Space: Black Holes
This learning block represents one week’s work. Aim to watch at least one video and choose at least one activity or project to complete.
There are two main videos to choose from about black holes. The first one is better for younger kids, the second one will appeal to older kids. Feel free to watch one, or both!
Now choose an Activity
Create a MOdel of a Black Hole
Materials you will need:
– Aluminum foil
– Flexible measuring tape
– A digital kitchen scale
– Pencil and paper
Blow up your balloon and tie it. Don’t make it too big! Medium size is just fine.
Now, wrap your balloon in a few sheets of aluminum foil. Make sure the whole balloon is covered.
Using your soft measuring tape, measure around the foil wrapped balloon to check the circumference. Now, place the foil wrapped balloon on the scale and see how much it weighs. Write down the circumference and weight of the foil wrapped balloon. These are your baseline measurements.
Give the foil wrapped balloon a squeeze. The pressure your hands put on the balloon are similar to the pressure gravity puts on a star before it dies and becomes a black hole. See how the balloon goes back into shape when you stop pressing on it? That’s the star resisting gravity’s push.
Now pop your balloon, without squishing the aluminum foil. Your star has now died.
Use your hands to put pressure on your ball of aluminum foil. Shrink it down just a little. Use your measuring tape to measure the circumference again and the scale to weigh it. Record your measurements.
Squeeze it down again, just a bit more. Record the circumference and weight again.
Repeat the last step 2 more times.
Finally, crush your ball of aluminum foil all the way down, while keeping it in a ball shape. Measure and record the circumference and the weight one last time.
What do you notice about your measurements? How did the circumference change compared to the weight? Your findings are similar to what happens when a star turns into a black hole.
Here’s a video on this activity in case you’d like to follow along!
See how a black hole behaves
Materials you will need:
– Stretchy material (a t-shirt works just fine)
– 1 heavy ball
– 1-3 marbles or other lightweight balls
– A bucket (or two people to hold your stretchy material tight)
– Large rubber band or strong tape to attach your stretchy material to the bucket
Attach your stretchy fabric tightly across the top of your bucket. When you are done, your bucket should look like it has a fairly tight fabric lid on it. (Alternatively, you can get two people to stretch your fabric between them to create a taut surface.) We are now going to pretend this fabric surface is space
Roll a marble across the taut surface of the fabric. What happens? Can you get it to roll fairly straight across?
Now, place a heavy ball on your stretchy fabric. What do you notice about the fabric now? Where does the heavy ball go?
With the heavy ball still sitting on the fabric, roll a marble on the fabric again. Now how does the marble behave? Can the marble roll fairly straight across the fabric? How does the heavy ball affect the movement of the marble?
If you have other balls at your house that are somewhat heavy, you can experiment and see how the weight of the ball affects the shape of the “space” around it.
This is a basic model of how a black hole works. The gravity of a black hole deforms space in such a way that things can’t help but fall in and, once they do, they cannot move freely to get back out…..just like your marble.
Black Holes: Related Projects
Improving Your Inference Skills
Did you know our Galaxy, the Milky Way, orbits a supermassive black hole at its center? This supermassive black hole is 400 million times as big as our sun and 28,000 light years* away from Earth.
* 1 lightyear= 5,878,625,370,000 miles so 28,000 light years is REALLY far away from Earth!
Although black holes can be really huge, they are actually invisible. Because they reflect absolutely no light, scientists cannot see black holes with their naked eye and must rely on their observation of stars and light around the black hole to identify the location of one.
As stars and light approach the event horizon– also known as the point of no return for falling into a black hole- they begin to behave in ways that alert scientists to the presence of a black hole.
When a scientist views outer space using telescopes and other specialized equipment, they can see billions and trillions of stars, planets, and other space objects. In order to notice odd behavior from stars and light that would indicate the presence of a black hole, scientists have to really practice their powers of observation and apply what they do know to a scenario they cannot actually see.
Having good observational skills and being able to make an inference (an educated guess) is something that is essential to being a scientist who is looking for black holes. One way to get better at noticing details and clues as a scientist is to practice.
For the next week, practice taking away one of your senses at a time and see what ways you might learn things about your environment without it being obvious. See if you can make an inference about what is going on around you based solely on related clues. Here are some examples:
1. Have someone else put headphones on and ask them to dance to whatever music they hear. Try to guess what kind of music they are listening to. Is it fast? Slow? Exciting? Relaxing? How did you know? What clues made you guess the way you did? Were you right?
2. Open a window on a breezy day and notice what changes in the room. If you couldn’t feel the wind, how might you know it was windy? Try going outside and doing the same thing. What changes in the environment when the wind blows?
3. Put a blindfold over your eyes and ask someone to pick a toy or item from your room. Ask the other person to describe it to you without saying what it is. Listen to the description but also listen to how the person describes it. Are they giggling? Are the whispering? Ask to hold the toy. See if you can guess what it is without looking. Were you right? If you were, which clue gave it away?
4. Go outside and see what signs of the season you can find. If you couldn’t see or read a calendar, how would you know what season it is? What did you observe to make an inference?
Being able to notice small details and make an inference based on them is how scientists find black holes that they can’t even see.
Much of our understanding of how our own galaxy looks comes from artistic representations based on scientific data. If you’d like to try your hand at something creative, try painting your own galaxy. There are many techniques for doing this. Here are a couple of videos to inspire you.
Books About Black holes
Click on a book to buy it from Amazon. Or, you can ask for them at your local library.
NOw Let’s Have some fun!
Here is a read aloud of There Was a Black Hole That Swallowed the Universe.