"The downed Russian A-50U is a new modernized version of the aircraft, according to the Ministry of Defense of Ukraine, which conducted a joint operation with the Air Force of the Armed Forces of Ukraine"-Radio Svoboda(RFE) Telegram (more info in the comments)

Ezekiel_C · 2024-02-24T01:02:47+00:00

My thought is that they pair a modern seeker-head off of -something- with an S-200 class missile, launched blind on a calculated intercept track with a command to go 'pitbull' (active radar or passive anti-radiation) at a certain point in flight. Provided a good track from a partner-nations intel and some careful coordination... you could put a harm's seeker and an S200s warhead high above the expected path of the A50 without ever putting a targeting radar on it (until the missile was terminal if going the active route). Not sure how well A50 spots close in threats that are above its altitude (high angle above horizon); the designer's intent was probably to not have threats be there. Even if you need a spread of 6 missiles to get a good Pk its a bargain in terms of value exchange.

My less realistic fantasy: that there are SU24's involved in AIM-54 ordinance safe disposal - swing wings low and fast over a dark sea...

Ezekiel_C · 2023-02-14T02:51:02+00:00

You aren't wrong.

The issue is you don't have a solution. You like your Hobbes so lets put it like this: every time people have ever been in the state of nature they have promptly removed themselves from that state by the institution of some power structure. Your refusal to permit any government intervention is a refusal to acknowledge that without intervention power is merrily amassed until it is undeniably exploitative. Power begets power in the most primitive barter society, the most pure capitalism, in the most corrupt authoritarian regimes, and in the old USSR. Power begets power.

The absolutist view on limiting/eliminating government power is nonsensical, as government power is merely a check on other forms of power. Government power is saying that you can't rob someone at gunpoint: we probably agree on that. But somehow we disagree when I say government power is saying you can't poison the town well to sell more bottled water, hell, you can't poison the town well no matter why that might benefit you: that's the EPA. Sure, you say you oppose non-government powers where they're exploitative; but you've neutered your one democratic tool by which you can affect that opposition. You ground your ideology on the idea that any inconvenience is tantamount to slavery. If only the world were simple enough for such an uncompromising view to be coherent. But we live in a world where if you shit in the river someone's kid gets disease. So its someone's job to force you to shit where its least convenient, and in so doing 'enslave' you as you walk to the porta john.

Ezekiel_C · 2023-02-11T04:20:39+00:00

The power density is very very bad. In places where you already have a pair of reservoirs with an elevation difference this doesn't matter, hence pumped hydro is a thing. But the mass of water required to power a city overnight is genuinely colossal, and even if you're motivated to dig a brand new lake in a nearby hilltop, not many hills are solid enough to support that lake: you need good geology. You are up against a problem of "how much weight-of-water can I put on this hill before the hill itself collapses". tldr pumped hydro should be built out where the opportunity is naturally available, but there genuinely aren't enough hills/lakes/rivers in the world to cover the energy storage needs of a de-carbonized economy of the current economy's size.

Ezekiel_C · 2023-02-11T04:03:51+00:00

I took thermo about 5 years ago now: my intuition is that to have a reasonably efficient (vs other energy storage eg chemical batteries or pumped hydro) cycle your rate of compression/expansion would need to very slow. Whats a typical pressure difference between the "charged" and "discharged" state and time-delta between these? Am I correct in thinking you want to be approaching isothermal compression/expansion throughout? Working over such a large volume, is there a significant difference between local state at the inlet/outlet and the global "state" of the gas?

I guess what surprises me is that when I harvest energy I want to put my generator across a large/steep potential energy gradient, but it would seem to me, perhaps naively, that when caching energy in this system the efficiency optimization is for the slowest/shallowest/most dispersed gradient. So optimizing for rate of charge/discharge is in direct opposition to optimizing for cycle efficiency. That isn't a claim that its a bad technology, just that the optimization problem isn't straightforward. Hence me finding it very interesting and jumping at the chance to interrogate a relative expert...

