November 25th, 2021

#7911: I had my doubts, too

Spinlaunch seemed like a solution in search of a problem.

The idea is to take a...vehicle? Spin it up in a vaccum, then let it go at just the right moment so that it flies upward at some appreciable velocity, then ignite rocket motors somewhere near the vehicle's apogee.

You see, getting things into orbit around Earth is difficult. It requires a hell of a lot of energy. Tajke the Saturn V, for example: the first stage was massive, and had to be, merely to get the entire rest of the rocket started. It couldn't push the lunar mission version into low orbit. What it could do was to get the rest of the stack high enough, and moving fast enough, that the second stage could make low orbit.

Now SpaceX has managed to build a reusable booster that can lift useful payloads. Like the Saturn V, it merely gets the second stage high enough, and moving fast enough, that it can make orbit. Unlike the Saturn V, it returns to Earth and lands itself for reuse later.

There have been a myriad of proposals for eliminating or reducing the size of the booster, though--that first stage of the rocket. The idea is to reduce the amount of fuel the vehicle needs to carry. The less fuel you need to spend on getting the load moving--and punching through the thick air near ground level--the more of your total liftoff weight can be payload.

The alternative that's seen use is to take the vehicle up in an airplane and drop it, way up high in the thin air. The speed of a jet aircraft is negligible compared to orbital velocity but you don't have to spend any propellant on fighting through 90% of the atmosphere. Also, your engines can be optimized for low/no pressure, which helps a lot for other reasons. Virgin Galactic uses this method; also some others that I'm not going to look up right now. It works reasonably well.

There are others, though, that haven't had much, if any, practical work done...and Spinlaunch is one such method: the catapult.

The idea behind a catapult-assisted launch is to give the vehicle some appreciable velocity and hurl it upwards. If you can get it even two miles up before you have to light your engines, you'll save that much fuel--and it's actually significant savings, too. But making a catapult that can get a rocket moving that fast is problematic, for a whole bunch of practical engineering reasons I don't feel like getting into right now.

Spinlaunch proposes to fix that by putting the vehicle into a circular chamber that's been pumped down to a vacuum, spin up the thing, and hurl it straight up, kind of like a sling and a stone. Their 1/3-scale test was successful, tossing their test object two miles straight up.

I wasn't impressed, though. There are some practical concerns I have regarding this method; though I have to admit the issues brought up in the linked post were not ones that had occurred to me.

First off, the vehicle has to be able to withstand a great deal of centripetal acceleration. Apparently the vehicle is (in the 1/3 scale test system) whirling at three revolutions per second--which is not surprising if you think about how much altitude they're trying to reach--and that has got to be generating a significant amount of force. Centripetal acceleration is something like velocity squared over the radius; that's a pretty long arm and it's moving fast, and for a given angular velocity, the longer that arm gets, the stronger the centrifugal force is. Translation: "Anything delicate go squish." What's the point of saving fuel if you have to build your vehicle extra-sturdy to withstand the lateral loading impressed on it by the launch method?

Second, your vehicle cannot be very large. It has to fit inside the spin chamber.

Third, SpaceX has demonstrated (very handily at this point) that useful payloads can be lifted--and very, very economically!--using reusable first stages. The more exotic methods (including catapults) would seem to be unneeded.

But then we come to the article, which adds another factor:
...[T]the projectile emerges from the "muzzle" of the launch tube crooked. ...because the projectile is *tumbling.* In retrospect this makes sense: while attached to the rotating arm, the projectile is rotating at about three revolutions per second. Once released...there is nothing to arrest that rotation. So it leaves the "barrel" tumbling. This would be *disastrous.* Even if the fins could stabilize the projectile in flight, a massive amount of launch energy would be wasted in the process....
There's a lot more detail in the post, but that's the gist of it.

All the fuel that you saved yourself by using a catapult, all the energy you didn't have to burn fuel to acquire--and you waste a good chunk of it on merely getting the pointy end into the wind.


Well, the one saving grace here is that it was a 1/3 scale "proof of theory", not a final working system. Perhaps they have plans to handle that issue, though I sure as heck don't know what that would involve. Maybe a maneuvering jet starts firing laterally as soon as the vehicle is released, to get rid of the unwanted yaw? They have to do something about that yaw moment, because otherwise the vehicle will tumble, as mentioned above.

Oh well.

#7912: Heck with it, a little bit of politics, even though it's a holiday

Because it's holiday-related politics.

Salvation Army, converged. Vox Day puts his two cents in on this one, but what I'm most interested in is something from his blockquote:
When asked about the rift over the woke curriculum by Newsweek, the Salvation Army's spokesman, Joseph Cohen, insisted the organization hadn't changed its ideology in any way.
...which is SA desperately trying to have its cake and eat it, too: they want to lecture whites on how racist they are but they also don't want those white people to stop donating to them.

I'm sorry to have to break the news to you guys, but the simple fact is that if you've decided that white people--as a class--need to apologize for being racist, you have changed your ideology. The idea that white people are inherently racist is one of the pillars of critical race theory, which is a leftist philosophy, which is (not incidentally) utterly inimical to Christianity for a variety of reasons.

So, not buying it. You guys decided to go woke; and if you now go broke, tough shit. Maybe you can get money from all the leftists whose favor you're trying to curry with this horseshit.

