Science Camp: Gravitational Waves

Week One: Follow the Happy Scientists

It’s September 14, 2015 in Hannover, Germany — 11AM to be exact — and a man named Marco Drago has just noticed something. Marco is a member of the Laser Interferometer Gravitational-Wave Observatory, and he’s just observed a gravitational wave (hurrah!).

But why are the scientific community FREAKING OUT about these things six months after the initial observation? Well, like all good scientists, they had to check — and recheck, and RECHECK, and RECHECK, until LIGO confirmed the discovery. They were sure.

Director of the National Science Foundation said, “Einstein would be beaming, wouldn’t he?” (Science Mag)

I find that my motto in life has become: follow the happy scientists, they’re sure to lead you somewhere good. This is the most buzzed I’ve seen the scientific community since the Higgs Boson. It’s magic.

So here I am — let’s learn about gravitational waves (INSERT CATCHY THEME SONG)!!!

What Are Gravitational Waves?

You have a bowl of soup. Anything with mass will affect your bowl of soup — if it’s alphabet soup, the letters will dip into it, effectively bending and warping it. If a letter moves at a decent speed, it will make waves.

Now replace the word soup with space-time, and the alphabet with planets, black holes, neutron stars, and the like. When these things accelerate — move faster, or in more science-y words, change velocity— they make waves.

Gravitational waves are ripples in the fabric of space and time that occur when a massive object accelerates. Basically, they are what the name implies. Thanks Einstein.

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Albert Einstein, German born theoretical physicist and all around Great Guy

What’s The Big Deal?

These ripples were predicted by Einstein’s General Theory of Relativity in 1915. He also conveniently mentioned that they would be SUPER hard to find, maybe even impossible, because they were so feeble they would be virtually undetectable.

The gravitational wave detected in 2015 and witnessed by our good pal Marco Drago took a LONG time to find. The discovery is not only proof of gravitational waves, but also of what it takes to find even the tiniest bit of evidence they’re out there.

To explain this, we need to go back to our bowl of soup.

So your bowl of soup is full of letters. Each one is bending and warping the delicious tomato flavoured space-time, others are creating waves through acceleration. What if we dropped a bowling ball in the mix? For one, the mass of the bowling ball would certainly bend the soup to a different extent — if the bowling ball accelerated, the waves would be much bigger than that of the letters. You would for sure get soup on your shirt.

What the soup analogy tells us is that the more massive the object, the more it bends space-time, and the more likely we are to detect the gravitational waves coming off of it. However, in actual space-time these waves aren’t nearly as easy to detect — they aren’t sitting right in front of you on your dinner table, getting soup all over your carpet.

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An artist’s impression of gravitational waves generated by binary neutron stars. R. Hurt/Caltech-JPL

The gravitational wave detected by LIGO here on Earth came from the merging of two black holes, an event that happened over a billion years ago. According to NASA, black holes tend to be 10 to 24 times the mass of our own sun — once the gravitational wave reached Earth, it was “about a thousandth the size of a proton” (SciShow Space).

Why The Heck Should I Care?

For one, the discovery of gravitational waves is another gold star to the record of Einstein’s Theory of General Relativity. In the book Einstein’s Masterwork author John Gribbin says the theory is so good, it’s regarded as one of the most securely founded theories of all time (176).

But enough of Einstein’s genius. I want to make one more trip back to our trusty bowl of soup.

We’ve gotten rid of the bowling ball — it isn’t needed for this analogy. All we need is our bowl of soup and a single letter. Let’s go with an H, for: Historic-Discovery-That-Could-Change-the-Nature-of-Science-Forever.

If this H is accelerating and making waves, and if those waves reach us and our super scientific data collectors, we can backtrack. We can use the waves to learn more about what is MAKING the waves — we can use the waves to learn more about H.

In space-time, this means we can learn a whole lot more about black holes, MERGING black holes, neutron stars — big events that essentially shook the universe and rattled the stars (if this sounds poetic, it’s because I stole it from Treasure Planet).

Gravitational waves aren’t JUST further confirmation of Einstein’s genius…They’re a tool scientists can use to learn even more. That’s pretty neat.

References and Further Reading (go forth children!!!)

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