Science | Archimedes' Principle Explained

How did Archimedes really develop his principle of displacement? Quiet at the back there. You might learn something… 

Wasn’t it something about him dashing out of a bath naked, shouting “Eureka”? Sorry, but no. Happily, the unembellished story is almost as exciting and you can feel incredibly smug the next time someone tells the ‘Eureka’ story by correcting them gently. Here’s what really happened. 

It all began when the rather suspicious-minded King Heiron II of Syracuse commissioned a crown to be made from pure gold. Characteristically, when the crown arrived, the King decided that he may have been tricked and perhaps the crown-maker had used some silver in there to make it cheaper. The King asked Archimedes to work out the truth of the matter. 

Archimedes took a mass of silver and a mass of gold, each equal in weight to that of the crown. We wish we had masses of gold and silver just hanging about the house but that’s not for here… He filled a bowl of water to the brim, put the silver mass in and measured the water displaced by it. He then repeated this with the gold. He found that the gold displaced less water than the silver, meaning the silver must be heavier. 

Next, like Poirot wrapping up an investigation, he refilled the water and put the crown in it. The crown displaced more water than the mass of gold did and the little grey cells immediately deduced that the crown must therefore contain silver as well as gold. “Eureka!”, he almost certainly did not say.

If you feel like a lovely big bath is missing from this story, you might instead enjoy our ‘My Place’ feature from April, which this month features spaces in which you can enjoy a soak in the tub. We particularly fancied a soak in the bath above, which belongs to @honeyjoyhome. 

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Magic | Do the Tablecloth Trick

Always harboured a secret desire to whip a tablecloth out from under a fully laid table? Us too. We’ve got good news… Anyone can do it!

Surprise your family and delight your friends with this impressive trick. And you don’t need to be Paul Daniels to have a go. Here’s how to do The Tablecloth Magic Trick…

1. You need a table with straight sides, not curved - that messes with the physics.

2. Choose the right cloth. It should have as little traction as possible on the table, so smooth, slightly silky material is great. The table should be clean and dry, too. You want that cloth to slide across it easily. Also, your cloth should have no hem. 

3. Place the cloth on the table with most of the ‘overhang’ on the side you’re going to pull from. 

4. Carefully lay your table with crockery and cutlery. You can start with unbreakable crockery if you’re nervous. It actually helps for the items on the table to be heavy, so you can weight glasses down, for example, by filling them with water, which also adds to the effect. Pop a red rose in a glass of water if you’re feeling showy. 

5. When you’re ready, grasp the tablecloth edge firmly with both hands and pull downwards towards your feet, quickly. Hesitate, or pull straight out to the side and you’ll mess it up. 

6. Take a bow. 

How does it work?

It’s more a feat of physics than a magic trick. There’s no sleight of hand involved. The tablecloth trick is an illustration of Newton’s theory of inertia in action. If an object is at rest, it stays at rest unless acted on by another force. So the tablecloth, when pulled, leaves the table and the items on it where they are because the force of it moving is not enough to move the items at rest on it. 

If you’d like to have a go at this trick and are in the market for a new tablecloth, you might like to read our Looking Back feature on the history of tablecloths in our May issue, which is adapted from The Elements of a Home: Curious Histories Behind Everyday Household Objects From Pillows to Forks by Amy Azzarito (Chronicle Books).

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Science lesson | the toast centre of the brain

Some fascinating facts about how your brain smells toast

There’s something strangely evocative about the smell of burnt toast. You can probably remember the last time you suddenly detected it and dashed for the grill. 

But did you know there’s a part of your brain specifically dedicated to smelling burnt toast? 

In 1950, Canadian Dr Wilder Penfield was working on a treatment for cerebral seizures that worked by zapping particular nerve cells with electrical probes. One of his patients was a woman with epilepsy who smelled burnt toast whenever she was about to have a seizure. 

With her sedated but awake, Dr Wilder removed part of her skull and stimulated various parts of the brain until the woman exclaimed “I can smell burnt toast!” He was able to remove this small bit of brain tumour and stop the seizures, and the process, which later became known as the Montreal Procedure would go on to help millions of people with epilepsy.

So next time you burn your breakfast, spare a thought for Dr Wilder Penfield and raise a crust to him. 

In our August issue, we’re celebrating more impressive work with toast, looking at some of the ‘toast art’ by Manami Sasaki (@sasamana1204), such as the one above. You can read more on p16. The August issue is in shops now, or you can buy it from our online store.  Buy this month's The Simple Things - buy, download or subscribe

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Science | why lavender calms

We all know that our lavenders blue (dilly dilly) make us feel a bit sleepy, but why?

