Flies See the World In Slo-Mo, Say Researchers

An anonymous reader writes "'The smaller an animal is, and the faster its metabolic rate, the slower time passes for it, scientists found. This means that across a wide range of species, time perception is directly related to size, with animals smaller than us seeing the world in slow motion.' No wonder it took so long to grow up!" Here's the original paper.

Comments

Seniors see the world at blazing speeds

[Russ1642]

Sitting in the left lane going ten under the speed limit while the world screams by.

Re:Seniors see the world at blazing speeds

[dpilot]

Actually no. He's quoting the "pediatrician's rule of thumb", approximately.

Final height as an adult can be guessed by doubling a boy's height at 2 years, or a girls height at 18 months. Worked pretty well for both of my kids. (one of each)

Re:Seniors see the world at blazing speeds

[Solandri]

You joke, but I really think there is something to this.

When I was in first or second grade (1970s), the U.S. was in the middle of its metric conversion program. We were taught the size of a cm vs an inch, the weight of a gram vs. an ounce, etc. I came up with some equivalencies on my own to help me remember everything. A cm was about the width of my thumb at the time. An inch was the length of of my folded middle finger. A foot was about the length of of my fist to my elbow... (Obviously none of these work anymore because I was a lot smaller back then.)

Then we got to time. How long is a second? I tried counting "one one-thousand, two one-thousand" in my head like my teacher had suggested. It was too fast. I eventually came up with a "one (pause) and a two (pause) and a..." chant which (for me) accurately measured out each second.

I'm in my 40s now and if I try my old timing chant, it's too slow. Each second I count takes nearly 2 seconds real-time. The "one one-thousand, two one-thousand" mnemonic now works for me. This also matches my memories of staring at the second hand on the clock in class, waiting for the time to pass so school would end. I watch a clock (with a second hand) today and it seems to move almost twice as fast as I remember it moving back then.

My timing hasn't changed. I started playing piano in second grade. When I listen to old tape recordings of songs I still play, my tempo hasn't changed. The only explanation I can come up with is that my verbal and visual processing has slowed down with age. My piano playing has had the tempo reinforced every time I hear a recording of a piece, so it gradually (to my brain) sped up over the years to keep pace with my slower processing.

Makes complete sense

[GodfatherofSoul]

I remember as a kid watching a sparrow fly through a chain link fence and thinking that kind of reaction time was impossible. Plus, when you look at the reaction time of smaller animals to a perceived threat (you trying to sneak up on one), we can't come close at our size.

Re:Makes complete sense

[Ogive17]

You haven't seen my reaction time when I spot a spider.

Re:Makes complete sense

[Jason Levine]

I've thought of this too every time I try to swat a fly that found its way into my house. Flies seem to be able to do aerial maneuvers in reaction to threats that you would think impossible given their tiny brains. I often wondered if it wasn't that they were so quick, but that (to them) I was moving so slow. This might also explain why they seem to like buzzing right by me when I'm trying to kill them. They're taunting the big creature moving in slow motion. "You think you can catch me? I'm right in front of you. Nope. Now I'm over here. Over here. Over here. Too slow. Try and catch me." *zips into another room*

Re:Makes complete sense

[Anonymous Coward]

To kill flies (on a horizontal surface) with a high success rate, slowly move your hands near the fly so that your hands are about three inches above the surface and six inches apart. You should have the fly centered between your hands. That's the hard part-- getting into that position without spooking the fly.

Now, as fast as you can, clap your hands once and leave them together. Usually the fly will fly straight up between your hands. Unfortunately, killing the fly may require some mashing your hands around, or you can catch-and-release the fly to the outdoors assuming you can get outside without the use of your hands. It is sometimes possible to maneuver the fly around so you can get it pinched between two fingers to free up one of your hands.

Have you ever tried to swat a fly?

[Anonymous Coward]

You practically have to be on meth to catch one. And then the problem is with the spiders in the corners of your eyes.

Re:So Ents see life fly by?

[ekgringo]

I think you've got it backwards and Tolkien was right. As I remember, the Ents were complaining that the much smaller hobbits were being too hasty. Their Entmoot took several hours just to get through the meet & greet stage and it took them a day or two to come to a decision to do something.

Re:So flies are 4 times as twitchy as we are?

[omnichad]

Fly swatters flick faster than we can move our own hands. In other cases, we can strategically hit one step ahead of where we think they'll be.

Re:Within a species?

[Oligonicella]

Correct. For those who don't believe this, go out in a field and catch a rabbit bare handed.

As for the bronto, it's not really possible to know because we do not know what type of myelin sheathing they had on their nerves. It could be that their nerves propagated signals at 2mph (Iow end) or 200mph (highest). We don't know.

If 2mph, a sixty foot animal's brain would get the signal in about three seconds, at 200 mph at .03sec. Or anywhere in between.

Not really relevant though as the bronts had ganglia along their spines that did the reactions. Say the tail was 25 of that 60 and you have a little under a second low end perception time.

Re:So flies are 4 times as twitchy as we are?

[Cyko_01]

just because their brain processes things faster it doesn't mean they can move fast enough to get out of the way. Consider the size of a flyswatter in relation to the size of the fly

I thought this was well known

[wonkey_monkey]

I honestly though this was common knowledge already. Maybe I'm a little slow.

Re:So flies are 4 times as twitchy as we are?

[c0lo]

Then why is it ever possible to swat a fly?

Why... that's elementary! The flys are so bored to death by watching you in slo-mo, some will fall asleep.

The fly part is not new, the correlation is

[amaurea]

I skimmed through the paper itself, and it seems like flies are only mentioned in passing. The paper mainly concerns itself with vertebrates, and their new result is that they have tested the hypothesis that smallness of body and high metabolism correlate with the flicker fusion frequency of the visual system, i.e. how fast a light has to flash before the flashing becomes invisible. They find the hypothesis to hold (like your teacher suspected).

The fact that flies have a very high flicker fusion frequency (270 Hz vs. 60 for humans under ideal lighting), has, however, been known for a long time, and is not a new result from this paper. In fact, houseflies have 2.5 times higher flicker fusion frequency than even the smallest and most active vertebrates tested in this study (actually, looking at their graphs, it seems like the housefly would be a huge outlier if they had included it).

The flicker fusion frequency is related to, but not the same thing, as how often an image needs to change in order to be percieved as motion. This difference is why 50-60 Hz CRT screens are annoyingly flashy to many, while 25 fps movies look fine. In the latter case, each image only changes slightly.

For a fly, watching a 25 fps movie would probably be similar to watching an 8 fps movie for a human.