I understand why someone living in the city might get a slice of pizza - they don't want to carry a box of pizza back to the office, and there is something nice about sitting down and having a quick bite.

But I have never understood why anyone buys a medium pizza, much less a small. If you understand what a circle is, and you understand what a dollar is, it makes no sense.

First, the dollar. The economics should be obvious; like buying any food in bulk, you can see there are fixed costs. A small pizza or a large has someone making it, it has an oven in a shop. Those costs are fixed regardless of which pizza you get. The actual ingredient differences between a small and a large are not a big cost.
In my previous article DC Versus AC I discussed how a diode can be used as a rectifier to convert alternating current (AC) into direct current (DC) because the diode allows current to flow in one direction, but not the other.

The diode is the simplest semiconductor electronic component, but the physics of how they work is perhaps somewhat complicated. There are many resources available on the web such as the Edison Tech Center semiconductor resource page.

New battery management technology could boost Li-ion capacity by 40%, quadruple recharging cycles

Long-life laptop battery the tech industry doesn’t want you to have ?

Fed up with the dwindling battery life of his BlackBerry Bold 9000, Carleton University chemistry student Tim Sherstyuk took a straightforward problem to his electrical engineer dad, Nick: Could the two of them come up with the technology to make a standard lithium-ion battery last longer?
Glastonbury - Britain's Oldest Glass Town

According to Wikipedia and many other online sources the origin of the name Glastonbury is unclear.  On the contrary, it could not be more clear.

While idly thinking about a long-ago visit to Glastonbury Tor I chanced to reflect on the name Glastonbury.  What, I wondered, was the true etymology of the name.  The 'witrin' in the old Celtic name Ynys Witrin seemed to me to resemble the Latin term for glass.  The modern Welsh equivalent 'ynys gwydr' means 'glass island'.  Could the 'glas' of Glastonbury mean glass?  What then of 'ton', which so often means 'town'.  Surely the name should be Glaston or Glasbury.  Why the apparent redundancy?
ESA, the European Space Agency, is my favorite space organization.

Yeah, I said it. The guy whose favorite movie is "The Right Stuff" and who could write a whole book on the Mercury program prefers the ESA over NASA. The reason is because ESA cares about outreach in a way that NASA doesn't. ESA does not care if you are the BBC or Science 2.0, if you call someone, they call back. If it involves more than a press release claiming it has 'implications for life on other planets' you are going to be stuck in a maze of bureuacracy.
For THE WIRED WORLD IN 2013 annual prognostication issue, predictions for the year by some of the luminaries in science media, I predicted that one of the Big 5 organs would be created.

The benefit is obvious; organs created from a patient's own adult stem cells mean no chance of rejection and no need for expensive immunosuppressive drugs. Science-fiction/ethical scenarios like raising animals or people for 'harvesting' by wealthy elites are off the table because a customized organ could be grown in the lab.
The fifth international school of Science Journalism will be held in the small town of Erice, in Sicily (Italy) between June 9th and 14th. The event is organized by the INFN, and I wish to publicize it here also because I will give a contribution there.

The general theme of the school this years is "The Digital World: Computing, Networks, and Us". From the "About" tab in the conference site:
Goodbye Ohm - Hello Heisenberg

Research reported earlier this month shows that electrical resistance in nanoribbons of epitaxial graphene changes in discrete steps following quantum mechanical principles.

In plain language, electron transport in a new variant of graphene doesn't obey Ohm's law: the resistance of the material is independent of current.  However, unlike the case with a normal conductor where you can stick a multimeter across any two points on a wire and measure the voltage, if you probe this new material you increase the resistance.  Shades of Heisenberg.

The origin of life remains a great mystery in biology. Continental drift has erased most of the record, until all that's left of the first half billion years of evolution are some millimeter sized zircons embedded in later rocks. These can tell us the composition of the early Earth's atmosphere (through pockets of air trapped in the crystals) but not much else. And there is much to discover. The most primitive microbes we know are far too large to be the first living cells, and modern DNA based life is far too complex.