We went home to Arkansas this past weekend to spend some time with family. This trip requires a chunk of driving across Mississippi. Most of Highway 72 across North Alabama and Mississippi is a divided, limited access road with the occasional stoplight. (Strange I know, but hey, welcome to the South.) Most of the stoplights come equipped with a second flashing white strobe-like light that flashes when the stoplight is red. I guess this cuts down on people running the lights.

Monday as we were driving we came to one of these lights and I hear “Cheese!” from the back seat. I turned around to see Eli making what we call his big cheeser face toward the strobe light.

I guess it looked like the flash of a camera to him.

I’m wondering if this means we need to cut down on the number of photos we take of him.

Hello, those of you who are visiting from Television Without Pity. This is not really a science blog, nor is it a television blog, but I do sometimes go on about both. For atomic bomb discussion beyond the bit where I grumble about Jericho, you might be interested in Child of the Cold War, which discusses how growing up with the threat of nuclear annihilation made Jericho‘s pilot seem better to me than it really was. There’s also the original report from the Manhattan Project scientists determining that a nuclear bomb wouldn’t destroy the entire world.

For all-around science neepery:

• Object permanence is more tricky than we thought
• Vaccines don’t cause autism
• My experience with an honest-to-goodness creationist science fair project

There are also the music videos we post every Friday night, thoughts on The Venture Brothers and Narbonic, and many many posts about rearing a two-year-old kid. Enjoy.

And for those of you who are regular readers and are right now saying, “er?”, TWoP linked to me for my Jericho rants.

We’ve been watching Heroes, the NBC show about superheroes. The premise is that otherwise-normal people develop superpowers. You’ve got your guy who can fly, your girl who can survive any injury, your guy who can read minds. And then you have your girl who has an alter-ego who takes over her body but does not otherwise give her superstrength or even change her skin color. She has super multiple personality disorder, I suppose. All I know is that I wouldn’t want to pick my superpower from the DSM-IV.

Also: Hiro is the bestest.

One thing I looked into during my research for the earlier Jericho post was the claim that Manhattan Project physicists were worried about atomic bombs igniting the atmosphere. It’s true, though they were worried about a run-away nitrogen fusion reaction, not actual ignition of the atmosphere. The scientists decided it wouldn’t happen. But don’t take my word for it. Take a look at the original summary report by Konopinski, Marvin, and Teller, which was declassified back in 1979. The report, number LA-602, concluded that you just couldn’t get a self-sustaining fusion or fission reaction out of the atmosphere no matter how hot you make things. You lose too much energy to various forms of radiation, including light via Compton scattering.

I worry sometimes about Eli’s behavior, but on the whole he is an extremely well-behaved kid. He says “please” and “thank you,” and follows most of our directions. A few weeks ago we were at the supermarket and the woman behind the meat counter said of Eli, “He minds so well!”

Since I am a generous and kind soul, I will show you how we manage Eli’s behavior.

The trick is to start cage training at an early age. Pretty soon your child will be comfortable with a pet-like existence.

Clear your cache to see the new photos!

Dear UPS,

I know you have a hard job. Moving all of those packages and getting them to their destination in a timely matter is no easy thing. I don’t mean to complain too much.

I lie. I mean to complain a lot. CAN YOUR EMPLOYEES NOT READ? The delivery guy did have the decency to look sheepish when he dropped off the package, though he didn’t tell us that we’d lost our right to refuse the package by opening it to check on its contents.

The reverse side can’t be as bad as the above, surely.

As regular readers know, I’ve been watching the CBS show “Jericho,” about the town of Jericho, Kansas and what happens after Denver vanishes in a nuclear conflagration. The drama has been so-so, but in the pilot I was hooked by the eerie and frightening sight of the mushroom cloud rising into the air.

So, into the second episode. We’re ticking along, the fine upstanding citizens of Jericho merrily worrying about the fallout that’s headed their way. Someone says that Denver was probably hit with a hydrogen bomb. “How are they different from nuclear bombs?” someone else asks. And the mysterious-stranger-with-a-secret ominously says, “They literally explode the air.”

