Deflagration to Detonation

 blather, history, Hmm..., news, science, youtube  No Responses »
Oct 132020
 

I used to work in ordnance back in my United Tech days… mostly stage separation and solid rocket motor ignition systems. With those, deflagration and detonation are two rather different concepts that you *usually* tried to keep separate. In short:

Deflagration: something’s burning. A piece of solid rocket propellant, a pile of gunpowder, a handful of boron potassium nitrate pellets, once they are ignited, will burn at a fairly constant rate typically measured in fractions of an inch per second.

Detonation: something undergoing an energetic and *really* *fast* chemical reaction. Your det cord full of pentaerythritol tetranitrate is reacting at around 20,000 feet per second.

The speed of the reaction is the thing that separates the two… slow vs. fast. Detonation typically moves through the material in question at faster than the local speed of sound. You’d think that “a quarter inch per second” and “five thousand feet per second” are far enough apart that the two concepts will never meet, but reality is quite different. That slowly burning pile of gunpower on the tabletop? Light a match to it and it’ll merrily burn away for a few seconds. You’ll get light, smoke, sound and heat. What you won’t get is any meaningful sort of blast or shock wave. Now, take that exact same handful of gunpowder and put it into a sealed, sturdy container and light it off. As it begins to burn, the gas generated has nowhere to go. The pressure very rapids begins to rise. For many pyrogens, the burn rate is proportional to the pressure. So a quarter inch per second at sea level can get blisteringly fast at a few thousand atmospheres. As a result, that gunpowder that would have produced no shock wave now has a burn rate well in excess of the speed of sound. If the container can hold the pressure just long enough, the whole thing will combust and *then* the container falls apart, and you get a cheerful little blast. Congrats, you’ve built a pipe bomb. Expect a knock on your door from the ATF momentarily to tell you what you’ve won.

Some materials, like BKNO3, are largely insensitive to pressure. Their burn rate is pretty much constant where in a vacuum or in a thousand atmospheres. These materials are handy for igniters in rocket motors, since they’ll operate the same in nearly every circumstance.

The stuff they put in bombs, though, can be tricky. The explosive of choice for the Brits and the US in WWII to today, RDX (and the chemically related HMX), is reasonably stable and has about 1.5 times the power of TNT. It’s great stuff if you want to blow stuff up. RDX is a dry crystaline powder (like salt), but when mixed with TNT and a bit of wax you get a castable substance known as Composition B, still used in ordnance today. Somewhat similar to Comp B is “torpex,” a mix of RDX, TNT and aluminum powder. Now largely obsolete, Torpex was used mainly for torpedoes, but was also used in some of the biggest bombs of WWII like the Tallboy and Grand Slam.

Now: shove a detonator (a small device that produces an actual detonation shockwave) into a blob of Comp B and set off the detonator, and the blob of Comp B will happily take that detonation and run with it. Note: Composition B is not the same as C-4 “plastic explosive” which is mostly RDX mixed with a small percentage of other chemicals that serve as plasticizers, turning the dry crystals into something like modeling clay.

Anyway, back to Comp B or Torpex: if, instead of a detonator, you take a blob of the stuff and set fire to it with a match, you will get… a fire. A simple fire does not provide what Comp B needs to proceed from deflagration to detonation, so the fire will most likely remain subsonic. But, like gunpowder, if you contain the burning Comp B in a pressure vessel, the pressure goes up, the burn rate goes up, and at some point the Comp P gets frustrated with piddly deflagration and goes high order. Blammo.

