For most of us, kid’s birthday parties are a nightmare that are best avoided. Having to supervise one would be an experience with few perks. One of which would be getting to eat chocolate cake. Another would be getting to blow party bubbles. Because, let’s be honest, you never get too old for playing with bubbles.
Yet despite their instant fun factor, soap bubbles never last very long and pop disappointingly quickly. Up close, each bubble is a small, air-filled balloon with delicate walls made of a soap and water mix. With a surface thinner than a human hair, the bubble wall is so fragile that a tiny particle of dust can be enough to pierce it. Sprinkling talcum powder on bath bubbles, for example, is like showering a layer of balloons with pins.
But bath bubbles would never be there were it not for the soap – it is extremely difficult to make bubbles in pure water. Water has surface tension – a tendency to want to stay together in blobs and drops. Without soap, each time you make a plain water bubble, the water will pull itself together causing it to quickly collapse. With soapy water though, the soap molecules get in between the water molecules, reducing its surface tension, making bubble-making possible.
It is possible to get longer-lasting, sturdier bubbles by adding glycerine (also spelt ‘glycerin’). A sweet-tasting substance used for sore throats (you can buy it from supermarkets and pharmacies), glycerine has a special ability of slowing down how quickly water can evaporate. Free-floating bubbles eventually pop when the water in its wall evaporates, but glycerine molecules will form weak bonds with water molecules, ‘sticking’ them together and keeping the water inside a bubble’s wall inside for longer.
If you like, you could add glycerine to your bath water for an especially frothy and sweet cleanse. More cheerful and cleaner – hurray for longer lasting bubbles!
Answer by Dr Stu
Question sent from ‘JJ’
Image source: croc attack!!! by Nizam Uddin, on Flickr
Nature hasn’t been overly kind to women. Let’s look at childbirth. It is harder and more dangerous for humans than any other animal: the female pelvis is (usually) only just big enough to squeeze a baby’s big head through. And periods – or menstruation – are another particularly human curse. Most female animals don’t bleed at all. Then to further add insult to monthly injury, pre-menstrual food cravings scupper any well-meaning intentions to live a healthy life… Clearly someone upstairs wasn’t looking too kindly on Homo sapiens.
It is quite common for women to have cravings for certain food in the lead up to a period. Surveys show that these foods are usually high in carbohydrate (e.g. bread, muffins), high in fat (e.g. cheese) or both (doughnuts, buttered popcorn, chocolate). This desire to load up on calories is a consequence of changing hormone levels and starts soon after ovulation.
Ovulation usually happens at around the mid-point of a menstrual cycle – i.e. between two periods. It is when an ovary releases an egg into a fallopian tube. After this point, there is a gradual increase in the hormone progesterone in the blood – and this continues right up until the time of menstruation. Progesterone is designed to prepare a woman’s body for pregnancy by getting the womb (uterus) ready on the off chance that an egg comes into contact with a lucky sperm as it travels down the fallopian tube. But progesterone has other effects. One being that it makes the brain’s appetite-controlling regions go off kilter, prompting a longing to eat more. And as the progesterone increases in the run up to the period, these cravings get worse.
It’s unfortunate, but there is a logic behind progesterone’s effects. In getting the body ready for a possible pregnancy, progesterone serves to ensure the body is nourished enough so as to support a growing baby. Eating more is nature’s way of doing this.
Sadly, there is no simple solution to regular chocolate cravings. There are some reports of certain contraceptive pills helping some women – although the research is inconclusive. As a guy, all I can do is offer sympathy and support when the going is rough. And never ever make insensitive jokes or puns about pre-menstrual symptoms. Now that’s a solemn promise. Period.
Answer by Dr Stu
Image source: ? |_ ?-\ ? Ø, on Flickr
Belly button fluff (or ‘lint’) seems to come from our underwear and trousers. Throughout the day, tiny bits of fabric get caught in the hairs beneath the belly button. Through mysterious forces not yet fully understood, these bits of lint travel up through the navel hairs, get mixed in with dead skin, fat hair and dust and come to rest in the belly button.
Various factors influence the amount and speed of navel fluff accumulation. People who are hairier (i.e. men) usually have a thicker ‘snail trail’ (that bit of hair beneath the belly button), allowing more lint to wriggle upwards. Overweight people also get more navel lint, owing to their deeper ‘innie’. Sadly, men are also more likely to be overweight than women.
If belly button fluff is causing you concern then here are some anti-fluff tips:
Answer by Dr Stu
Image Source: Justina Davies, on Flickr