Look Around You! - the source

A while back I posted about the BBC show Look Around You!, a parody of distance learning shows from the late 70s and early 80s. I find the parody hilarious, but I have come to understand through the years that satire is only funny if you're in on the joke.

So, I'd like to let a few more folks in on the joke. I'm assuming that the Look Around You! shows are spoofing British versions of the shows from the videos below. Admittedly, the shows below are a little more plot-driven that Look Around You! is, but it's still a paper thin plot.

The videos below are from KET, Kentucky Educational Television, the PBS network that I grew up watching on the Louisville PBS stations. They were designed to help prepare adults for their GED (General Education Development) tests. If those tests were passed - and they're still around and available - then the person would effectively have earned a high school diploma.

The shows would be played on local PBS or often available as VHS tapes at local libraries. Students would watch the shows and work through a workbook that they would have ordered and purchased in advance. I remember shows in math and English, but I assume that there were also social studies and science shows, too. The shows that I remember tended to have loose plots tying the lessons together. 

There was the English program...

...the math program...

You can even check out what the workbook would have looked like thanks to the magic of YouTube.

And, yes, I remember watching some of the shows because I was that nerdy. I would have been in elementary or middle school at the time and likely would have looked at most of the concepts as being things I already knew.

But, man, I was always down for some 3-2-1 Contact. 

Breathing The Heaviest Non Toxic Gas

That's funny...and at least somewhat dangerous.

In the above video Cody - I assume that's his name, the YouTube channel is Cody's Lab - breathes in sulfur hexafluoride, a dense, inert gas known to deepen the sound of your voice similarly to how helium raises the pitch of your voice.

Cody then immediately breathes in perfluorobutane, an even more dense gas that makes your voice even deeper.

He then comments, "wow, that's actually hard to get back out of your lungs." 

And there's the danger. 

Neither sulfur hexafluoride or perfluorobutane are reactive or toxic. They won't do anything themselves to your body. but they will push the air out of your lungs and make it tough for that air to get back into your lungs. The perfluorobutane, apparently, is even more effective at blocking your lungs from taking air back in because it's just that much denser than air...

• Density of air - approximately 1.225 kg/m³ (source)
• Density of sulfur hexafluoride - 6.17 kg/m³ (source)
• Density of perfluorobutane - 11.21 kg/m³ (at 28.9^oF source)

So, neither of the gases will hurt you, but they will prevent your body from getting air - which sort of includes a rather important thing to your survival, oxygen.

I'm hopeful that Cody had somebody else around to call for help just in case he didn't get air back in quickly enough.

I'm also hopeful that he didn't do that demonstration too frequently because both gases are also potent contributors to the Greenhouse effect, sulfur hexafluoride being almost 24,000 times more effective than CO2 in warming the planet (source), and perfluorobutane being 4800 times more effective than CO2 (source).

Mentos & coke - in oil?

I'm skeptical as to the veracity of this video short.

The video purports to show the mentos and (diet) coke experiment but performed underneath a layer of oil.

I feel like that's far less reaction that I would expect to see from the reaction - even under a vegetable oil 'cap' layer.

So I went hunting and found a few more videos.

This one fits more with what I would expect to see - at least it does at about 0:50. The freshly opened 2L of Coke has Mentos dropped straight into it moments before the 2L is lowered into the oil. You can see a similarly - if slightly less violent - reaction at 2:50 when multiple Mentos are dropped into a full layer of Coke at the bottom of the aquarium. Both are more vigorous than the video up top.

What exactly is the goop inside a lava lamp?

Unless the lamp has broken, the 'lava' is inside the glass, so shouldn't they be 'magma' lamps?

Hah, see, that's funny.

And some lava lamps have an important use in internet security, but what's inside them?

I'll say that I appreciate the presenter's sense of humor. YRMV

Clearly...

To the seriousness, the recipe is, as the presenter admits, rather finicky. Add a little of this, add a little of that, try adding a little more of a third thing. Repeat until it works. 

For a classroom activity, I would want a much more precise so my students could get a higher rate of success. I'm guessing that they might not be as persistent as the presenter. We've talked about the students needing a bit more grit and perseverance, but I'll admit that I would likely get frustrated with trying the method that the presenter presents.

I am curious about the IMFs in the braklean (still available as tetrachloroethylene (with CO₂ propellant, by the way) and how well it mixes into the paraffin. 

Curious...might be a fun summer project, but I'm happy to just buy a lava lamp.