Top 10 Christmas Science Demonstrations

It’s Christmas time, and here at science made simple we’re looking forward to the festivities. Here are some Christmas science demonstrations to keep you going and entertain your relatives – enjoy!


1.  Multi-coloured Christmas Brandy

Lighten up your Christmas pudding this year with some burning brandy. Who knows why we do it really, but bringing out food on fire once a year seems to work. Brandy burns blue because of the sugar infused in it. Other chemicals can make the flaming Christmas pudding glow in different colours.

It’s well known by scientists that different chemicals burn with different colours. For example, copper sulfate burns green, and potassium chloride burns purple. However, chemicals such as these can be toxic to the human body in large enough doses, and should not be added to food! However you can put sodium chloride into the brandy, which is common table salt. This results in the brandy burning a clearly visible yellow colour due to the sodium chloride (similar to that of street lamps). Of course, yellow flames aren’t that exciting as that’s the colour of normal fire!

2. The Endurance of the Queen

The Queen’s speech is about ten minutes long. Although, it’s really more like seven minutes. And if you take out the national anthem maybe six. Actually, she talks so slowly, if she’d just talk like the rest of us we could have it over and done with in four…!

Anyway, if forced to watch the Queen’s speech on Christmas Day, you can make the whole thing a bit more fun. The illusionist David Blaine became a pretty big thing back in 2002 for a stunt where he stood atop a pillar in the centre of New York for 35 hours. One of the things he commented on is how hard it is to stand deadly still and rigid in one spot without moving. Your body just really starts to ache and itch to move after a while.

So the challenge… stand rigid through Her Majesty’s royal speech. The first few minutes may seem fine, but after a while your feet will start to ache and you’ll be itching to move, and just hoping it’ll end. Can you resist the urge to move your feet and displace the pins and needles?

There’s a tip used in the army, for soldiers on show who must stand still, that wiggling your toes helps subvert the pain, and it’s true, it does somewhat. The reason for this is that the pins and needles effect is caused first by a cutting off the blood supply and thus oxygen to nerves, and then allowing the blood flow again. When this happens, the starved nerves are suddenly reinvigorated with oxygen, and thus send out confusing messages to the brain until normal blood flow is resumed!

3.  Deceptive Mince Pies

Everyone knows mince pies are made of two components: the mincemeat on the inside and the pastry on the out. But the properties of these two foods, like that of many other pastry goods, are interesting in terms of how they give up heat.

The mincemeat inside is more thermally conductive than the pastry outside. This means it heats up quicker. But it also means it is more willing to give up heat, and this in turn means it ‘feels’ hotter than the pastry on the outside, even if both are actually the same temperature. It may sound counter-intuitive in some ways, but this means you can have a mince pie which appears to have two different temperatures!

And by this logic, you can make a mince pie very hot in the microwave, then leave it out and it will appear deceptively cold on the outside. Likewise, when taking a mince pie from a fridge and leaving it in a warm room, the outside will appear warm and toasty until you bite into it.

The best science experiments can be eaten afterwards


4.  Origami Christmas Tree

Last month our trainee presenter Abby “fumblefingers” Read succeeded in creating various origami animals for our top ten blog. Following on from this theme, the newest science made simple trainee, Simon “papercut mountain” Jones, was asked to take over and make his own Christmas related origami.

With a bit of research, we found a great way to make a large origami Christmas tree. It’s actually constructed from four similar modules that slot together. You can try it here with this video:


Below is Simon’s origami version; the top one is somewhat questionable, but all in all it comes along nicely. Needs a bit of decoration, don’t you think?


5.  Christmas Card Loop

A quick one. Get a Christmas card from your least favourite relative, and make a small display for the rest of the family. Follow the simple steps below and you can turn a card or piece of paper into a massive loop, big enough to climb through!

6.  Re-lighting a Candle

Here’s a good trick for the Christmas dinner table, if you’re allowed burning candles as decoration. Get a lit match or a splint and light it from the candle. The art of this trick is to blow out the candle and then quickly move the match back to re-light it. You’ll find the newly extinguished candle will re-light very quickly, often you don’t even have to touch the candle wick with the match. Try it for yourself or watch our video:

The reason for this effect is because there’s still a lot of hot air left around the candle, and the candle wick is still very hot. This only lasts for about a second, but it does mean the candle has more initial energy and is more ‘willing’ to re-light without as much effort as is usually needed to get the candle wick warmed up.


