Sarah McLachlan Science

A Mystery: Why Can’t We Walk Straight?

More like building a mystery*. Perhaps I am missing something, but I’m having a hard time understanding the “mystery” behind this. From a physics standpoint, we know that a moving object will travel at constant speed in a straight line if and only if there is no net force acting on it. Forces along that path will change the speed, so we don’t have to worry about that, and vertical forces can be ignored, since we aren’t going to start levitating or submersing ourselves in the ground. Which leaves us with the last component, which is perpendicular to the path. An acceleration perpendicular to the path gives you — ta da — circular motion. Physics 101.

I’m guessing the problem is in the assumption that the human brain could remove all biases in our locomotion and produce only forces along the direction of travel, without visual cues for feedback. Why would you assume that to be true? The surprise might be that there are biases rather than fluctuations, which would lead to a random walk (in the perpendicular component), but that’s still not a straight line. Assuming no noise processes at all is just naive.

*no data on if this effect holds while wearing sandals in the snow

Spot Welding Has Nothing to Do with Dogs

Cocktail Party Physics: welding: a matter of life and death.

The arc works on the same principle as spark plugs: electrons build up on the tip of the electrode. Charges of the same type want to be as far as possible from each other, but there’s only so much space on the tip for the charges to sit. When the electrons reach a critical concentration, they are so repulsed by each other that they jump through the air gap to get away from each other. Once in the metal that you’re trying to join, the electrons are free to move around and maximize their distance from each other.

I learned a little about how to arc weld when I was young — my neighbor had a machine, and many odd bits of iron got welded together for practice.

Impossible Songs

That post about Science on the Simpsons made me think about science in music. More specifically, science that’s wrong in song. This is actual problematic physics, not some mention of fantasy or fiction, in which the rules of science might not apply. Here are a few I can think of off the top of my iPod:

 

Creedence Clearwater Revival, Up Around the Bend

You can ponder perpetual motion

OK, so pondering perpetual motion may not be impossible, but is ultimately fruitless

 

Jefferson Starship, Girl With the Hungry Eyes

I like to move at the speed of light
Albert says I can’t, but I can

 

B-52s, Planet Claire

She drove a Plymouth Satellite
Faster than the speed of light

 

Barenaked Ladies, It’s All Been Done

The whole song is about immortality

 

A Google search shows there are a lot of lyrics using speed of light as a literary device, like “living at the speed of light,” but I don’t think those count. But I did find this one:

Coldplay, Speed of Sound

Look up, I look up at night,
Planets are moving at the speed of light.

 

Feel free to add more in the comments.

Blogging: You're Doing it Wrong! (Part III)

(Thoughts from Science Online 2011) (Part I) (Part II)

One of the sessions I was really looking forward to was entitled “The Entertainment Factor – Communicating Science with Humor,” moderated by Brian Malow and Joanne Manaster. Because I am really interested in saving on my long distance incorporating humor into my posts. There was a lot of good advice in the session, up to the point of telling people how to be funny — which isn’t a shortcoming, because I don’t think you can do that. There are opportunities to do this, because we tend to use analogies to explain science concepts, and humor is often about exaggerating any kind of absurdities when making comparisons, so there’s a natural fit to do that, and even point out where the analogy fails, as it always will, in making simplifications. And telling funny stories about life in the lab is common enough, because it happens to everyone.

I think there are several “don’ts” that go along with this as well. Don’t force the joke, and this is a subset of some of the other writing tips I heard in other sessions. You may have this great line, be it a joke or some science tidbit, that you really want to include in your post, but it has to naturally flow from the writing. If you “write around the joke,” it’s usually going to end up as bad writing. It’s like laying down tile on the floor — you might have a great pattern in the center of the room, but none of the edges match up with the walls and obstacles, and ends up being a crappy job because you can’t trim all the tiles to fit. Bite the bullet and let go of the notion that the great pattern has to be exactly centered.

Another limitation is this balance between writing to your audience without excluding too many potential readers. Brian had asked be during the break preceding the session to say a bit about science cartooning, which I did when discussing this. A cartoon — especially one panel cartoons — don’t afford the opportunity for background explanation. So if you do a cartoon that relies on the readers knowing about the physics “spherical cow” joke, such as this, you are going to exclude potential readers who aren’t familiar with the joke. And the topic of your post may not lend itself to explaining the joke. I imagine the same applies to science standup comedy as well. You can’t do a couple-minute lecture just to set up a joke and be effective at it. You either have to have an audience that already has the background, or already be in a position where you are explaining the concept. Otherwise it won’t work.

Here’s another perspective on the session, at Observations of a nerd: So this biologist walks into a bar…

——

Completely unrelated to this was a session called “How Can We Maintain High Journalism Standards on the Web,” and it was attended mostly by the professionals. Most of the session focused on ethics standards and disclosure and avoiding the appearance of bias, which means Pepsigate came up (surprise!) and other related subjects as well. I get that most responsible journalists don’t want their work tainted by the appearance that they are endorsing a product or service, which can be questioned by links or undisclosed sponsorships or targeted ads. A lot of their credibility is tied up in their objectivity. But I think there’s more to it. One thing that was mentioned only briefly was knowing what you are writing about, and from the perspective of a scientist who happens to write a blog, that’s where my credibility is. And it wasn’t clear that the writers understood this, or to what extend they understood this, because the conversation never went in that direction. Yes, it’s bad if you have taken money or some kind of favor from the target of your writing, but that really doesn’t come up much when you do a post translating a research result into a post for a wider audience. What’s important there is getting the science right. Because if the part you know and understand is wrong, you lose confidence that the author got any of the rest of the article tight.

Coupled to this is the idea that being objective means staying out of the fray and reporting both sides of a story. Not getting involved in the dispute. This comes up in stories that have a political or ideological slant to them, but what bothers me is the effort that goes into making sure both sides of the story are heard, and the lack of effort that goes into pointing out that the two sides are not equal. When the weight of evidence is heavily on one side, and the opposing arguments are weak and full of quote mining and cherry-picking, being fair means pointing this out. It’s not presenting the arguments as being equally valid — that’s giving extra weight to one side in order to balance the see-saw when the situation is inherently unbalanced. The reporter needs to stand on the fulcrum.

But the discussion didn’t afford me the chance to discuss that. Good thing I have a blog. Both are important. As one participant put it, your allegiance is to the readers. This means you have to be free from bias, or at least disclose potential sources of bias, but you also have to be correct in what you are writing about and present a story that has the least amount of distortion to it. It does no good to write a story on global warming, taking great care to avoid any appearance you’ve been influenced by big oil (or big research, if there is such a thing), only to get the science wrong and give the impression, say, that there has been no warming since 1998. It would be like implying that George Will has any idea what he’s talking about. There’s no scientific integrity there.

I think the lesson here is this: there is more than one thing that props up one’s credibility.

Part IV