Physicist Calculates Trajectory of Tiger At SF Zoo 713
KentuckyFC writes "Is it really possible for a 350-pound tiger to leap a 12.5-foot barrier from 33 feet away? (Said another way: a 159-kg tiger, a 3.8 m barrier, and 10 m away.) A physicist at Northeastern University has done the math, a straightforward problem in ballistics, and the answer turns out to be yes (abstract on the physics arXiv). But I guess we already knew that following the death of Carlos Souza at the paws of Tatiana, a Siberian Tiger he had allegedly been taunting at San Francisco zoo at the end of last year."
35mph sure - but not uphill! (Score:2, Informative)
Re:Never mind the physics (Score:5, Informative)
Actually, I believe they DID kill it with a shotgun - just not loaded with birdshot. Slugs. You don't use a high powered rifle in a setting like that, or bet your life on a handgun. A 12-gauge with slugs will definitely kill something that sized, no problem.
Re:Hmm (Score:5, Informative)
Re:Call in the lawyers (Score:3, Informative)
Yes, the zoo was negligent. It should have known the safe parameters for a tiger enclosure.
However, in the law, there's a doctrine called comparative (or contributory negligence). This means that where two people are negligent and one gets hurt, his or her recovery is reduced by his or her own proportion of the fault.
F'rex: A jury looks at this situation and says "Boy, the zoo sure was negligent, they should have built a higher wall. But boy, did this guy act stupidly, entering the enclosure and taunting that tiger. We're going to split the fault between them. And his total economic worth (over the rest of his life) was $800,000 (since he clearly wasn't that bright)."
Then the judge comes along and says--"okay, the award is $800,000.00. But the moron was 50% at fault. Therefore, his family gets $400,000.00."*
* Actually, in some states, he gets nothing, because his fault was not less than that of the other idiot.
But you can't argue that the zoo's not at least partially at fault. It clearly had an enclosure that wasn't adequately designed to keep the tigers in. The fact that the person who got hurt provoked the tiger doesn't lessen the fact that the enclosure failed to do what it was supposed to do.
--AC
A high school physics problem, good for an olimpic (Score:1, Informative)
However, in its present form the paper is not publishable in a scientific journal, much more should be done.
Re:Lateral velocity != jumping velocity (Score:3, Informative)
In any event given the maximum known speed of the tiger it should have been a simple matter to know that it was capable of jumping out of its "cage". Converting lateral velocity to highly inclined is called jumping perhaps you've heard of it. Also at 35 mi/hr the tiger wouldn't need as steep an angle as it could leap from farther away.
My cats at home don't seem to have a problem with going from a near full run to near straight up if they want to, enough so that I can easily imagine a large cat going from full run to only 55 degrees.
Not exactly... (Score:3, Informative)
Still, it's a damned shame. For the tiger, that is. Not for the drunken nimrod who was teasing her, going so far as to pass the barriers erected to keep the public back from the animals, according to the evidence found at the scene.
What a load of crap. (Score:4, Informative)
There does appear to be problems with the way the SF zoo is being operated now, but this particular case is a long standing condition that neither the public caretakers, private owners, nor the AZA made any effort to fix.
Re:A word on tiger behavior (Score:5, Informative)
1. Tigers have practically no natural instincts when it comes to being predators. Tigers in the wild have to be trained by their mothers how to do things like hunt, climb trees, eat properly, etc. These are things that a human cannot teach. Therefore, any tiger born in captivity cannot be released into the wild and survive. It simply does not have the skills necessary.
2. Look at the way these tigers were trained. Just two bites, and then they get their kill. They can eat it whenever they want. Now observe the way that they killed the 40 animals released into the zoo. Killing frenzy? Yes. By all definitions, that's a killing frenzy. But was that killing frenzy a product of their instincts? No! If you've done any research or paid attention to anything about tigers, you would quickly learn that my first point is quite correct and proven. Tigers have no natural instincts when it comes to killing their prey. Again, observe how it was trained to hunt and how it slaughtered the wild animals: in the same fashion. This is because it knows no other way to kill animals. You say, 'welcome to the world of wild animals.' I say, 'welcome to the world of tigers not being properly trained by their human caretakers.' All tigers are in captivity are oversized house cats, and about just as aggressive. This means yes you need to be careful, but it means no they're not just going to kill you because they're hungry.
