Mar. 16th, 2014 09:36 pm
bunsen_h: (Popperi)
I'm having mixed feelings about the new version of the Cosmos TV series.

It's good to have any kind of show teaching reasonably accurate science stuff in an entertaining way.  But... a lot of the graphic stuff isn't accurate.  Our solar system's asteroid belt, and the cloud of debris that coalesced into Earth, have been depicted as being like the typical sci-fi movie dense cloud of rocks.  A blood stream, with "our ship of the imagination" zipping through it, is startlingly devoid of blood cells.  A depiction of a DNA double-helix is bizarrely decorated with lines of light more-or-less-randomly connecting things, making it look like it's covered with cobwebs.

Is it a Brannon Braga thing?

ETA: Some of the spoken science is pretty wrong-in-scale as well.  In this evening's episode, Tyson made some mention of molecules so tiny that a million of them would fit inside a grain of sand.  Seriously?  That's some orders of magnitude off even if we were talking about them fitting across the grain of sand.  Then cube the error.  I recall squawking about some similar error last week.
bunsen_h: (Popperi)
I've just been catching seeing bits and pieces of the show, in passing.  Now it seems that the humongous totally-secret arctic Virus Research Station of Solitude has a nuclear reactor level.

My levels of bogglement keep escalating.  SyFy's original movies are usually terrible SF; this original series is worse.
bunsen_h: (Default)
When a statistic is reported as "plus-or-minus X, 19 times out of 20", it means that 1 time out of 20, the value will not be within plus-or-minus X.  (That is, the people who did the survey rolled a d20, and if it came up 20 — or 1; depends on the local rules — they got to make up some other number.)  If the results being measured follow a "normal" bell-shaped distribution, about 1 time out of 400, the real value will be outside plus-or-minus 1½ X of the reported value.
bunsen_h: (Beaker)
Further thought on my post yesterday...  If you really had a bucket with one hundred pounds of an isotope with a half-life of 3 years or so, it would have to be a very special bucket.  And you and your neighbors would probably not be happy.  If your hypothetical bucket-o-zappy-crap really lost 50 lbs. by conversion to energy in three years... it would be emitting 21.6 gigawatts on average.
bunsen_h: (Beaker)
I've recently been reading The Disappearing Spoon by Sam Kean (Little, Brown and Company, 2010).  It's a sort of anecdotal meander around the periodic table, touching on each element at least once.  (The title refers to an old practical joke, in which a spoon is moulded out of gallium.  When the spoon is put into a cup of hot beverage — or, for that matter, left too long in someone's hand or mouth — it melts.)

The structure seems to be a bit forced.  I get the impression that the material was rearranged several times, from the way that some people and some elements are mentioned several times — not that material is repeated, but the phrasing of the "see also this other chapter" stuff and the way the descriptions are split between the two sections.  In some cases, an element gets less coverage in its "own" chapter than in another chapter where it's compared to some other element.

The book isn't bad, but it could be better.  It's the sort of thing that Asimov did well, and the anecdotal stuff is less engaging than, say, the books by Richard Feynman or Oliver Sacks.

My main complaint about the book is that it's sloppy.  I keep hitting things that make me say "No, that's not right" in my head.  I gather that Asimov had the same problem when he was writing some of his non-science books, such as the ones about Shakespeare or the Bible, but his science writing was usually rigorously correct (at least, as far as then-current information went).  He didn't let the explanations for non-scientists drag his content away from accuracy.  I'm finding The Disappearing Spoon rather irritating.  One paragraph I read yesterday had no fewer than three "gotcha"s.

Detailed grumbling lies beneath... )

I've got the book on loan from the library, with about another week before I have to return it.  At the moment, my brain is mushy enough that I don't want to start either of the new books I just had delivered from Amazon (Seanan McGuire's One Salt Sea and Patricia Wrede's Across the Great Barrier); I want to wait until I can enjoy them properly (which will likely involve reading the earlier books in each series first).  I'm going to continue to read it for now, but if the irritant frequency gets any higher, I'll probably give up.  Perhaps I should just go back to one of my Asimov essay collections.
bunsen_h: (Default)
I was recently pointed towards the "10:23 Campaign", with their YouTube video about "homeopathic vodka".  They explain that a "30C" homeopathic solution, with 30 dilutions by a factor of 100 each, has almost no chance of even a single molecule of solute remaining.  The overall dilution factor is 1:10030, or 1:1060.

This stirred a vague memory of having read that if one took a glass of water, poured it into the ocean and mixed thoroughly, then took back a glass of water, one would end up with some dozens of the original water molecules in the glass.  I decided to try the calculation.

