A new book provides the answers to all those questions that you've probably wanted to know for ages....
Read answers to quirky questions
By TIM SPANTON
Published: 11 Oct 2008
The Sun
WHY do fingernails grow after death? Why is custard powder pink until you add liquid? And will cracking your knuckles cause long-term harm?
These are some of the trivial but intriguing scientific questions posed by inquisitive readers of New Scientist.
Now the answers, provided by other well-informed readers, have been collected in fun book Do Polar Bears Get Lonely?...
Here we reveal a selection of the best queries and their enlightening responses.
Q HOW do you get the stripes in toothpaste?
A Leonard Marraffino licensed his striped toothpaste invention almost 50 years ago in the US.
The first commercial version in the UK was called Signal.
Behind the nozzle a hollow pipe extends a little way back into the toothpaste tube.
The white paste travels down this pipe. Around the pipe is the funnel-shaped neck of the tube and at the nozzle end of this are tiny holes. When filling the tube, red paste is first squirted into the funnel-shaped neck.
Then the white toothpaste is added and the end of the tube sealed.
When you squeeze the tube, the white paste flows out through the pipe but it also compresses the red paste, forcing it through the tiny holes into the pipe to form stripes.
Q WHY do hair and fingernails grow after death?
A This is something noticed by fresh-faced, first-year medical students when confronted with dead human bodies to dissect.
All the bodies have slightly long fingernails and the male ones have stubble.
However, anatomy demonstrators assure our future doctors that nails and hair do not grow after death. The phenomenon is the result of the surrounding tissue drying out and shrinking back, giving the impression of growth.
Q I USED to suffer from athlete’s foot until my father told me to pee on my feet when showering. How does this work?
A Most treatments for this skin infection caused by ringworm fungi involve keeping the skin drier or applying a fungicide.
The urea in your urine is not concentrated enough for its antifungal effect to work.
So the most likely answer is that, knowing you have peed on your feet, you rinse and/or dry them especially carefully, removing the dead skin cells the fungi use as food.
Solution ... custard conundrum
Q WHY is custard powder pink until you add liquid, when it becomes yellow?
A This powder is often coloured with tartrazine yellow or quinoline yellow food dyes mixed with sunset yellow.
These colours are yellow in solution with water but in their solid state the dominant sunset yellow is more orange-red.
This looks pink when mixed with the other ingredients.
Q IN films a hero often evades bullets by jumping into a river or lake. How far below the surface does he need to dive?
A Any object moving through a medium experiences a drag force tending to slow it down. For a denser medium like water, the drag force is much larger than it is in air.
For a typical bullet with a velocity of just under 1,000ft a second, the depth over which it slows in water is barely a few metres, so a 10ft dive is more than adequate.
Q MY father used to hang a chain from the back of our car to prevent my sister from getting car sick. Does it work and, if so, how?
A Car sickness is caused by a conflict between movement seen by the eyes and that sensed by the inner ear.
It was once believed that the cause was undischarged static electricity generated by the car’s tyres and the road.
Even if it had been true, any beneficial effect of the chain would have ended as it lifted off the ground when the car sped up.
Pint ... cold hard facts
Q WHY does a glass of cold draught lager hold its head longer if pulled in two or three pours, rather than one?
A If you pour in one pull the foam grows under uniform conditions producing relatively few, large bubbles that pop quickly. By pausing during pulling, the turbulence of the next pull shears large bubbles into more numerous, smaller bubbles.
Q HOW long would it take a coconut to float from the Caribbean to the west of Scotland?
A The chances are it would sink long before reaching Scotland.
However in 1992, 29,000 rubber ducks spilled overboard during a storm as a container ship crossed the Pacific.
Many of them have now reached the Atlantic through the Northwest Passage, travelling at up to twice the speed of ocean currents. So, hypothetically, a coconut could take 16 months to make the journey from the Caribbean.
Q I’VE read that cracking my knuckles does no harm, but I am far from convinced.
A The sound is caused by a bubble of nitrogen gas forming in a joint when it is stressed, which then pops. There is little evidence knuckle cracking causes arthritis.
S-no-w mates? ... polar bear
One US doctor went so far as to crack the knuckles on just one hand for 50 years to see if a difference developed between that hand and the other. There wasn’t.
Q DO polar bears get lonely?
A Loneliness is a reaction to deprivation of company when company is appropriate.
But for polar bears company usually represents threat so they do very well by themselves.
Males sometimes wrestle harmlessly to establish dominance.
Q IN a worst-case scenario, if one had to eat parts of oneself, which non-organs would be the most nutritious? Nails? Hair? Earwax?
A Nails and earwax are almost indigestible, unless you pressure-cook them for a long time, preferably in mild acid.
If we take nutrition to mean energy or proteins and the like, then bone marrow or fat tissue would be the most rewarding.
Q WHY do mosquitoes bite one individual but not another?
A The most definite attractants are lactic acid, carbon dioxide, warmth, certain fatty acids and other compounds from sweat or its bacterial decomposition.
Notoriously, Limburger cheese and unwashed socks are rich sources of such chemicals.
© New Scientist 2008. Extracts from Do Polar Bears Get Lonely? And 101 Other Intriguing Science Questions, edited by Mick O’Hare (Profile Books, £7.99 paperback). To buy a copy from The Sun Bookshop for £7.99 including free P&P ring 08700 715517 or go to thesunbookshop.co.uk.
thesun.co.uk
Read answers to quirky questions
By TIM SPANTON
Published: 11 Oct 2008
The Sun
WHY do fingernails grow after death? Why is custard powder pink until you add liquid? And will cracking your knuckles cause long-term harm?
