technoquest

Q. What effect does colour have on your mood?

A. No conclusive research seems to have been done on this topic. In some tests, colours had absolutely no effect on mood. In others, definite effects were seen. People tended to feel more tired after filling in a form printed on red paper than they did after filling in one on green paper. Workers in a red office apparently make fewer mistakes than workers in a green office but they feel much more stressed-out. Young children seem to be happier in a pink room, rather than a blue one. So, some research says colour does affect mood, and some says it doesn't.

Q. What generates the noise of thunder?

A. A lightning flash heats the air around it to about 1,000C. This is about a sixth as hot as the surface of the Sun. As things become hot they expand. This rapid heating of the air causes it to expand quickly resulting in a shockwave that rushes out as a sound wave from the lightning bolt. It is this sound wave that is the thunder. The reason we hear different types of thunder - the long roll or the short crack - is due to the path the lightning takes. Imagine a flash that starts a kilometre above our heads and travels diagonally to hit the Earth a kilometre from our feet. Every point on that path is (very roughly) the same distance from us so the sound from every point of the flash hits us at about the same time. This makes a kind of loud "crack". Now imagine a flash that starts about a kilometre up and ends close to our feet. The sound from the start of the flash's path has to travel much further than the sound from the end and will, as a result, reach us much later. This creates the long, slow roll of thunder.

Q. How do you use the hands of a clock to find North?

A. Point the hour hand of the watch at the Sun. Half way between the hour hand and 12 o'clock is South. North is the opposite direction.

Q. The Earth is tilted at an angle of about 23 degrees to the vertical. How would life be affected if it were not tilted at all?

A. This tilt is responsible for the seasons in the northern and southern hemispheres. At the equator the tilt has less effect, so if the tilt was removed we could all expect constant 12-hour days and (depending on local geography) rather pleasant equatorial type weather.

Q. Why do we cry?

A. It seems that crying in an emotional context is a social signal, much like smiling or frowning. It is instinctive behaviour that tells other people how we're feeling. It probably serves no physiological function.

Questions and answers are provided by Science Line. You can use its Dial-a-Scientist service on 0345 600444

CHRISTOPHER RILEY

Start your day with The Independent, sign up for daily news emails
ebooks
ebooksA special investigation by Andy McSmith
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

Ashdown Group: Technical Presales Consultant - London - £65,000 OTE.

£65000 per annum: Ashdown Group: Technical Presales Engineer - central London ...

Recruitment Genius: Physiotherapist / Sports Therapist

£20000 - £50000 per annum: Recruitment Genius: A Physiotherapist / Sports Ther...

Recruitment Genius: Sales Executive / Advisor

£8 - £9 per hour: Recruitment Genius: Sales Executives / Advisors are required...

Recruitment Genius: Warehouse Operative

£14000 - £15000 per annum: Recruitment Genius: An opportunity has arisen for a...

Day In a Page

Homeless Veterans campaign: Donations hit record-breaking £1m target after £300,000 gift from Lloyds Bank

Homeless Veterans campaign

Donations hit record-breaking £1m target after huge gift from Lloyds Bank
Flight MH370 a year on: Lost without a trace – but the search goes on

Lost without a trace

But, a year on, the search continues for Flight MH370
Germany's spymasters left red-faced after thieves break into brand new secret service HQ and steal taps

Germany's spy HQ springs a leak

Thieves break into new €1.5bn complex... to steal taps
International Women's Day 2015: Celebrating the whirlwind wit of Simone de Beauvoir

Whirlwind wit of Simone de Beauvoir

Simone de Beauvoir's seminal feminist polemic, 'The Second Sex', has been published in short-form for International Women's Day
Mark Zuckerberg’s hiring policy might suit him – but it wouldn’t work for me

Mark Zuckerberg’s hiring policy might suit him – but it wouldn’t work for me

Why would I want to employ someone I’d be happy to have as my boss, asks Simon Kelner
Confessions of a planespotter: With three Britons under arrest in the UAE, the perils have never been more apparent

Confessions of a planespotter

With three Britons under arrest in the UAE, the perils have never been more apparent. Sam Masters explains the appeal
Russia's gulag museum 'makes no mention' of Stalin's atrocities

Russia's gulag museum

Ministry of Culture-run site 'makes no mention' of Stalin's atrocities
The big fresh food con: Alarming truth behind the chocolate muffin that won't decay

The big fresh food con

Joanna Blythman reveals the alarming truth behind the chocolate muffin that won't decay
Virginia Ironside was my landlady: What is it like to live with an agony aunt on call 24/7?

Virginia Ironside was my landlady

Tim Willis reveals what it's like to live with an agony aunt on call 24/7
Paris Fashion Week 2015: The wit and wisdom of Manish Arora's exercise in high camp

Paris Fashion Week 2015

The wit and wisdom of Manish Arora's exercise in high camp
8 best workout DVDs

8 best workout DVDs

If your 'New Year new you' regime hasn’t lasted beyond February, why not try working out from home?
Paul Scholes column: I don't believe Jonny Evans was spitting at Papiss Cissé. It was a reflex. But what the Newcastle striker did next was horrible

Paul Scholes column

I don't believe Evans was spitting at Cissé. It was a reflex. But what the Newcastle striker did next was horrible
Miguel Layun interview: From the Azteca to Vicarage Road with a million followers

From the Azteca to Vicarage Road with a million followers

Miguel Layun is a star in Mexico where he was criticised for leaving to join Watford. But he says he sees the bigger picture
Frank Warren column: Amir Khan ready to meet winner of Floyd Mayweather v Manny Pacquiao

Khan ready to meet winner of Mayweather v Pacquiao

The Bolton fighter is unlikely to take on Kell Brook with two superstar opponents on the horizon, says Frank Warren
War with Isis: Iraq's government fights to win back Tikrit from militants - but then what?

Baghdad fights to win back Tikrit from Isis – but then what?

Patrick Cockburn reports from Kirkuk on a conflict which sectarianism has made intractable