Author Topic: Science that makes you cringe  (Read 1962 times)

citoyen

  • Cat 6 Racer
Science that makes you cringe
« on: April 22, 2019, 08:13:20 pm »
I thought we had a thread on this subject already but I can't find it so...

Listening to Mary Anne Hobbs on 6music this morning, she introduced her “All Queens” playlist by saying, “Now it’s time for music made by humans with the X chromosome - the best kind.”

Well, yeeeees... I suppose they are the best kind of humans.

Re: Science that makes you cringe
« Reply #1 on: April 22, 2019, 08:32:11 pm »
Indeed all Humans have the X chromosome

hellymedic

  • Just do it!
Re: Science that makes you cringe
« Reply #2 on: April 22, 2019, 08:56:12 pm »
Even those with Turner's Syndrome...

Giraffe

  • I brake for Giraffes
Re: Science that makes you cringe
« Reply #3 on: April 23, 2019, 08:08:27 am »
My 'favourite' show for really bad 'science' and 'engineering' was Scorpion
https://en.wikipedia.org/wiki/Scorpion_%28TV_series%29
It even featured a large room where the air was being pumped out to extinguish a fire: it seemed to need a hard vacuum - can't imagine a room with ordinary walls, lot of glass etc. taking that; also doesn't need to be that hard - and featured a shot of a plastic bottle collapsing! Must have been a Microsoft vacuum - didn't suck.
2x4: thick plank; 4x4: 2 of 'em.

Re: Science that makes you cringe
« Reply #4 on: April 23, 2019, 08:21:58 am »
My 'favourite' show for really bad 'science' and 'engineering' was Scorpion
I had to stop watching that, which given my low threshold for cheesy American TV is saying something.
Sorting my life out, one shed at a time.

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Science that makes you cringe
« Reply #5 on: May 02, 2019, 02:58:13 pm »
At Scouts last week, I gave the little terrors* a survival on the moon exercise I'd stumbled across. List of items, rank in importance when a hypothetical space ship crashes on the moon etc etc.

One item was a pair of automatic pistols, with ammunition.  The "official" answer said that these could be used as propulsion devices, presumably in an action/equal and opposite reaction kind of a way.  I and several of the scouts were not convinced. Discussing it later with The Boy, he pointed out that the force exerted on the bullet will be equal to mass x acceleration and that mass is independent of gravity. This further argued against the official answer. Presumably the reactive force is the kick of the gun against the shooter's hand, which as far as I know isn't that much.  But does the reduced gravity of the moon come in to it?

Over the the massed minds of yacf.


*A few weeks before I'd set them the task of identifyig the source of the quotation "steely eyed missile man". They do a lot of googling in exchage for a bar of chocolate.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Re: Science that makes you cringe
« Reply #6 on: May 02, 2019, 03:05:33 pm »
Sorry, but I don't know the answer...its 40 years since I did this stuff, but you may find the following Youtube video from PBS Spacetime interesting and helpful.....

https://www.youtube.com/watch?v=iaN0xg2VQSo


 :thumbsup:
Cats to the left of me, cats to the right of me, cats sitting on my keyboard making far more sense than I do.

Kim

  • Timelord
Re: Science that makes you cringe
« Reply #7 on: May 02, 2019, 03:10:14 pm »
Moon's gravity only comes into it if you're using the force of the explosion to fight gravity in some way.  So if you shoot into the 'air', the bullet will travel further than on earth (even before you take the lack of air resistance into effect).  And if you try to use the recoil as an Orion-style propulsion system, you'll fail to get off the ground slightly less badly.  I'd be wary of an automatic weapon overheating and jamming if operated in hard vacuum (in a least-of-your-problems kind of way).

But the real reason for taking a pistol into space is to defend yourself from BEARS if you suspect your return trajectory to Earth may strand you somewhere remote.

Conceivably the ammunition might come in useful if you wanted to start a fire for some reason, or maybe even improvise a pyrotechnic actuator for something.  Or you could use the butt of the pistol to apply ham-fisted monkey force to some recalcitrant item of space hardware.  Or you could shoot a hole in your spacecraft, perhaps while murdering a crew member.  Personally, I'd rather have an extra roll of duct tape.  Not even NASA can improve on duct tape.
Careful, Kim. Your sarcasm's showing...

