Author Topic: Science that makes you cringe  (Read 1807 times)

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Science that makes you cringe
« Reply #25 on: May 03, 2019, 10:35:21 am »
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.

As well as checking for of a lathe etc, make sure the passenger list includes This Old Tony or Stefan Gotteswinter
Another item listed was a self inflating life raft. The official answer was this may be useful as the CO2 cartridges to inflate it could be used to help leap chasms inna jet propulsion stylee. Again, we didn't think there would be enough gas to do so.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Kim

  • Timelord
Re: Science that makes you cringe
« Reply #26 on: May 03, 2019, 02:17:55 pm »
If you're inna spaceship that's crashed on the moon, I'm not sure why you'd want to do all this bouncing around anyway.  Surely the best approach is to either fix the spaceship, or if that's not viable, sit tight and stay alive until somebody with a working spaceship or lunar rover can come and rescue you.

If your spaceship is equipped with a device for converting CO2 to oxygen using copious amounts of electricity, it might come in useful there.

Or spread the raft out to increase your crash site's visibility from space...
To ride the Windcheetah, first, you must embrace the cantilever...

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Science that makes you cringe
« Reply #27 on: May 03, 2019, 02:34:40 pm »
Ah, sorry. The mission, should you choose to accept it, is to trek 200 miles across the lunar surface to the mothership.  Whether this is the same mothership that our Tidy Haired Thought Leader works in wasn't mentioned.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Kim

  • Timelord
Re: Science that makes you cringe
« Reply #28 on: May 03, 2019, 03:18:51 pm »
Oh, so they really are doing The Martian[1]...

Hmm, speed of an unladen Apollo astronaut was about 2.2km/h, so that's about 146 hours of moonwalking.  Potentially in a suit with consumables rated for 8 hours.  I think you'd need to science the shit out of that, especially if your plan hinged on continued availability of sunlight...


[1] Mostly the non-potato stuff that barely made it to the film.
To ride the Windcheetah, first, you must embrace the cantilever...

T42

  • Tea tank
Re: Science that makes you cringe
« Reply #29 on: May 03, 2019, 03:32:17 pm »
Work of a moment to build a trolley to personhaul extra consumables. Next problem is your, er, waste pouches filling up. Science the shit out of that.
I've dusted all those old bottles and set them up straight.

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Science that makes you cringe
« Reply #30 on: May 03, 2019, 03:40:28 pm »
Oh, so they really are doing The Martian[1]...

Hmm, speed of an unladen Apollo astronaut was about 2.2km/h, so that's about 146 hours of moonwalking.  Potentially in a suit with consumables rated for 8 hours.  I think you'd need to science the shit out of that, especially if your plan hinged on continued availability of sunlight...


[1] Mostly the non-potato stuff that barely made it to the film.

I set the Scouts a question most week, the product of my fevered brain. The purpose is to get them to remember a simple message and to get them to work out where to look stuff up.  A couple of weeks ago I asked them to work out which film I'd watched as I flew to Australia, the only clue being it referred to a "steely eyed missile man".  The answer on the card is Apollo 13, but one gave the answer The Martian. Damn Ridley Scott and his hat tipping.
There are two ways you can get exercise out of a bicycle: you can
"overhaul" it, or you can ride it.  (Jerome K Jerome)

Kim

  • Timelord
Re: Science that makes you cringe
« Reply #31 on: May 03, 2019, 05:14:32 pm »
Was it in Apollo 13?  I probably need to re-watch that.

It was originally a reference to John Aaron saving the Apollo 12 mission by being a *massive* nerd.  The whole CO2 scrubber thing was over-egged in the Apollo 13 film, because "You know that thing we worked out on a simulation several missions ago?  How did we do it again?" doesn't make for very good drama.

But that's okay, because if it hadn't been for that scene, I doubt Andy Weir would have written The Martian.

Ob-xkcd:

To ride the Windcheetah, first, you must embrace the cantilever...

