It’s a chilly day and I have a candle sitting on my desk as I work. The bright sunlight throws a silhouette of the candle onto the wall and it shows the shadow of something emanating from the top of the candle – the shadow behaves in a similar way to a vapour of steam or smoke as it rises. But when I look above the candle I cannot see anything – there is no smoke or steam visible to the naked eye without the benefit of a shadow. What am I seeing?

Yesterday we had no electricity for four hours.

I lit some candles, including the tealight in my aroma lamp (I have no real tea warmer, have to buy one at last when I go to Germany for Christmas), then I removed from the aroma lamp the little pot which should contain water and essential oil, and put on a cheese sandwich wrapped in aluminium foil. It took its time but the cheese got soft and the surface of the bread crispy. Then I put about 250 ml of water in my steel camping cup and closed it with aluminium foil and put that on the aroma lamp. Before it got more than lukwarm the light wet back on (I had not started all these manipulations immediately, only about 1,5 hours before the electricity came back) but I decided to finish the experiment. When the candle was finished the cup felt hot but the water wasn`t boiling. I put a teabag in but it was definitely not hot enough to make decent tea.

I konw a tealight and tea-warmer should not make the tea boil in usual conditions.

But I used less water, a metal container and I closed it more tightly than a teapot is closed. You can easily make a spoonful of water boil on a candle, anyway.

If I had reduced the distance between candle and cup (by using a tea-warmer instead of an aroma lamp) and used the whole candle only on that task, might I have succeeded in bringing the water to boil?

I've noticed that masking tape often looses its stick after a while, but sometimes quicker than other times. Does this have anything to do with the heat and humidity? If so, how?

Hot food contains more heat therefore more energy. Does this mean that it will give more energy to whoever eats it or just make them temporarily hotter by heating them on the inside?

When stiring soup or porridge and the like you can see the effectiveness by the reduced release of steam bubbles. 

I have thought just plain circular stiring may not be the best as it could leave the outside and inside content permanently outside or inside. However, trying figure eight and different methods all appear less effective than simple circular stiring.

Is there any best way to stir liquids?

When I put large bed sheets in the tumble dryer they sometimes roll up into a ball and are still wet when the drying cycle has finished.Since smaller items do not seem to do this is there a threshold at which the area of the fabric gets too big for the dryer and rolls up? Would folding it a few times to make it smaller help and what effect would this have on drying time as if you fold it too many times this would have the same effect as it being rolled into a tight ball and it not drying properly? Has anyone devised a cunning method of putting their large sheets into the dryer that stops them from rolling up?Paul GaultNewcastle-under-Lyme, UK.

When I heat a tomato-based soup or pasta sauce either in the microwave or on the oven hob, the sauce splutters and spurts all over the place as it heats, usually leading to a clean up of the oven or microwave afterwards.

However sauces or soups that contain no tomato (e.g. chicken or beef soup, cheese sauce, gravy) don't produce this mess despite being cooked in exactly the same way.

What is it about tomato based products that cause this irritating culinary reaction?

when cold the milk poured with a neat stream whereas after microwaving it sloshed all down the side of the jug.

An age old debate between my grandfather and my mother.

He insists on hot days to close the house up and pull all the blinds down.

My mother however opens all the blinds and every window to let air through.

Who is right? I know there are many factors but surely one must be generally cooler than the other.

If it helps we live in a humid Queensland climate, would it make any difference if it was a dry hot environment?