How do robots learn to walk?

Hmm, well this might be a little off topic from my usual blog posts but I recently recorded an interview with Chris Lehnert, a PhD student at the Queensland University of Technology.

His research is based on programming elastic robots to teach themselves how to move. Pretty interesting stuff, so check it out!

I found it particularly interesting hearing about the differences between rigid and elastic robots. I’m comforted to know that once these elastic robots hit the streets that they won’t be taking anyone’s head off by mistake!

And if you want to see what Chris means when he talks about elastic robots, have a look at this video.

Next time on Science MIA, I’ll be looking at what the differences are between various types of fuel. Thanks for reading, leave any comments you might have, and feel free to ask any of those science questions you’ve been wondering about!

Have you ever really thought about fuel?

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Why do I get dizzy when I spin around?

Photo courtesy of Kester D'Amaud

I’m sure we all remember back when we were young spinning around and around until we were dizzy. Whether we did this by running in circles or by spinning a swing and then letting it unwind*, we all loved that feeling. But did you ever wonder just how this all works?

Our sense of balance (or ‘equilibrioception’ if you want to use the fancy scientific word) relies on information from several parts of our body, but mainly from our eyes and our vestibular system. You’ve never heard of your vestibular system? Really? Well, that’s fair enough. It’s a rather unasuming little section of our inner ear, make up of three semi-circular canals filled with liquid.

Each of these three canals is in a different alignment to detect different types of movement. One detects the sort of movement you do when nodding your head. Another detects thesort of movement you do when cartwheeling. The third one detects horizontal, rotational movement or, you guessed it, the sort of movement you do when spinning around.

While it’s this third canal that we’re particularly interested in, they all work in the same way. The canals have a small section lined with hairs that detect movement in the fluid. When we turn a little bit, the fluid moves slightly and the hairs register this movement and convert it into electrical signals that tell our muscles to adjust and keep us balanced. This can also automatically adjust our eyes to keep things in focus while we move. Neat, right?

But when we spin over and over again, the fluid gains momentum and even when we stop, the fluid keeps moving. Imagine stirring a cup of coffee for a while – even when you stop stirring, the coffee keeps swirling around in the mug. So while the fluid in our vestibular system keeps spinning, we keep on getting messages telling us we’re still turning around. Our eyes are trying to adjust for this movement but can’t, and are simultaneously noticing that actually, we’re standing (more or less) still.

All these confusing and conflicting messages cause our muscles to move us off balance and our vision to get very mixed up – the combination of which gives us the feeling we know as dizziness! Check out the video below of the effects of spinning on our feline friends.

Thanks for reading, feel free to leave a comment and ask any science questions you want me to answer!

*I prefer the swing  method, though this did once result in a pot-plant collision and a trip to the emergency room – I still have the scar to prove it!

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Filed under Balance, Physics, The human body

Why does my funny bone feel so funny?

There's nothing humorous about your humerus

Ahh, the funny bone. The most pointlessly painful part of the human body. Now I know there’s a reason we feel pain – if it didn’t feel pain when we hurt ourselves we’d be doing a lot more damage to our relatviely fragile bodies. But why, even if we just tap our ‘funny bone’ lightly, do we feel a ridiculous amount of pain and tingling?

Well let’s start with the name of the so-called  ‘funny bone’. A lot of people already know that the term funny bone came from a play on words on the bone in our upper arm – the humerus. Humerus sounds a lot like humourous, and add that to the strange tingling we get when we hit our elbow, and you get the ‘funny bone’! The only problem is that it’s not actually the bone that we’re hurting. Bones don’t feel pain – nerves do, and in this case it is our ulnar nerve causing all the fuss.

Our ulnar nerve is named after the ulna bone that, along with the radius bone, makes up our forearm. Unlike most nerves, the ulnar nerve is unprotected by bone or muscle. In fact it’s the largest unprotected nerve in the body. This is why, even though we might hit other parts of our body just as frequently, we don’t hit such big nerves anywhere else, and the funny feeling is restricted to our ‘funny bone’.

So we’ve covered why the ulnar nerve hurts, but why then, you might ask, is it in such a stupidly exposed place? Well, unfortunately, that’s the way evolution goes – it doesn’t make us perfect, just good enough to survive. That’s why we are all born with a pointless tailbone, and why emus can’t walk backwards. As long as we’re still alive, evolution has done it’s job!

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Why does my singing sound better in the shower?

Singing in the shower: One of the great joys of life, shortly before watching trashy tv but after seeing puppies being confused by their own tails. Photo courtesy of Sebastian Ortiz

Hi, my name’s Caitlin and I’m a shower singer. Well, let’s be honest, I sing a lot, and not necessarily very well, but I do enjoy it.  And I’m sure that most of you, like me, have noticed that you sound a lot better in the shower than anywhere else.

Is it a psychological thing? With no-one there to judge you, do the insecurities holding you back disappear, unleashing your true singing potential? Well, sadly, no. There are three main reasons your voice sounds better in the shower, and they are all to do with the shape of your shower, and the material it’s made up of.