Re: Science that makes you cringe
« Reply #32 on: May 03, 2019, 10:24:18 pm »
Also, on the moon or in space, would it be possible to fire a pistol without first removing your space gloves? In which case, the escaping oxygen would probably move you further than firing the gun would have done anyway. Although with unfortunate side-effects.

ElyDave

  • Royal and Ancient Polar Bear Society member 263583
Re: Science that makes you cringe
« Reply #33 on: May 03, 2019, 10:44:01 pm »
Also, on the moon or in space, would it be possible to fire a pistol without first removing your space gloves? In which case, the escaping oxygen would probably move you further than firing the gun would have done anyway. Although with unfortunate side-effects.

Thinsulate gloves, they'll do the trick
“Procrastination is the thief of time, collar him.” –Charles Dickens

Re: Science that makes you cringe
« Reply #34 on: May 04, 2019, 12:44:57 am »
You'd need to be careful where you pointed the gun, anyway. There's nothing much to slow a bullet down in space. You might kill someone on Alpha Centauri in about 1.3 million years' time. For that matter, of course, the gun you threw might hit them on the head, if the universe were to stay around for long enough.

T42

  • Tea tank
Re: Science that makes you cringe
« Reply #35 on: May 04, 2019, 08:03:16 am »
Douglas Adams would have made something of that.

Anyway, I'm perplexed that none of NASA's efforts have included wire coat-hangers in the cargo manifest. I'm convinced that if the wire coat-hanger were to be eliminated civilization would collapse.
I've dusted all those old bottles and set them up straight.

Tim Hall

  • I want to eat the fleeting shade of your lashes
Re: Science that makes you cringe
« Reply #36 on: May 04, 2019, 08:03:42 am »
You'd need to be careful where you pointed the gun, anyway. There's nothing much to slow a bullet down in space. You might kill someone on Alpha Centauri in about 1.3 million years' time. For that matter, of course, the gun you threw might hit them on the head, if the universe were to stay around for long enough.
Rather pleasingly, one of the scouts suggested you might shoot yourself in the back.
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 #37 on: May 04, 2019, 09:17:38 am »
 :thumbsup: :thumbsup: :thumbsup: :thumbsup:

I'm not sure now whether to try this on my Scouts, or whether it's all got just too complicated ??? ??? ???

Kim

  • Timelord
Re: Science that makes you cringe
« Reply #38 on: May 04, 2019, 02:34:45 pm »
Rather pleasingly, one of the scouts suggested you might shoot yourself in the back.

 :thumbsup:

AIUI the lunar gravity is too lumpy to make really low orbits like that possible, which I reckon is proof that the universe has no sense of humour.

*googles*

https://en.wikipedia.org/wiki/Apollo_16#Particles_and_Fields_Subsatellite_PFS-2

Perigee of 6 miles!
To ride the Windcheetah, first, you must embrace the cantilever...

Re: Science that makes you cringe
« Reply #39 on: May 04, 2019, 02:47:53 pm »
Periapsis or perilune no? :D
Miles cycled 2014 = 3551.5 (Target 7300 :()
Miles cycled 2013 = 6141.4
Miles cycled 2012 = 4038.1

T42

  • Tea tank
Re: Science that makes you cringe
« Reply #40 on: May 04, 2019, 04:01:09 pm »
AIUI the lunar gravity is too lumpy to make really low orbits like that possible, which I reckon is proof that the universe has no sense of humour.

Oh, I dunno: a gravitational field you can't rely on is quite a good joke, really.
I've dusted all those old bottles and set them up straight.

Morat

  • I tried to HTFU but something went ping :(
Re: Science that makes you cringe
« Reply #41 on: May 06, 2019, 09:24:44 pm »
A quick google shows the recoil energy of a .45 pistol to be 1200 ft/lbs or 1600 Joules.

Sounds like a lot to me, but of course it's a momentary impulse rather than sustained thrust.

Over to the rocket scientists :)
Tandem Stoker, CX bike abuser (slicks and tarmac) and owner of a sadly neglected MTB.