These are some of the trivial but intriguing scientific questions posed by inquisitive readers of New Scientist.
Now the answers, provided by other well-informed readers, have been collected in fun book Do Polar Bears Get Lonely?...
Here we reveal a selection of the best queries and their enlightening responses.
Q HOW do you get the stripes in toothpaste?
A Leonard Marraffino licensed his striped toothpaste invention almost 50 years ago in the US.
The first commercial version in the UK was called Signal.
Behind the nozzle a hollow pipe extends a little way back into the toothpaste tube.
The white paste travels down this pipe. Around the pipe is the funnel-shaped neck of the tube and at the nozzle end of this are tiny holes. When filling the tube, red paste is first squirted into the funnel-shaped neck.
Then the white toothpaste is added and the end of the tube sealed.
When you squeeze the tube, the white paste flows out through the pipe but it also compresses the red paste, forcing it through the tiny holes into the pipe to form stripes.
Q WHY do hair and fingernails grow after death?
A This is something noticed by fresh-faced, first-year medical students when confronted with dead human bodies to dissect.
All the bodies have slightly long fingernails and the male ones have stubble.
However, anatomy demonstrators assure our future doctors that nails and hair do not grow after death. The phenomenon is the result of the surrounding tissue drying out and shrinking back, giving the impression of growth.
Q I USED to suffer from athlete’s foot until my father told me to pee on my feet when showering. How does this work?
A Most treatments for this skin infection caused by ringworm fungi involve keeping the skin drier or applying a fungicide.
The urea in your urine is not concentrated enough for its antifungal effect to work.
So the most likely answer is that, knowing you have peed on your feet, you rinse and/or dry them especially carefully, removing the dead skin cells the fungi use as food.
Solution ... custard conundrum
Q WHY is custard powder pink until you add liquid, when it becomes yellow?
A This powder is often coloured with tartrazine yellow or quinoline yellow food dyes mixed with sunset yellow.
These colours are yellow in solution with water but in their solid state the dominant sunset yellow is more orange-red.
This looks pink when mixed with the other ingredients.
Q IN films a hero often evades bullets by jumping into a river or lake. How far below the surface does he need to dive?
A Any object moving through a medium experiences a drag force tending to slow it down. For a denser medium like water, the drag force is much larger than it is in air.
For a typical bullet with a velocity of just under 1,000ft a second, the depth over which it slows in water is barely a few metres, so a 10ft dive is more than adequate.
Q MY father used to hang a chain from the back of our car to prevent my sister from getting car sick. Does it work and, if so, how?
A Car sickness is caused by a conflict between movement seen by the eyes and that sensed by the inner ear.
It was once believed that the cause was undischarged static electricity generated by the car’s tyres and the road.
Even if it had been true, any beneficial effect of the chain would have ended as it lifted off the ground when the car sped up.
Pint ... cold hard facts
Q WHY does a glass of cold draught lager hold its head longer if pulled in two or three pours, rather than one?
A If you pour in one pull the foam grows under uniform conditions producing relatively few, large bubbles that pop quickly. By pausing during pulling, the turbulence of the next pull shears large bubbles into more numerous, smaller bubbles.
Q HOW long would it take a coconut to float from the Caribbean to the west of Scotland?
A The chances are it would sink long before reaching Scotland.
However in 1992, 29,000 rubber ducks spilled overboard during a storm as a container ship crossed the Pacific.
Many of them have now reached the Atlantic through the Northwest Passage, travelling at up to twice the speed of ocean currents. So, hypothetically, a coconut could take 16 months to make the journey from the Caribbean.
Q I’VE read that cracking my knuckles does no harm, but I am far from convinced.
A The sound is caused by a bubble of nitrogen gas forming in a joint when it is stressed, which then pops. There is little evidence knuckle cracking causes arthritis.
S-no-w mates? ... polar bear
One US doctor went so far as to crack the knuckles on just one hand for 50 years to see if a difference developed between that hand and the other. There wasn’t.
Q DO polar bears get lonely?
A Loneliness is a reaction to deprivation of company when company is appropriate.
But for polar bears company usually represents threat so they do very well by themselves.
Males sometimes wrestle harmlessly to establish dominance.
Q IN a worst-case scenario, if one had to eat parts of oneself, which non-organs would be the most nutritious? Nails? Hair? Earwax?
A Nails and earwax are almost indigestible, unless you pressure-cook them for a long time, preferably in mild acid.
If we take nutrition to mean energy or proteins and the like, then bone marrow or fat tissue would be the most rewarding.
Q WHY do mosquitoes bite one individual but not another?
A The most definite attractants are lactic acid, carbon dioxide, warmth, certain fatty acids and other compounds from sweat or its bacterial decomposition.
Notoriously, Limburger cheese and unwashed socks are rich sources of such chemicals.
© New Scientist 2008. Extracts from Do Polar Bears Get Lonely? And 101 Other Intriguing Science Questions, edited by Mick O’Hare (Profile Books, £7.99 paperback). To buy a copy from The Sun Bookshop for £7.99 including free P&P ring 08700 715517 or go to thesunbookshop.co.uk.
thesun.co.uk
