Tiger, Tiger, Burning Bright

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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.

Obamastroid

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The Onion: Republicans Vote To Repeal Obama-Backed Bill That Would Destroy Asteroid Headed For Earth

“This law is a job killer,” said Rep. Virginia Foxx (R-NC), who argued the tax increases required to save the human species from annihilation would impose unbearably high costs on businesses. “If we sit back and do nothing, Obamastroid will result in hundreds of thousands of lost jobs, which we simply can’t afford in this economy.”

“And consider how much money this program will add to our already bloated deficit,” Foxx continued. “Is this the legacy we want to leave our children?”

Just Passing Through

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What is a Neutrino…And Why Do They Matter?

Brief summary of neutrinos. There’s a strange quote at the end, though, which bothers me more than the “give off puffs of energy” tucked into the explanation.

“If 100 years ago, I told someone that the universe was filled with massless, chargeless particles with no energy, I wonder if they’d have believed you,” Conway said

I’m not believing you now. The article just got done saying that neutrinos aren’t massless, and how do they have no energy? I wonder of the quote was mangled or is out of context.
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One Fish, Two Fish. Cold Fish, Big Fish.

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Need to breathe

Oxygen content varies with temperature, which affects the growth rate and maximum size of fish.

This is why your guppy remains tiny, although you feed it nutritious food twice a day. “If you want bigger guppies,” Pauly says, “keep them in water as cold as they can tolerate and make sure your tank is well aerated.”

Aeration, indeed, works wonders for fish in captivity, and this is why fish farmers aerate their ponds: not only does this prevent early morning mass mortalities (when naturally dissolved oxygen is at its lowest), but the fish convert their food much better than without aeration. Aquaculture practitioners have known this for at least half a century, but until Pauly incorporated this into his theory, biologists had not seen the link to fish growth.

Hägar the not-so-Horrible Physicist

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Did Vikings navigate by polarized light?

The saga describes how, during cloudy, snowy weather, King Olaf consulted Sigurd on the location of the Sun. To check Sigurd’s answer, Olaf “grabbed a sunstone, looked at the sky and saw from where the light came, from which he guessed the position of the invisible Sun”2. In 1967, Thorkild Ramskou, a Danish archaeologist, suggested that this stone could have been a polarizing crystal such as Icelandic spar, a transparent form of calcite, which is common in Scandinavia2.

… And it Comes Out Here

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Giving Light a Spin

Ordinary, unpolarized light can be thought of as an equal mixture of clockwise- and counterclockwise-rotating, circularly polarized waves. To create pure, circularly polarized light, a filter can absorb one polarization state and let the other pass through. Such filters are not hard to make, but they are inefficient, since half of the initial light is lost. Liquid crystals are known to emit circularly polarized light, and light from certain semiconductors can become polarized when a magnetic field is used [1]. But these systems are rather large and inflexible in their design.

True, but this ignores lasers which emit linearly polarized light, which can be circularly polarized with a quarter-wave retarder. But there are probably advantages to having it all as a monolithic compact system.

(I also wonder what will happen when someone notices that this system uses a swastika shape, which from a technology standpoint is not particularly surprising — you need a chiral shape, and straight lines are generally the easiest to etch (it has to be a pattern supported by the crystal structure of the material). But given the conservapedia invent-a-furor over relativity, who knows what will happen in the blogohedron?)

Take a Load Off

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Flat-ish horizontal space always seems to be at a premium in any lab I’ve worked, and it always fills up. Portable area, which isn’t on the floor (less bending and lifting), is even more so — we have several carts that are supposed to be for temporary equipment, but “temporary” is subjective — sometimes the cart sits there for months on end. Since that invariably leaves nothing free, we have this:

 


 

No place for people to sit, but the frequency synthesizer and some tools/components can relax. It gets bad enough that there are times when only one lab stool is free, but it turns out not to be a big deal, since only one section of lab bench (where the best soldering station is located) is remotely likely have any free space on it.

It's That Time of Year Again

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I just realized that I’ve passed my Third Blogoversary! Google tells me that three is the Leather Anniversary, which sounds pretty kinky.

I’ll take this opportunity to invite regular visitors who are inclined to leave a comment to give a short summary of who you are/what you do. Do did you come for the physics and stay for the silly posts, or was it the other way around?