Per the United States Geological Survey, the total amount of water on Earth is about 1.386 * 109 km3.  Most (96.5%) of this is in the oceans; for the sake of simplicity I'll ignore that factor.  In more useful units, this is 1.386 * 1021 L.

Assume a 250mL glass, i.e. about 8 oz., imperial.  Mixing this into the volume of the ocean gives a dilution factor of 1:(1.386 * 1021 L)/0.25 L or 1:5.544 * 1021.

That 250 mL of water has a mass of about 250 g.  Water is about 18 g/mol, and the conversion factor of moles to molecules is Avogadro's number, 6.02 * 1023.  So the number of molecules in the glass of water is (250 g) * (1 mol / 18 g) * (6.02 * 1023 molecules/mol) = 8.36 * 1024 molecules.

Applying the dilution factor, we end up with (8.36 * 1024 molecules) / 5.544 * 1021 = 1510 molecules.  If you took that glass of water, mixed it thoroughly with all the water on Earth, and refilled that glass, you'd have about 1500 of those original molecules back.  (If your starting volume was only a tablespoon, or 14.8 mL, and you did the mix-and-refill thing, you'd still have a statistical average of 5.3 molecules back in your spoon.)

In contrast, if you applied the "30C" homeopathic dilution to your glass, you'd have (statistically) 8.36 * 10-36 molecules.  That is, only 1 chance in 1.2 * 1035 that you'd have even one molecule left.

(And if you want to talk about the water having a "memory" of the original substance, consider all the other places that water has been, and should "remember" just as clearly.)
bunsen_h: (Beaker)
This evening on Torchwood: Miracle Day, I saw:
Spoiled warning for Torchwood... )
Who do these people think they are — Star Trek?
bunsen_h: (Default)
On this morning's The Bottom Line, David Suzuki said that tidal energy (along with all other energy sources used by humans except geothermal) "ultimately comes from the sun".

I'm somewhat resistant to this description.
bunsen_h: (Guinea pig)
I saw "portable air conditioners" advertised on a sign in front of the neighborhood "Best Buy" store a couple of weeks ago. My first reaction was "How's that supposed to work?" If it doesn't have a connection to outside, where's the heat supposed to go? And the pictures sure didn't show anything other than the central unit, standing in the middle of a room.

My second thought was that it would be amusing to ask one of the salescritters, just to see what he'd say. Since the usual (though not invariable) hiring criteria for employees at "Best Buy" and "Future Shop" seem to be a combination of utter cluelessness and glib dishonesty. As in "I have no idea what the answer to your question is, but I'll make up something which I hope sounds good."

So I went in and asked a salescritter standing near the pile of boxed units. "I was just wondering... how do these work? Where does the heat go?"

He looked at me and proudly announced, "The air conditioner makes the heat go away. It cools the room. They work great! We had one running here a couple of weeks ago, it was awesome!"

"Yes," I said, "but where does the heat go?"

"The air conditioner sucks it in and gets rid of it."

"It can't," I said. "You can create heat, from electrical energy or whatever. You can move heat around. But you can't just make heat go away."

"Um." He paused. "There's a pan of water in the bottom."

"You mean it evaporates water to cool the air? Yes, that would cool things down, but you'd end up with a lot of humidity. It'd feel terrible."

"No, no, it sucks water out of the air. It dehumidifies."

"But that creates heat, the heat that went into evaporating the water in the first place. Is this just a dehumidifier?"

"No, it's an air conditioner. Which also dehumidifies. It, uh, well, we had one working, and it was really good."

"Is there a set of instructions or documents or something, which tells how it's supposed to work?"

"Uh, no... well, maybe, um..." He floundered a bit more, then spotted a colleague. "Wait a minute, let me ask this guy." He walked over and had a brief low-voiced conversation, with gestures, then brought the other guy back.

The other guy explained that the unit had a blower, and a venting hose which ran out the back of the unit. Its other end was to be stuck outside, through a window or door. The system pushed hot air out that way. Salescritter #1 had forgotten about the venting hose, and it's carefully omitted from all the pictures (though it's mentioned in the fine print on the boxes as being "included"). I suppose that it would be something of a sales disincentive to show prospective customers that moving this portable air conditioner around involves somewhat more than just lugging the main module.

Okay, yeah, this thing would work. Sort of. But it would be grotesquely inefficient, even if the internal heat-transfer system worked well. In the first place, heat would be radiating from the venting hose back into the room. In the second place, any hot air that is blown outside would, of course, be replaced by warm outside air drawn back into the room/home. A normal air conditioner tries to avoid exchanging air; one wants only to move the heat outside.

Advice to the consumer: Avoid.

My impression of the standards of "Best Buy" salescritters hasn't changed, either.

June 2017



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