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.
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.
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.
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.
So it turns out that octopuses (yes, you can say octopi or octopuses) are not solitary creatures. They actually sometimes live in colonies. Here’s a video of one colony called “Octlantis”. One discovered earlier is called “Octopolis”.
So my son and I go to St. Joseph, MO to see the eclipse. And the clouds roll in. And it rains a bit. We get to see some of the partial before totality, but only get to see 4 seconds of totality. This is the pic I took with my phone:
The best photo I’ve seen from St. Joseph was this one.
Hope you saw a better eclipse than we did. Even so, experiment_1 said that it was worth it.
So, there’s this total solar eclipse thing happening on August 21st. If you’re not going to be in the 70 mile wide band of totality that crosses the US, then you might want to see it using one of these livestreaming sites. Especially if you’ll be trapped indoors in a cube farm.
This article explains that every year the Earth produces a certain amount of renewable resources. On August 2nd, humans have used up that amount of resources. This means that as we continue to use up resources, we are using up resources that the Earth will not be able to renew for next year.
Two neat things from an AskReddit post.
cubosh said: Take every planet in our solar system, line them up so they are all touching, and they will fit inside the space between earth and our moon, with room to spare.
>to which jbhall36 said: Take every planet in our solar system, line them up so they are all touching, fit them in the space between Earth and our moon, and the gravitational force would be catastrophic and likely kill everything on Earth.
>>to which Rogukast1177 said: You don’t need the “likely”
>>>to which pinkbutterfly1 said: You do need the “likely”. Because Tardigrades. http://www.bbc.com/earth/story/20150313-the-toughest-animals-on-earth
A while ago I write about Graham’s Number, which is really migraine inducing. Another (much smaller) number is how many ways you can shuffle a standard deck of 52 cards. Here’s what VerbableNouns said (which really was written by techniforus):
One of my favorite is about the number of unique orders for cards in a standard 52 card deck.
I’ve seen a a really good explanation of how big 52! actually is.
- Set a timer to count down 52! seconds (that’s 8.0658×1067 seconds)
- Stand on the equator, and take a step forward every billion years
- When you’ve circled the earth once, take a drop of water from the Pacific Ocean, and keep going
- When the Pacific Ocean is empty, lay a sheet of paper down, refill the ocean and carry on.
- When your stack of paper reaches the sun, take a look at the timer.
The 3 left-most digits won’t have changed. 8.063×1067 seconds left to go. You have to repeat the whole process 1000 times to get 1/3 of the way through that time. 5.385×1067 seconds left to go.
So to kill that time you try something else.
- Shuffle a deck of cards, deal yourself 5 cards every billion years
- Each time you get a royal flush, buy a lottery ticket
- Each time that ticket wins the jackpot, throw a grain of sand in the grand canyon
- When the grand canyon’s full, take 1oz of rock off Mount Everest, empty the canyon and carry on.
- When Everest has been levelled, check the timer.
There’s barely any change. 5.364×1067 seconds left. You’d have to repeat this process 256 times to have run out the timer.
Now, that gives you some inkling of how big 52! is, but that’s nothing compared to Graham’s Number which I mentioned earlier.
My 6th grade is studying waves. Part of this involves making waves using slinkies. I know that slinkies are fun toys, so there’s a whole harangue about treating them carefully and not playing with them. Nonetheless, it didn’t take 2 days until someone turned one into abstract art.
Now, I know that slinkies aren’t expensive, but it’s the principle of the thing. Now I don’t have enough for all the groups.