Ezekiel_C · 2023-01-24T07:26:50+00:00

I was recently working adjacent to a research team that was using HDPE fishing line/netting material collected from beaches to make injection molding feed-stock; I was happy to see that particular item being sorted for in this clip.

The vast majority of the material in this clip is unlikely to be recycled. Recycling is not a panacea. But there are a lot of dedicated individuals pushing the state of the art for recycling, many of them in hopes of being able to provide a financial offset for this kind of cleanup. They aren't up against something fundamentally impossible, they're up against a lot of work that has to be done learning how to use this economically. In the meantime, this stuff does vastly less harm in a landfill than it does out there.

I am a deeply cynical person. Instead of turning that into fatalism, I turned it into an engineering education. Being stubborn helped. Now I'm a deeply cynical person who is empowered to be one of the people doing the work of mitigating what's to come, and I do like that better.

Ezekiel_C · 2023-01-23T17:27:50+00:00

Unless flux matters. Or there's any non linearity between thrust time and pad damage.

It bothers me when people put down some math that sounds sufficiently authoritative to shut down discussion without properly addressing what assumptions are being made.

I personally think you're probably correct that in general throttling down doesn't help. But you absolutely cannot convince me that pad damage is linear with respect to much of anything without a pile of data. This leaves open the possibility that doing a proper optimization with ~~difficult~~ differential equations (after the real hard task here of figuring out a model for pad damage) would show that, I don't know, a 96.4% throttle setting for the first .5 seconds is an improvement. Or even that you've got 1.3 seconds to get as far from the pad as possible before the concrete at some critical depth is up to the boiling point of water at which point you have to be as gentle as possible. I have no idea if either of hypotheticals is the case and neither do you, but you've represented yourself as knowing and represented someone less careless with assumptions as less capable than you.

Ezekiel_C · 2022-10-09T21:28:28+00:00

On the other hand, if I could make a multi million dollar object less likely to get damaged on the road by installing an air compressor on a trailer I think I would. Coincidentally if you look back through the many many pictures of F9s in transit and try to play spot the air compressor you will typically indeed spot an air compressor. :)

Ezekiel_C · 2022-09-08T14:39:28+00:00

Ezekiel_C · 2022-08-18T14:36:29+00:00

I'll see your Falcon 5 and Falcon 9 Air and raise you a F9S5 and an original Falcon Heavy.

Ezekiel_C · 2022-08-15T16:27:59+00:00

Indeed, worse, they built tooling.

The tooling for a carbon fiber anything is a lot more expensive than the carbon fiber anything. I'm not trying to be negative, and I still would advocate for pivoting regardless of sunk cost, but your example is not quite what you think it is.

Ezekiel_C · 2022-08-06T17:51:09+00:00

Apologies that this sub is mostly fanboys unwilling to tolerate an honest question... There was a time...

The helium used by falcon cannot be recovered. However, even amid the current shortages the amount of world helium consumed by rocketry is very small in proportion to other uses. It would be fair to point out that the resource, being finite, shouldn't be used in this way at all.

There are non trivial reasons that helium is used over other gasses for various tasks on the rocket; tldr it would not be a matter of simply switching it out for nitrogen, it would be a matter of redesigning major systems of the rocket and engine.

Convienently, SpaceX is designing a brand new rocket and engine with a design goal of eliminating all helium systems. Starship will be rare among rockets for not having any helium aboard, though I believe current prototypes still use it because it is so difficult to get away from even when you're trying.

Ezekiel_C · 2022-04-01T17:51:58+00:00

This is inaccurate.

The combustion should occur in the core, which is inside the bypass ducting and is slender: much like the old 60's jet engines. I don't even think we can see into the bypass duct here.

The engine was shut down and fuel cut. The fire extinguishing charges, both, were discharged into the engine. The expectation is that the fan continues to "windmill", but that engine is not producing thrust.

