How high could I jump if my legs were as powerful as a house cat's hind legs?

[Blake]

That’s nice. I didn’t say anything about what you’d said about running starts. I said your cites say nothing about running starts.

My mistake then. Apologies.

Care to point out why this whole running start thing is even relevant?

For the same reason that it’s relevant in high jumping. A running start allows an animal to throw its weight around a lot easier.

Please explain why we should think your cites actually support your claim.

Because they state outright that cats can only jump to about 1 metre. They state outright that humans and cats can jump to about the same height.

I don’t think I understand the question. They support my claim because the say exactly the same thing as my claim. They agree with my claim. How else can a reference support a claim?

[Gorsnak]

*Originally posted by Blake *
For the same reason that it’s relevant in high jumping. A running start allows an animal to throw its weight around a lot easier.

But this is in violation of the laws of physics. As I said, horizontal velocity in no way impacts the amount of energy which is required to elevate a mass. Horizontal velocity can be deflected upwards with a ramp, but in the case of things not on wheels, or air cushions, or other low-friction devices, this doesn’t work. Hence, running starts are irrelevant. High jumpers use a running start in order to i) place their bodies in a better position to apply downward force with their legs, and ii) to store the kinetic energy required to perform aerial contortions. Primarily the latter. Note that these contortions do nothing to move the body’s centre of gravity higher - they only arrange the body in such a fashion that the portion of the body directly over the bar is higher than the body’s centre of gravity. Cats, as many people have said, prefer to leap from a crouching position, not with the aid of a run-up. Given what I know about feline physiology, I strongly suspect that a run-up would actually decrease the height they could jump, as they wouldn’t be able to use as many muscle groups simultaneously as they can from the coiled crouching position.

Because they state outright that cats can only jump to about 1 metre. They state outright that humans and cats can jump to about the same height.

Point me to where they say that, please. Your first cite says "This is why grasshoppers, cats, people, and horses can all jump about a meter. " This is (A) exceedingly broad and vague, (B) a lecture in physics, not biology or zoology, © addressing the question of the relevance of size to jumping, and nothing else. I submit this cite isn’t even trying to make a specific claim regarding the leaping ability of cats. Your second cite doesn’t mention cats, but does mention that leaping ability will not vary with size, though it will vary with differences in muscularity and skeletal structure. Insofar as this is relevant at all, it supports those claiming better jumping from cats, as cats are clearly physiologically specialized for jumping, while humans are not.

Your third and fourth cites come back as 404 errors after repeated attempts to access them, but the portions of them which you cite are merely repetitions of the ‘size is irrelevant to the height of the jump’ mantra, which is of course irrelevant to the discussion at hand. No one is arguing that size is relevant. People are arguing that physiological differences are relevant.

So please, explain to me why your cites do anything to support your claim that no animals can jump higher than “about a metre.”

[Blake]

High jumpers use a running start in order to…… store the kinetic energy required to perform aerial contortions.

And how does that differ from “A running start allows an animal to throw its weight around a lot easier”?

So please, explain to me why your cites do anything to support your claim that no animals can jump higher than “about a metre.”

“h tends to be constant irrespective of the animal.”
“Variations among individual fleas, horses or people are large, but healthy members of any jumping species raise their centers of gravity about one meter when they leap.”

You apparently cannot understand that a reference stating that height remains constant irrespective of the animal means that height remains constant irrespective of the animal.

You apparently also cannot understand that a reference stating that all members of any jumping species raise their centers of gravity about one meter when they leap means that no members of a jumping species raise their centers of gravity more than about about one meter when they jump.

Since that is the case I give up. You are beyond my ability to help.

[netscape_6]

bolding mine

http://www.wtv-zone.com/BigCats/serval/servals4.html

Like the caracal, the serval will leap into the air to swipe at low-flying birds, it’s long legs enable it to leap 10 feet off the ground. It has also been seen hooking fish out of streams. Reptiles, frogs, lizards, and invertebrates make up any shortfall in the diet.
They tend to wander farther afield then most cats in pursuit of prey, covering up to two and a half miles each night.

http://www.explorit.org/science/cats.html

Serval: Felis serval
The serval is found in several areas in Africa, mostly in the mid latitudes of the continent. These are tall cats with a small head, large ears, and short tail. The coat is yellowish-buff lighter across the belly, and with some blackish markings. The serval hunts in grasslands and other open country generally in the early morning or at dusk and feeds on rodents, birds and lizards. This cat can run fast over short distances and is** capable of jumping 3m (10ft) straight off the ground** into the branches of a tree. It purrs like the domestic cat and communicates with a load, high-pitched call.

