Friday, January 22, 2016

Professional Left Podcast #320

"People never lie so much as after a hunt, during a war or before an election."

-- Otto von Bismarck



cousinavi said...

Re: guns in space / cracking the seal
"Let the vacuum in..." ?
Normally I'd let that pass but it came in the middle of an exposition on Newton's Laws of Motion in zero G.

Mister Roboto said...

John Michael Greer writing at The Archdruid Report has some insight into the Trump political phenomenon that might not be what some folks want to hear, but that makes it all the more important to read and consider.

Ivory Bill Woodpecker said...

Speaking of Mein Trumpf:

GOP strategist says Trump supporters "masturbate to anime"

Miss Kasuga reacts

Neo Tuxedo said...

I find that the Archdruid's posts are immeasurably improved, not to mention made immeasurably more honest, if you imagine, superimposed on the center of your screen, in blinking red letters, the words


Alternatively, Plate 21 of William Blake's The Marriage of Heaven and Hell:

I have always found that Angels have the vanity to speak of themselves as the only wise; this they do with a confident insolence sprouting from systematic reasoning.
Thus Swedenborg boasts that what he writes is new; tho' it is only the Contents or Index of already publish'd books.
A man carried a monkey about for a shew, & because he was a little wiser than the monkey, grew vain, and conciev'd himself as much wiser than seven men. It is so with Swedenborg; he shews the folly of churches & exposes hypocrites, till he images that all are religious, & himself the single one on earth that ever broke a net.

Unknown said...

some verse ideas:

Imagine there's no Donald
Looking you in the eye
No hate before us
Spoke in the open sky
Imagine the government working for today

Imagine there's no Ted Cruz
You'll thank me if you do
Nobody there to scare you
No xenophobia too
Imagine all the smiles you'd see every place

and you definitely need a line for all the awesome governors brought to us by the GOP

Robt said...

Staying with imagine, I offer one verse

Imagine I shoot dead someone
Like Putin in front of everyone
no hell to pay as a toll
as long as I am high in the polls.

Don't let time pass you by. So much more is coming so fast. Like the return of Tina Fey...............

Let me just say
Right wingin, Bitter Clingin , proud clingers
and Nazi Doppelgangers........................Yes, your read that correct.

Richard Luken said...

Guns in Space.

I think that Driftglass was referring to "breaking the seal" on a space suit, thereby exposing the person wearing that suit to the vacuum of space, which I would not think would be necessarily harmful to the person firing the weapon, unless he or she damaged their own space suit in the process of getting off the shot.

As for his comment about Newton's Third Law, which I usually think of as being: "for every action there is an equal and opposite reaction." So a person firing a gun in space, or anywhere else, is subject to this law: it's usually known as "kickback" and depending on the force created by the exploding gunpowder, it can be quite significant, even under gravity here on earth. My father enjoyed relating a story of his uncle's double barreled 10 gauge shotgun. It seems that on more than one occasion the person handling the gun, being startled by an flushed covey of birds, "reared back and (unintentionally) pulled both triggers and fired off both barrels at once." The kickback on each occasion broke the shooter's collar bone, and sent him "rolling backwards down the hill."

But in addition to Newton's Third Law, the Second and First Laws must also be applied to our hypothetical "space shooter." The second law states that F=m*a. So the force applied in the action and reaction will be the same; however, because the shooter's mass is much greater than that of the bullet, the shooter's acceleration will be much less a=F/m. But the shooter will still be accelerated in the opposite direction of the bullet. And both bullet and shooter again will come under Newton's First Law: being in motion they will stay in motion unless acted upon by an external force. If I am recalling my high school physics, because they are accelerating, the speed of both the bullet and the shooter will continue to increase over time, until acted upon by on outside force. Which could be the bullet hitting its target and the shooter hitting an object behind that has enough mass to decelerate him or her. But whatever stops the shooter, it could be very unpleasant, though probably not as unpleasant as being hit by the bullet.

Still, as Harlan Ellison pointed out in his otherwise scathing review of the movie "Enemy Mine," he was not offended by the fact that the sidearms were conventional guns, because of their simple rugged construction and reliability.*

*Sorry, but I'm not up to tracking down HE's exact argument about gunpowder based weapons. I'm pretty sure that the review is reprinted in "Watching" and I recommend it for it's opening Ellison rant, in which he recounts the great number of stories and movies that have used the same situation (including "Heaven Knows Mr. Allison.")that is the basis of the plot of "Enemy Mine."

I find myself wondering if the combustion of gunpowder that creates the force driving the bullet would occur in the in the vacuum of space. Isn't gunpowder dependent on oxygen to "catch fire" and explode when the firing pin hits the primer? Of course, that doesn't mean that a space gun couldn't use bullets having an anaerobic explosive (Mentos and Diet Coke?) creating the force to send the bullet on its way.

Habitat Vic said...

Richard Luken,

Gunpowder contains its own oxidizer (no Mentos & Diet Coke needed). Its made of Sulfer + Charcoal + Potassium Nitrate. The last item, also called saltpeter, has a formula of KNO3 - and is the source of oxygen for combustion within the shell casing/gun barrel. There would be no need for any external oxygen, or atmosphere for that matter. Going further, many higher power and/or more accurate cartridges fill the space within the brass casing almost completely full of gunpowder (its called load density - don't ask why I know this). So even if the bullets were sitting around in a vacuum, they wouldn't "leak out" any significant amount of air within the bullet (and the bullets, particularly military, are somewhat sealed anyway- mostly to be kinda waterproof).

Lastly, a a bullet fired in the vacuum of space would perform even better than on earth. It wouldn't have to push against a plug of air to get out of the barrel, and once outside the barrel, would not have an atmosphere to slow its velocity. No need for a silencer either. No air is no sound, plus no supersonic crack.

pluky said...

in reply to Neo Tuxedo, this is exactly why I stopped reading him.

Richard Luken said...

Habitat Vic

Thanks for pointing out the features of the chemical composition of gunpowder (containing an oxidizer) that would enable it to explode in the vacuum of space. While I knew the basic components of gunpowder, I was ignorant of the fact that saltpeter is an oxidizer.

New_Damage said...

@Richard Luken

I enjoyed your post, but as far as…

If I am recalling my high school physics, because they are accelerating, the speed of both the bullet and the shooter will continue to increase over time, until acted upon by on outside force.

…I am afraid that it is not quite correct. Once the propellant of the initial firing of the gun has depleted itself, the bullet will have reached its top velocity due to that fact. That bullet will then remain in constant motion (velocity and direction) until it is acted on again by some other force. If this weren't the case, we could never send satellites to other planets.


Richard Luken said...

Thanks New Damage.

You are correct and I appreciate the correction: when the force applied reaches zero, the mass will stop accelerating (F=m*a). At that time its velocity (speed in a particular direction) will remain constant until it is acted upon by another force. My old high school Physics teacher Mr. Allen would be mortified that I confused an explosion with a constant force (like gravity). Dho!