Six quirky science experiments you can do on yourself right now

Science isn’t just something you do inside a laboratory, out in the field or beyond the reaches of our solar system, as Spoken Nerd’s Domestic Science series sets out to prove. Here are some mind-bending experiments you can conduct without even getting out of your chair.

1. Spin your foot and draw a six at the same time (spoiler alert – you can’t!)

First, lift your right foot off the ground slightly. If your right foot is already dangling off the ground because you have short legs, this is your chance to shine.

Now start rotating your foot clockwise. Keep that going, and then with your right finger, try to draw a big figure "6" in the air. The challenge is to complete the 6 without messing up what your foot is doing.

It’s almost impossible and you’ll probably find your foot doing all sorts of mad movements. Our brains have evolved to be good at controlling our bodies in rhythmic coordinated ways, which makes us good at walking and running without having to think about it all the time. But it’s very difficult to break out of, even when you’re concentrating really hard on it, as this experiment shows.

2. Ring finger riddle

Put your hands together like you’re giving yourself a high five. Well done! Doing science feels good already.

Now fold down your middle fingers. Try to separate your thumbs: no problem. You should also be able separate your index fingers and your pinkies without much difficulty. Well done again! What you won’t be able to do is separate your ring fingers.

This one is all about the tendons in your hand. They’re the strings of tough connective tissue that pull your fingers back, and every finger has a separate tendon except for the middle and ring finger. They share one between them, and that’s what makes it much harder to move those two fingers independently.

3. Have you taken the next evolutionary step?

Hold out your forearm with your palm facing upwards. Now pinch your thumb and index finger together and bend your wrist so that your hand moves up. There’s an 85 percent chance you’ll see a tendon pop up on your wrist.

This tendon is connected to your palmaris longus muscle. This muscle isn’t in your body because you need it, but because your evolutionary ancestors needed it. It’s useful for scrabbling around like a monkey, but modern humans don’t do that anymore – except during the Black Friday sales.

The muscle is what’s known as “vestigial”, except for the 15 percent of us that don't have it. If that’s you, congratulations, you have taken an extra evolutionary step, expect a phone call from the X-Men any day now.

Actually, this muscle and tendon do serve a purpose, for those who still have it. It’s useful precisely because it’s useless. When a tendon or muscle is needed for reconstructive surgery, this is the go-to area for your own “spare parts”.

4. Ohmmmmmmmmmm

If you’ve ever tried mantra meditation then you’ve already inadvertently conducted an experiment on yourself. A mantra is a phrase you repeat again and again in your head. It’s known to aid relaxation, but there is some science behind it too.

It’s all to do with something called "Semantic satiation". Basically, if you repeat a word or phrase enough times, it starts to sound really weird and lose all its meaning. Try it now with the words Domestic Science. Repeat the phrase in your head and it will start to lose its meaning – which would normally be something like “hilarious show on Radio 4 about science”.

Normally, hearing a word or phrase causes a particular pattern of neurons to fire in your brain. These firing neurons are literally you understanding the meaning of the words; the semantics of the words.

But as is so often the case in the brain, when your neurons fire repeatedly they become temporarily inhibited; they stop firing. But it’s the firing neurons that are literally how you understand the meaning of the words! So when the neurons stop firing, you stop understanding. The words lose their meaning inside your head.

This might help to explain the effectiveness of mantra meditation. Removing all meaning from your brain is a pretty good way to relax.

5. Floating finger sausage (not as rude as it sounds)

Put your two index fingers together in front of your face, like ET would do if he was trying to heal his left index finger with his right. Make sure they’re nice and straight and horizontal. Now focus your eyes on something behind your fingers. You should experience a "double vision" of your touching fingers. And it will appear as though you are now holding a weird sausage between the tips of your fingers. The sausage will have nails. Slowly move your fingers apart and you should start to see a floating sausage.

This tells us something really interesting about the way we process information from our eye and nothing interesting about sausages. When we receive conflicting images from our eyes, like when you see double, your brain will suppress one of the images. So one eye is telling you, "This is the end of your finger", and the other eye is telling you, "No, no. Your finger is still going", but only one of these messages can win the battle inside your brain.

6. Feel an extra ball (again… not as rude as it sounds)

1. Tear off a little bit of paper and scrunch it into a ball about the size of a pea.

2. Place it on the palm of your open hand.

3. Cross the index and middle fingers of your other hand.

4. Put your crossed fingers on top of the ball so it nestles between them.

5. Look away or close your eyes.

6. Roll the ball around a little between your fingers.

You should start to feel two little paper balls in your hand. This is called the Aristotle illusion, after his written description of the phenomenon more than 2,000 years ago.

You are actually using two senses in this experiment and they’re not playing nicely together. One of the senses you’re using is touch, clearly, but the second sense is less obvious because it’s not one of the classic list of five that you might have learned in school: taste, sight, touch, smell, and sound. Scientists don’t agree on how many senses humans actually have, but they all agree that it’s more than five.

It’s your "proprioception" that is giving us problems here. This is your sense of your body’s position space and what it’s doing, but unfortunately it’s just not very accurate.

So in our paper ball scenario, your brain doesn’t account for the unusual position of your fingers and makes the naive assumption that they are uncrossed. In which case, the only way the normally outer edges of your fingers could be stimulated at the same time is if there were in fact two balls.

For more experiments you can do in the comfort of your own home, listen to Domestic Science or read Festival of the Spoken Nerd’s book The Element In The Room, published by Cassell.

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