technoquest

Questions and answers provided by Science Line's Dial-a-Scientist on 0345 600444

Q What happens to waste from aeroplane toilets?

A It's a myth that it can leak out and fall to the ground in huge frozen blocks. Waste on aircraft is stored in tanks, which are pumped out later on the ground. The bits of ice which can fall from a plane generally come from the wings, where ice accumulates from water vapour in the clouds.

Q How do they put stripes in toothpaste?

A Basic toothpaste is white. Coloured gels are then made in separate steel mixers, and each colour is piped to a specially designed nozzle which keeps the colours separate as they are pumped into the tubes - which are filled from the bottom up at a rate of about 250 per minute, and sealed. The stripes are carefully formulated to be stiff enough not to flow into a single messy mix, yet soft enough to be squeezed out of the nozzle. Because each tube is filled to capacity, the colours can't normally mix up.

Q Why do we crave chocolate?

A Chocolate contains large amounts of phenylethylamine, which is also present in our bodies and released during sexual arousal, heightening sensation and raising the heart rate. It also contains methylxantine and theobromine, which have similar effects to caffeine. And if that isn't enough, it is solid at room temperature but melts at just below body temperature - that is, in your mouth.

Q Where do comets come from?

A Comets are made up of rock and ice left over from the time when the solar system was formed. Dutch astronomer Jan Oort suggested in 1950 the existence of a cloud of comets 50,000 times as far away from the sun as is the Earth. The Oort Cloud is thought to contain about 100 billion comets, some of which can get nudged out by gravitational interactions with passing stars and then fall into closer, elliptical orbits about the sun. Other comets may also come from the Kuiper Belt, which is closer to the Earth than the Oort Cloud but contains smaller objects.

Q What is the funny bone?

A The funny bone is actually a nerve which runs through a groove in a bone very close to the surface of your skin. It's called the ulnar nerve because it runs through the ulna, the outer of the two bones of the forearm. The ulnar nerve provides sensations for the wrist and hand. At the elbow, the ulna sticks out, and both it and the ulnar nerve are very close to the skin, making them easy to bump or knock. If the nerve itself is hit, you get a very painful physical reaction, and when things hurt a lot, you get very emotional, which means you laugh (or cry, or both) a lot.

Q How does a lie detector work?

A Lie detectors work on the principle that anyone who's lying will be nervous, and nervous people tend to produce more adrenaline, which makes their hearts beat faster, their skin temperature rise and makes them sweat more. A lie detector basically measures how these things change during questioning. However, people generally get nervous anyway if they're being questioned, while some people can control their heart rate if they concentrate. So, lie detectors aren't foolproof indicators of guilt.

You can also visit the technoquest World Wide Web site at http://www.campus.bt.com/CampusWorld/pub/ScienceNet

Questions for this column can be submitted by e-mail to sci.net@campus.bt.com

PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
Life and Style
ebooksA superb mix of recipes serving up the freshest of local produce in a delicious range of styles
Life and Style
ebooksFrom the lifespan of a slug to the distance to the Sun: answers to 500 questions from readers
Voices
voices
Sport
Roger Federer is greeted by Michael Jordan following his victory over Marinko Matosevic
tennisRoger Federer gets Michael Jordan's applause following tweener shot in win over Marinko Matosevic
News
peopleJustin Bieber accuses paparazzi of acting 'recklessly' after car crash
Arts and Entertainment
Oppressive atmosphere: the cast of 'Tyrant'
tvIntroducing Tyrant, one of the most hotly anticipated dramas of the year
News
i100
Independent
Travel Shop
the manor
Up to 70% off luxury travel
on city breaks Find out more
santorini
Up to 70% off luxury travel
on chic beach resorts Find out more
sardina foodie
Up to 70% off luxury travel
on country retreats Find out more
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

ES Rentals

    iJobs Job Widget
    iJobs General

    Technical Manager – Heat Pumps

    £40000 Per Annum dependent on experience: The Green Recruitment Company: They ...

    Test Job

    TBC: Test Recruiter for iJobs: Job London (Greater)

    Senior Developer - HTML, CSS, PHP, JavaScript, VBA, SQL

    £30000 - £35000 per annum + benefits: Ashdown Group: We are working with one o...

    Senior Developer - HTML, CSS, PHP, JavaScript, VBA, SQL

    £30000 - £35000 per annum + benefits: Ashdown Group: We are working with one o...

    Day In a Page

    Kate Bush, Hammersmith Apollo music review: A preamble, then a coup de théâtre - and suddenly the long wait felt worth it

    Kate Bush shows a voice untroubled by time

    A preamble, then a coup de théâtre - and suddenly the long wait felt worth it
    Robot sheepdog technology could be used to save people from burning buildings

    The science of herding is cracked

    Mathematical model would allow robots to be programmed to control crowds and save people from burning buildings
    Tyrant: Is the world ready for a Middle Eastern 'Dallas'?

    This tyrant doesn’t rule

    It’s billed as a Middle Eastern ‘Dallas’, so why does Fox’s new drama have a white British star?
    Rachael Lander interview: From strung out to playing strings

    From strung out to playing strings

    Award-winning cellist Rachael Lander’s career was almost destroyed by the alcohol she drank to fight stage fright. Now she’s playing with Elbow and Ellie Goulding
    The science of saturated fat: A big fat surprise about nutrition?

    A big fat surprise about nutrition?

    The science linking saturated fats to heart disease and other health issues has never been sound. Nina Teicholz looks at how governments started advising incorrectly on diets
    Emmys 2014 review: Can they genuinely compete with the Oscars

    Can they genuinely compete with the Oscars?

    The recent Emmy Awards are certainly glamorous, but they can't beat their movie cousins
    On the road to nowhere: A Routemaster trip to remember

    On the road to nowhere

    A Routemaster trip to remember
    Hotel India: Mumbai's Taj Mahal Palace leaves its darker days behind

    Hotel India

    Mumbai's Taj Mahal Palace leaves its darker days behind
    10 best pencil cases

    Back to school: 10 best pencil cases

    Whether it’s their first day at school, uni or a new project, treat the student in your life to some smart stationery
    Arsenal vs Besiktas Champions League qualifier: Gunners know battle with Turks is a season-defining fixture

    Arsenal know battle with Besiktas is a season-defining fixture

    Arsene Wenger admits his below-strength side will have to improve on last week’s show to pass tough test
    Pete Jenson: Athletic Bilbao’s locals-only transfer policy shows success does not need to be bought

    Pete Jenson: A Different League

    Athletic Bilbao’s locals-only transfer policy shows success does not need to be bought
    This guitar riff has been voted greatest of all time

    The Greatest Guitar Riff of all time

    Whole Lotta Votes from Radio 2 listeners
    Britain’s superstar ballerina

    Britain’s superstar ballerina

    Alicia Markova danced... every night of the week and twice on Saturdays
    Berlin's Furrie invasion

    Berlin's Furrie invasion

    2000 fans attended Eurofeurence
    ‘It was a tidal wave of terror’

    ‘It was a tidal wave of terror’

    Driven to the edge by postpartum psychosis