7.  Wrapping Paper Goggles

Here’s one for the myopic (short sighted!) among us. Instead of trying to flatten and reuse old wrapping paper for presents, why not make a funky pair of working glasses. It’s a very simple process and yet it does actually improve vision!

First, get some kind of glasses frame, if you have a spare pair lying around. Perhaps some old sunglasses with the lenses popped out? If not, some kind of hastily constructed frame from some old bits of wire might suffice.

Now for the sciencey bit; cut out two small squares of wrapping paper the size of post-it notes, and carefully using scissors, punch a small hole into the centre of each. Attach these pinhole lenses to your frame, and give them to a short sighted person (or yourself, if applicable), to look through instead of their regular eyewear. You should find that they can see better than without them, even though there are no glass lenses to refract the light!

How does this work? Well, the pinhole actually blocks out a lot of the light entering your eye, except the light which enters head-on. As the eye does not need to bend the additional light surrounding the pinhole, it can make more effort to focus properly on the small amount of content in front of it – and that makes our vision better.

I can see again!


8.  Three Wise Paperclips

Here’s a quick one that you can do with a suitable sized piece of paper and a few paperclips. This trick works particularly well on cheques or paper money, if you want to risk damaging them, but if not cut out some wrapping paper into a similar rectangular shape. Now fold your paper into an S shape, connecting the two sides of the paper with a paperclip in the locations shown on the diagram below. You can continue doing this a few more times if possible, to create more zig-zagging paper held together by paperclips.

Place paper between paperclips like so, and then pull on both ends

Now, hold onto both ends of the paper and pull hard. The paper should stretch out again, in the process pinging off the paperclips. And when they come off, they’ve been forced into each other and have combined into a small chain!

This trick works great. We tried it up to six paperclips, at which point it stopped working! See what limit you can reach.


9.  Paperchain loops

All ready for the office Christmas party

If you’re making paper chains this Christmas, why not use twisted loops to make a longer (but less stable) chain? The technique is pretty simple and is outlined below!

Stage one involves making a loop with a twist, known as a Möbius strip. Then, using scissors, cut length ways along the loop, all the way round, including round the twist. You should end up with two attached loops now. You can continue this process to try to make even thinner and longer twisted loops, until eventually the paper gives in.


10. Christmas Cracker Extinguisher

Here’s one we discovered by accident while looking into the properties of Christmas crackers. When you pull a cracker, the bang sound is caused by a tiny explosion of powder in a cardboard strip hidden inside the cracker. This highly reactive substance called Silver Fulminate; in it’s pure form it is so volatile it can explode under the force of its own weight! However, the stuff they put in christmas crackers is in very small quantities and is combined with sand, so it’s much less dangerous.

When the cracker is pulled, the tugging force is great enough to spontaneously ignite the silver fulminate and make the familiar ‘crack’ sound. However, here at science made simple we were trying to discover other ways this strip could be looked at. After all, anything is interesting if you explore it enough! We tried crushing it and rubbing it together to set off the powder, but to no avail.

And then some rather odd discovery befell us. When we burnt the christmas cracker strip over a candle (taking all the necessary safety precautions!), it blew the candle out. This at first appears counter-intuitive; after all, an explosive should cause the flame to grow bigger! Yet using our knowledge of physics, we can assume that the small explosion which occurs creates an outward blast of sound, and with this, an outward vibration. This vibration is big enough to act like a quick breath, which blows out the candle. Check out of video below to see how we did it – but don’t try and replicate it yourself, playing with fire and small explosives is dangerous business!

We also found in our archive, a video of science made simple’s Wendy Sadler doing a piece on the explosive in Christmas crackers for ITV Wales a few years ago! You can watch the really rather nice video here:

Merry Christmas to all, and to all a good night!

Posted in Activity, Exploring Science
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