BBC Knowledge 2017 02

QUESTIONS

AND ANSWERS

16 February 2017

ISTOCK, GETTY X2, PRESS ASSOCIATION, LAURENTIU HUIANU/WELLCOME IMAGES, SCIENCE PHOTO LIBRARY

Computer security is becoming more and more

advanced, and computer systems are complicated,

so it is a more difficult task to attack or intrude into

well-established computer networks. In this respect,

hacking is more difficult and requires greater

expertise compared to 20 years ago. However, there

are more and more internet-enabled devices in the

world, many of which run relatively simple software.

Therefore, there are endless opportunities for

hackers to exploit the security loopholes in central

heating controllers, smartwatches, websites,

smartphones, games consoles, CCTV cameras,

vehicle controllers or even electronic toilets. PB

Is hacking getting harder?

A minority of people are ‘colour blind’, in that they see colours

as duller than usual and have difficulty distinguishing certain

colours. These problems aside, whether your experience of red

is the same as mine is a tricky philosophical question because

we can never truly know each other’s subjective experience.

What’s for sure is that the same object can be perceived as being

a different colour by different people, depending on the

assumptions their brains make about the background lighting.

Just look at the ferocious internet argument in 2015 over whether

a striped dress – pictured on Tumblr – was white and gold or blue

and black (Google ‘the dress’ to read more). CJ

Do we all see the same colours?

Light has long been

known to slow down whenever it

passes through a medium such as air

or glass. Light also interacts with the

molecules in its surroundings. But

over the years, some theorists have

proposed that the speed of light in a

vacuum may have been far higher

during the Big Bang. While this would

solve some of the technical problems

concerning the early Universe,

there’s no compelling evidence that

this is the case. RM

Does the speed

of light ever change?

VITAL STATS

The time, in seconds, of

the longest ever lightning

flash. It occurred in

France in 2012.

16 February 2017