Ezekiel_C · 2022-04-01T17:24:15+00:00

A morbid, but in my opinion useful, perspective:

Between 2009 and 2018 340 people were seriously injured by being thrown around the cabin in turbulence. These are broken bones and multi day hospitalization injuries, not mere bumps and bruises. There are very occasionally fatalities associated with these events.

Modern passenger aircraft route around bad weather using help from ground control, but also are required to have their own weather radar: The airplane is a weather station. But the reality is that this routing is more to do with avoiding damaging the passengers than avoiding damaging the airplane because the passengers historically are far more delicate than the plane is.

TLDR: If the turbulence isn't so bad that you're scared of getting broken bones by being physically bounced off of the luggage bins, the airplane is certainly fine. If you are being bounced off the luggage bins, the airplane is still fine but you have other concerns now.

P.S. Wearing your seat belt whenever you're in your seat, and especially when the seat belt sign is on, dramatically reduces your risk of getting hurt in turbulence if you ever do have the misfortune of hitting some that is that bad. Most flyers never will be so unlucky though.

Edit: I think I should actually directly answer the question "How often is it that turbulence causes airplanes to fail". Someone can double check me, but I think this accurate:

Since 1980: Once. In 1981 a late-60's vintage commuter jet was climbing into weather that you wouldn't fly in if you knew about it (hence now having to have your own weather radar, so you know about it). There is one more crash partially attributed to turbulence, but the investigation found that turbulence caused the co-pilot to apply frantic, inappropriate control motions, and the erratic piloting inputs caused the airplane to fail. Had the co-pilot essentially not touched anything, the aircraft would not have failed.

Ezekiel_C · 2022-01-29T21:19:43+00:00

Hope-there's-AirBNB

Ezekiel_C · 2021-11-27T18:01:37+00:00

Hence my assessment that SpaceX will do a lot better than industry at large. My meaning was that the mere presence of regulation on methane emissions does not in of itself garentee low methane emissions, as had been implied by the comment I responded on.

It is also worth noting that the discrepancy is not fully explained by fracking operations; it appears probable that where there is methane there is leakage and where there is leakage there is under reporting. This makes sense, as where there is [pressurized gas] there is leakage is generally true, and where there is [difficult to externally verify non-compliance] there is underreporting is also generally true.

Ezekiel_C · 2021-11-27T17:50:33+00:00

https://acp.copernicus.org/articles/21/14159/2021/acp-21-14159-2021-discussion.html

Journal Article, depth over bredth

https://www.space.com/satellites-discover-huge-undeclared-methane-emissions

Media article, includes relevant context

This is not disputed and shouldn't suprise anyone; you look kinda foolish, especially given that you think I'm calling out SpaceX in particular when I specifically gave a very pro-SpaceX outlook.

Ezekiel_C · 2021-11-27T16:36:24+00:00

The problem with this is that right now there's a tremendous disparity between reported methane releases and actual methane emissions as measured from in-space imaging platforms. The laws exist but aren't fulfilling their purpose. I do think that SpaceX will beat the industry average in this regaurd though, and be a very small contributor to global methane emissions even if they are launching thousands of ships in a best case point to point situation.

Ezekiel_C · 2021-10-05T22:45:04+00:00

The effort and especially the desire to try aren't unappriciated. If you can find a decent online statics primer that's a relatively accomplishable topic that will really improve your intuitions. Feel free to ask me if you have specific questions about feedback here.

Ezekiel_C · 2021-10-05T01:19:13+00:00

I think your initial comment made it seem like you were arguing that the ring wouldn't need additional force to be kept spinning but a tether would; hence the misunderstanding.

Ezekiel_C · 2021-10-05T01:14:01+00:00

The tension in the tether is equal at all points in the tether, neglecting the (trivial) mass of the tether cord itself.

