How to smash a wine glass with your voice

For reasons which will hopefully become clearer as the year goes on, my internet search history has been getting weird. Weirder than usual. Last year, I found myself searching things like “Linear Discriminant Analysis”, “Photosystem II”, “Electron transport chain” and “can you take ibuprofen and paracetamol at the same time?” (you can totally do that without dying by the way but I am by no means a medical professional).

This week, I’ve found myself looking for decidedly more fun things. Including the topic of today’s post: Can you break a wine glass with your voice?

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The answer is yes, but there are some caveats.

First of all, you need to be able to sing. Sound is essentially a vibration of the air around the object making the noise. The faster the vibration, the higher the sound and when I say “fast” I mean it. If you think about how fast you can wave your hand back and forth, you’d need to multiply that by about 20000 times to be able to hear your hand…. and you probably wouldn’t have a hand anymore…

Sound waves are what’s called “longitudinal waves”, meaning they move back and forth horizontally rather than, say, waves in the ocean which move up and down. When a thing makes a sound, it’s pushing the air out in really fast compressions. These compressions hit your ear and, through a complex process involving teeny tiny bones and millions of neurons, your brain converts them to sound. This is part of the theory behind the glass smashing. Point your horrifically powerful voice towards a glass and it starts to get bombarded by compressed air. The higher the sound, the faster the vibration which increases the amount of air hitting the glass and boom! It should explode.

But there’s actually one other thing happening; resonant frequency. If an object is hit with just the exact right pitch of sound, it will start to vibrate. Crystal glasses are really really good at resonating depending on the pitch of the sound. The more the glass vibrates, the more the molecules making it up are disrupted. If you hit a glass with a mallet, it makes a ringing noise. Match the frequency of the ring with your voice and you’ve got a very good chance of breaking it. Especially if it’s got a few cracks in it already.

So essentially, you need to be good, you need to be loud and you need to be very, very lucky. Like this guy on Mythbusters that one time. Awesome right?

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Why you should be excited about Gravitational Waves

If you had asked me before Wednesday last week, the implications of the Laser Interferometer Gravitational-Wave Observatory’s (LIGO) impending announcement, I would have spent about thirty seconds floundering wildly before sighing and admitting that no, I hadn’t a clue.

And so I did some reading.

Turns out, the discovery of Gravitation Waves, announced on Thursday, is one of the greatest scientific breakthroughs of the 21st Century so far. Here’s why.

First things first, we need to understand a little bit of history, specifically the work of the one and only Albert Einstein. In 1916, on the back of his Theory of General Relativity, Einstein predicted the existence of minuscule ripples in the fabric of space and time. Remember the Gedanken experiments I mentioned in my last post? Well General Relativity began as a giant thought exercise.

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The effects of objects with mass on the curvature of spacetime (www.livesciences.com)
Imagine you’re sitting on a trampoline underneath an oak tree. An acorn falls onto the stretched material; where does it go? It rolls towards you. The trampoline is spacetime, and you are the Earth. Gravity, Einstein realised, is caused by objects of mass warping the curvature of space and time. (Wibbly wobbly, timey wimey).

So how do we know this is actually a thing?

Well my favourite example of this warping can be found in the practicalities of timekeeping in GPS satellites. Because of the effects of the Earth’s mass on time itself, the closer you get to the centre of the Earth, the slower time moves. So satellite clocks need to be set slightly faster (about 45 millionths of a second faster) than those on the surface of our planet or else they would give us a location up to 10 km out of sync! Isn’t that insane?

Everything in the universe that has mass causes waves. There are waves moving through you right now. The thing is, these waves are smaller than miniscule. Which is why we needed to wait for something immense. Billions of years ago and light years away, two black holes began to circle one another. Black holes, in terms of general relativity, form gigantic warps in spacetime due to their mass. When these two began to merge, it resulted in giant ripples, like when you throw a rock into a pond. On September 14th, 2015, LIGO was able to measure one of these ripples.

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http://www.space.com
LIGO is a facility in the USA specifically designed to look for gravitational waves. Its strange cross shape is deliberate. A laser runs down each arm of the in order to measure the distance between the detector and the end of the arm with an intense level of precision. Any changes in the distance the laser travels indicates a distortion in spacetime.

