Daily Archives: February 4, 2011

He Ain't Heavy

Posted on by

Uncertain Principles: Heavy Heavy Water

So is it plausible that barrels of heavy water might’ve sunk, while barrels that contained ordinary water floated?

One thing not considered, or another way of looking at the problem: given the conditions of February in Norway, what if the heavy water had already frozen inside the full barrel. Would heavy ice float? It has a density of 1.0177 g/cm^3 (vs 0.917 for regular frozen water) and freezes/melts at 3.82 °C. Water has a maximum density of 1.0 g/cm^3. Even not inside of a metal barrel it would definitely sink, if it were 100% D2O. If the barrel were 10 kg, then we could suffer 50g/L of “missing” deuterium, which is roughly 50% “heavy.” More if the barrel were slightly more massive. 200 L of regular ice would give displace up to an extra (1000-917)*0.2 = 16.6 kg of water, meaning it could support 36.5 lbs of metal at neutral buoyancy. I thing we’re still in “plausible but not proven” territory.

Run for the Hills

Posted on by

“Natural Preservatives in Toiletries” and “Essential Oils” are areas in which one can get a PhD — and are considered scientific disciplines — in the UK. At least, that’s according to the Advertising Standards Authority. I know next to nothing about the structure of bureaucracy across the pond, but the question why an advertising board gets to decide what is and isn’t science doesn’t pass the sniff test. I know that in the US, the Federal Trade Commission enforces truth in advertising, but it’s the Food and Drug Administration, and arguably science-backed body (rather than a bunch of Mad Men), that sanctions companies for misleading drug ads. If that’s not enough, it turns out you can get a Bachelor of Science degree in herbal and homeopathic medicine.

Official: PhD in ‘Essential Oils’ or ‘Natural Toiletries’ = ‘a Scientist’

I also find, via ZapperZ, that astrology is a science in India.

Tiger, Tiger, Burning Bright

Posted on by

We were working on a laser system recently (and by we I mean someone in the group other than me, because if it were me, I would say I’ve been working on the laser, all the live long day. But I digress…) The laser system is fiber-coupled, which means it is now umbilically tethered to other equipment, and can’t venture far from its mommy. Which puts it right behind a door, and that puts in danger of being whacked (Honeymooners style rather than Goodfellas style), so we wanted to eliminate traffic through the door. It’s been my experience that simple signs* (like “Keep Out”) are ignored, so I posted a warning on some yellow label tape, and snark ensued.


(click to unleash the full tiger)

(N6 is our IT department, and NMCI is a locally-much-reviled navy/marine computer infrastructure + network that almost everybody tries to avoid using. We hates it.)

*We all have experience with “Wet Paint” or “Danger — Hot” signs, and people touching, just to make sure, or some reverse-psychological compulsion. As a result I’m tempted to put “Do Not Lick” signs on some equipment, because of the inner Homer Simpson some people have will shout, “Oh Yeah? I’ll show you!” and tongue marks will appear. Best to put them on the high-voltage devices.