Science Sunday: Killer Mice Are No Joke

Read this NPR story.

Sure enough, the scientists found one set of neurons in the amygdala, a structure involved in emotion and motivation, that became active when a mouse was pursuing prey. They found a second set of neurons in the amygdala that became active when the animal was biting and killing.

Then the team used a technique called optogenetics to create mice in which both sets of neurons could be controlled using light from a laser. That gave the researchers “an on-off switch for either or both of the circuits,” De Araujo says.

“When we stimulate [both sets of] neurons it is as if there is a prey in front of the animal,” De Araujo says. “They assume the body posture and actions usually associated with real hunting.”

Horrified yet? I know, this is research, simply to learn. But how far are we away from this?

I don’t want to be alarmist here, but –

No, scratch that. I do want to be alarmist. Mind control is a long-standing trope of science fiction, but this… They don’t control the mouse, they simply make it want to do what they want it to do.

They reprogram it.

They take away its little mousy free will.

This is an early, crude step on a long road; but sooner or later that road ends with somebody deciding what other people want, how they respond to the world.

But who decides? And for whom? If you think it’s a good idea, just remember: it’s virtually certain that you’ll be one of those reprogrammed, not one of the elite. Who should be your slave master? Will you willingly be a slave? A happy slave who wants to be enslaved?

On Science Sunday, I’m supposed to look for the story potential in some recent scientific work. Well, the potential I see here is horrific, dystopian, and totalitarian.

And I worry how long it will remain fiction.

Science Sunday: The Boom Star in My Back Yard

Prof Larry Molnar Credit: Calvin College

“What’s a Boom Star, Martin?”

It’s two stars that are going to collide in 2022, creating a Red Nova dubbed the Boom Star.

“Why do you say it’s in your back yard, Martin? Isn’t that kinda close?”

Well, of course, the stars won’t be in my back yard. But that’s where the research was done to discover this impending collision: at Calvin College in Grand Rapids. Not precisely my back yard, but close enough to give me a sense of regional pride. This is world-class astronomy work, headed up right here in West Michigan. Dr. Molnar presented his paper at the American Astronomical Society last week. You can read a preprint version here.

So what’s going to happen? From the Telegraph article linked above:

Before their meeting the two stars were too dim to be seen by the naked eye, but in 2022, the newly formed Red Nova will burn so brightly in the constellation Cygnus that everyone will be able to to see it.

“For the first time in history, parents will be able to point to a dark spot in the sky and say, ‘Watch, kids, there’s a star hiding in there, but soon it’s going to light up,” said Dr Matt Walhout, dean for research and scholarship at Calvin College, Michigan, where the prediction was made.

For around six months the Boom Star will be one of the brightest in the sky before gradually dimming, returning to its normal brightness after around two to three years.

That. Is. So. Cool!

Now for Science Sunday, I like to explore the story implications of a scientific discovery. One obvious implication: suppose one of these stars had an inhabited planet? What would happen to the occupants? Nothing good, I fear. Would they live long enough to see the Red Nova engulf their planet? Or would the approach of the other star tear them out of orbit from their primary, either pulling them in to a fiery death or tossing them out into the cold darkness of space? Neither would be a good fate.

Though in the latter case… If they had time to move their civilization underground… Hmmm…

Of course, we don’t know if a binary system could have a planet in a stable orbit long enough to evolve intelligent life. The odds seem kinda long for that. But it’s not impossible. Might be a good story there.

I hope to interview Dr. Molnar for a future Science Sunday. Stay tuned!

Science Sunday: Near Earth Objects

Inspired by this Sci-News article, I was going to write about Near Earth Objects (NEOs) and what would happen if one hit us.

But then Radiolab did it so much better than I could. Take a listen. Or watch it here, with dino-puppets!

So I want to take a different approach to the topic: deflecting a NEO. There’s a lot on the topic on Wikipedia, including links to sources. What I find interesting here are these crunchy bits:

  • “It has been estimated that a velocity change of just 3.5/t × 10−2 m·s−1 (where t is the number of years until potential impact) is needed to successfully deflect a body on a direct collision trajectory.” I don’t want to minimize the challenge here, but that’s not nearly as bad as I’d feared. 0.035 meters per second, divided by the number of years of warning. That’s 1.3 inches per second. Suddenly the task seems feasible. Except…
  • A typical NEO of interest is 140 meters in diameter. Assuming for simplicity that it’s a sphere, that’s 1.43676E+12 cubic centimeters. Assuming a density similar to Earth’s (5.5 grams per cubic centimeter), that’s 7,902,152,721 kilograms. For round numbers, call it 8 million tonnes. We don’t have to move it fast, but there’s a lot of it to move.
  • That means that with one year of warning, we need to impart 4.84E+06 joules of kinetic energy. If it’s one month, we need 6.97E+08 joules. Two years: 1.21E+06. In case it’s not obvious yet, early detection makes a big difference in the cost of deflection!
  • For those (like me) who aren’t accustomed to thinking in joules – especially large numbers of joules – here’s a comparison: “The terajoule (TJ) is equal to one trillion (10^12) joules. About 63 TJ of energy was released by the atomic bomb that exploded over Hiroshima.” So that’s 6.3E+13 joules from a small, primitive atomic blast. That’s 90,000 times what we need for an average NEO with a month’s warning!

We can do this. It’s a matter of engineering, politics, diplomacy, commerce, logistics, and orbital mechanics, but we can do this.

Now for Science Sunday, I want to look at the story potential in the science, so here are some thoughts…

The figures above are for the smallest NEOs we’re currently tracking. They come larger – more rare, but they do. If I change my spreadsheet for a dinosaur killer (10km across), the energy requirement is 1.76E+12 joules (with one year warning). That’s a little bigger, about 3% of a Hiroshima blast. Still pretty feasible. But with one month warning, it gets a lot worse: 2.54E+14 joules… something like 4 Hiroshimas, assuming 100% of the energy went into moving the rock. It won’t. I’m not a nuclear engineer nor a rocket scientist, so I can’t guess what the actual efficiency would be. No better than 50%, I’m sure, since half the blast points away from the rock. A big nuclear blast ought to do it, if used right, so it’s still possible.

But when we talk about “warning”, what we’re really talking about is time between the blast and the possible impact. If we see that dinosaur killer two years out, but it takes us 22 months to decide to act, we are dead as the dinos. Somehow we have to get that nuclear device out to where the rock is. Right now we spend years – decades, even – planning relatively simple space missions. This one won’t be simple, and it has to be done right the first time. So a major source of story conflict can be the diplomatic and political effort to get people to act when they don’t believe they have to – until it’s too late.

Now I’ve been talking about nuclear deflection because it’s the simplest to calculate and explain, but that’s only one of many proposed methods. Kinetic impact, rocket engines, ion drives, gravity tractors, mass drivers… They’re all different ways to add that tiny delta V to that great big rock; and no matter which method you use, the required change in kinetic energy is the same: a lot, but not impossible.

Of course, as Carl Sagan warned, if you can deflect an asteroid away from the Earth, you can also direct it toward the Earth. That seems suicidal, but it might work for a doomsday weapon.

And always remember: this isn’t fiction, it’s probability. A dinosaur killer hit us before. If we take no action, one will hit us again. It’s only a question of when. We can’t answer that question without data, so watch the skies!