Why do I mention all this out of the blue? Cuz why not, that’s why. I’ve been working non-stop on Illustrated Aerospace History Subject Book 2 for a while, taking a break now and then only to watch civilization being torn apart and cast down by the worst people the US has produced since the Commies and the Klan. So while you might think that watching scumbags block roads and assault passersby and tear down statues brings thoughts of deflagration to detonation transitions to my mind, it was actually a news report out of Poland:

Biggest World War Two bomb found in Poland explodes while being defused

A British Tallboy bomb with 2,400 kilograms of explosives was found in a river and was being defused when it detonated. The story is lean on the details I would have preferred, but it seems that it was being burned in place. This is a perfectly cromulent way to dispose of a bomb: drill a hole in it, set it on fire. If the hole is big enough, the gases escape and the pressure doesn’t rise. Hole *isn’t* big enough, you’ve made a pipe bomb. If the thing is underwater, the pressure of the water will actually make things more difficult if your goal is to keep things at deflagration. What the story leaves out is if that’s what the plan was. Another perfectly valid way to defuse a bomb is to just blow the damn thing up. When you do it that way you are pretty well assured that you’ll get it all, but there is of course the little problem of whether or not the blast is going to fark up the surroundings. In a river… seems like the best way to go is detonation. But as you can see in the video below, there is some nearby property, including some sort of observation tower, that could have been trashed but instead seems to get a bit of a light wash.

 

Well, back to the ol’ CAD machine…

 

 Posted by at 5:07 pm

Deepfake actors: a suggestion for studios

 art, blather, Forward!, Hmm..., politics  No Responses »
Oct 112020
 

An interesting article on how the deepfake of Nixon reading the “moon landing has failed speech” was created:

Inside the strange new world of being a deepfake actor

The process requires an actor to basically be a “puppet” for the final product, akin to motion capture. With current technology, both the appearance and the voice of the actor can be transformed into those of someone completely different. The line that jumped out at me:

The actor, in other words, serves as a puppeteer, never to be seen in the final product. The person’s appearance, gender, age, and ethnicity don’t really matter.

Huh. Pay attention to that, Hollywood. Here is how you can make non-insulting historical epics and still hope to win an Academy Award. Recall the new diversity rules for Oscar contenders:

STANDARD A:  ON-SCREEN REPRESENTATION, THEMES AND NARRATIVES
To achieve Standard A, the film must meet ONE of the following criteria:

A1. Lead or significant supporting actors

At least one of the lead actors or significant supporting actors is from an underrepresented racial or ethnic group.

      • Asian
        • Hispanic/Latinx
        • Black/African American
        • Indigenous/Native American/Alaskan Native
        • Middle Eastern/North African
        • Native Hawaiian or other Pacific Islander
        • Other underrepresented race or ethnicity

Huh. Well, folks, here’s your loophole. Let’s say you want to make a Viking saga, or something from Shakespeare or something about King Arthur or Peter the Great or Charlemagne or the Thirty Years War or Leonardo da Vinci or… whatever. but you’re pretty sure it’ll be an Oscar contender. What to do? Simple: hire, say, Idris Elba to play King Arthur and Viola Davis to play Lancelot and Salma Hayek to play Morgana and Hari Kondabolu to play Merlin. And then replace them in post: John Wayne as Arthur, Cary Grant as Lancelot, Marilyn Monroe as Morgana and Richard Harris as Merlin. You have, in fact, done what the Academy standards wanted you to do, and yet you’ve also made a reasonably accurate version of the flick.

As the technology improves, the argument for using real – and real expensive – actors to portray their un-deepfaked selves will get weaker and weaker. The world is full to overflowing with perfectly good actors who can portray anyone… they just don’t look the part. Now they won’t need to. We could soon enter an era where “acting” and “appearance” become wholly separate commodities. Actors might be known by name, but not by face. And regular schmoes with no acting chops whatsoever could make a good bit of extra cash by selling the rights to their appearance… go into a booth, strip down to your skivvies (or further, for extra cash) and you are 3D scanned to ridiculously high precision. Perhaps even X-rayed or sonogramed to get the skeleton right. Takes ten minutes and you’re back out onto the street. A year later you get a letter telling you that, hey presto, you’ll be portraying Darth Blarg in Star Wars Episode 15, The Sith Cash Grab. Two years later the checks start rolling in… a few tens of thousands for use in the movie, a few more tens of thousands for all the posters and T-shirts and action figures that use your likeness. Not a lot of money by current Hollywood standards, but all you did was stand there and strike a few poses for a few minutes.

 Posted by at 3:54 pm

Cruise To Nowhere

 blather, Hmm..., news, ships  No Responses »
Oct 092020
 

Hmmm.

