This week the Nobel Prize winners in six different categories are being announced, starting on Monday with prize for physics – my favorite subject! The award was given to Rainer Weiss, Barry Barish, and Kip Thorne for the detection of gravity waves. It turns out you can model these pretty easily at home or in the classroom.
If you were to ask anyone to name a physicist, odds are they would answer Newton or Einstein – two guys so famous they don’t even need full names. I could have said Isaac and Albert and you would still know whom I meant. This year’s Nobel Prize winners in physics brought about a better understanding of gravity – a topic Newton gets credit for “discovering” but for which Einstein gets credit for increasing our understanding.
Here are the basics. Einstein theorized that space, time, energy, and mass were all connected. We describe the universe as part of the “space-time continuum” and we know that mass and energy are interchangeable thanks to his famous equation E = mc2. One affect of this theory of how the universe works is gravity waves. That is, anytime something accelerates – when you hit the gas on your car, a skater spins around or when two black holes collide – waves are sent out on the space-time continuum at the speed of light. The problem is that most of these waves are EXTREMELY weak. Only the most massive waves, from two black holes colliding, has the faintest chance of being detected.
Rainer Weiss did a lot of the groundwork starting almost 50 years ago by figuring out how to avoid background noise. He also designed a detector using lasers, which became the Laser Interferometer Gravitational-Wave Observatory (LIGO) – designed to detect a change even smaller than the nucleus of an atom. On September 14, 2015 the lasers detected a tiny little quiver that signaled two black holes colliding 1.3 billion light years away from earth. The discovery confirmed Einstein’s theory and increased our understanding of how the universe works.
This video from the New York Times illustrates the idea beautifully.
Model the Space Time Continuum
It’s actually fairly easy to make a model of the space-time continuum. All you need is a big sheet of lycra, large clips and a round hoop. If you’re doing this at home, a hoola hoop is perfect or for a larger space like a classroom just use some thin PVC pipe and connectors. Stretch the lycra fabric over the hoop, secure with the clips and Voila! You have a model of the universe! Collect some heavy balls and marbles. Put a heavy ball in the middle (or just a few golf balls) and roll a marble around the edge to model the orbit of a planet around a star. This video, made to show teachers how to use this model in the classroom, has some other great ideas for showing other phenomena in space.
And here’s another video that shows the assembly of the space-time continuum and some other cool features you can demonstrate.
So what about Gravity Waves?
If you flick or tap your lycra universe quickly you will see a wave travel across the surface of the fabric – this is a gravity wave! Steve Mould does a great job of explaining how to model the collision of two black holes in our lycra universe with just a small piece of wood, 2 toy wheels and a drill.
More about Gravity Waves and the Nobel Prize
Nobel Prize in Physics 2017 Press Release