Plutonium

Source - https://xkcd.com/2115/

Rollover Text - It's like someone briefly joined the team running the universe, introduced their idea for a cool mechanic, then left, and now everyone is stuck pretending that this wildly unstable dynamic makes sense.

See, it's funny because the concept of a solid chunk of metal just generating energy for billions of years is just ridiculous.

Except that it isn't.

Nitromethane Jet Bottle - Looks Awesome in 4k Slow Motion - aka Whoosh Bottle

The whoosh bottle is among my favorite demonstrations.

It's easy as pie to set up. It allows some phenomenal chemistry to be shown (limiting reactants, combustion, exothermic reactions, energy transfer).

And it looks gorgeous.

I'm not sure that the nitromethane woosh bottle adds anything cool, but the slow-mo, 4K video definitely does.

$500,000 of Calcium - Periodic Table of Videos

I think it's necessary to watch the below video first to understand the above video.

Take a couple of minutes. I'll wait.



It's the moment at 2:50 where they mention at the "cost of the calcium they consume is 10% of the operation costs of the machine" that got me.

That and the fact that Yuri Oganessian is there...talking. He's only the second person to have had an element named after himself while he was alive and the only person currently alive to have that happen.

He is among the greatest chemistry (or physicists) alive.

Back to the calcium, though. I initially wondered about why the calcium would be so amazingly expensive, thinking maybe it had to do with simple purification to make sure there weren't any non-calcium contaminants. But I hadn't thought about the need to only use heavy isotopes of calcium - specifically calcium-48 - for the nuclear synthesis. Purifying calcium's mixture of calcium isotopes into just calcium-48 (0.187% of all calcium atoms according to wikipedia and confirmed by webelements) is apparently tough...and expensive.

I especially appreciate that the Professor mentions (at 1:40 in the top video) that his shaky hands prevent him from even touching the vial of calcium-48 carbonate.

Where Do Trees Get Their Mass?

Last week we saw a video that asked us what happens to the mass you lose when you lose weight.

This week we look at the reverse. Where does the mass come from when a tree grows?

It's a remarkably similar answer because generally, reactions are reversible.

This question is incredibly subtle, and not even high-level science students get it right...



As a side note, I can see through Dr Derek at about 3:50.

The mathematics of weight loss | Ruben Meerman | TEDxQUT (edited version)

Mrs Heckman and I were having a discussion one time about what happens to the fat - or whatever else - you burn when you lose weight. My contention at the time was that the fat was turned into carbon dioxide and water vapor which was eventually exhaled from your body - mostly as carbon dioxide but less as water vapor.

I don't, honestly, remember what her contention was...because it was wrong.

I do love the explanation of what the arrow (at about 5:00) actually means.

In the long run, it's just conservation of mass, and when we're talking about 'invisible' gases, it's an incredibly slippery concept for being so simple.

In all honesty, if my students could successfully answer the question he asked of the sunbathers on Bondi Beach, I'd be pretty happy about their conceptual understanding of chemistry.

There's a flip side to all this, and I'll post about that next week.

How Not to Put Out a Metal Fire - with Steve Mould

I remember watching WGN a couple of decades ago about a fire at a metals recycling company in Chicago (maybe this one?) The thing that fascinated me at the time was watching the firefighters spray water on the fire, have it explode, and repeat the process a couple more times. The fire chief at the time - in my deep memory, at least - said something to the effect that they knew the explosion was likely but that they were trying to dump enough water on all at once to cool the fire enough to stop the burn. Not enough water = explosion, though.

In the above video - the Royal Institute - Steve Mould shows why magnesium fires are such a bear to put out. They don't - as the article linked above says - 'produce their own oxygen', but they do tear oxygen off of carbon dioxide and water. Once that happens, then, the fire allows the hydrogen and oxygen (from water - or oxygen and carbon (from carbon dioxide) to react with the magnesium or with each other producing an even hotter flame.

Hmmm...seems magnesium's active or something.

(And I don't think - at 2:55 - you 'can actually see [the beaker filling with carbon dioxide]', Steve. My understanding is that carbon dioxide is invisible. What I think you're seeing is fog, condensing water vapor due to the coldness of the dry ice.)

Bagged Water in Space Has Weird Bubbling Behavior

I'll admit to being a sucker for just about any 'in space' video.

Here we see - and the space.com article explains - air bubbles not separating from the water surrounding them in a plastic bag 'in space'.

It looks impossible but makes absolute sense because it's not the IMFs that separate water from air on Earth's surface but rather the pull of gravity. Gravity pulls more strongly on the more dense water, so the water goes down and pulls together to 'push' the air upward.

No gravity, no pull...no buoyancy...no separation.

How cool is that?