Who Watches the Watch, Man?

Who Watches the Watchman?

Let’s say you own a big building full of valuable stuff. How do you make sure that the night watchman patrolling your factory floor or museum galleries after closing time actually makes his rounds? How do you know he’s inspecting every hallway, floor, and stairwell in the facility? How do you know he (or she) is not just spending every night sleeping at his desk?

If you’re a technology designer, you might suggest using surveillance cameras or even GPS to track his location each night, right? But let’s make this interesting. Let’s go a century back in time to, say, around 1900. What could you possibly do in 1900 to be absolutely sure a night watchman was making his full patrol?

The Casimir Effect

The Casimir Effect and Nanomachines

In London’s terminology, the van der Waals/London/Casimir-Polder/Lifshitz interaction is a dispersion force, but it sounds far more exciting and mysterious when called “the Casimir effect” and described in terms of zero-point energy and quantum-mechanical vacuum fluctuations. Cranks find it fascinating and hucksters profit.

The UnReagan Effect

Putting UP a big wall. 6,000 km along the Sahara.

BLDG BLOG: SAND/STONE

Clarifying the biochemical process through which his project could be realized, Larsson explained in a series of emails that his “structure is made straight from the dunescape by flushing a particular bacteria through the loose sand… which causes a biological reaction whereby the sand turns into sandstone; the initial reactions are finished within 24 hours, though it would take about a week to saturate the sand enough to make the structure habitable.”

Laser With Controllable Polarization

Laser With Controlled Polarization: Innovation Opens Door To Wide Range Of Applications In Photonics And Communications

To achieve the results, the researchers sculpted a metallic structure, dubbed a plasmonic polarizer directly on the facet of a quantum cascade (QC) laser. The QC laser emitted at a wavelength of ten microns (in the invisible part of the spectrum known as the mid-infrared where the atmosphere is transparent). The team was able to control the state of polarization by generating both linearly polarized light along an arbitrary direction and circularly polarized light.