And when the dust settled, the mug lay broken, and neither man could attest to being, "The Word's Greatest Physicist"

10:10
Peter ] ] ] ] ]
"The reason for this drift has eluded physicists who have dedicated their careers to the SI unit of mass. No plausible mechanism has been proposed to explain either a steady decrease in the mass of the IPK, or an increase in that of its replicas dispersed throughout the world."
I DIDN'T KNOW YOU CAN DEDICATE A CAREER TO THIS

10:10
k.s.hood
I guess you don't know how academics work then
Narrowest fields ever

10:10
Peter ] ] ] ] ]
I think the thing that gets me is
physicists
multiple

10:10
k.s.hood
Well, its probably less than 10
I want to believe there are precisely two
Who both hate each other

10:11
Peter ] ] ] ] ]
hahaha
you and I we should write a novel

10:11
k.s.hood
Hopefully your writing skills are better than mine

10:12
Peter ] ] ] ] ]
it'll be about the theft of the international kilogram
from the perspectives of both rival physicists

10:12
k.s.hood
Ha

10:12
Peter ] ] ] ] ]
we will each assume the viewpoint of one
the conclusion would be
it was stolen by a physicist
working on metres
to secure more grant money
to build the perfect metre

10:14
k.s.hood
That sounds suitably ridiculous
The general public might even find it plausible
The solution is of course, to note that the metre scientist did something that broke academic integrity, ruining his career
This something will not be related to stealing the prototype

10:20
Peter ] ] ] ] ]
"…and he looked upon his creation with trebidation, his pièce de résistance, a metre perfect in every way. He savoured it, caressing its body with his eyes, gently. This, he thought, will finally bring him the citations he deserved."
10:21
I think there should be explosions somewhere
also he drops his metre
altering its atomic configuration
it will never be perfect again
some things are not for the realm of men

The best defense is...malnourishment?

Generally speaking, in order to increase stopping power from a bullet, you increase the trauma that it creates.

Hollow points accomplish this by expanding on target to create a larger wound channel.

There are some problems with this. Hollow points are prohibited under the Hague Conventions that NATO ascribes to (even though they are the most frequent type of bullets used by civilian agencies). Another problem is that you reduce the penetrative power of the bullet, which is fine inside a warm body because it means that the kinetic energy is being dissipated into the surrounding flesh but not so good against kevlar.

Full-metal jacket military rounds are designed instead to yaw at very specific velocity and resistance profiles. Ideally you would be able to penetrate a vest and then it would tumble and fragment inside the target's mass to increase stopping power.

With this background, let me get to my funny anecdote: NATO forces have discovered that enemy combatants in Afghanistan often have too little muscle mass to initiate yawing, contributing to reports of poor stopping power.

Sometimes hot-knife-through-butter isn't the preferred approach.

Don't use it, lose it

People think that the easy dissemination of information makes it difficult to lose knowledge in the modern age.

Actually, it's extremely easy to to lose knowledge. Especially technical expertise. So much of it is very specialized and only existent in the private hands of corporations. And within these corporations, specific and important facts are only kept in the minds of a handful of people.

If the engineers depart and the line workers depart, without replacement, you've already lost most of the knowledge.

For instance, the principals of an internal combustion engine are well known, and there's quite a bit more than that circulating around in papers. Do you think that's enough to reconstruct a modern car engine? Engine fundamentals from the Model T to the Fiesta haven't changed. But over the last century, Ford has figured out how to squeeze out more than 3 times the mileage and 6 times the power with an engine volume of half the size. Do you know what they did? Do you think your educational institution knows what they did? Not a chance, unless your professor worked in a very specific field within the industry. Even then, his knowledge grows more outdated year by year as Ford engineers continue to squeeze out a few more percentage points of performance year by year.

Or let's say that you already know that you can get a 5% efficiency gain by tweaking the inlet aero. How would you know where to tweak? You'd have to go through all the testing that was done before, and you'd need to design and build the infrastructure to conduct the tests in the first place.

It's the same across all fields, from cars to bridges to computers. Good luck building a modern virtual machine using the Dragon Book. And that's still only talking design knowledge.

Im CAD hat's passt.

It fits in CAD. Not good enough.

You can't learn how to build something without actually building it and, more than anything else, this is something kept exclusively in the minds of workers. And god help you if the toolset had been struck already (which is common), because now all of sudden all of your work instructions are worthless without the accompanying equipment. Now you have to redesign and rebuild the infrastructure too and go through the teething process all over again. Think you can make a violin from an instruction book? Nope, you learn by building a violin and a lot of crappy violins.

