Scienec: Technoquest

Q: What is the smallest spider in the world?

The smallest spider is the Mygalomorph spider from Borneo, whose body measures just 0.5mm long - the size of a coffee granule. The largest is the goliath bird-eating spider, the largest of which has a leg span of 29cm (11in) - the length of your forearm.

Q: How long do spiders live?

Ordinary spiders live for about a year, although up to five to six months of this may be spent in the egg stage. However, some South American tarantulas can live for as long as 20 years, while some tropical jumping spiders only live for three months.

Q: How is snake venom produced?

Venom is produced at the back of the snake's head (behind the eyes). Glands similar to those that produce our saliva make and store a cocktail of venoms, toxins and enzymes, which travel through ducts to either fangs or groves in the teeth. The venoms work in different ways: they can paralyse prey (cobra venom affects the nervous system) or digest tissues and organs (rattle snakes) which helps them in their food intake.

Q: Is there such a thing as a bionic eye?

People may be either blind from birth or have lost their sight through disease or an accident. For those born blind, an artificial eye may not be all that useful as their visual cortex has not been trained to see. For those that have lost their vision later on in life, a bionic eye (an implant that replaces damaged retinal cells) may restore some of their sight.

Retinal implants are constructed from 25 electrodes just a thousandth of a millimetre thick, and incorporate a miniature solar panel. When the panels absorb light, tiny currents are generated in the implants which then stimulate the ganglion cells beneath, bypassing damaged retinal cells.

So far, the implants have worked in animals and in one human volunteer who had gone blind through glaucoma. The patient could see a light shone in the eye, and make out simple letters. If more electrodes are used, the wearer's vision might be even better. Next, the researchers will need to make an implant that does not corrode in the salty solutions of the eye, and will not slice into the retina (the implants are razor sharp as they are so thin). Researchers remain hopeful that eventually such implants may restore sight to some blind people.

Q: Why do your eyebrows grow as you get older?

The continued growth of hair in men is thought to be due to the male sex hormones (androgens). Hair in different parts of the body varies in its sensitivity to androgens and eyebrows, nose, ear and patches on the top of the shoulder respond to continual high levels of the hormones. It therefore does not usually appear in women, who have much lower levels of androgens. Why evolution should have produced them is unclear. There is, however, a hint from some species that females seek out males who are older because that shows they are good at surviving and so must have a fit set of genes. The males of these species develop outward signs of their age. Perhaps going grey and sprouting ear and nose hairs was once attractive to women and so men showing them were successful at getting their genes into the next generation.

You can also visit the technoquest World Wide Web site at http://www.sciencenet.org.uk

Suggested Topics
Have you tried new the Independent Digital Edition apps?
Arts and Entertainment

ebooksNow available in paperback
Arts and Entertainment

ebooks
Arts and Entertainment
Christopher Eccleston (centre) plays an ex-policeman in this cliché-riddled thriller

TV review
Arts and Entertainment
Lena Headey looks very serious as Cersei Lannister in Game of Thrones

TV This TV review contains spoilers
Arts and Entertainment

film
Arts and Entertainment
Wiz Khalifa performs on stage during day one of the Wireless Festival at Perry Park in Birmingham

music
Arts and Entertainment
Festival-goers soak up the atmosphere at Glastonbury

music

Arts and Entertainment
Star Wars creator George Lucas

film

Arts and Entertainment

music

Arts and Entertainment
A shot from the forthcoming Fast and Furious 7

film

Arts and Entertainment
The new-look Top of the Pops could see Fearne Cotton returns as a host alongside Dermot O'Leary

TV

Arts and Entertainment
The leader of the Church of Scientology David Miscavige

TV

Arts and Entertainment
No half measures: ‘The Secret Life of the Pub’

Grace Dent on TV The Secret Life of the Pub is sexist, ageist and a breath of fresh air

Arts and Entertainment
Art on their sleeves: before downloads and streaming, enthusiasts used to flick through racks of albums in their local record shops
musicFor Lois Pryce, working in a record shop was a dream job - until the bean counters ruined it
Arts and Entertainment
Serial suspect: the property heir charged with first-degree murder, Robert Durst
TV review
Arts and Entertainment
Igarashi in her

Art Megumi Igarashi criticises Japan's 'backwards' attitude to women's sexual expression

