Science: Technoquest

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

Q Why are our elbows better than our hands when testing the temperature of babies' bath water?

A Although there are more nerve endings in the hands and feet, the skin in these regions is usually quite thick and shields our skin temperature receptors from any temperature we are trying to measure. Using a region of our body which has thinner skin is more effective. It also leaves your hands free to hold the baby.

Q How and why do frogs sing? Is it because they're territorial?

A Frogs have a larynx and vocal chords like other vertebrates, so sound production is essentially the same as in humans, birds and mammals. However, different species show a range of singing ability, from virtually silent to very loud calls. They probably sing for several reasons - advertising for a mate, intimidating predators or even to get other males to release them from a mating embrace. Generally, males call and females stay silent - or quietly call back to let the male know they're there. Some frogs are territorial only in the breeding session, while others may guard an area all year round.

Q How does a Venus fly trap digest a fly?

A When a fly enters the Venus fly trap, it knocks a trigger hair that sets the trap. It's not until the fly moves again and triggers another hair that the trap is sprung and the plant closes its "jaws". Once the jaws are closed, the plant lets out digestive juices which dissolve the fly. The juices and dissolved fly are absorbed by the plant. This is similar to how food is digested in our stomachs.

Q How does water move around in a tree?

A Water molecules are very good at sticking together - where one goes, the rest will follow. This is called surface tension. When you pull on one molecule, the rest tend to move, too. Water is sucked out of the tree by evaporation from its leaves; this pulls water up from the roots.

Q Why do male spiders let themselves be eaten by females after mating?

A Only a few species of spider go through this bizarre ritual. The males often try to escape, but as females are many times larger, this is not easy. The males' drive to pass on their genes to the next generation is greater than their desire to live long but ultimately mortal lives. Sacrificing themselves to the female also provides her with extra nutrition, improving her chances of fathering his offspring.

News
peopleHowards' Way actress, and former mistress of Jeffrey Archer, was 60
Sport
Romelu Lukaku puts pen to paper
sport
News
Robyn Lawley
people
Arts and Entertainment
Unhappy days: Resistance spy turned Nobel prize winner Samuel Beckett
books
PROMOTED VIDEO
News
people
Life and Style
Troy Baker and Ashley Johnson voice the show’s heroes
gamingOnce stilted and melodramatic, Hollywood is giving acting in video games a makeover
News
i100
Life and Style
Phones will be able to monitor your health, from blood pressure to heart rate, and even book a doctor’s appointment for you
techCould our smartphones soon be diagnosing diseases via Health Kit and Google Fit?
News
people
Extras
indybest
Travel
Ryan taming: the Celtic Tiger carrier has been trying to improve its image
travelRyanair has turned on the 'charm offensive' but can we learn to love the cut-price carrier again?
News
ebookA unique anthology of reporting and analysis of a crucial period of history
Sport
Usain Bolt confirms he will run in both the heats and the finals of the men's relay at the Commonwealth Games
commonwealth games
Life and Style
Slim pickings: Spanx premium denim collection
fashionBillionaire founder of Spanx launches range of jeans that offers 'thigh-trimming construction'
News
Sabina Altynbekova has said she wants to be famous for playing volleyball, not her looks
people
News
i100
Life and Style
tech'World's first man-made leaves' could use photosynthesis to help astronauts breathe
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.

iJobs Job Widget
iJobs General

SAP Project Manager

competitive: Progressive Recruitment: SAP PROJECT MANAGER - 3 MONTHS - BERKSHI...

SAP Project Manager

competitive: Progressive Recruitment: SAP PROJECT MANAGER - 3 MONTHS - BERKSHI...

Senior Investment Accounting Change Manager

£600 - £700 per day + competitive: Orgtel: Senior Investment Accounting Change...

Microsoft Dynamics AX Functional Consultant

£65000 - £75000 per annum + benefits: Progressive Recruitment: A rare opportun...

Day In a Page

Save the tiger: The day America’s love of backyard tigers led to a horrific bloodbath

The day America’s love of backyard tigers led to a horrific bloodbath

With only six per cent of the US population of these amazing big cats held in zoos, the Zanesville incident in 2011 was inevitable
Samuel Beckett's biographer reveals secrets of the writer's time as a French Resistance spy

How Samuel Beckett became a French Resistance spy

As this year's Samuel Beckett festival opens in Enniskillen, James Knowlson, recalls how the Irish writer risked his life for liberty and narrowly escaped capture by the Gestapo
We will remember them: relatives still honour those who fought in the Great War

We will remember them

Relatives still honour those who fought in the Great War
Star Wars Episode VII is being shot on film - and now Kodak is launching a last-ditch bid to keep celluloid alive

Kodak's last-ditch bid to keep celluloid alive

Director J J Abrams and a few digital refuseniks shoot movies on film. Simon Usborne wonders what the fuss is about
Once stilted and melodramatic, Hollywood is giving acting in video games a makeover

Acting in video games gets a makeover

David Crookes meets two of the genre's most popular voices
Could our smartphones soon be diagnosing diseases via Health Kit and Google Fit?

Could smartphones soon be diagnosing diseases?

Health Kit and Google Fit have been described as "the beginning of a health revolution"
Ryanair has turned on the 'charm offensive' but can we learn to love the cut-price carrier again?

Can we learn to love Ryanair again?

Four recent travellers give their verdicts on the carrier's improved customer service
Billionaire founder of Spanx launches range of jeans that offers

Spanx launches range of jeans

The jeans come in two styles, multiple cuts and three washes and will go on sale in the UK in October
10 best over-ear headphones

Aural pleasure: 10 best over-ear headphones

Listen to your favourite tracks with this selection, offering everything from lambskin earmuffs to stainless steel
Commonwealth Games 2014: David Millar ready to serve up gold for his beloved Scotland in the end

Commonwealth Games

David Millar ready to serve up gold for his beloved Scotland in the end
UCI Mountain Bike World Cup 2014: Downhill all the way to the top for the Atherton siblings

UCI Mountain Bike World Cup

Downhill all the way to the top for the Atherton siblings
Save the tiger: The animals bred for bones on China’s tiger farms

The animals bred for bones on China’s tiger farms

The big cats kept in captivity to perform for paying audiences and then, when dead, their bodies used to fortify wine
A former custard factory, a Midlands bog and a Leeds cemetery all included in top 50 hidden spots in the UK

A former custard factory, a Midlands bog and a Leeds cemetery

Introducing the top 50 hidden spots in Britain
Ebola epidemic: Plagued by fear

Ebola epidemic: Plagued by fear

How a disease that has claimed fewer than 2,000 victims in its history has earned a place in the darkest corner of the public's imagination
Chris Pratt: From 'Parks and Recreation' to 'Guardians of the Galaxy'

From 'Parks and Recreation' to 'Guardians of the Galaxy'

He was homeless in Hawaii when he got his big break. Now the comic actor Chris Pratt is Hollywood's new favourite action star