Wrote an answer on Quora on a question about DNA.
Everytime math comes into my science class, the students always groan. “Why do we have to do math? We already had math class?” But math and science are linked. In fact, the math has to be there. And it can be really interesting how this happens. A number of years ago, one of my favorite youtubers did a trilogy of videos on this.
The first is on Fibonacci numbers, which seem to pop up all over the place. This then leads to one of my favorite irrational numbers: Phi (Φ). Everyone knows about Pi, but phi is pretty awesome too. Well, actually the golden ratio, which is also used all over the place, and mathematicians use phi as shorthand, kind of like they use pi for the ratio of the circumference of a circle to the diameter.
It turns out that when plants want to grow leaves, but not have the upper leaves be right above the lower leaves, they frequently put the leaves phi degrees away from the previous leaf. How do they do that? It’s not like they have protractors know about geometry or anything. It turns out that it’s really simple, as vihart gets to. It’s just growing where there’s more protein that tells the plant where to grow new leaves. This automatically ends up with the leaves being phi degrees apart. It’s really cool!
Anyway, here are the videos:
Ah, agriculture. That wonderful way of raising crops. Started about 10,000 years ago.
Or did it?
It turns out that humans aren’t the only one’s who raise crops for food. Ants have been doing it for much longer. On particular ant, Philidris nagasau, doesn’t just eat a particular fungus, but when an ant colony splits, they carry a start of the fungus to the new location. They’ve been doing it for over 8 million years, much longer than Homo sapiens has been around.
Lifehacker just did an article on Food Myths. That is, things that people think are true, but aren’t. The full article explains each. Here are the myths:
- Myth: Eat a hearty breakfast, first thing in the morning.
- Myth: You need small meals every 2-3 hours.
- Myth: You need to eat immediately after a workout.
- Myth: You need to stop eating a few hours before bedtime.
Researchers have found a new dwarf planet in our solar system. It’s about the size of Iowa, and is the 6th dwarf planet. It’s official name is 2014 UZ224. It’s currently about 91 times as far from the sun as Earth is (Pluto averages 39 times). It’s just inside the orbit of Eris. It’s orbital period is about 1100 years.
Humans have trouble understanding very large and very small quantities. Stuff over a million, or smaller than 1/1000th is just difficult for us to conceptualize. For example, we tend to think that a billion isn’t that much bigger than a million. But there are 1000 millions in a billion.
Likewise, our understanding of time and how long ago things happened is kind of fuzzy. Here is a great visualization of time. (there are some naughty words in there, beware if you are of timid sensibilities)
Google’s autonomous cars can teach us a lot of things. This Lifehacker article gives good hints on what kinds of things we should be learning from our soon-to-be codrivers.
- Pay attention to where others are going, and how fast they are moving. This will help you to anticipate your future moves. And it doesn’t only apply to cars. If you see that a bicyclist is approaching a parked car, you know that they will be moving over. Make room for them or slow down.
- Turn signals are helpful, but don’t trust that the other driver is using them properly. I know that I’ve forgotten to cancel mine sometimes, or turn it on too soon. But it helps to anticipate what the other driver will probably do soon, including moving into your lane.
- Maintain proper following distance. You should be keeping 3 seconds of distance between you and the car in front of you, so you can react and slow down if needed. Many times other drivers will move into this space. Don’t get upset about this. Just give enough space again. Personally, I like to go a little slower than the prevailing traffic on the highway. This makes driving much less stressful. The difference in timing is minimal, and the reduced hassles more than makes up for it.
The autonomous cars will be “driving like a grandma”, that is, playing it safe. This can upset us, but it really is better to be driving this way. Life isn’t a race. If we treat it as one, we place ourselves, and others, in danger.
It turns out that the nearest exoplanet is right next door. Of course, the neighborhood is kind of on the large side. In this case, next door is 4.2 light years ago, orbiting Proxima Centauri, the closest star, not counting the sun. Proxima Centauri is a very small star, class M, and puts out very little light compared to what we’re used to. This planet (Proxima b) is orbiting in the habitable zone, the so-called goldilocks zone, where liquid water would be possible.
This makes it theoretically possible that life could evolve there. But this is unlikely since the amount of X-ray or Gamma-ray radiation from the star is about 100 of the amount we get, which would break down DNA very quickly. Any life would have to store genetic information in a very robust chemical. Because class M stars are so small, the habitable zone is also very small. Proxima b’s year is about 11.2 of our days long; it’s orbit would be well inside Mercury’s orbit.
Popular Mechanics has a good article on the planet.
Do you get carsick when you try to read in the car? It’s very annoying for someone who really likes to bury their nose in a book. There’s this time in the car going somewhere—maybe a couple of hours. Why waste that time just staring out the window, when you could be reading? But once you start reading, your stomach tells you, in no uncertain terms, that you’re going to be sick soon.
Well, it has to do with how your body interprets mixed messages. Your vestibular system in the ears is constantly telling your brain that you’re moving. At the same time, your eyes are looking at a book that isn’t moving. These mixed messages tell your brain that something’s wrong. And the only thing that leads to this kind of mixed messages—at least the only thing for many millions of years of evolution—is that you’ve been poisoned. The body’s reaction to thinking that it has swallowed something really nasty is to un-swallow it. You know, throwing up.
This doesn’t affect everyone to the same degree, which is just individual variation. Maybe you have genes that don’t get as upset about this. That’s good if you like reading in the car. But it doesn’t bode well if you inadvertently swallow some poison.
As this video from AsapScience shows, not driving at a steady rate helps create traffic jams. Even when there really isn’t any other cause of traffic at all. Just watch.