Arts and Entertainment
Could Ed Sheeran conquer the Seven Kingdoms? He could easily pass for a Greyjoy like Alfie Allen's character (right)

tv Singer could become the most unlikely star of Westeros

Arts and Entertainment
Beyonce, Boris Johnson, Putin, Nigel Farage, Russell Brand and Andy Murray all get the Spitting Image treatment from Newzoids
tvReview: The sketches need to be very short and very sharp as puppets are not intrinsically funny
Arts and Entertainment
Despite the controversy it caused, Mile Cyrus' 'Wrecking Ball' video won multiple awards
musicPoll reveals over 70% of the British public believe sexually explicit music videos should get ratings
Arts and Entertainment
Lena Headey as Cersei Lannister and Ian Beattie as Meryn Trant in the fifth season of Game of Thrones

TV
Arts and Entertainment

book review
Arts and Entertainment
It's all in the genes: John Simm working in tandem with David Threlfall in 'Code of a Killer'

TV review
  • Get to the point
Latest stories from i100
Have you tried new the Independent Digital Edition apps?

ES Rentals

    Independent Dating
    and  

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

    Not even the 'putrid throat' could stop the Ross Poldark swoon-fest'

    Not even the 'putrid throat' could stop the Ross Poldark swoon-fest'

    How a costume drama became a Sunday night staple
    Miliband promises no stamp duty for first-time buyers as he pushes Tories on housing

    Miliband promises no stamp duty for first-time buyers

    Labour leader pushes Tories on housing
    Aviation history is littered with grand failures - from the the Bristol Brabazon to Concorde - but what went wrong with the SuperJumbo?

    Aviation history is littered with grand failures

    But what went wrong with the SuperJumbo?
    Fear of Putin, Islamists and immigration is giving rise to a new generation of Soviet-style 'iron curtains' right across Europe

    Fortress Europe?

    Fear of Putin, Islamists and immigration is giving rise to a new generation of 'iron curtains'
    Never mind what you're wearing, it's what you're reclining on

    Never mind what you're wearing

    It's what you're reclining on that matters
    General Election 2015: Chuka Umunna on the benefits of immigration, humility – and his leader Ed Miliband

    Chuka Umunna: A virus of racism runs through Ukip

    The shadow business secretary on the benefits of immigration, humility – and his leader Ed Miliband
    Yemen crisis: This exotic war will soon become Europe's problem

    Yemen's exotic war will soon affect Europe

    Terrorism and boatloads of desperate migrants will be the outcome of the Saudi air campaign, says Patrick Cockburn
    Marginal Streets project aims to document voters in the run-up to the General Election

    Marginal Streets project documents voters

    Independent photographers Joseph Fox and Orlando Gili are uploading two portraits of constituents to their website for each day of the campaign
    Game of Thrones: Visit the real-life kingdom of Westeros to see where violent history ends and telly tourism begins

    The real-life kingdom of Westeros

    Is there something a little uncomfortable about Game of Thrones shooting in Northern Ireland?
    How to survive a social-media mauling, by the tough women of Twitter

    How to survive a Twitter mauling

    Mary Beard, Caroline Criado-Perez, Louise Mensch, Bunny La Roche and Courtney Barrasford reveal how to trounce the trolls
    Gallipoli centenary: At dawn, the young remember the young who perished in one of the First World War's bloodiest battles

    At dawn, the young remember the young

    A century ago, soldiers of the Empire – many no more than boys – spilt on to Gallipoli’s beaches. On this 100th Anzac Day, there are personal, poetic tributes to their sacrifice
    Dissent is slowly building against the billions spent on presidential campaigns – even among politicians themselves

    Follow the money as never before

    Dissent is slowly building against the billions spent on presidential campaigns – even among politicians themselves, reports Rupert Cornwell
    Samuel West interview: The actor and director on austerity, unionisation, and not mentioning his famous parents

    Samuel West interview

    The actor and director on austerity, unionisation, and not mentioning his famous parents
    General Election 2015: Imagine if the leading political parties were fashion labels

    Imagine if the leading political parties were fashion labels

    Fashion editor, Alexander Fury, on what the leaders' appearances tell us about them
    Phumzile Mlambo-Ngcuka: Home can be the unsafest place for women

    Phumzile Mlambo-Ngcuka: Home can be the unsafest place for women

    The architect of the HeForShe movement and head of UN Women on the world's failure to combat domestic violence