Einstein himself never thought a day would come when technology would reach a level of sensitivity able to detect gravitational waves. And it wasn’t as though he didn’t have faith in the scientific and engineering communities. According to Jorge Cham of PhD comics, finding these waves is like detecting a change of 5 mm in 1,000,000,000,000,000,000,000 metres.

So now that scientists have proven without a shadow of a doubt that they exist (you can read the paper here), what next?

This discovery means about as much to the field of astronomy as the invention of the telescope. It opens up an entirely new way of observing our universe. We’ll be able to see closer to the moment of the Big Bang than ever before. Theoretically, galaxies and stars that are beyond the current range of our telescopes, will be reachable.

I don’t know about you, but I think Einstein would be more than proud.

 

Gedanken experiments: the art of avoiding fork-in-hand situations

I want you all to do something for me. Don’t worry, this won’t be horrifyingly embarrassing; you can do this sitting down and in the comfort of your own home. I want you to imagine placing your hand onto the table in front of you and pressing down. The force needs to be equal and constant.

Ok you can stop now. (Take your hand away from the table – you’re supposed to be thinking, not doing).

I want you to imagine that you’re pressing down with the same hand and the same amount of force. This time, instead of the table, you’re pushing your hand onto a fork (bet you’re glad you’re imagining now right?). Which one are you reluctant to do? Which one hurts more? If you answered “the fork!” then you’re absolutely right and your sense of self-preservation is clearly working.

What I just asked you to do is what’s called a “Gedanken” experiment. It’s a common device used in science communications to illustrate an idea without, say, the fuss and bother of calling an ambulance to deal with any awkward fork-in-hand situations.

The term was coined by none other than Albert Einstein. In his first language, German, it means “thought experiment”. Einstein famously used this method to develop and communicate his theory of general relativity. His memoirs are riddled with stories from his imagination that led him, step-by-step, to his ground-breaking conclusions. Like this one:

I was sitting on a chair in my patent office in Bern. Suddenly a thought struck me: If a man falls freely, he would not feel his weight. I was taken aback. This simple thought experiment made a deep impression on me. This led me to the theory of gravity.

Einstein concluded, through further thought and relation to everyday situations like riding in a lift, that within a given system, it is impossible to tell the difference between effects relating to gravity and extra acceleration. General relativity. You may also have heard the story of a night spent imagining himself riding a light beam… It’s a little hard to do in real life so Einstein had to be creative and then come back and prove his thought excursions were legitimate in other ways.

So why the weird and slightly worrying fork experiment?

Well sometimes it’s hard to demonstrate a principle to an audience without involving ridiculously convoluted or horrifically dangerous demonstrations. The use of the table vs fork experiment to illustrate that pressure decreases with increasing surface area, gives an audience something to relate to. I’m sure you winced at the thought of pressing your hand onto something sharp? Yes?

Then I declare the thought experiment a success.

IT’S DONE!

To my dear, valued and loved four subscribers to this languishing blog.

I’m back!

Which can only mean one thing: I’VE HANDED IN MY THESIS!

 

and done

That’s right; that glorious image is me holding it. It was tangible. It existed. It was done.

Of course, I can’t really jump the gun just yet. There’s still a bunch of editing left to do once my anonymous examiners get back to me with comments and changes but submitting the thing is huge.

So what now?

Well for one thing, you’ll get to see this face some more. Focusing on my thesis was the right choice but I missed writing here. I’ve missed writing about things that interest me, things that are exciting, things that make you laugh and writing for its own sake. I’ve loved dabbling with science communication so much that I’m going back to University for another year (I know! Don’t look at me like that. After this year, that’s it. I promise) to study how to do it properly. Until November, I’ll be studying with the Centre for the Public Awareness of Science (CPAS) at the Australian National University (ANU), learning all about exhibition design, new media, science writing and how to use these to effectively communicate complex concepts to a non-scientific audience. It’s a lot trickier than it looks, I’m discovering… not to mention exceedingly out of my comfort zone.

And so this blog is going to turn into my chance to practise skills I’ll learn throughout this year… and to brag about how my homework for tonight was to learn and perfect the art of balloon animals. My life is hard.