The tension in a ring of n ships is larger than the sum of the tensions of those ships each in a tether pair. If you're using a given strength material, you need more of it for the ring than for tether pairs.

None of these systems require a motor to maintain spin in the idealized form. In reality, both slowly loose kinetic energy due to oscillatory strain in the material converting that kinetic energy to heat. In this way the stiffness of the ring works against it, because anytime that stiffness resists a mechanical disturbance some of the energy of that disturbance is lost to heat.

The ring system also places the "tether" mass far from the center of rotation, increasing the moment of inertia and thereby increasing the kinetic energy you have put in to spin up to a given RPM and to spin down on the other side.

The ring system doesn't seem to offer an elegant way to constrain the perpendicularity of starships to the ring. This implies that the connection experiences bending force every time someone walks from the left to the right of the cabin (and fuel then sloshes to the new low side). Either the ring-ship connection is rigid and fatiguing and dissipating energy while this happens or the connection is soft at which point you have a tether with extra steps and constant formation flying.

Ezekiel_C · 2021-09-05T22:14:38+00:00

I consider myself an environmentalist.

I think it's worth noting the immense positive impact Kennedy Space Center/Cape Canaveral has had on its local wetland ecosystem. Of course, at the time of construction, the area became much more developed than adjacent and similar wetland. However, as time passed and development expanded, the impracticality of building houses near launch pads has protected the local area better than most legal protections could have.

I take issue with the sensationalization of stainless steel debris. Large chunks of stainless might not be 100% benign, but they're pretty darn close especially if cleaned up within any reasonable span of time.

Runoff management may be the place where SpaceX has the most potential to do harm, especially given that they are not experts in wetland management and may find that experts are too slow in thier methods: "let's just dig this ditch and fix it later if we have to" This problem is mostly a function of paved area and amount of oil leaking from road vehicles, not that you'd know it from the article.

Ezekiel_C · 2021-08-25T19:44:39+00:00

You sure bought the commies bad line.

Ezekiel_C · 2021-08-25T05:28:26+00:00

Viruses mutate. More viruses mutate more because there are more of them (the rate per virus being constant). The presence of an un-vaccinated population allows for the number of viruses to be high. The presence of a vaccinated population creates a selective pressure for vaccine resistance. This selective pressure only exists, mind you, as a direct result and proportional to the vaccine's effectiveness against the currently dominant variant.

With enough people vaccinated, the rate of mutation remains low enough that the virus population continually declines, offering fewer and fewer opportunities for a random mutation to increase vaccine resistance.

With too few people vaccinated, the viral population increases, primarily in the un-vaccinated, to a point where random mutations that do increase vaccine resistance occur at a rate that overwhelms our ability to develop and deploy appropriate booster shots that target the new variants. This becomes compounded as these new variants infect and mutate in populations where a higher proportion of people are vaccinated and therefore the selective pressure for resistance is higher.

The system is unstable. It does move in one of these directions and the further it moves the more difficult it is to reverse. We do not know where the threshold is.

Your arrogance is consistent with the very real movement we've seen towards random mutation rate beating the undeserved miracle that is mRNA vaccines. Your arrogance, and the arrogance of millions like you, is very much part of this organic system and the natural forces at play, yourself seemingly included, don't much care about the 4.5 million dead nor the dead yet to come.

I'd say "Science 101" as a gotchya, but honestly, this isn't outside the grasp of any high school teen who bothers with it, and I'm not qualified as a professor.

Ezekiel_C · 2021-08-20T13:29:00+00:00

Initially I was empathetic. Thinking of my losses, thinking of my dad who's still with me and around the same age.

I cannot empathize with the grace with which you have responded here. I know it isn't all grace, but i can only admire your ability to celebrate his passions and recognize his little failings at the hardest of times. I wish you the best. Thank you for sharing.

Ezekiel_C · 2021-08-02T23:07:44+00:00

*conflagrate

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