Singapore introduces ‘cruises to nowhere’ for travel-starved locals

In short… load half the number of passengers onto a cruise ship, set out to sea, pull into no ports, return home. All passengers and crew to be tested for Commie Cough prior to boarding.

I’ve been on a grand total of one cruise, an Alaskan coastal cruise some years ago. It pulled into several ports for excursions, but it seemed to me that the cruise itself was the main point of the exercise. I imagine that a cruise ship around – but not quite to –  interesting locales, complete with notably fewer passengers, could sell quite well, even at a substantial markup. Close off the interior cabins, sell only the exterior cabins – the ones with good views and lots of fresh air – test the crew *daily,* go bonkers with the luxuries, and these things seem like they’d do quite well.

 Posted by at 10:15 am

Finally, some evidence of right wing domestic terrorism

 AARRRGH, blather, Crazy, dumbassery, Forward!, Gah., news, politics, ಠ_ಠ  No Responses »
Oct 082020
 

Recent months have seen a  lot of histrionics about “right wing domestic terrorism,” including tarring the Proud Boys as white supremacists, while kinda ignoring the fact that their leader is this guy:

Yeah, not exactly standard white supremacist leadership material, but, hey, what are facts doing trying to get in the way of a narrative?

So, after half a year of leftists doing billions in property damage, directly murdering dozens and indirectly murdering hundreds to thousands by:

  1. Tying up police and fire resources
  2. Advocating for the defunding of police, in many cases succeeding, leading to greatly reduced policing in many areas

… the media continues to enable leftist violence and mayhem and murder while screeching about nearly universally phantom right wing violence. Until today! Finally, something for them to crow about!

13 charged in plot to kidnap Michigan Gov. Gretchen Whitmer

Michigan Attorney General Dana Nessel said:
“The individuals in (state) custody are suspected to have attempted to identify the home addresses of law enforcement officers in order to target them, made threats of violence intended to instigate a civil war, and engaged in planning and training for an operation to attack the capitol building of Michigan and to kidnap government officials, including the governor of Michigan.”
Yes, indeed, bad people planning bad things. But take the first two claims: targeting law enforcement officers and threatening violent insurrection. UMMMMMMM… hello, ALL THE REST OF 2020???
 Posted by at 5:27 pm

The Trump Train

 AARRRGH, blather, Crazy, Forward!, Meh., news, politics, youtube, ಠ_ಠ  No Responses »
Sep 302020
 

I watched the debate last night. I sat there aghast the whole time thinking “This. This, right here… this is a ᛋᚺᛁᛏ show.” Now, it seemed to me that whoever was in charge of getting Gropey Joe his meds was on the ball; he didn’t have as many senior moments as I expected. But I think Trump… man, I dunno. He was a little too Trumpey, I thought. But what the hell do I know. I thought sure he was doomed to utter defeat in 2016, and instead Hillary is now a minor footnote in the annals of political corruption.

Trump is, in my opinion, a rather horrible person. Why? Because of his behavior. But Biden? He is also a horrible person… because of his politics, who he pals around with, who he enables and supports. As much of a clown as Trump is, his *policies* are pretty damn good. Gropey Joe certainly would not have given us the USSF. What he would give us is the Harris Administration, which is on course towards getting that Civil War II underway. So… if it’s the choice between a vulgarian boor with sensible policies and a Creepy Comrade, I’m’a voting for the clown.

And it’s clear that the performance enhancers that Biden was on that allowed him to more or less withstand Trump last night have faded off today:

 Posted by at 1:54 pm

Electrifying cars

 blather, Hmm...  No Responses »
Sep 102020
 

As you’ll recall from the Disney flick “20,000 Leagues Under The Sea,” one of the defensive features of the submarine Nautilus was the ability to electrify the outer surface. Thus when the sub was boarded by a bunch of cannibals while high-centered on a coral reef, Captain Nemo threw a switch and the invaders got electrozapped until they retreated off the boat.