The scent of lavender has long been used to make us feel relaxed or sleepy. And apparently, it’s not only the association with vast fields in Provence, swaying in a purple haze. Nope. Lavender’s benefits have proper scientific roots. 

It’s all to do with linalool, a fragrant alcohol found in lavender extract. Researchers at Kagoshima University in 2018 found that mice exposed to the smell showed fewer signs of anxiety. 

Linalool interacts with the neurotransmitter (or chemical messenger), GABA (gamma aminobutyric acid), to quieten the brain and nervous system, which makes the whole body feel more relaxed. 

However, while the effects of lavender on the brain were accepted, until recently, it was not known what the ‘sites of action’ (where it got in) were of linalool.

The Kagoshima experiment found that mice who had no sense of smell did not experience the same anti-anxiety effects when sniffing lavender as mice that could smell, thus proving that the effect of linalool is on the olfactory neurons in the nose, rather than on the bloodstream via the lungs, as previously thought. 

So, once the smell hits the olfactory neurons, messages are sent via long ‘wires’ to neurons in a part at the front of the brain called the ‘olfactory bulb’, which also stores memories and emotion. From here, GABA gets involved and when GABA attaches to a protein in your brain known as a GABA receptor, it produces a calming effect. Messages are sent to various parts of the nervous system, relaxing the entire body. 

If you’ve not found all that information terribly relaxing, you might want to just pop a few drops of lavender essential oil on your pillow. Or why not pick up a copy of our July ‘Embrace’ issue, which has a feature by Lia Leendertz on recipes that use foraged lavender. We particularly like the lavender and blueberry buns. One of them is enough to relax us right into a nice nap of an afternoon.

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Hanger: the struggle is real

Do thoughts of delicious food bring out the hulk in you when hungry?

If you know someone who suffers from ‘hanger’ (the condition of becoming particularly irritable when hungry), it might be time to cut them some slack. Or perhaps just cut them a slice of cake. It may sound like an excuse to either fly off the handle, or snack at will for the sake of peace, but scientists say ‘hanger’ is a genuine phenomenon.

Sophie Medlin, lecturer in nutrition and dietetics at King’s College, London, told Radio Four’s Woman’s Hour recently: “We’ve long recognised that hunger leads to irritability, but the wonderful world of social media has merged the two words and we now know it as ‘hanger’.”

And (here comes the science bit) “When our blood sugars drop, cortisol and adrenaline rise up in our bodies - our fight or flight hormones.” These then cause the release of neuropeptides, which affect the way the brain works. “The ones that trigger for hunger are the same ones that trigger for anger and rage. So that’s why you get that sort of same response,” she explains.

So now you know.

And if all that has made you hungry, well, we wouldn’t want you to leave in a bad mood. Please enjoy this recipe for Crunchy Indian Spiced Chickpeas (pictured above), which appears in our November issue and is taken from Sight, Smell, Touch, Taste, Sound: A New Way to Cook by Sybil Kapoor, (Pavilion) with photography by Keiko Oikawa.

Crunchy Indian Spiced Chickpeas

Makes 2 bowls

1 x 400g can chickpeas, drained  and rinsed

¼ tsp ground turmeric

¼ tsp chilli powder

¼ tsp ground cumin

¼ tsp ground coriander

¼ tsp amchoor powder (dried sour mango), optional

1 tsp fine sea salt, or to taste

1 tbsp cold-pressed sunflower oil

½ tsp lemon juice, or to taste

1. At least 30 mins before cooking, rinse, drain and pat dry the chickpeas on paper towels. Spread them out in a single layer on a plate.

2. Preheat oven to 200C/Fan 180C/Gas 6. Mix the spices and salt in a small bowl.

3. Place the chickpeas and oil in a separate bowl and mix well, before adding the spice mixture. Toss until completely coated, then tip onto  a non-stick baking sheet and spread the chickpeas into a single layer.

4. Bake for 35 mins, giving the tray the odd shake. If you prefer your chickpeas floury inside, remove after 35 mins. If you prefer them crunchy throughout, turn the oven off after 35 mins and leave inside for a further 15 mins.

5. Once done, leave the chickpeas in their roasting pan and season with the lemon juice. Leave until cold, then serve as needed.

These make a great snack for a chilly November evening. We recommend serving them with friends and your choice of drink, and our November Playlist, all about food, on in the background. Feeling calmer yet?... Good.

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