See how we've decided to stop going to the moon for a couple of decades and suddenly it's a pain in the ass to figure out how to do it again. And that's with all of the previous generation's artifacts around, more computing power than our predecessors could ever imagine and an extremely competent corp of people who've been shooting things into space non-stop in the intermediate period. Sure you don't have to go though the paradigm shift breakthroughs again, but most of being able to do something is just grinding, and that's a feat that'll need to be replicated if you ever forget. Technology has not dark age proofed us.

Applied Math

If I spend $20 a day and get $10 a day and I have a control volume of $100 a day, then that's like I'm losing $10 a day and I'd be out of money in 10 days.

Now lets say I have chocolate coins. If I get twenty coins a day and eat ten, and then I end up with ten coins in my pocket everyday. Except I don't except because some of the coins will melt together, so we add a reaction term.

Now, we can't use it in this form because it's too complex. What we can do is we combine it with what we've empirically determined in Fick's Law. Fick's Law to the rescue!

"Does anyone else get the feeling like they understand everything in this class and at the same time-"

"Absolutely nothing at all? Yes."

Going nukes

Here's the thing, Fukushima I-1 is one of the oldest reactors in service with TEPCO, built to withstand 8.2 earthquakes. It survived an earthquake 5 times the intensity, followed by a tsunami and ultimately failed because the backup backup generators shipped in by the military had the wrong power sockets.

And nobody died.

Nobody will die.

By all means this should be indicative of how safe nuclear power is. But that's not what the public is going to take away from this. For instance, Sen. Lieberman (I-CT) wants to impose a moratorium on further building any plants in the United States. I wasn't aware that the midland United States was tsunami central; just, keep these things away from Cali.

I guess expecting the media, as stupid as they are, to get nuclear reactors right was a doomed prospect from the beginning. Not that TEPCO did much to help, I heard the press conferences on the NHK being described as, "shit from the source".

Okay.

Hey, Mr. Lieberman! Mr. Lieberman! You live in Connecticut right? That's where Electric Boat is; how do you feel about the nukes getting built in your backyard right now? 774s don't sail on lollipops and sunshine, you know.

Your parents must be soo hood, Oleksi

The hottest fires don't actually make the hardest steel; the trick is fast quenching of γ-iron to under the martensitic transition temperature. Admittedly, the truth is quite poor as a tagline.

Thanks, internet

Someone has kindly provided ASCII art illustrating the difference with a tsunami:

●[４m Wave]
　　　　　　　　　　　　

　　　　　　　　　　　　　　　　　　　　　　　　　　波
　　　　　　　　　　　　　　　　　　　　　　　　　波
　　　　　　　　　　　　　　　　　　　　　　波波 　　　　　　　　●
　　　　　　　　　　　　　　　　　　　　波波波　　　　　　　　　人
波波波波波波波波波波波波波波波波－－－－－－－－－－－－－－

●[４m Tsunami]
　　←[Extending offshore for miles]

　　　　　　　　　　ゴゴゴゴゴゴゴ‥　　　　　　　　　

波波波波波波波波波波波波波波波波波波
波波波波波波波波波波波波波波波波波　　
波波波波波波波波波波波波波波波波 　　　　　　　　 Σ　●
波波波波波波波波波波波波波波波波　　　　　　　　　　　人
波波波波波波波波波波波波波波波－－－－－－－－－－－－－－－

Peter Wu says
gogogogo
wait are the waves made of waves?
lol, yeah I think they are

crobert says
no it's made of mud and cars and buildings and other shit it swallows

Peter Wu says
no I meant in the ascii

crobert says
lol yes
there's a version where it's made with
waves and mud and cars and buildings and fire

I was like oh boy Gibbs energy of mixing!

I understand physchem!

But then I actually watched the video and I was like, oh crap, Reynold's numbers, that's not physchem, it's fluids; I don't know what anything is going on in fluids!



Actually, I think it's equivalent to a parallel plates flow problem. Since the outside wall is stationary and the inside is moving, the velocity gradient means the "mixed" colours are actually discrete sheets overlaid on top of each other. If you turn it enough, the process will still become irreversible.

Materials

Anytime I see an aeronautical piece of equipment contacting anything in a movie now, I am going to think, "Oh no! Crack propagation of scratches into catastrophic failure by metal fatigue!"

The exception is Iron Man; I will just continue assuming that his suit doesn't get scratched.

edit: To elucidate- given the same bulk material, surface smoothness increases stress cycles before failure. And this is true with roughness on the scale of angstroms, so visible scratches are huge.