He probably said something after that, but I couldn’t hear it over my choked-back cries of rage.

So: a short primer on nuclear weapons. I’m a physicist, so you know I’m right.

Fusion and Fission Weapons

Nuclear weapons fiddle with atoms’ nuclei to release a whomping huge amount of energy. They come in two flavors, depending on whether they use fission or fusion.

Fission bombs were the first kind created. When people talk about atomic bombs, this is usually what they mean. The idea is that you take an atom and, using neutrons, split it into smaller bits, plus neutrons and some leftover energy. If you get enough of the right kind of material smushed together, those extra neutrons from one atom splitting causes other atoms to split, and so on and so on. The result is a cascade of splitting atoms and a huge amount of energy released in a split-second. In other words: big boom. To smush the radioactive material together, you can shoot a bullet of the material into a target made of the same material, or you can surround a core of the material with normal explosives and squeeze it down like play-doh in your fist. Dangerous play-doh.

Fission bombs are okay, and they’re dead easy to make if you’ve got the right uranium or plutonium hanging about, but you run into a couple of problems with them. One, they can explode too early, before you’ve smushed all of your material into a compact-enough mass to make the fission reaction run away. Then you get a small boom and a lot of left-over radioactive material that gets spread around. Hello, dirty bomb! Two, at best you get an explosion that’s equivalent to around 700 to 750 kilotons (kt) of dynamite, because you can only use up so much of your radioactive fuel before it all goes kablooey. 750 kt is a lot, but you’ll want something bigger when your next-door neighbor drives up in his shiny new weapon of mass destruction.

Enter the fusion bomb. Instead of splitting atoms’ nuclei apart, fusion bombs smush nuclei together. You start with something like hydrogen (or, really, a version of it called tritium) and squeeze it together until you have helium and a whole bunch of energy. The hydrogen bit is why they’re sometimes called “hydrogen bombs.” In theory you could squeeze the tritium together with regular explosives. In practice, you do it with a separate fission bomb. Fusion bombs are really effective, using almost all of their nuclear fuel, so you can build bombs that are small enough to be delivered by rocket or whatever but still pack one hell of a wallop. How big? Megatons (Mt). The USSR detonated the world’s largest fusion bomb in 1961. It had a yield of 50 Mt.

Both fission and fusion bombs are nuclear bombs. And, he says, finally getting to the punchline, they do not literally explode the air. I mean, c’mon. The real difference is that hydrogen bombs are much more powerful and efficient.

(ETA: phanatic pointed out that, in effect, nuclear weapons do explode the air. The overpressure and shock wave aren’t caused by the bomb’s plasma ball, like I had thought, but by the gamma rays ionizing the air and causing ozone and other smog-like products, which is then heated by the bomb’s x-rays. The effect is common to both fusion and fission weapons. My only defense is that, as I say in the next paragraph, I thought they were referring to the concern that nuclear bombs would ignite the atmosphere.)

The only thing I can figure is that the writers remembered that the Manhattan Project scientists were afraid that a nuclear explosion would ignite the atmosphere. It doesn’t happen. Atmospheric nitrogen requires much higher temperatures to fuse than you get in the center of the nuclear fireball, which cools surprisingly quickly because the fireball is expanding so fast.

So, to sum up: hydrogen bombs are different because they’re super-powerful, requiring a fission bomb to set them off. They do not literally explode the air. While they sort-of explode the air, so do regular fission weapons.

Hey, that was kind of fun. While I’m on a roll, let’s discuss fallout!

Fallout

In the same episode, everyone’s afraid of the fallout coming from Denver. Run! Hide! Put plastic sheeting over your windows and doors to keep it out and you’ll be okay!

Er, no. Not even close. Here’s the thing: fallout is radioactive. When a nuclear bomb cranks up, it makes all kinds of nasty radioactive byproducts. Many of them tend to be unstable, which is both good and bad. Good: they decay rapidly. Bad: in decaying, they toss off beta and gamma radiation the way college students toss down tequila. All of that plastic sheeting will keep out the fallout particles themselves. The radiation that the particles are emitting? Ha ha, he laughs hollowly.