* * *

Ivermectin works against the Wuhan Coof. The most interesting aspect of all this is how tenaciously the medical system fights against trying Ivermectin as a "last resort" when someone is dying of the thing. The judge rules correctly when he asks (I paraphrase), "What can it hurt?"

Oh, gee, this drug might cause nausea or diarrhea or dizziness. The man is DYING. I don't think a little wooziness is going to hurt anything.

But you see, the point is that any time someone's life is saved by Ivermectin, it's another data point to a conclusion which our medical system really doesn't want Americans to see: the vaccine is utterly worthless, and giving everyone $3 worth of pills is enough to stop the damned Wuhan Coof cold. It worked in India, it worked in Japan--it works everywhere it's tried.

Meanwhile, heavily vaccinated countries are seeing another surge in cases, because the vaccine doesn't work.

And, as always, the only motivation necessary is "money". Ivermectin is $3 per person. The vaccine is $30-$50-$90 a head. Hospitals get government money for each Wuhan Flu case they handle--up to a hundred thousand dollars each--and if people can get over the thing quickly and at home with $5 worth of over-the-counter drugs, all that lovely money goes away.

And to hell with how many people die of vaccine injuries along the way.

* * *

The Waukesha terrorist is a real piece of work, all right. One thing I notice in that article is the picture showing him in court. Unless I am sorely mistaken, that GoreTex-muumuu-looking thing he's wearing is a bulletproof, eh, garment--and he'd better be glad for it, because I'd wager that people in Wisconsin are mad enough that someone might just peg a few rounds at that fucking waste of life.

* * *

If I keep going in this vein, I'm going to get pissed off, and I don't want that on a holiday. I only woke up around 6:15-ish out of habit; then I sat down here with a PBJ and a can of Mountain Dew Zero and started bloviating.

I am going back to bed to get some more sleep.

#7913: A quiet holiday

I was thinking, the other day, about what it means to be an introvert.

Okay--no one who knows me thinks I'm the life of the party. Any extroverted tendencies that I had got squished out of me in kindergarten. I ended up being a shy kid. No shame in any of that.

Of course I was picked on a lot in school. Bullies have their own twisted logic, but as far as I was concerned, I was perfectly fine with none of them liking me--as long as they left me alone. That was really the sticking point.

I mean, if I don't like someone? I don't go out of my way to say anything to them, or even to deal with them. I'm not a sadist, so I don't get the whole "it sure is fun to hurt people" thing; but generally speaking, if I hate someone, I find them unpleasant to be around. Why should I seek them out specifically to dump on them?

Because I never really understood that, I was baffled by it. I figured, fine, you don't like me, you want to exclude me--go ahead! You guys do your own thing and I'll do mine and neither of us has to put up with the other, and I promise I won't bother you unless I'm invited to.

But bullies aren't happy unless their targets are unhappy. So if you're fine being alone, reading a book over in the corner--that just doesn't sit right with them, and they can't just relax and live their lives without first making sure that you're as unhappy as they can possibly make you. Maybe you're happy, maybe you're not, but they're not going leave you alone and take the risk that you might be satisfied with the situation. The bully is constitutionally incapable of leaving you alone, sitting in the corner.

There is, in there somewhere, a metaphor for leftism. I'm going to have to think about that.

Anyway--as an introvert, being in a loud, crowded place is decidedly not for me, and when I have to be in them I need time out to decompress. I like the quiet. Parties are exhausting.

Back in the pre-Cambrian when Thanksgiving was held here at the family homestead, at least I had my bedroom to which I could retreat. We never had a huge crowd, though, either--before grandma died, it'd be Mom's side of the family, maybe a couple of others.

I'm trying to remember the last big Thanksgiving that was held in this house, the last time the whole "famn damily" congregated here. Can't be 1990 because that was the year my first niece was born. Might be 1991, or 1992? But there was a year we had the last big Christmas which might have been 1992 or 1993; I can't really remember. (A mere thirty years ago. Slacker.) It was in the 1990s, though; since my brother and his wife bought their first house, Thanksgivings were held at his house. (Because he's a doctor, on call, needs to be 15 minutes from the hospital, etc etc.) Anyway, the Thanksgivings at my brother's house are well-attended and very, very loud. It doesn't help that the living spaces of the house are all hardwood and tile and no rugs, so it's one vast echo chamber. And like I said, I don't really do well with those situations. Having to get up and shower and dress up and drive somewhere and make inane chitchat and wait for dinner and then eat and sit and wait to go home while everyone else watches sportsball games, with the TV on extra-loud and everyone trying to talk over it, and nowhere is there a quiet indoor space where you can go to get away from it for a couple of minutes--

I kind of miss the gatherings, but the ones I miss are the ones from my childhood.

There is nothing more lovely than being able to celebrate a holiday at my own pace. That includes being in my home office listening to the wind chimes and letting my subconscious work out scheduling for cooking the feast while I sit here and jam on the bones.

#7914: A clip episode? Seriously??

Ore wo Suki nano wa Omae dake ka yo episode 10 is a freaking recap. The dang series is thirteen eps, guys! WTF.

Anyway, I skipped it and went to ep 11. Two eps left in the series. But I've got plenty of Just Because! to watch. That'll be my third viewing of that series. Maybe I like it. Huh?