Watching recent episodes of criminals in the street swarming cars and preventing them from proceeding, it occurs to me that the ability to flip a switch and electrify the outer panels of the vehicle might be a useful ability. Someone throws themselves onto your vehicle, you could gently persuade them with 50,000 volts of persuasion to get *off* your vehicle. Is this a practical possibility? Would it require so much modification so as to be essentially a whole new vehicle? I kinda think you’d have to have a non-conductive fiberglass skin with metal studs every few centimeters, each pair connected to a reduced-power version of a stun gun. Modern computer and sensor systems would allow the system to select which set of studs to electrify based on pressure; Tesla-level cameras and whatnot should allow the system to *see* where threats are and adjust the Dumbass Deflector accordingly. That seems like a whole lot of bother to go to, but as we start slipping deeper into the Cthulhu Era, this sort of thing might be more and more reasonable.

Alternatives to electrification:

  1. Skin panels that get real hot. 200F should probably do it. Energy intensive.
  2. Skin panels that vibrate unpleasantly. Probably noisy and heavy.
  3. Skin panels that “sweat.” Anything from simple water to skunk stank.
  4. Combine 1 and 4: skin panels that emit hot steam. This could be simplified with discrete emitters underneath or between panels. Especially around the front grill, which is where most of the problems lie anyway.
  5. Skin panels that project small, short points, like thumbtacks. Heavy again.
  6. Back to 3… but it sweats *glue.* If they’re going to plop themselves onto your car, making them stick there could prove entertaining, if probably illegal. But here’s the thing: if it’s illegal for *you* to detain them, why isn’t it illegal for them to detain *you*?
 Posted by at 11:53 pm

“Birds of Prey:” an incomplete review

 blather, Meh., ಠ_ಠ  No Responses »
Sep 032020
 

A lot of people don’t like the DC “cinematic universe” movies like “Batman V Superman,” “Suicide Squad” and “Justice League.” I like them… ok. They have flaws, but for the most part I find them entertaining enough that in the Before Times I saw most of them in theaters. But I didn’t go to see “Birds of Prey,” largely because:

1: It just didn’t look good or interesting

2: There was a lot of woke rubbish about it.

It is now on HBO/Hulu. So a few days ago i fired it up while doing CAD work. If nothing else, I have the TV on as background noise; I can binge watch half a season of some show or other while working and, when I finally look up from my screen, realize that X hours have gone by and I’ve absorbed absolutely none of what transpired on the TV. So with that in mind, judge for yourself what it means that I got something like 30 or so minutes into “Birds of Prey” and intentionally turned it off. It’s badness was so overpowering that it blew right through my ramparts of inertia, inattention and indifference. That is, in a way, rather impressive.

 Posted by at 2:23 am

Boy, those lines collapse *fast*

 art, awesomeness, blather, Crazy, dumbassery, Forward!, Hmm..., politics, wisdom, youtube  No Responses »
Sep 012020
 

Gee, when cops are actually allowed to do their jobs, those badasses in Antifa turn out to just be larping weenies.

Prepare yourself for the feel-good movie of the summer:

This whole summer of insanity could have been nipped in the bud if the mayors of Antifa-infested towns had simply allowed their police to police. Around here, the riots lasted… one night, maybe? The night it started, not only did the local cops show up to say “not just no, but hell no,” cops from nearby towns showed up. Cops from another state showed up. The police told the rioting morons that their nonsense would not be allowed and told them loudly enough and with sufficient backup. And what did the rioters do? Tucked tail and went home (after killing a few of their own, because of course they did). There have been threats and rumors since then, the odd door kicked in (one of the comic books shops near me got kicked in, as did the closest thing to a model kit-equipped hobby shop, because of course they did), but nothing like the nonsense in Portland or Chicago.

Watching this and other videos makes it clear that while Antifa and their ilk are certainly ready willing and able to carry out acts of violence and terrorism, they are themselves little more than cardboard cutouts. They truly are NPCs, programmed to make a loud noise and chuck the odd Molotov cocktail, but they largely seem ill prepared to stand up to even halfassed resistance from the good guys.

