Category Archives: Links

Hup, Two, Three, Four

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Stepping Feet Illusion and radial version

Many other illusions at the site, including some favorites such as

Pinna-Brelstaff Illusion though I never actually call it that

Roget’s ‘Palisade’ Illusion I’ve seen a similar effect while walking past a door and seeing a crt monitor through the narrow gap between the door and jamb.

Motion Binding has a subtle demonstration about orthogonal dimensions really being independent

Here’s the index in case you want to pick and choose, rather than march through all of them

News From the World of 'Alternative' Energy

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At some point, I think solar and wind power will not be considered “alternative.’ But for the moment …

Cheap “Popcorn Ball” Solar Cells Set Efficiency Record
A record for this type of cell, though — not for photovoltaics in general.

This efficiency is only about half that of traditional silicon solar cells found on roof tops and calculators but with the lower price its is enough to stay competitive with the silicon cells.

The technology that will save humanity
Of course, solar thermal does have the drawback of needing a certain amount of real estate. Rooftop photovoltaic panel systems are probably going to help “save humanity” as well.

Big oil to big wind: Texas veteran sets up $10bn clean energy project

Over the next four years he intends to erect 2,700 turbines across 200,000 acres of the Texan panhandle. The scheme is five times bigger than the world’s current record-holding wind farm and when finished will supply 4,000 megawatts of electricity – enough to power about one million homes.

Biodiesel Mythbuster 2.0: Twenty-Two Biodiesel Myths Dispelled

MYTH #22: Biodiesel is only used by crazy hippies and Willie Nelson.

FACT: Tell that to the US military, especially the US Navy (which is the largest single user of biodiesel), the National Parks Service, Postal Service, NASA, municipalities across the country, and more than 130 school districts and universities.

OK, but you’d be surprised at the number of crazy hippies in the US military. Very surprised

The Ten Most Beautiful Experiments

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NY Times book review

Johnson’s list is eclectic and his outlook romantic. “Science in the 21st century has become industrialized,” he states, with experiments “carried out by research teams that have grown to the size of corporations.” By contrast, Johnson (a longtime contributor to The New York Times) favors artisans of the laboratory, chronicling “those rare moments when, using the materials at hand, a curious soul figured out a way to pose a question to the universe and persisted until it replied.”

The “materials at hand” is one thing that continually amazes me. I read details of some century-old experiment and am reminded that their apparatus and supplies were hand-crafted, often in the same lab. You read about Rutherford doing alpha-scattering experiments in pure nitrogen. Did he order a tank of compressed nitrogen from the local welding-supplies shop, like I do? Of course not.

The nitrogen was obtained by the well-known method of adding ammonium chloride to sodium nitrite, and stored over water.

(My well-known method involves the internet and a credit card)

The Battery-Powered Rats of NiMH

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This reminds me — I need some new batteries. A few of mine just died from overcharging.

Adventures in Rechargeable Batteries

For one thing, there’s the issue of discharge rate. It turns out that massive 2500mAh capacity of the Energizer rechargeable battery doesn’t mean much when the battery drains itself within a month.
[…]
So putting a larger number on the box is ultimately a method of fooling consumers with marketing. Where have we seen that before? Oh right, everywhere. Caveat emptor.

The Wikipedia entry on NiMH batteries mentions that the hybrid/pre-charged batteries have an advance that reduces the discharge rate

A new type of nickel-metal hydride battery was introduced in 2005 that reduces self-discharge and, therefore, lengthens shelf life. By using a new separator, manufacturers claim the batteries retain 70 to 85% of their capacity after one year when stored at 20 degrees Celsius (68F). These cells are marketed as “ready-to-use” or “pre-charged” rechargeables. Besides the longer shelf life, they are otherwise similar to normal NiMH batteries of equivalent capacity and can be charged in typical NiMH chargers.

(via Daring Fireball)

The World's Worst Toaster

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The World’s Worst Toaster

Fortunately it doesn’t belong to me. But the web experience described does — I buy stuff for the lab. I run across the “bad toaster” interfaces all the time. For the life of me, I don’t get why certain segments of the science/tech world won’t tell you how much things cost, or make you click through a bunch of links to be able to add something to my shopping cart. I would think that, by now, most companies would have learned that every extra step — every mouse click — is an opportunity to decide to shop elsewhere. Meh.

Random Nonphysics Post

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You Say Organic Potato, I Say Poisonous Lump of Neurotoxins

I was thinking of weaponized potatoes, and was going to entitle this “Potato in the Hole!” but that quickly brought up a decidedly uncomfortable mental image.

But it’s not just potatoes that can kill you with their toxins. Apple seeds contain cyanogenic glycosides, which can release hydrogen cyanide gas when acted on by enzymes; chocolate containes theobromine (as does tea and cola), which can stimulate the heart to the point of cardiac arrest; and caffeine is a fatal neurotoxin that can also cause miscarriages in pregnant women.

I will continue to throw myself on rogue chocolate that threatens anyone, because I am selfless that way.