Ugh. No. Blake was not “citing research,” much less “vetted research.” The cites were to lecture notes. Which is a perfectly valid cite, just not “vetted research.” The real issue is that he was misinterpreting what his cites actually said. The cites were discussing scale effects, and how they cancel out when you calculate jumping height. That’s useful to explain why a flea the size of a human can’t jump hundreds or thousands of feet in the air, but only “about a meter.” Man-sized cats can jump only “about a meter” also, but **Blake **was reading a level of accuracy into his cites that was never intended to be there.
And though multiple people were “citing something they’d seen personally,” it certainly wasn’t “everyone else,” as more than one person pointed out the issues I mention above. Your characterization of the thread as “a case of vetted research vs some eyewitness testimony” is probably how Blake would also characterize it, but that characterization is factually incorrect. Your impression that it is so likely comes from Blake’s rather wordy defense of his own ignorance, which is somewhat similar to the subject of this thread.
Eh. Having lived with house cats for nearly twenty years, IMO it’s silly to suggest that they can’t jump over a meter when of a mind to do so. In point of fact, I keep their food on a countertop just a touch under a meter (about 38 inches) and they routinely clear that height without having to drag themselves up. (I also have a cat who has, on occasion, leaped into a large open-topped rabbit cage easily 42 inches. The rabbit Does Not Like This.)
Okay, that’s what I get for assuming things without actually looking at the links. But still, the point is, he was talking about what experts say after research, while everyone else was saying how they feel after trying to remember what they’d seen.
I’m confused by something here. Do you think a tiger can jump sixteen feet or not?
How do you measure the height of a jump anyway? Is it just how high the lowest part of the body is at the top of the jump? (“Top of the jump” being defined as the point in the jump where, whatever the lowest part of the body at that point is, its higher than the lowest part is at any other part of the jump?)
**Blake **was talking (primarily) about what physicists teaching undergraduate courses have to say about scale effects, and how animals orders of magnitude difference in sizes all jump to similar heights. Characterizing that as “what experts say after research” is misleading, given that most of the experts had a general rather than specific expertise, and the discussion was intended to be about scale effects rather than physiological differences of different species.
Of the “everyone else,” some people were offering anecdotal evidence, others were offering counter-cites from zoos and such - cites which were no less valid than what was being offered by Blake.
I dunno. Maybe, maybe not, maybe it depends on how you define jump. Why does it matter?
Hi Frylock. Again, I’m not someone with strong analytic abilities, but here’s my rough definition of jump height: The difference between the height of the jumper’s center of gravity at the instant the jumper leaves the ground, and the maximum height reached by the jumper’s center of gravity.
And that answers your question not at all. How do you determine the center of gravity? However in the videos such as the nice cougar video you can get a good idea of how high the cougar’s back legs get off the ground in the fully extended position. And you can tell when the cougar’s pelvis has stopped going up, even though the legs are swinging up higher
So, I guess slow-motion video analysis is the best method of determining jump height.
Some more anecdotal video evidence: Sandwich, the Amazing Jumping Cat. The vid isn’t nearly as good as the cougar clip, but the cat is right next to a human which makes for easier measuring. Between the 46 and 48 second mark, Sandwich’s head goes from groin height (with back feet still on the ground) to about shoulder height.
As a point of information the Wikipedia article on the Galago says:
[INDENT]Galagos have remarkable jumping abilities, including the ability to jump up to 2 metres (6.6 ft) vertically. This is thought to be due to elastic energy storage in tendons of the lower leg, allowing far greater jumps than otherwise possible for an animal of their size.[/INDENT]
The footnoted reference paper isn’t shown as being available online.
How that affects the various discussions in that thread I won’t try to analyze.
I’ve been searching for an inappopriately long time for videos of jumping housecats. The only one I could find that even comes close to looking like a jump of more than a meter was one where the cat jumped from a toilet seat to the top of the shower curtain–but watching carefully (and it definitely takes a second or third carefuly viewing) you can see that it grabs the rod and pulls itself up.
If cats can jump higher than a meter, and if there are “my cat can jump high!” videos on the internet, it’s very surprising to me if there are no videos of cats jumping higher than a meter.
Even if it grabbed the rod and pulled itself up, the difference in height between a toilet seat (about fifteen inches, according to a quick search) and a shower curtain rod (about seventy-two inches, ibid) still leaves nearly 1.5m. If we’re measuring a jump as the length from the starting position of the back feet to the final position of the back feet, that’s still a meter for reasonably-sized cats.
Oh, I see. The scale effects citations discuss the jump height of various species from fleas to horses, whose body-sized length scales span 3+ orders of magnitude. A common scale misconception is to assume that a flea, which can jump something like 200X its own body length, could be scaled up to man-size and jump hundreds of meters in the air. But that’s not true: the flea would only be able to jump “about a meter.”
But “about a meter” is an order of magnitude statement, a height distinguished from 10 or 100 meters, not a precise measurement. Two meters is “about a meter.” Three meters is “about a meter,” particularly when you recognize that physiological differences between species will affect actual performance.
But I would think that the farther you get from one meter, radically fewer species would be able to perform that well. Five meters sounds like it’s really pushing it to me, particularly if you specify an unaided jump straight in the air, measuring total center of mass motion starting from the point when the feet leave the ground. In fact, three meters sounds like it’s pushing it to me, but that’s just based on intuition, not any hard facts.
If one witness picks Frylock out as the guy who robbed the bank I might not
give the testimony full credit. If 10 witnesses do so then I am going to think
Frylock needs to spend a few years in jail.
One eyewitness may be unreliable, but there are millions of cat-owners.
A huge of majority of which never said they saw a cat raise its center of gravity over a meter.
I mean for all I know cats can do it. But I haven’t found any actual evidence that they can other than reports from people predisposed to interpret what they’ve seen that way even if what they actually saw wasn’t a case of it.
That’s been addressed–the animal apparently has a special mechanism which stores energy over time and releases it for the leap. Blake was of course talking about jumps that don’t involve such energy storage mechanisms.