http://www.robstewartphotography.com/facts/Serval.asp?i_id=424

Lifestyle

Servals are extremely adaptable. They can hunt either day or night, although they tend to be nocturnal, hunting only in the early morning, late evening or at night, mainly to escape the African heat. They dwell mostly on the ground, but are adept tree climbers as well. They have extremely long legs, a long body, a small head and extra large ears. The serval is reported to be able to hear a rodent moving as far as 20 feet away. They can also hear their prey underground and their long legs enable servals to reach into a burrow to get at the rodent inside. Rodents make up the major portion of the serval’s diet, making the serval a less annoying predator to farmers than other wild animals, despite the fact that servals occasionally prey on farm animals. Usually, however, they stick to small animals, including birds, reptiles and fish, when there are no rodents present.** Servals can leap as high as 10 feet off the ground to catch a bird,** and have a unique style of pouncing straight up in the air, and then directly down on its prey. Servals have a very high success rate when hunting. Most cats get prey in one of ten attempts—servals have a success rate of 50%. Usually a solitary animal, servals sometimes join up to hunt down larger prey such as a small antelope. Capable swimmers, servals are fond of water and live near water sources such as marshes or rivers surrounded by forest and grasslands. Serval fur is sometimes sold as cheetah or young leopard fur, both of which are endangered and protected animals.

http://www.pacifier.com/~jtsmith/fs-data.htm

Servals in the wild are known to be highly specialized rodent catchers, Servals use their large ears to catch their prey in tall grass. They are also known to eat frogs, lizards, birds and insects. Servals in** the wild have been observed to leap as high as 10 feet in the air to knock flying birds to the ground,** where they use their long legs to deliver a “knockout punch” to stun their prey. The Serval has large, funnel-shaped ears that swivel to pinpoint the source of a noise. It also has two white markings on the back of each ear (white flashes) which are used when communicating with other cats. For example, to express aggression, the Serval’s ears will be held upright. This serves as an aggressive message to other cats. The white flashes are also used to help kittens or cubs follow their mother in dark forests or at night.

The Servals habitat ranges from dry open plains grasslands through w

http://www.serval-cats.com/

Hunting Techniques: The serval is a specialised hunter and has very sophisticated hearing to assist it in its task of hunting it’s small prey. The long legs of the serval allow the cat to see over the tall savannah grasses for signs of movement of their prey. In short bursts the cat is also able to reach high speeds and is able to jump up to 10 feet off the ground to catch birds.

http://www.kirshner.org/animals/savannah.php

The Serval hunts rodents, lizards, and amphibians on the ground, but they can also climb trees to hunt birds. This cat has quite sophisticated hearing to assist it in pinpointing its small prey. Notice their large, round ears. Servals have uniquely long legs which serve to aid in prey detection, enabling the cat to see over tall grass for signs of movement. The Serval will leap vertically to pounce down directly onto its unsuspecting prey. Servals are also able to reach high speeds in a short run and are capable of jumping up to 10 feet off the ground to catch birds. As you look at the markings on Savannah, notice her circles and stripes. The serval is a unique cat because of its coat.

many of those cites mention the 10 foot jump is for hunting birds. I have never seen a Serval hunt but House Cats hunt by either pouncing (which a cat, Serval or not, would have to get a lot closer then 10 feet to have much of a chance) or by leaping straight up and grabbing the bird right out of the air. One cite even mentions “Servals in the wild have been observed to leap as high as 10 feet in the air to knock flying birds to the ground”. Servals are close enough to house cats to interbreed and produce fertile offspring (cite) . So if Servals are close enough to house cats to interbeed then it seems likly that house cats would have some pretty good jumping ability of there own.

[Gorsnak]

*Originally posted by Blake *
And how does that differ from “A running start allows an animal to throw its weight around a lot easier”?

It differs in that the contortions, as I explicitly mention, do nothing whatsoever to increase the height of the jump. They only serve to put the body of the jumper in a position such that the portion of the body directly over the bar is higher than the centre of gravity of the entire body. I said this in so many words in my last post. Why must I repeat it?

Your cites are so broad and vague as to be useless. About a metre? What range does that cover? Within 10%? Within 50%? Within an order of magnitude? Without further qualifications, the statements are meaningless. Given the now outright flood of cites providing direct evidence that some feline species can do 3x better than “about a metre,” I can only conclude that “about a metre” means anything within a factor of 3. Frankly I have no idea why you think a rule of physics demonstrating that scaling both motive force and mass in direct proportion to one another will result in the height of jumps remaining constant in absolute terms rather than in proportional terms should mean that creatures with physiology specialized for leaping cannot leap higher than creatures without such specialization. I also don’t understand why you think physicists would know more about zoology than zoologists.

