Wednesday, December 31, 2014
I don't know what to say about this video. There isn't necessarily a massive amount of science being shown or explained here. There's pretty much just awesomely cool, slow-motion video of steel being shaved off of a rotating cylinder and shooting straight at the camera.
Yes, there's a ton of science involved in ensuring that the bit is harder than the steel, that the bit is replaceable, that the bit stay cool enough not to melt from the friction.
But none of that is shown in this video.
Tuesday, December 30, 2014
The Elements Unearthed tells the tales of a science teacher, David V Black, at the Walden School of Liberal Arts in Provo, Utah. Black's vitae is an impressive list of projects that he and his students have taken on through the years.
Perhaps most impressively, though, Black took our ASM summer, teacher workshop in Ogden, Utah two summers ago (in 2013) and put together an outstandingly thorough report on his time there and the labs and demonstrations during the week.
If you're considering the camps, check out Mr Black's report of the camps. You can get a good idea - with some pictures - of what you'll be getting yourself into.
Yeah, the message at 0:14 says, "[PVA] dissolves without leaving any harmless residue." That seems like a double negative - without leaving...harmless. It's a little confusing there, admittedly, but I'm going to chalk that up to Infhidro Soluciones en Film Hidrosoluble isn't a native English-speaking company.
PVA packaging can be pretty outstanding stuff. Just bundle up anything you need to later dissolve into water. Make the package exactly the right amount to be measured out and dosed.
Just don't make it something edible because the PVA isn't exactly something you'd want to ingest.
And maybe don't make the stuff inside the PVA package pretty enough that kids will want to pop the PVA packages like candy when they will then explode like little poisonous bombs in the mouth...sort of like a Detergent Gusher. See, Consumer Reports recently posted that The New York Times reported that in 2012 and 2013, over 17,000 children were poisoned (thankfully some in minor ways) by PVA detergent pods.
During every mention of new versus old pennies, the cost of coin production comes up. Invariably, I say something vague about the cos of production of a penny having risen over the years until the production cost out-stripped the value of a penny - meaning that the government was losing money on every penny it produced.
I've never actually done the research on those details, however. I just keep telling students that they can look it up. I don't think any of my students ever took me up on that offer, though, because none of them came back with evidence asking for extra credit - as I'm sure they would.
Thankfully The Washington Post recently published an article on our government continuing to lose money every time it mints a penny - or a nickel, even.
I did not know that the production cost of a nickel was higher than the five cents for which the government can then 'sell' the nickel.
Just in case The Post chooses to put the article behind a paywall or into an archive at some point, I've grabbed it into Word then published it via Scribd.
The simplicity of science - observations, hypotheses, repeatable tests - rears its gorgeous head in this video.
In today's episode of science, an observation is taken that fresh, charged batteries don't bounce. In fancier language, they have a very low coefficient of restitution. Old, discharged batteries, on the other hand, bounce just fine. They have a much higher coefficient of restitution - not like a full one or anything, just higher. Hence our first step: observation.
So the narrator of today's video makes a couple of hypotheses: gas build up (increasing pressure) or gel build up (damping the bounce).
Then we get to the repeatable tests. He builds a nice, little set-up to drop the batteries consistently ensuring that the observations are real and consistent. The set-up gets modified a bit to instead drop a piece of brass onto the different batteries. One hypothesis (the gas build up) finds itself on shaky ground. A further test - drilling into the batteries to allow any pressure to be relieved - fairly well dispells the hypothesis entirely.
So, the narrator cuts the batteries in half (I hope he wore goggles) and sees the change in the discharged batteries. I particularly like the analogy to the dead blow hammer as it relates to the gel-filled, new, un-discharged battery.
I will readily admit to having a weak spot for things that change and can change back. I buy pretty much every color-changing, plastic cup that I find and have them all lined up in the window of my classroom. So the sight of this thermoplastic changing from rigid and opaque to pliable and translucent and back again is just too much for me.
I'm sending my money to the Land Down Under to get me some Plastimake.
Does anybody know the conversion from US dollars into whatever the Australians use as money? Barbie shrimp, I think?
Update: turns out that these things are available from Educational Innovations, too. They've been in the goodie boxes that we give away each of the past few years. Sign up for a workshop, and you might win this stuff.
Tuesday, December 2, 2014
Yeah, it's a shill for Corning, but I'm okay with that because corning makes some pretty frickin' cool materials, and the Mythbusters guys - Adam Savage and Jamie Hyneman - are pretty solidly entertaining.
We get some history of glass developments, a look at modern developments in Corning glass (optical fiber, willow glass - check 7:00 for the phenomenally flexible willow glass), and then...well, an end.
Luckily there is also The Glass Age (part 2) from the same folks. Here we get a few destructive tests with older cell phones, an explanation of Prince Rupert's drops, and a windshield glass explanation.
I have to admit that I found this story from the not-school-appropriately-named I F*&(ing Love Science website. It's honestly way more entertaining and informative than I want it to be because I can't ever share these links on my class Facebook page - which I hate.
That's I hate not being able to share the links.
Not that I hate my class Facebook page. I don't. I actually like it a fair bit.
The video shows an in-development product designed to clot blood nearly instantly. It's apparently a polymer made of plant-derived polymers extracted from plant cell walls - like Lego blocks according to the company's co-founder and CEO.