You probably heard the news about the recent observation of ripples space-time, but you might not understand what it means. And maybe you could continue on that way if it weren’t for the curious kids in your house demanding explanations. I’m here to help!
Resources for Understanding and Explaining Gravitational Waves to Kids
One hundred years ago, Einstein predicted the existence of gravitational waves. That is, he suggested that space-time had ripples or curves as part of his theory of general relativity. These ripples were first indirectly observed in 1974. But it wasn’t until September of 2015, that they were more directly observed for the first time.
LIGO, the Laser Interferometer Gravitational-Wave Observatory, was created by scientists from the California and Massachusetts Institutes of Technology. In 2008 it was upgraded to Advanced LIGO and the project ultimately grew to involve a group of researchers (I’ve read numbers ranging from 600-1000) around the world that sought to directly observe what had never been seen before and develop a new field of astronomy. Indeed, this effort involved scientist from many disciplines physicists, astronomers, optical engineers, and data and computer scientists.
According to the MIT LIGO site, “Advanced LIGO can be optimized for the search for the gravitational cosmic background – allowing tests of theories for the development of the universe at only 10-35 seconds after the Big Bang.”
Here’s a great overview about what it means to hear a ripple in space-time from the New York Times. This is the best of the lot.
This video, Gravitational Waves Explained, is helpful.
The Guardian’s “Explain it to me like I’m a kid” piece falls short. Their explanations would not have worked well with my kids either. They would have caused a flood of more confusing questions and likely spawned a series of nightmares or daytime fears about getting sucked into a black hole or other astronomical collision. And the accompanying video is also rather “meh.”
Give a listen to the gravitational ripple at about two seconds in.
NASA has an explanation of gravitational waves and more with several videos to illustrate key points.
This Write Science post by Shane Larsen includes lots of background information from a gravitational wave astronomer, as well as information and loads of links. Admittedly, it’s written for adults, but the more you read, the more you might be able to pass that new knowledge along.
Becky Douglas also shared some thoughts on the recent research, which BTW, she and Shane both played a role in it.
If you really want to make the basic concepts above come alive for kids try these ideas. This section contains affiliate links:
Take a trip to you local trampoline center of bouncy house. What does it feel like to jump solo versus having a friend jump next alongside you on the same trampoline? Think in terms of ripples.
Toss rocks or small objects into a body of water to watch the ripples. Start by throwing in one object at a time. Then drop two or three in to observe the waves as they spread and cross one another. You can do this in a bathtub, but it’s more fun to do it out in nature.
Take a woven jump rope or clothesline and stretch it out with a person holding each end. Start with one person jerking her arm to create a wave that will travel along the rope to the person at the other end. Take turns so that each holder gets a chance to do this (it’s fun!). The person can send little waves or big waves. Can her partner send a matching wave in return? Which takes more energy? Imagine how much energy is need to cause ripples in space-time! If you didn’t already watch the video of from the New York Times site, do it now.
Edited to add: I woke up with a big “D’oh!” this morning. How could I leave out Water Blobs as a fantastic way to study ripples? I’m guessing if you record a video like the one below, but play it back at a slower speed, you’ll be able to get an even better look at the ripples. Water Blobs are a delight your sense of touch and lots of fun to play with and on. And as you’ll note below, my boys worked in a nice study of gravity as well.
Another waking thought included using play parachutes to study ripples and waves. Parachutes are always a good time!
Imagine that, instead of bouncing many balls as pictured, the children were holding the parachute somewhat taut, but with just a bit of slack and you tossed small, fairly lightweight ball into the center. They wouldn’t feel much. But if you tossed in a ball with more mass into the center, that might cause enough of a ripple that they would be pulled off-balance and toward the center. It’s a concept to play around with, but be careful because I see the potential for heads to knock together and nothing ruins a good time like a couple of concussions.
Ooh, an old memory just came flooding back. When my oldest was in preschool, I used to do an engaging monthly science project with his class. We had a set of rubbery planet balls, each about 3 inches in diameter (this is the closest I can find on Amazon) and for
my our session on outer space my son decided we should enclose the balls one of our 6-foot play parachutes and then dramatically fling it open, sending the balls flying into our small audience to simulate the Big Bang. That boy is now a high school senior, by the way.
If you have any other tips on how to talk about gravitational ripples with kids, be sure to comment below. This kind of stuff blows my mind. When we renovated our kitchen, we almost couldn’t fit in our new refrigerator because the planner’s measurements were off by nearly half an inch, even though he took them in the actual physical space. And yet the Advanced LIGO can detect a change in wavelength that’s a “fraction of a width of a proton…an echo of a marriage of two black holes… that happened a billion years ago.” Mind. Blown.