Re: Science that makes you cringe
« Reply #8 on: May 02, 2019, 03:15:05 pm »
Curious Droid did an interested video on Project Orion which can be found here:

https://www.youtube.com/watch?v=7dUYfDg3G2A
Cats to the left of me, cats to the right of me, cats sitting on my keyboard making far more sense than I do.

Cudzoziemiec

  • Solar powered, tea fuelled cycle-wol
Re: Science that makes you cringe
« Reply #9 on: May 02, 2019, 03:16:55 pm »
BEARS? Maybe SOUP DRAGONS.
A cup of tea is the perfect bridge between real life and cake.

Kim

  • Timelord
Re: Science that makes you cringe
« Reply #10 on: May 02, 2019, 03:18:44 pm »
BEARS? Maybe SOUP DRAGONS.

YACFers know that the sure way to defeat a soup dragon is with DHL, not firearms.
Careful, Kim. Your sarcasm's showing...

ian

  • fatuously disingenuous
    • The Suburban Survival Guide
Re: Science that makes you cringe
« Reply #11 on: May 02, 2019, 03:20:23 pm »
He's correct that it's mass, so gravity is irrelevant (and why you only fall over if you fire a big gun, though given the attitude of some NRA types, that might just be a swoon before they head off somewhere quiet with their gun for a bit of vigorous polishing).

As for the Moon, pretty useless against aliens too, since they will have probabilistic weaponry that might kill you. If not today, then yesterday. Regardless, they're the type of weapon that's very accurate spatially if not temporally.
!nataS pihsroW

Re: Science that makes you cringe
« Reply #12 on: May 02, 2019, 03:36:09 pm »
Larger guns have significant recoil: https://what-if.xkcd.com/21/

caerau

  • SR x 3 - PBP fail but 1090 km - hey - not too bad
Re: Science that makes you cringe
« Reply #13 on: May 02, 2019, 04:25:23 pm »
Interesting that last link there.  Makes me wonder about the accuracy of the scenes in Predator with Jesse Ventura  :-D   Not that it was ever all *that* believable of course.


(and all other films where people carry about mini-guns that are designed to fire from helicopters and stuff)
It's a reverse Elvis thing.

Re: Science that makes you cringe
« Reply #14 on: May 02, 2019, 04:31:35 pm »
Interesting that last link there.  Makes me wonder about the accuracy of the scenes in Predator with Jesse Ventura  :-D   Not that it was ever all *that* believable of course.


(and all other films where people carry about mini-guns that are designed to fire from helicopters and stuff)

Totally unrealistic.

Quote
For movie use, armorers slow down the M134 minigun's rate of fire to conserve ammo, and to allow the spinning barrels to be visible to the movie audience, with a hidden power cable for the firing scenes, and using blank ammo to ease recoil. Nonetheless the prop is still extremely physically demanding, hence the actors wielding it are physically imposing and often have bodybuilding backgrounds. Generally, such depictions will totally ignore the weapon's need for external power, and sometimes even forget that it requires a source of ammunition. In practice, a man-portable M134 minigun would be nearly impossible to manage as an individual infantry weapon, and highly impractical for a human being to either carry or operate. A scaled-down version of the M134, the XM214 Microgun, never reached production status for such reasons.

https://en.wikipedia.org/wiki/Minigun#Fiction_and_popular_culture
"Whoever fights monsters should see to it that in the process he does not become a monster. And when you look long into an abyss, the abyss also looks into you." ~ Friedrich Nietzsche

ian

  • fatuously disingenuous
    • The Suburban Survival Guide
Re: Science that makes you cringe
« Reply #15 on: May 02, 2019, 04:33:15 pm »
Here you go:

https://youtu.be/0nUADMhYO1c

You can only carry a few seconds of ammo and I imagine the battery is hefty, so no jumping through the air and firing one-handed. Save that for AR15s.

I fired a .45 and that about took my arm off.