Most showers are made of tiles and other hard, non-absorbent surfaces, and they are usually enclosed rectangles. When we sing – or talk, shout or gargle for that matter – we create soundwaves. Different notes have different frequencies depending on whether they are high or low. High notes have faster frequencies (like the purple line in the image below) and low notes have slower frequencies (like the red line).

Sound waves of different notes have different frequencies

When we create these sound waves, they will travel out of our mouths until they hit something. In a shower, they very quickly find a nice sound-reflecting surface – your tiles.  Rather than escaping, the sound waves bounce around your shower, and becomes louder as there are more sound waves hitting your ear. This is the first reason your voice sounds better in the shower – more volume = a more powerful sounding voice.

The second reason is very closely tied into the last one. Well lets be honest, in a shower, everything is pretty close to everything else. In addition to making the sound louder, all these sound waves bouncing off the walls create an affect known as reverberation or just reverb. You’ve heard it before, it’s what karaoke machines do to try and make people seem not quite so terrible.

Reverb is essentially a whole lot of echoes all very suddenly. If you were in a cave (and why wouldn’t you be?) the echoes come off the cave walls which are usually rather far away. In a shower, they’re nice and close, and you get a lot of echoes all at once. In addition to giving a nice echoey sound which you can hear here: An Example of Reverb – it also smoothes out the pitch of your singing. They noise becomes somewhat blurred, and so you even when your notes are as wobbly as jelly, they sound like they’re stable. This won’t help if you’re singing half an octave off key, but if you’re already close this makes it even better. So secret number two to shower singing – reverb!

The final trick to sounding better in the shower is resonance. Because of the distance between the walls of the shower, certain sound wave frequencies are amplified more so than others. In showers these tend to be nice low bass notes, which gives your voice a nice rich quality.

Remember, having a shower curtain instead of a solid door, or having something softer than tiles on the walls can reduce the impact of all of these.  MOST importantly, reverb only applies INSIDE the shower, so anyone listening to you from outside will hear a much louder but probably rather wavering voice. In fact, because you pitch your singing off what you can hear, the reverb is actually tricking you, and you will most likely actually be singing even less in tune than normal. So beware of anyone else lurking outside when you start shower singing!

So there you have it – Volume, Reverb and Resonance, all working together to make you sound like a pro. Leave a comment and be sure to watch out for the next post on Science MIA!

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Filed under Around the home, Physics, Sound, The human body

Why do my ears pop when I fly in a plane?

We’ve all been on a plane before and had our ears pop. Well I’m assuming you have. If not, hopefully you’ve at least spent some time going up and down hills and had your ears pop then. Not the most unusual phenomena our bodies like to throw at us, but still quite an annoying one at times.

Watch this video for a quick explanation, or keep reading for something a bit more in depth!

The reason our ears pop is all to do with pressure. Not the sort of pressure you feel when you have to finish all those assignments for uni, or when your boss brings forward a deadline from next month to tomorrow. This pressure is all about the air.

Air doesn’t weigh much, but when you have an entire atmosphere of it sitting on top of you, it gets pretty powerful. At sea level, every square centimetre of surface area has 1kg of air pushing on it. Imagine 1 litre of water pushing on your thumbnail. Now imagine 1 litre of water on every square centimetre of your entire body. All added up, you have about 3 elephants worth of air pressure on your body all the time. We don’t feel this pressure because we have about 3 elephants worth of pressure inside our body pushing out too. It’s only when the pressures become unequal that we notice it.

The higher you are, the less air there is above you, and the lower the air pressure. When we go up in a plane we reach heights of more than 10km above sea level, and the air pressure is much lower. The air in our ears however, has nowhere to go, and so the pressure stays the same.  This comparatively higher pressure wants to escape, and pushes on our ear drums in an attempt to do so.  Our ear drums stretch slightly, making our ears ache and reducing our hearing.

The air does have one escape route however – through the oddly named Eustachian tubes that run from our ears to the back of our throat. They are usually closed but we can open them by moving our jaw – yawning, swallowing and chewing gum all do the trick! Now some of the air can leave our ears and the pressure is equal again.

The opposite happens as the plane descends – the air pressure outside increases again, and the pressure is unequal. Sore ears, fuzzy hearing, you know the drill. A few yawns and a stick or two of gum and you can let the air back into the Eustachian tubes, equal the pressure out, and have a lovely time waiting for your things at baggage claim.

Unfortunately, not all Eustachian tubes are alike, and some people have more trouble with changes in air pressure. Sinus infections, middle ear infections and smoking can all stop them from working properly, which means a lot more time before the pressure evens out again.

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Science MIA

Welcome to Science MIA!

If you’ve ever wondered about any of the strange things that happen in our world, from ‘Why does my singing sound so much better in the shower?’ to ‘What is the real difference between all the types of fuel?’ then this is the site for you!

If you have only a mild knowledge of or interest in science, never fear! Science MIA is here to answer these sort of questions and any others you might have, hopefully in a simple and (at least mildly) entertaining way!

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