What you want is as much mass between you and the particles as possible. More mass means more radiation is absorbed by the stuff between you and the fallout and less is absorbed by you directly. The beta radiation isn’t so bad. It’s the gamma rays that’ll get you. They penetrate like crazy. Your best bet is to put a lot of earth between you and the fallout, so your basement is better than your attic. Just over three and a half inches of dirt will cut the gamma radiation flux in half. A reasonable rule of thumb is that you want five to ten times that thickness to give you really good protection, so you’re looking at one and a half feet to three feet of dirt for really good protection. If you’re lucky enough to use concrete instead, you can get by with one to two feet.

What about air? you ask. Won’t it bring in the nasty fallout particles? Yes, but most of the really dangerous stuff has the consistency of sand, so it’s not too hard to filter out.

But do not sit near your house’s entrance and listen to the probably-radioactive rain pattering down.

That’s enough for now. I’ll probably have more grumbles later, like people who think that drinking iodine is a good substitute for potassium iodide pills, and saying that storms travel from Denver to wherever Jericho is supposed to be in Kansas in two hours. What, they have 100-mile-an-hour winds to blow the storms the 200 miles from Denver to the Colorado-Kansas border?

I have joked from time to time about Eli reaching his terrible twos, but here lately we’ve been dealing with a whole range of behavior ranging from the annoying to the downright troublesome. He has moved from testing the limits to hurling his little body at the fences and trying to break through. This has culminated in him getting in trouble at school last week. Tuesday he was pushing other children, and when he was told to go sit in time out, he told the teachers, “No!” After a bit of that, he got to go to the office. That meant that Misty got to go to the office when she went to pick him up. Thursday there were more shennanigans, though thankfully the office was not involved.

I understand that this is just what toddlers do, honest. And I know that Eli is practically a saint compared to many other toddlers, capable of walking across a river of milk flowing from overturned sippy cups. That doesn’t keep me from becoming so annoyed that I don’t want to spend time with him, making me feel even worse when I calm down later.

This misbehavior comes in waves that last a few weeks at most, so I’m holding on and waiting for this to pass. Then again, a woman at church told me, “Oh, they don’t act better when they get older. They act differently.” She had this big grin on her face, the kind that is a neon advertisement for the “misery loves company” bromide.

So I pushed her down and then ran from the teacher.

I’ve been grooving on The Venture Brothers for a while now. For those of you who haven’t seen it, it’s a 30-minute show on Cartoon Network’s Adult Swim block of programming. The Venture Brothers started out as a semi-parody of the old Johnny Quest series, but has since grown into its own twisted, hilarious thing.

Ben Edlund is friends of the show’s two creators. Edlund is the guy behind the Tick, and has worked on Firefly and Angel. If you saw the puppet episode of Angel, you’ve seen his work. He’s turned in a couple of scripts for The Venture Brothers, the most recent of which, “¡Viva los Muertos!”, played this week. The episode contained an off-kilter parody of the Scooby Doo gang in their later years. Fred was replaced by Ted, a bully who manipulated the others. Daphne had become Patty, compliant and beaten down by life. Velma was now Val, chain-smoking her way through the episode and explaining how the Y chromosome is an incomplete X chromosome and therefore men are but damaged women. Shaggy had become Sonny, drugged out and distraught that no one but he ever heard Scooby — pardon me, Groovy — talk, and Groovy kept telling him to kill prostitutes. Edlund had gone beyond the obvious “ha ha, they’re all stoner hippies” jokes and made them all disturbing psychopaths.

I didn’t realize it until a friend pointed it out to me, but they were all psychopaths because they were based on real-life crazy people from the 1960s and 1970s, the heyday of Scooby Doo. Ted is Ted Bundy, he of the charming personality and thirty deaths to his credit. Patty is Patty Hearst, who was kidnapped and brainwashed by the Symbionese Liberation Army. Val is Valerie Solanas, who wrote the S.C.U.M. Manifesto and shot Andy Warhol. Sonny was David Berkowitz, better known as the Son of Sam, the serial killer who claimed that his neighbor’s dog told him to kill.

And that is how you turn a parody into something far more disturbing.