About Chris Riley

I'm a middle school science teacher in New Jersey.

Which falls faster, feathers or a bowling ball?

Of course, here on Earth, it’s the bowling ball. But why?

The answer is air resistance. Those darn air particles slow down the low mass feathers. They try to slow down the high mass bowling ball, but have little effect. So the feathers take longer to fall.

But what if you could remove those pesky air particles? Well, they did this on one of the later Apollo missions, but you can also do this on Earth. If you have the right equipment. Fortunately, NASA does.

No, you haven’t seen a picture of a black hole

There have been lots of pictures of black holes, it’s just that they aren’t really pictures—they’re illustrations, or computer generated. Since no light can leave a black hole, you can’t ever see anything from inside the event horizon.

Here’s a good article on Vox showing what we’ve actually seen from black holes, and what we might see after the Event Horizon Telescope project gets setup.

Teachers Sharing

Today we had a faculty meeting where we shared some of the special things we do. Some of the things that were mentioned were screencastify, quizizz, peardeck, and edulastic. I’ll be looking into using one or two of these in the future.

Which way is down?

This seems like a very simple question. But as this video from vsauce shows, it’s anything but. This goes into things way past my middle school classroom, including general relativity, spacetime, and geodesics. Things are simplified in middle school, and it’s still a difficult thing for kids to get. More below the video.

In middle school we’re more interested in the Newtonian view rather than the spacetime view. For us, down is towards the center of the Earth. It’s the same for people on the other side of the Earth (say in Australia (I’m in New Jersey, USA)). For them, down is still towards the center of the Earth, but that’s in a different direction. My down and their down point in close to opposite directions. That’s because the concept of “down” is a local direction, not a universal one. My down is different from the down of my friend who lives in New Zeeland. This can be a difficult thing for 13 year olds to understand. It helps to show it on a globe, with little stick figures drawn on a folded up sticky notes.

An impossible star? No, it just means that we don’t know everything yet.

So stars are born, they live, and they die. Large stars die in a supernova. And that’s it.

Except that it isn’t. Scientists have found a star that has had multiple supernovas. One in 1954, the other in 1993. This is impossible given our current understanding of how stars work. Which means that we need to change our understanding. Our current theories are wrong and need to be changed. This is the exciting part of science, when our understanding has to change to fit the facts.

Research may help block unwanted thoughts

Have you ever had a thought that just keeps on coming up even though you wish it would just stop? This is very common with people who have PTSD, depression, anxiety, and more.

Research done at the University of Cambridge has found that one particular neurotransmitter, GABA, may be the key to help avoid these thoughts in the future. Research using FMRI and magnetic resonance spectroscopy have found that the presence of GABA can inhibit the activity of connected memory neurons. It may be that increasing the amount of GABA could help reduce the amount of persistent unwanted thoughts.