But so is time?
Have you ever wondered how hawks can react to their preys movements with such lightning speed, or how frustrating it must be to move as slow as a sloth? Research shows that each animal actually perceive time moving on different scales, so is relative to the creature.
Researchers studied the “critical flicker fusion density” of 34 vertebrates and found that body mass and metabolism are key influencers on how time is perceived. Generally speaking, the smaller an organism the faster its metabolism and the slower time seems to pass.
The critical flicker fusion density is the point at which a rapidly flashing light is seen as a solid unblinking light as the flashes merge together, and is an indicator of how fast the eye is processing images. The higher the frequency of flashing seen, the higher the resolution, and the slower time appears to move.
Credit: Daily Mail
“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” says researcher Prof Graeme Ruxton, but this is exactly what happens to the tiger beetle. This beetle actually runs faster than its eyes can process, essentially running so fast it blinds itself. To overcome this they have to stop every now to re-evaluate the position of it’s prey and confirm or adjust. Considering their top speed is around 5mph covering 120 body lengths a second while the fastest humans can do around 5, it is small wonder the world becomes a blur.
Being faster than your hunter or prey is essential to survival, either in speed of movement or in reactionary speed. A predator that hacks the time perception system and uses it to their advantage is the Swordfish.
A team of researchers found that the Swordfish has a highly specialized heating system that specifically warms the eyes and brain up to 10°C–15°C above ambient water temperature. This heating allows them to process images up to 10 time faster, essentially slowing time down and making tracking their prey and reacting more effective.
An unrelated but amusing fact is that contrary to popular belief swordfish do not use their “swords” to spear their prey, but swing it around to stun or injure them before eating them.
A common saying I hear a lot as a dog owner is how each human year equates to 7 dog years, and it turns out their is a grain of wisdom in this. Dogs can take in visual information at least 25% faster than humans, so a human year is actually perceived longer for dogs, perhaps not as long as 7 years though.
It is interesting to think about how despite how us humans view the world, it can be moving at a completely different pace to another organism.
I have been writing a few big articles that I will publish post holiday (this backpacking biologist is off backpacking again!), but I thought I would trial a series of “short” articles when the more in depth articles are being worked on. Let me know what you think!