, or both, of themselves. I realized that luck-minimizing framings are popular within entrepreneurial settings, and particularly in cultures where we're all "temporarily embarrassed millionaires," but it would be far healthier if we took on board the role that fortune plays in success. We would be, for example, far more heroic if we were facing odds, rather than a grind with a guaranteed success at the end.

The Dictator's Handbook by Bruce Bueno de Mesquita and Alastair Smith

Everyone should read it. You think you know politics, but you haven't even begun until you've read this book.

Must. Not. Pick. At. Scab...

> Do we even had a model for Fussion that is energy poasitive? The only Fusion reactors we know to work, work by converting gravitational potential energy into light/heat through fusion this is how stars operate.

> All fusion reactions so far require an external input of energy not only to start them but often to sustain them and even those which are self sustaining for a short period of time grind to a halt once you try to extract energy from the system.

That was your original question. It contains, as everyone is aware, your original statement that stars work by converting gravitational potential energy into light and/or heat through fusion. This claim is patently incorrect. It is false. It is misleading. It is a red herring, and a canard. You seem susceptible to it, for some reason. My only advice is to just set it down, over there, and don't play with it. The only winning move is not to play.

> And does this model including the confinement energy is energy positive or not.

Sigh. There is no "confinement energy." This is a physics-sounding phrase that you seem to have coined. Set "confinement energy" down over there next to your original question. It's poison.

> This requires energy so instead of trying to explain me high school physics...

Sigh, again. How much energy, quantified, in the mathematical language of physics and engineering? How much in comparison to the energy released quantified, in the mathematical language of physics and engineering? While these are technical questions, the answer, given by physicists and fusion researchers since well before ITER, is: "We get way more energy out. Full stop. Solved problem. Tokamaks work, with a lower size limited by magnet technology, but not by first law physics. (Implicitly, people who question this at length are cranks.)"

You simply have no basis to go around demanding "a model." If it hit you in the face, you wouldn't recognize it. You, personally, can't quantify this "require[d] energy." You, personally, therefore have no reason, other than obstinance, to think you have some relation between the amount of energy released from a fusion reaction and the energy necessary to create the conditions for fusion. None. No other reason. Pure mulishness. The question is dumb. You are dumber for having asked it, and I am dumber for having read it. It is contagiously, toxically dumb. Please stop. There is no longer any nice way to say any of this to you.

And the one thing you need more of is high school physics, not less.

> ...do we have a model which allows for the extraction of energy form [sic] a fusion reaction that does not cool it down until it stops[?]

Which fusion reaction? Where? So, you can set a solar panel up to do "extraction of energy" from the Sun. Experimentally, this has not shut down fusion in the Sun. So, yes? We have a model? Further, there's no way to not "extract energy" from a fusion reaction, whether or not that "extraction" shuts it down. You, and I, generally exist at a lower temperature than fusion reactions. Ergo, we are extracting energy via radiation from every fusion reaction in the Universe, via heat transfer.

> If we want to simulate gravity in say space there will be an expense to that in terms of say rotating a drum which means we need to expand some energy to do so.

There's a legitimately beautiful and elegant answer to all this energy nonsense in that thought experiment. The answer leads to even more beautiful math about energy, momentum, ground states, and stability. It would be wasted, here.

I'm going to go have a shower, and maybe a drink. This has been an awful waste of time.

No energy is being continuously invested by gravity. It is not "keeping the reaction going" in that sense. It's simply freshman physics that tells us that forces only do work when they act through a distance. Because the star's surface is not moving inward, it is not doing work, i.e., giving energy, to the star. Furthermore, the Sun, for example, is probably slowly expanding right now. It will start to do so in time, at any rate. That is, the work done by gravity on the Sun will be negative during that time, and fusion will continue. You just aren't making any sense. You are either not trained in physics, or have failed to understand what you have learned. You could begin to piece together a better education in it by simply following up on my replies in this thread. Please, take it from me, you do not know what you are talking about, and your concerns are therefore not valid. I thought I could help, but you seem to be a tough case.

In short: Forces only do work by acting through a distance. Work is energy. If no work is being done, no energy is being produced. Therefore, gravity is not "energizing" the reaction, because the net motion of the star towards its center is zero when it is in equilibrium.

In shorter: No motion => no work. No work => no energy. No energy => no problem.

"...the fact that is triggered and constantly maintained by gravitational collapse."

What you have written is not a fact. Forces only do work when they act through a distance. Gravitational potential energy only comes into play during the ignition of a star. After equilibrium is reached, to the extent that the star's diameter is "static" potential energy calculations no longer come into play. No "potential energy" is being "converted" into fusion energy. It's just not a thing.

"...stars are in constant balance between gravitational collapse and their outward pressure caused by fusion."

Because of this balance, no work is being done by gravity. That is, no energy is being released by the force of gravity moving a mass through a distance.

"All I want to know is if we have a proven net positive model for this reaction because so far I haven’t been able to find one."

It's literally E = mc^2, but it's not "net positive." It's net zero. Matter is converted into energy. That's it.

"So no I don’t ignore the role of gunpowder in a gun,..."

It's an analogy, and it's straightforward enough that the onus is on you to work out the pieces a little better than you have. HINT: The "energy needed to create the gunpowder..." is the binding energy in the various nuclei.