[Blake]

It differs in that the contortions, as I explicitly mention, do nothing whatsoever to increase the height of the jump. They only serve to put the body of the jumper in a position such that the portion of the body directly over the bar is higher than the centre of gravity of the entire body…

Which, if you had read the thread, you should realise is exactly what I said with respect to cats catching birds. Running jumps and contortions serve to put the body of the cat in a position such that the portion of the body directly over the bird is higher than the centre of gravity of the entire body.

I don’t think you have read this thread at all.

Your cites are so broad and vague as to be useless.

Whatever you reckon. University Professors seem to think they are useful. I’ll trust them over you.

[Gorsnak]

*Originally posted by Blake *
Which, if you had read the thread, you should realise is exactly what I said with respect to cats catching birds. Running jumps and contortions serve to put the body of the cat in a position such that the portion of the body directly over the bird is higher than the centre of gravity of the entire body.

I don’t think you have read this thread at all.

Well, you can say that, but you’ll be wrong. When leaping onto a fridge, fencepost, etc, the cat’s body remains in a more or less constant attitude. No contortions. When it’s leaping for a bird, any contortions are aimed at juxtaposing the cat’s mouth and the bird. They are nothing like the fosbury flop. In fact, your statement is ludicrous on its face. The portion of the cat’s body directly over the bird?!? Huh? The cat is jumping at the bird, not over it. How can you even suggest this with a straight face?

Whatever you reckon. University Professors seem to think they are useful. I’ll trust them over you.

Your professors are attempting to make a point about scale and jumping. They are not attempting to make a point about the leaping ability of any particular species. Physics, not biology. Are you going to respond to all those zoological cites or not? Observations trump theory every day of the week.

[Blake]

When leaping onto a fridge, fencepost, etc, the cat’s body remains in a more or less constant attitude. No contortions.

And no one has ever said otherwise. Isn’t that good?

When it’s leaping for a bird, any contortions are aimed at juxtaposing the cat’s mouth and the bird.

You know squat about cats. When attacking airborne prey, in fact almost any prey, cats hit with the claws and drag the prey to the mouth.

The portion of the cat’s body directly over the bird?!? Huh? The cat is jumping at the bird, not over it.

Oh I see. So a cat can use contortions to move parts of the body over a bird, but it can’t use those contortions to grab the bird. It has to just pass right over. Of course :rolleyes:

Gorsnak you bore me.

[Gorsnak]

*Originally posted by Blake *
**And no one has ever said otherwise. Isn’t that good?

You know squat about cats. When attacking airborne prey, in fact almost any prey, cats hit with the claws and drag the prey to the mouth.

Oh I see. So a cat can use contortions to move parts of the body over a bird, but it can’t use those contortions to grab the bird. It has to just pass right over. Of course :rolleyes:

Gorsnak you bore me. **

Whatever. You’re the one asserting that cats engage in fosbury flop-like behaviour, and it’s a ridiculous assertion.

Let me get this straight. You are now claiming that when the afore-cited servals leap 10 feet in the air to catch birds, they’re really only raising their centre of gravity by “about a metre”, but contorting themselves in such a way as to get portions of their bodies 10’ in the air? Is there are reason why you continue to dodge the 10’ serval cites and the 15’ cougar cites?

[Eleusis]

Blake, your cites are making a point about scale. A flea can jump three feet, and if you make it the size a of person, it can still jump three feet. A basketball player can jump three feet, and if you make him one hundred feet tall, he would still jump three feet. Nobody is disputing this.

But you are hellbent on ignoring differences in physiology that DO make a difference. A jackrabbit can jump higher than a turtle. A cat can jump higher than a person.

This study, using 18 domestic cats, found a correlation between hind limb length, fat mass and jumping performance (Take Off Velocity).

These results suggest that increasing limb length does positively affect TOV … The positive effect of longer limb length on TOV will be decreased, however, in animals with high body fat contents.

Differences in physiology within one species are even greater throughout the animal kingdom.

Interestingly, while my cite does not provide the height of the highest jump, it does say maximum recorded Take Off Velocity was 410.8 cm s[sup]-1[/sup]. Can somebody please do the math to calculate the highest point of the cat’s center of mass would have reached?

[Desmostylus]

Originally posted by Blake
**You apparently cannot understand that a reference stating that height remains constant irrespective of the animal means that height remains constant irrespective of the animal.

You apparently also cannot understand that a reference stating that all members of any jumping species raise their centers of gravity about one meter when they leap means that no members of a jumping species raise their centers of gravity more than about about one meter when they jump.

