Interesting Links for 21-11-2021

[andrewducker]

TDoR 2021: Remembering the 462 transgender people killed in the last year

(tags:murder transgender LGBT viacmcmck )

Wired's 90s predictions of how the future could go wrong have basically all happened

(tags:thefuture predictions Doom )

I see the Labour purges continue

(tags:Labour OhForFucksSake )

The "Great Green Wall" Didn't Stop Desertification, but it Evolved Into Something That Might

(tags:trees desert viaNancyLebov )

There are times when being a rules lawyer is a wonderful thing

(tags:rules )

Families in Cornwall offered £1,200 to take relatives out of NHS hospitals and free up space as crisis deepens

(tags:Cornwall UK NHS Doom )

SpinLaunch Flings a Test Vehicle Kilometers Into the air. Eventually, it'll Throw Them Almost all the way to Orbit

(tags:space )

Comments

[cmcmck]

Thanks for reminding people about TDOR.

Not a single politician here of any stripe said a dicky bird yesterday.

That tells me all I need to know, I suppose. :o(

SpinLaunch Positives

[danieldwilliam]

Very much looking forward to much much cheaper space launches.

And I note the development of the 3D printed aerospike nozzle recently.

SpinLaunch Negatives

[danieldwilliam]

I reckon one could repurpose SpinLaunch as an intercontinental ballistic missile system relatively easily.

Re: SpinLaunch Negatives

[andrewducker]

Anything that can launch things into (near) orbit can act as one, I'd imagine.

The biggest question, for me, is how often one device can launch things, and how tough they need to be.

Re: SpinLaunch Negatives

[danieldwilliam]

Agreed, anything that gets a mass up to sub-orbital hieght can probably be used as as an ICBM.

I think the slightly concerning thing here is that thus turns a small rocket in to an intercontinental one. Secondly, this is pretty legitimate civilian tech. Thirdly, if it's a cheaper launch vehicle it's a cheaper missile launcher.

You are right about the frequency of use question. One launch a day vs one launch a minute changes the dynamic of use hugely.

Re: SpinLaunch Negatives

[danieldwilliam]

I'm thinking particularly of non-state actors here.

Re: SpinLaunch Negatives

[armiphlage]

It's a way to bypass ITAR limitations for sure.

If you have access to a plasma cutter, steel plate, truck parts, and a well-equipped automotive shop, you could create a balanced but massive rotating steel disc with a spiral channel sandwiched inside, balanced on truck axle bearings. No need for it to be in a vacuum if you're using a disc instead of a rotating arm. Use electric motors to spin it up to speed, then insert projectiles at the hub. As the projectiles slide down the channel towards the rim, they absorb rotational energy from the mass of steel; your rate of fire is limited only by how fast your electric motors can feed energy back into the disc.

You could get higher RPMs with carbon-fiber discs, but for multiple shots the mass of steel is actually an advantage.

As launch costs would be so low, there would be no need to have machined projectiles, or even explosive charges. A shower of old-fashioned cast-iron cannonballs would be able to destroy fuel tank farms, aircraft in revetments, and other fragile stationary targets.

Of course, as it's notoriously hard to change the axis of a spinning disc, this wouldn't be good to use against moving targets. If you're using truck parts, it'd likely be best to spin your disc about a horizontal axis (no need for thrust bearings). You therefore wouldn't be able to traverse left or right, but you'd be able to adjust range through timing when the projectile is released (either by carefully timing when you drop them in at the hub, or with a solenoid at the rim of the disc).

A steam-powered centrifugal gun from the late 1800s was able to do 15 twelve-pound rounds in 16 seconds.

https://en.wikipedia.org/wiki/Centrifugal_gun
https://www.youtube.com/watch?v=--2XlPziMY8

[dewline]

1. An ongoing sadness...

2. Prediction # 3 seems to have been proven out as "Russia did both of those things, and is working on exporting the cruelty model to the rest of the world". We may yet succeed at defeating Prediction # 8, though. As for the rest...well...

4. Well, there's one more bit of progress for the new fascist international to want to undermine.

rules lawyer

[cellio]

I can't believe that worked either! Perhaps the person handling the scheduling thinks it's a dumb rule, too.

Great Green Wall

[anna_wing]

Also a lesson about foreign development agencies that don't pay attention to local circumstances.

I still remember the woman from an aid organisation that shall remain nameless, parachuted into Myanmar in the afternath of Cyclone Nargis from, I believe, Sudan, asking what the military government was doing about clearing the "rubble" from the storm surge. This after a half hour presentation with lots of pictures showing very clearly that most of the structures in the villages affected had in fact been built from bamboo, coconut or nipa palm trunks, or mangrove wood.

Re: Great Green Wall

[andrewducker]

Yeah, it's always important to understand the context you're operating in. And not just assume that everywhere is just like home.

The "Great Green Wall" Didn't Stop Desertification, but it Evolved Into Something That Might

[anef]

This made me feel happy, and hopeful.

Re: The "Great Green Wall" Didn't Stop Desertification, but it Evolved Into Something That Might

[andrewducker]

Me too! Things can be improved!