Note (12/2015): Hi there! I'm taking some time off here to focus on other projects for a bit. As of October 2016, those other projects include a science book series for kids titled Things That Make You Go Yuck! -- available at Barnes and Noble, Amazon and (hopefully) a bookstore near you!

Co-author Jenn Dlugos and I are also doing some extremely ridiculous things over at Drinkstorm Studios, including our award-winning webseries, Magicland.

There are also a full 100 posts right here in the archives, and feel free to drop me a line at secondhandscience@gmail.com with comments, suggestions or wacky cold fusion ideas. Cheers!

· Categories: Uncategorized
What I’ve Learned:

Turing test: where men are men, except sometimes they're not.
“Turing test: where men are men, except sometimes they’re not.”

Like most computery sorts of things, Turing tests are only properly understood by a few pale geniuses who know how slide rules work and never have anything to do on Friday nights.

(Except to argue about the “proper” understanding of Turing tests. And catch up on Eureka reruns.)

But a Turing test basically boils down to one simple question:

Can a computer convince an “average interrogator” that it is human — and not, in fact, a computer?

The Turing test was first proposed by British mathematician and computer scientist Alan Turing in the 1950s. This was around the time when people first began to wonder whether machines could someday think on their own. Only nobody could precisely define what constituted “thinking”, exactly, and computers the size of post offices could scarcely rub two digits together, so the question went mostly nowhere.

That’s when Turing — now considered the father of theoretical computer science — posed his question, which was much easier to test. Whether the computer can “think” or not, can it fool people into believing it’s a live, thinking person? Turing tests come in a few flavors, but they mostly work like this:

An interrogator types questions to two test subjects — one of whom is flesh-and-blood human, while the other is motherboard-and-capacitor machine. Each answers via text — no cheating where one of the voices sounds like C-3PO or Bender — and after a few rounds, the interrogator decides which is the human. If he or she chooses the computer more than thirty percent of the time, the machine passes the Turing test.

And then Skynet probably gets built and melty-face Robert Patrick comes back in time to kill John Connor and all of human civilization will depend on Arnold Schwarzenegger saving our asses again, which seems way less likely now that he’s a member of the AARP.

Still, people perform Turing tests. Probably because they want to know when to start hoarding canned food and electromagnetic pulse bombs.

For decades, Turing tests were pretty non-apocalypse-portending. A gadget might do okay with questions limited to one subject, or when trying to pass itself off as a paranoid schizophrenic. But until recently, no computers had gotten especially close to passing a Turing test using what science would consider an average interrogator.

(In contrast to life outside science, where Siri and chatbots and Japanese girlfriend simulators have been talking people into giving away money and marriage proposals for years.

Clearly, the bar for “average interrogator” is just a leeeetle bit lower in some parts of the digital world.)

But just this week, a computer managed to pass a Turing test administered in London, fooling thirty-three percent of interrogators into believing it was a thirteen-year-old boy.

Which some might argue is only a small step up from a paranoid schizophrenic. Still — progress.

Of course, many in the artificial intelligence community don’t pay much attention to Turing tests. There are many ways to run one, and (see above) many ways in which people allow themselves to be fooled by relatively unsophisticated programs. Besides these difficulties, some computer scientists question the very relevance of Turing tests in the modern age. The goal of AI, after all, is to make machines more intelligent — not to make them more like humans.

I’ll leave it to the reader to decide how wide the chasm is between those two goals. Just remember — we created Two and a Half Men. So there is a chasm. Clearly.

Image sources: Computer Science Unplugged (Turing test cartoon), Futurama Point (angry Bender), What Culture (Robert Patrick/T-1000), OffTopics (The Termin-older)

· Write a comment


· Categories: Uncategorized
What I’ve Learned:

DNA polymerase: come with me if you want to replicate.
“DNA polymerase: come with me if you want to replicate.”

DNA polymerase is an enzyme present in every living cell. Hay cells, jay cells, even George Takei cells. Oh, my.

In these cells, DNA polymerase has one job — just one job — and it’s both the easiest and hardest job on Earth. Biology textbooks would tell you that job is to “replicate” the cell’s genetic material, reading and copying DNA so when the cell splits, both new cells contain a full set of genes.

And that’s true, in the same way it’s true that Tito Jackson recorded twenty Jackson 5 records. He did — but he had a hell of a lot of help.

It’s the same with DNA polymerase. It plays an important role in replicating DNA, sure, but it’s led to the job site by an entourage of support proteins, propped into place, and prompted for its lines. Each bit (or “base”) of DNA to be copied is a cue, and it’s DNA polymerase’s job to add the right complementary base in response. There are four different kinds of bases, so it only has four lines to remember.

This is why DNA polymerase’s job is the easiest in the world. It’s treated like a star. It gets driven to the set, carried to the stage, and it barely has to study a script. It just reads a cue and delivers the right line, out of four choices. It’s the gig of a lifetime.

Actually, I imagine it’s a lot like Arnold Schwarzenegger’s life these days. He probably does the odd public appearance for pocket change, followed around by a gaggle of handlers. They’d behave like the DNA replication helpers — getting him to the podium, making his hair look nice and prompting him for the appropriate line:

If it’s a Terminator convention, he’ll say: “I’ll be back!

At a children’s event: “It’s not a tumah!

At a GOP fundraiser: “I’m the Governator!

For a crowd of Predator fans worried about Anna: “Get to da choppa!

So wherever he goes, a flunky whispers into his ear: “Terminator”, “children”, “GOP” or “Anna”. And Arnold gives the proper response.

(Maybe the flunky even shortens it to one-letter codes: T, C, G and A.

Aw, yeah. You biochemical geneticists see what I did there.)

So DNA polymerase’s job is simple — as easy as a T-800 following a four-path if-then logic loop. Which is to say, it’s easy to do once. Even a few times a week, a la the former-Governator.

But there’s the rub. Human DNA polymerase reads and matches a DNA base about fifty times per second.

(E. coli polymerase is even faster, around one thousand matches per second. If you can picture a bacterial Arnold Schwarzenegger, moving at twenty times the speed. Hasta la nightmare, baby.)

That’s why DNA polymerase has the hardest job in the world. Our genomes are three billion bases long, and in rapidly-dividing cells like skin or hair or stomach lining, the replication never stops. One mismatch could create a mutation that kills the cell, or cause out-of-control growth into cancer. (“Then it IS a tumah!”) Yet our DNA polymerases are extremely accurate, mismatching less than once every ten million bases — and they can even correct their occasional mistakes.

Which is good news for us. It’s no big deal if an aging actor accidentally tells a bunch of six-year-olds to “get to da choppa!“. But our inner Ahhhnolds get their lines right — all the time, nearly every time, and without the help of cue cards. That’s why if it bleeds… we can find DNA polymerase inside it.

Actual Science:
How Stuff WorksDNA replication
The OncologistThe molecular perspective: DNA polymerase
WileyDNA replication
Asian ScientistDemystifying Rule-Defying DNA Polymerases

Image sources: Vanderbilt University (DNA replication), Fanpop / Michael Jackson (Jackson 5), Screening Notes (“Tumah!”), New England Biolabs and TalkBacker (polymerase T-800)

· Write a comment