Monday Science Links

This week's science:

• David Morgan-Mar at Irregular Webcomic has a post about Newton's third law: think about what your feet are actually doing to the ground. You plant your foot, and then your foot tries to push the ground backwards. This is easy to see if you imagine walking and accidentally stepping on a skateboard. Which way does your foot propel the skateboard? Backwards, not forwards. So your feet are definitely pushing backwards. Newton to the rescue! Your feet provide a force to the Earth, which means the Earth provides an equal force to your body, in the opposite direction. The entire Earth being pretty difficult to move, the result is that its reaction force pushes you forwards, rather than you pushing the Earth backwards*. When you walk, your feet are pushing backwards, and it's only through the magic of Newton's Third Law that you get where you want to go.


• Sean at Cosmic Variance looks at an essay predicting the end of the world because of the LHC: A recent essay in the New York Times by Dennis Overbye has managed to attract quite a bit of attention around the internets — most of it not very positive. It concerns a recent paper by Holger Nielsen and Masao Ninomiya (and some earlier work) discussing a seemingly crazy-sounding proposal — that we should randomly choose a card from a million-card deck and, on the basis of which card we get, decide whether to go forward with the Large Hadron Collider. Responses have ranged from eye-rolling and heavy sighs to cries of outrage, clutching at pearls, and grim warnings that the postmodernists have finally infiltrated the scientific/journalistic establishment, this could be the straw that breaks the back of the Enlightenment camel, and worse. Since I am quoted (in a rather non-committal way) in the essay, it’s my responsibility to dig into the papers and report back. And my message is: relax! Western civilization will survive. The theory is undeniably crazy — but not crackpot, which is a distinction worth drawing. And an occasional fun essay about speculative science in the Times is not going to send us back to the Dark Ages, or even rank among the top ten thousand dangers along those lines.


• Calla at Cocktail Party Physics has a different take: Nielsen and Ninomiya start to make some bold statements including but not limited to the idea that it is God who hates the Higgs (Even though he created it? Make up your mind, God.). He hates it so much that he "avoids" it (maybe they dated and it ended badly?), and to do this he must stop the LHC from starting up. It's like your friend who doesn't want his ex-girlfriend to show up at your party so he just starts telling people to say that it's cancelled so she won't come but won't feel uninvited and then he goes back in time and causes a wiring problem at your party. God is that guy, I guess. I'm not joking when I say that Nielsen and Ninomiya then go really far off the deep end and suggest that the wiring malfunction and resulting explosion at the LHC in 2008, which delayed particle collisions for over a year, were a result of this jinx. Following that up, they suggest that if their theory is correct, another accident will occur and people could get hurt or even die. To even make this suggestion is irresponsible unless you really believe that your theory is correct. Are we supposed to take this as a warning? If you are willing to suggest that this could happen, even under your extreme circumstances, then aren't we forced to take it seriously to prevent injuries and deaths? These are real people you're talking about. It's really tasteless.


• Jonah at The Frontal Cortex blogs on research showing making mistakes helps learning: In the latest Mind Matters, the psychologists Henry L. Roediger and Bridgid Finn review some interesting new work by Nate Kornell and colleagues, which looked at the advantages of learning through error. Conventional pedagogy assumes that the best way to teach children is to have them repeatedly practice once they know the right answer, so that the correct response gets embedded into the brain. (According to this approach, it's important to avoid mistakes while learning so that our mistakes don't get accidentally reinforced.) But this error-free process turns out to be inefficient: Kids learn material much faster when they screw-up first. In other words, getting the wrong answer helps us remember the right one.


• And going mainstream, here's an article by Amy Wallace from Wired on the anti-vaccination movement: Today, because the looming risk of childhood death is out of sight, it is also largely out of mind, leading a growing number of Americans to worry about what is in fact a much lesser risk: the ill effects of vaccines. If your newborn gets pertussis, for example, there is a 1 percent chance that the baby will die of pulmonary hypertension or other complications. The risk of dying from the pertussis vaccine, by contrast, is practically nonexistent — in fact, no study has linked DTaP (the three-in-one immunization that protects against diphtheria, tetanus, and pertussis) to death in children. Nobody in the pro-vaccine camp asserts that vaccines are risk-free, but the risks are minute in comparison to the alternative. Still, despite peer-reviewed evidence, many parents ignore the math and agonize about whether to vaccinate. Why?

Enjoy!