Since that is the case I give up. You are beyond my ability to help.**

Originally posted by Blake

about 4 foot doesn’t seem unrealistic

I’m quite happy to accept that. In fact I never said any differently. The dispute was with the OP and numerous anecdotes of cats jumping 6 feet. Once we get to 5’ we are talking another 50% height, which is no longer equivalent. 6’ is over an 80% increase.

Vertical jumping in Galago senegalensis: the quest for an obligate mechanical power amplifier

In assessing the mechanical capabilities of musculo-skeletal systems, the analysis of maximal jumping is exemplary, as the natural demands imposed on the system are maximized too (see, for example, Sellers 1992). The involved stresses are high and impact-like (cf. Bennet-Clark 1976, 1977), and the energy required for every new leap has, theoretically, to be delivered de novo by the muscles (see, for example, Bennet-Clark 1976, 1977; Gunther et al. 1991; Crompton et al. 1993). In his theoretical analyses on the energetics of jumping and the effects of size, Bennet-Clark (1976, 1977) noted that animals, perfectly capable of delivering the jumping energy instantaneously, can have difficulties when the rate at which the work has to be done to attain a certain height exceeds the muscle power. In other words, instantaneous power output capabilities of muscles can constrain jumping performance. This is primarily true for the smaller animals, as the power that is instantaneously required is directly proportional to the available acceleration distance (i.e. leg length in most of the cases). Therefore, jumpers might benefit from a mechanical power amplifier that releases previously stored energy at an increased rate (see, for example, Bennet-Clark 1976, 1977; Emerson 1985; Alexander 1992).

The bushbaby Galago senegalensis (Lorisiformes) is well-known for its enormous jumping capabilities (see, for example, Hall-Craggs 1964, 1965, 1974; Jou¡roy & Gasc 1974; Jou¡roy et al. 1974; Gunther & Niemitz 1982; Jou¡roy & Gunther 1985; Gunther 1985, 1989; Jou¡roy 1989; Demes & Gunther 1989; Gunther et al. 1991, 1992; Sellers 1992; Crompton et al. 1993). The highest reliably reported vertical jump for a 0.250 kg animal is 2.25 m (Hall-Craggs 1965), which corresponds to a displacement of the centre of gravity during the flight phase of approximately six body lengths (tail not included). Based on this information, and assuming a constant acceleration during the push-off, Bennet-Clark (1976) estimated a specific power output of 2350 W per kilogram of muscle, provided that the jump is instantaneously powered by the contractile components of the muscles. (It was assumed that 40% of the body mass consists of muscles involved in jumping.) Such a value is well above the maximally attainable output deduced for vertebrate muscle (for example, 860Wkg[sup]-1[/sup] theoretical maximum for pigeon flightmuscles (Pennycuick & Parker 1966); 270-371 Wkg[sup]-1[/sup] calculated and measured for frog hindlimb muscles (Lutz & Rome 1994; Marsh & John-Alder 1994); 380 Wkg[sup]-1[/sup] for typical fast glycolitic fibres (based on data presented in Herzog (1994))).

Game, set and match. Now go away. :rolleyes:

[Critical1]

“The height all animals can jump to is about 3.3 feet,”

ok this is bs, not to nitpik but if you can find me evidence that elephants can jump even 3 inches I will be one startled Doper.

so my guess is the 3ft the elephants cant jump was given to the cats.
that and I am naming my next cat blake…maybe

[Blake]

ok this is bs, not to nitpik but if you can find me evidence that elephants can jump even 3 inches I will be one startled Doper.

FFS, do you bother to read the thread before taking quotes out of context? Did you read that reference? Did you see the bit where it said “jumping species”? You yourself admit that elephants are not a jumping species so what the hell are you talking about?

[Mangetout]

Good find Desmostylus; did you employ any special or elaborate searching techniques that you’d like to share?

[dylan_73]

Desmostylus: Thank you.

[Desmostylus]

Thanks, Mangetout. No special techniques, just 15 minutes of free time.

No worries, dylan_73.

[jjimm]

Ditto on the thanks.

This has been so painful.

[Mangetout]

I still intend to carry out the cat experiment and try to capture some video footage; I’m pretty sure that, given the right motivation(whitebait), I will be able to coax my sister’s cats to jump up onto the shed roof, which is at least seven feet above the ground.

Watch this space.

[Desmostylus]

Having (hopefully) cleared up this obscene hijack, perhaps we can get back to the OP’s question.

[Jman]

Desmostylus, you beat me to it…I found that article this morning and was all set to post it when I got home. If that article doesn’t convince him, then he has no hope. It even clearly states that it is referring to the animal’s center of gravity.

Like he said…game, set, match.