 Posted by at 6:35 pm

Moonbase

 blather, dumbassery, Forward!, Hmm..., news, politics, spacecraft, THIS is why Trump won, ಠ_ಠ  No Responses »
Aug 252020
 

The Trump campaign published their second term agenda. It is pretty much a list of what you’d expect… generic reasonable aspirations and talking point, few of which are even remotely controversial. Behold:

Trump Campaign Announces President Trump’s 2nd Term Agenda: Fighting for You!

The agenda says this about the space program:

Launch Space Force, Establish Permanent Manned Presence on The Moon and Send the First Manned Mission to Mars

Which is frankly not a whole hell of a lot. Of course, this being 2020, “not even remotely controversial” results in “I’ll take that challenge” from the usual crowd. Behold an entire opinion piece written to decry those few words about the moon:

Trump Wants a Moonbase

In case you’re wondering about the quality of the piece and it’s author and don;t wish to give them clicks, here’s a summary:

Last night, Trump released his second term agenda, incredibly specific guidelines for xenophobic totalitarian rule sprinkled with pipe dreams. Among the former is the usual parade of fascistic talking points: “teach American exceptionalism,” prosecute the “violent extremist” group antifa, deport “non-citizen gang members,” hold China “accountable” for covid-19, eliminate sanctuary cities. The latter variety is contrasted with such gems as “return to normal in 2021” and establish a “permanent” “manned presence” on the moon.

A base. On the moon. A moonbase, if you will.

Uh-huh. Note what the author considers fascism: enforcing laws against rioting and arson and assault and murder and illegal immigration. More specific to determining the value of the author:

he somehow bloated the military with a Space Force, in spite of the total absence of warfare in space currently.

Huh. There’s no war in space *now,* so there’s no need to plan for it.

GENIUS!

But even more… are we sure there’s no war in space right now? Are we absolutely certain?

Bah. Journalism is dead.

 Posted by at 2:13 pm

Not a good year for Goodyear

 blather, dumbassery, Forward!, Hmm..., news, politics, wisdom, youtube, ಠ_ಠ  No Responses »
Aug 202020
 

So a photo came out claiming to show a slide at a “diversity” class at Goodyear, the manufacturer of tires. The slide showed what is, and is not, acceptable political sloganeering on employee clothes during work hours, and it’s kinda remarkable:

In short, according to this slide it is acceptable to show off left-wing slogans, but not right-wing or centrist slogans.

This, rather predictably, caused a bit of a kerfuffle, including a tweet by Trump suggesting that people buy their tires from someone other than Goodyear:

 

And so Goodyear’s PR people banged out a reply where they claim no ownership of the slide or the diversity “training” session:

And now audio has come out that supports the original story that Goodyear had a policy allowing leftist propaganda, but not centrist or right-wing:

And so now Goodyear has responded *again,* this time admitting that the slide was indeed from a diversity mind control session and that the slide was prepared by a Goodyear employee, but that it somehow does not reflect Goodyear’s positions. Further, they will now allow employees to show support for the police (but apparently not for the radical notion that all lives matter):

Goodyear is of course a private company and thus can crank out whatever rules they like.  But blatantly partisan rules such as these are bound to create strife. Especially when a simpler and far more equitable and fair solution – not to mention one less likely to result in employees beating the tar out of each other – is to simply ban all political expressions on company property. No signs, pins, shirts, hats. Zero, zip, nada. Quick and easy, perfectly legal, completely fair. But no, they wanted to appear woke and *specifically* allowed employees to display support for an organization, founded by Marxists, currently at the forefront of a wave of criminality and misery sweeping Americas cities. How did they think this would work out well for them?

Goodyear may have themselves a problem. But another issue is concerning, and not for the first time: that original image of the offending slide would have been simplicity itself for *anyone* to create with Powerpoint. Post a fake image online, and BOOM, a major corporation takes a shot to the nads. Now in this case, it’s looking more and more like it’s an accurate depiction of an actual Goodyear indoctrination session… but it would be easy to fake. People really should hold their fire for just a little bit just to make sure that they’re not being hoodwinked.

 Posted by at 5:49 pm
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