Stars simply do not "work by converting gravitational potential energy into light/heat through fusion." The "light/heat," or energy, that stars produce comes from the mass defect of the fused atoms. Basically, the binding energy of He is less than the binding energy of the (net) 4 H atoms that go into the reaction. It works so well in the sun because of the long confinement times and the long transit time for energy to get from the center of the the star to the exterior.

"...while I’m not by any stretch of the imagination an expert in fusion physics...I can at least understand conservation laws..."

I don't think that you have a firm a grasp on their application as you seem to suspect, though I agree you don't understand the physics of fusion. Your reasoning is analogous to neglecting the contribution of smokeless powder to the performance of a rifle, because a rifle is just "converting" the energy stored in the hammer spring into energy in the bullet.

That's the best I can do for you. Good luck!

> Aren't watches anachronistic, though?

This is perhaps the best pun ever to appear on HN. I hope it was intentional!

> And if the employees placed thier [sic] values over profits, why are they still there?

There is probably more than one kind of profit. I think that if you've got a mortgage on a SV condo or house, and made plans for your financial life based on your income without knowing what the company you work for was or would be up to, you may be in a pretty good position to say that it's okay for you to accept a salary as you protest the action or actions of the company. Not to mention, strikes or other means of civil (commercial) disobedience might have more of an impact than simply leaving. By placing the onus on Google to fire you, you have PR and legal leverage (wrongful termination, if your moves are careful (IANAL)) to change the situation, whereas if you leave, you just go quietly into that good night, and the situation is guaranteed to continue. Complicity isn't always a black and white matter.

> I wonder if they are going to refuse their stock based compensation?

Stock-based compensation, I imagine, is on a vesting schedule. The same discussion as above applies, except that some of that compensation represents value that may be notionally "clean," having been earned outside the scope of the bad acts, either temporally or organizationally. It also represents earned compensation. Finally, its refusal would only serve to enrich Google, the ostensible bad actor in this instance.

However, what sickens me most about the OP's drive-by rhetoric is its reflexive turn toward reactionary complacency. It seems to say that those without sin only are allowed to cast the first stone, but really universalizes something like original sin to justify complete complacency. Further, it ignores the power imbalance between employer and employee, and minimizes the bravery of those who are speaking and acting out against injustice. It's despicable.

In the extreme, two successive trades, where the first gains 110% and the second loses 100%, “average” out to a 5% return. However, you don’t want to make that pair of trades.

The Froude number appears to be a dimensionless parameter. Dimensionless parameters and the Buckingham Pi Theorem are fundamental to physics, and especially fluid flow. It boils (ha!) down to the ideas that 1) A fundamental law of physics must have consistent units, and 2) Dimensionless quantities function as similarity parameters. The Reynolds Number is arguably the most famous of these (alright, Mach number <sighs>), the ratio of inertial to viscous forces in a fluid flow. ("How much like water divided by how much like honey" is a pretty good heuristic.) You can actually derive fundamental physical laws through dimensional analysis. Powerful stuff. One could do far worse than tracking down as much as one can about these principles as early in one’s engineering or scientific career as possible. It’s as big a shortcut in the hard sciences as Latin is for medicine.

What is presented without evidence can be dismissed without evidence. But this statement can be dismissed twice: Not only is it not established that brevity gives life meaning, it isn’t established that life even has or needs meaning!

While the article title is sensational, it’s encouraging to see SENS getting wider traction in the public imagination. A lot of the other proposed therapies seem to involve genetic engineering, and this one seems more somatic, more at the scale of designing a drug to work at the scale of cells, vs the scale of DNA. It seems, to my interested layperson’s mind, that a rough and ready treatment is more likely at this scale, albeit one less likely to result in 4-digit lifespans, measured in years. This does make one of my fears more imminent, which is what to do with things like teeth, the vitreous humor, extant arthritic damage, and other systems and organs, the effects of aging for which the body has more or less lost or never had cells in place that can be recruited for repair. Time will tell. With any luck, we’ll have loads of it!

> //sarcasm is not even enough to describe this lunacy that's eating the world//

The author’s “accidental racism” phrasing is a little awkward, but the idea is there. The point isn’t that “whitelist” and “blacklist” are “racist terms.” Clearly, they are not. The point is that members of the audience for your documentation, paying members and influencing members, could be harmed by them in certain contexts. We don’t always have control over the context or situation in which the user encounters the documentation. For example, I could say that your response is "hysterical," indicating that I find the notion that this is "eating the world" to be overly emotional and alarmist. If you, or another reader, were female, you might then object that "hysterical" shares its root word with "uterus," and its etymology and current shading indicates "characteristic emotional and mental weakness that stems from having a uterus, i.e., from being or being like a woman."

Writing is an exercise of power. It is even more so than verbal speech, in the context of documentation especially, because it provides no forum for the user, your paying user, to clarify and to point out offenses. And take a deep breath, because even if this lunacy eats the entirety of software documentation, the world will be nowhere near consumed. You might even be richer for it, in both senses of the word.

A quick Google image search reveals that the airfoils on the Disco do not have rear-facing steps. These steps are the defining feature of the KF foil family.

One thing I like about this idea is that there doesn't seem to be the impact that, for example, a hydroelectric plant would have. In other words, because the streams are intermittent, and because most of the flow seems to be restored by overflow downstream, you don't interrupt things like migratory fish.

It's a neat concept. It gets the water beneath a thermal mass, stabilizing its temperature and preventing evaporation. The water can become available to deep-rooted plants and trees, too. I wish I'd thought of it!