The Big Freeze

Daily Mail, January 2003

The big freeze is here. And while at first we may love the look of snow-covered  fields, frost on hedges, and ice coating the rivers and canals, the beauty of snow-covered countryside soon begins to fade when we realise that everything has come to a standstill. Cancelled public transport, frosted windscreens, slippery frozen pavements, and burst water pipes soon have us wishing for a less seasonal spell.

But science can offer plenty of practical advice to help us through this trying  time. So here are my ten top scientific tips to overcome the winter blues.

1. Bird Bath

Everyone likes to see birds outside the window drinking from a thoughtfully-provided bird bath, but in this season the bird is more likely to  hit  the  frozen surface of the bath, skid across the ice and disappear off the other side.

Until recently the RSPB recommended filling the bath initially with hot water. Then someone pointed out that hot water often freezes more quickly than cold water.

This amazing fact was known to Aristotle, but was lost to science until it was rediscovered by a Tanzanian schoolboy in 1969. His name was Mpemba, and the effect is now named in his honour.

Physicists have spent the last thirty years trying to explain the Mpemba effect, but still haven't reached a complete consensus on its origins. That doesn't stop us from using it to help our friends the birds, though.

By filling your bird bath with cold water, rather than hot water, the onset of freezing is likely to be considerably delayed.

(We can also use the Mpemba effect to help ourselves. Next time you run out of ice and feel like a gin and tonic, put hot water into the ice cube maker rather  than  cold  water. The ice will be ready much more quickly, and you will be able to enjoy your drink sooner.)

2. Alcoholic Answer

Another way to help birds enjoy a winter drink is to stop the water in your bird bath from freezing in the first place. The process is called freezing point depression, a scientific term which perfectly reflects the mood of the season.

Just about anything that will dissolve in water makes it harder to freeze, but one of the best materials is alcohol.

Ethylene glycol, the principal component of car radiator anti-freeze, is an alcohol. 

nfortunately it is a rather poisonous one, definitely not to be recommended for addition to bird baths (although some people have done just that, with fatal results for the birds).

Far better to use ordinary alcohol. This may not be too good for the birds either, but it is the cat's whiskers when it comes to releasing a frozen car lock. Just pour a capful of gin or vodka over the recalcitrant lock, and you are away.

For birds, the best bet is probably sugar. A kilogramme added to each litre of  water will take the freezing point to below minus five degrees C. Use fruit sugars, such as fructose, if you can, as it's better for their digestion.

3. Walking On Ice

The salt that grit trucks pour onto the roads acts as an antifreeze, causing the snow and ice to melt. It also helps to have tyres with a really effective grip, and the same principle can be applied to pedestrians.

Wear  shoes  with  soles that have a ripple tread, and in severe conditions carry  a  small  bag of salt. Don't sprinkle it around willy-nilly, though. Occasionally, pour a little pile down in front  of you and tread in it firmly, trapping the salt in the ripples of the soles so that it has an effect over a number of steps.

4. The Perfect Snowball

Another  way  to  melt snow or ice is to apply pressure. Part of the reason why skates work  is because of the pressure they apply to the ice, which melts to produce a thin film of water over which the skate glides.

The same principle can be applied when it comes to making snowballs that will stay firmly  together as they speed through the air. It's easier to produce high pressures by focussing the applied force on a small area, so make a number of miniature snowballs first and the squeeze these together to produce one large, and very effective, final product.

5. Snowflake Secrets

And if you do find yourself the victim of a snowball attack, you can always fight back with  some impressive scientific facts. Did you know, for example, that snowflakes emit a high-pitched scream when they land on water? The noise comes from trapped air bubbles vibrating spontaneously at 200,000 times a second. Following the 1931 publication of a book of 2,500
photographs, it was asserted that no two snowflakes are the same. However, in 1988 an American meteorologist discovered two flakes that appeared to be exactly the same shape.

6. Stay Ahead of the Cold

Insulation is another key factor in winter comfort. We lose some 30% of our body heat  through our heads, so wrap them up well in wool or some other insulating  material. If you want to make a fashion statement, try making a balaclava out of bubble wrap. This is an effective insulator because of the stagnant pool of air inside each bubble.

7. (Bubble) Wrap Up!

Heads aren't the only things that need insulating. Outdoor pipes are particularly vulnerable  because of the peculiar, and very irritating, property of water that it expands as it freezes. This  is why ice floats on the surface of water - because it has expanded, it is less dense. That's great news for the fish, because ice is a great insulator and the water underneath remains liquid so that the fish can still swim.

It's very bad news for water pipes, though, so wrap them up warm. Just about anything will do  - cloth, bubble wrap, even old leaves from the garden. Just use something.

When thinking of insulation, don't forget the plants, where the expansion of water on freezing is a real killer, because it bursts the plant cells that hold it. Again, the secret is to insulate the plant securely (bubble wrap, again, is ideal) so that the small amount of heat that the plant
produces as it slowly respires is held in and prevents the plant from freezing.

8. Keep Moving

Our own body heat is our best ally when facing the rigours of winter. We can generate more of  it by vigorous movement, just so long as it isn't carried away by the resulting air movement.  Again, the secret is insulation. Keep the heat in; don't waste it.

9. Keeping Your Coffee Hot

Your body isn't the only thing that you want to keep warm in winter. What about your cup of freshly poured coffee? Should you add the milk immediately, or will the coffee stay hotter if you wait to add the milk until you are just ready to drink it?

The unambiguous scientific answer is to add the milk immediately, because the coffee will then lose heat to the air more slowly, since it is closer to the temperature of that air. It also helps to give the coffee a stir to remove the patches that appear when you first add the milk. These are called Bernard cells, which are spontaneously produced vortices that arise when cold and hot liquids are imperfectly mixed. Stirring removes them and makes the temperature more even.

10. That Bloated Feeling

Winter is a time when we all tend to over-eat. My excuse is that I need the energy, but I still end up with that bloated feeling, caused by gases that are released when intestinal bacteria get to work on the food that I have ingested.

The socially unacceptable results can be concealed by wearing underpants that contain a charcoal-impregnated filter that absorbs the gases (believe it or not, these are actually available commercially!). Better still is to use an old Australian bushman's trick, and chew on a bit of charcoal from the wood fire. This absorbs the gas as it is formed. If you're fussy, you can buy charcoal tablets that perform the same function. Either way, that bloated feeling will be a thing of the past.

P.S.  Finally, and if all else fails, you can use your freezer for a little happiness - the ultimate summer desert, champagne jelly!

Pour a little champagne into a saucepan, and warm it to blood heat (put the rest in the refrigerator to cool). Dissolve into the pan the contents of packet of jelly (enough to make a pint) and allow to cool with frequent stirring. Distribute the resulting liquid between six champagne glasses, and top each one up with cold champagne, stirring carefully with a very cold spoon that has been kept in the freezer.

This should  leave  enough  champagne  in the bottle for an extra glass to drink while you put the jellies in the refrigerator to set, which may take 6-8 hours. If you've done the job properly, they will come out full of fizz and bubble.

Why am I telling you this now? Because you may as well start practising. At the very least, the rigours of winter will seem far less formidable.

© This article is copyright Len Fisher. Please email Len Fisher to seek permission to reproduce part or all of the above article.

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