ETA: watch the fellow slide backwards when he lets off a sustained burst. Put him on a skateboard and he'd be moving...
!nataS pihsroW

Kim

  • Timelord
Re: Science that makes you cringe
« Reply #16 on: May 02, 2019, 04:47:17 pm »
https://en.wikipedia.org/wiki/Minigun#Fiction_and_popular_culture

AKA by Rankin fans as "one of those amazing rotary machine-guns like Blaine had in Predator".
Careful, Kim. Your sarcasm's showing...

caerau

  • SR x 3 - PBP fail but 1090 km - hey - not too bad
Re: Science that makes you cringe
« Reply #17 on: May 02, 2019, 07:59:02 pm »
Y’know I knew all that  :facepalm: - perhaps we need an ‘I’m being flippant’ smiley of some kind.
It's a reverse Elvis thing.

ian

  • fatuously disingenuous
    • The Suburban Survival Guide
Re: Science that makes you cringe
« Reply #18 on: May 02, 2019, 08:02:22 pm »
I personally was happy to find that an America was up for firing a mini-gun by hand (or strap) and thus demonstrating that they can indeed be used for personal protection. Take that, victim disarmers!
!nataS pihsroW

Re: Science that makes you cringe
« Reply #19 on: May 02, 2019, 11:24:48 pm »
One item was a pair of automatic pistols, with ammunition.
On the moon, I can't see these being much use. In space, equal and opposite reaction would mean that you could fire into space and start yourself moving, very slowly, back towards your spacecraft, if, say, your spacewalk happened to have gone wrong and left you stranded.

The difference being that friction on the surface of the moon would prevent you moving. Unless you jumped in the air and then fired the gun. In which case, even on the moon, you would probably jump about 1mm further than if you'd just jumped normally.

In either situation, throwing the gun might work better, because it's heavier than a bullet. (Maybe I'm underestimating the recoil from a pistol. I've never fired one.)

Also, throwing the gun doesn't depend on the gunpowder, or whatever chemical propellant they use in guns these days, actually working in a vacuum.


Kim

  • Timelord
Re: Science that makes you cringe
« Reply #20 on: May 02, 2019, 11:53:14 pm »
Agree that throwing the pistol is likely to be more useful as a means of propulsion.  For optimal specific impulse you'd remove the propellant from the cartridges and install it in an appropriately designed solid fuel rocket engine.  (Was a lathe and assortment of high-temperature alloy stock amongst the ship's manifest?  Every astronaut should have them.)  It's all about optimising the velocity of those exhaust gases.

AIUI the propellant, like all good explosives, contains its own oxidiser, so should work in the absence of air.  The thermal environment could be quite hostile to something not engineered for it, thobut - not only does the temperature on the surface of the moon vary between boiling and minus bloodyhellhowmuch, but a machine designed with convection cooling in mind (which is surely most hand-held firearms) will have difficulty dissipating heat in a vacuum.  That's likely to be bad if you operate it at high rates of fire.

How your pistol (and ammunition) behaves outside a sane temperature envelope left as an exercise for the gun nut, but I'm predicting either a disappointing sound-doesn't-travel-in-a-vacuum absence of a 'click' at a critical moment, or some sort of undesirable BANG.
Careful, Kim. Your sarcasm's showing...

Jaded

  • The Codfather
  • Formerly known as Jaded
Re: Science that makes you cringe
« Reply #21 on: May 02, 2019, 11:54:30 pm »
It’s simple. You keep one loaded pistol, as a priority.

It’s for the inevitable murder-suicide.
If you don't like your democracy, vote against it.

Re: Science that makes you cringe
« Reply #22 on: May 03, 2019, 08:07:02 am »
A blackpowder rifle with a really long barrel would be much more efficient. Loaded with not a lot of powder; you want it burning and expanding all the way down the barrel but not outside of the barrel. That's my intuitive feeling on the subject. The oxidizer is in the powder, so of course it will work in a vacuum.
<i>Marmite slave</i>

ian

  • fatuously disingenuous
    • The Suburban Survival Guide
Re: Science that makes you cringe
« Reply #23 on: May 03, 2019, 10:11:41 am »
You're still confined by the mass ejected from the barrel, so on that basis a .50 slug will give you more of a nudge than a .22 caseless round, unless it was fired at very high velocity and in significant numbers (which I suppose they are).

Modern high-fire-rate guns will have recoil suppression by circulating the hot exhaust gases, which I guess would really give you all the happiness of a very warm gun in short order.
!nataS pihsroW

T42

  • Tea tank
Re: Science that makes you cringe
« Reply #24 on: May 03, 2019, 10:26:56 am »
Trailer for The Wandering Earth based on a shortish story by the excellent Cixin Liu suggests that a gravitational spike from Jupiter will cause the Earth to hit it, and only heroic action can save blah blah.  Betcha things get actioned, someone gets tasked, people just do it and it all gets fixed with a great big explosion. Most scientific.

Oh, I hope not.
I've dusted all those old bottles and set them up straight.