Flies live in Matrix time: How the insect sees rolled up newspaper moving in slow motion and buzzes away from danger quickly
Flies avoid being swatted in the same way that Keanu Reeves dodges bullets in the film The Matrix – by watching time pass slowly.
To the insect, that rolled-up newspaper moving at lightning speed might as well be inching through thick treacle.
Like Reeves side-stepping slow motion bullets, the fly has enough time to escape.
Research led by Trinity College Dublin suggests that time perception is related to a creature's size
Of course, time is really passing at the same speed.
But the fly’s eyes send updates to its brain far more frequently than a human’s eyes, and its mental processes are similarly much more rapid than ours.
The result is that a fly sees objects moving slowly in comparison to its own rapid reactions.
It makes a decision and buzzes away from danger far more quickly than a human can follow it with a newspaper.
But flies are not the only species to perceive time differently.
Many animals smaller than us see the world in slow motion. For instance, flies can perceive light flickering up to four times faster than we can
A dog's visual system has a refresh rate higher than that of the TV screen so all they see is a flicker of lights
HOW TIME MOVES FOR THESE ANIMALS COMPARED TO HUMANS
Housefly- 6.8 times slower
Rhesus macaque- 2.4 times slower
Dog- 2 times slower
Cat- 1.4 times slower
Tiger salamander- 1.3 times faster
Blacknose shark- 2.2 times faster
Leatherback turtle- 2.7 times faster
European eel- 2.8 times faster
Research led by Trinity College Dublin, in collaboration with the University of Edinburgh and the University of St Andrews, suggests that time perception is related to a creature's size.
For instance, dogs process information at twice the rate of humans, which is why they usually aren't interested in television.
Television screens flicker to provide the illusion of constant images to humans.
But a dog's visual system has a refresh rate higher than that of the TV screen meaning that all they see is a flicker of lights.
Smaller, more agile creatures had the most refined ability to perceive information in a unit of time, said the researchers writing in the journal Animal Behaviour.
In other words, they were able to see more flickers of light per second.
In a similar way, time seems to speed up for larger creatures.
An example is the leatherback sea turtle which perceives time 2.5 times faster than a human.
However, the researchers highlight the tiger beetle as one animal who doesn't fit this rule.
The leatherback sea turtle is thought to perceive time at a rate that is around 2.5 times faster than a human
'The tiger beetle is an unusual one,' Dr Luke McNally told MailOnline.
'They take in very little information with their eyes, and run faster than their eyes can keep up.
'They essentially blind themselves, and take a stop-start approach to finding prey, hurtling towards them in the hope they'll hit something.'
'Another strange one is the swordfish. When they are hunting their time perception is almost the same as humans, as they deliberately heat up their eyes.
'The rest of the time, time goes around five times faster for them. This is because they perceive one fifth of the information we do per second,' added Dr McNally.
Time perception is just another aspect of evolution and survival, the scientists believe.
Scientists worked this out by flashing a light in rapid flickers in front of animals.
If the flashes are close enough together, an observer sees them as a continuous blur.
But researchers found that the flicker speed at which flashes seemed to merge together was different for different species.
‘A lot of researchers have looked at this in different animals,’ said Dr Andrew Jackson of Trinity College Dublin.
‘Interestingly, there’s a large difference between big and small species.
‘If you look at flies, they can perceive light flickering up to four times faster than we can. You can imagine a fly literally seeing everything in slow motion.’
The animals studied as part of the research covered more than 30 species, including rodents, eels, lizards, chickens, pigeons, dogs, cats and leatherback turtles.
'Having eyes that send updates to the brain at much higher frequencies than our eyes do is of no value if the brain cannot process that information equally quickly,' added Professor Graeme Ruxton, from the University of St Andrews.
'This work highlights the impressive capabilities of even the smallest animal brains.
'Flies might not be deep thinkers, but they can make good decisions very quickly.'
Some animals may exploit differences in time perception to their advantage, according to Dr McNally.
'For example, many species use flashing lights as signals, such as fireflies and many deep-sea animals,' he said.
'Larger and slower predator species may not be able to decode these signals if their visual system isn’t fast enough, giving the signallers a secret channel of communication.'
Dr Jackson added that this could also explain why time seems to speed up as we get older but move slower for children.
Time doesn't fly... if you're a fly! How the insect sees rolled up newspaper moving in slow motion and buzzes away from danger quickly | Mail Online