3. Which leads me to my third point. where you say:
4. You know nothing of tigers. (See opening sentence)
Re:Never mind the physics (Score:2, Informative)
Hunters in Africa (whom I think are total losers for shooting animals instead of just shooting pictures of animals) don't carry shotguns, with or without slugs. They carry high powered rifles. The term "elephant gun" refers to just such a gun.
Usually the only other gun a cop will have with him, besides his semi-auto pistol sidearm, would be a shot-gun. Shot-guns are nice in Urban settings as they don't over-penetrate walls and accidentally kill bystanders who might be standing a ways away or in another room/house/building. In any case, if they did use a shot gun to kill the Tiger it was only because they didn't have a high powered rifle with them.
Re:Hmm (Score:4, Informative)
Until someone sets up a camera.
And then some thin mesh wire.
Don't assume that animals are dumb because they live in water
Projectile motion (Score:3, Informative)
Clearing a 12.5 ft barrier at 33 ft away just didn't feel intuitively possible, so I found a projectile physics toy to test it:
Projectile Motion [virginia.edu]
In SI, the values are 12 m/s at an angle of 55 degrees with a mass of 160 kg, clearing a 3.8 m barrier at 10 m away.
I had some recollection that 45 degrees was the optimum launch angle, but apparently that maximizes distance, not height. Mass doesn't factor into the calculations unless you include air resistance, which the paper neglects.
The surprisingly sensitive factor is launch velocity. Lose 1 m/s and you smack into the middle of the wall. Gain 1 m/s and clear a 16 ft barrier, landing 52 ft away. It still seems phenomenal to actually get a tiger's horizontal velocity redirected at 55 degrees.
We had a long discussion about this in torts.. (Score:3, Informative)
Basically, the subject here is one of civil liability. The kids - all under the age of 18 - all had alcohol and marijuana in their bloodstream at the time of the incident (according to police reports). Their alleged taunting could be used against them, not to completely excuse the zoo from guilt (although they'll try), but to reduce the damages. Generally speaking as to torts, a jury can find a defendant partially liable for their own injuries.
I don't think there's too much question here as to the zoo's liability - they failed to build a wall capable of keeping the tiger in, and failed to keep their team of snipers (as per their own emergency plan) on the zoo during all times it was open. But, the zoo will pen its hopes on the theory above, arguing that the kids are at least partially liable. They do have a point - this tiger has certainly faced taunting in the past, and no results like this occurred. But the case for the kids, I think, is a much better. one.
The zoo knows it's trying to shoot the moon by removing full liability from itself, but they could have a reasonable shot at reducing the damages if it goes to court.
Re:Hmm (Score:5, Informative)
Re:Absolutely not surprising (Score:3, Informative)
Re:A lot (Score:1, Informative)
I assume anyone who has been bullied can sympathize with the tiger. "Tragically," for the idiots, they were not dealing with a peer, but an efficient killing machine whose only limitation was imprisonment - an obstacle that the tiger was finally pushed to overcome (for the first time in how many decades?).
I think what's most interesting in this case is that the tiger only attacked the three people tormenting it. The cops were forced to shoot, not when the tiger turned on them, but when it continued to attack its previous victim. That tiger wanted justice on three specific people.
They DID NOT have slingshots. (Score:3, Informative)
1) This is the same tiger (Tatiana) that attacked and seriously injured a zookeeper [sfgate.com] (Lori Komejan) who was only doing her job just one year ago. The zoo initially blamed the attack on the zoo keeper.
From a later article [sfgate.com]:
2) Zoo director Manuel Mollinedo is incompetent and demoralizing [sfgate.com]:
3) The zookeepers knew the wall was too low [sfgate.com]:
4) The police didn't find any slingshots in the cars or on the brothers, anything unusual on their cellphones, foreign objects in the enclosure, or any witnesses to back up any suggestion of taunting, and suspended the investigation [sfgate.com].
You can find more articles in the special section that SFGate has just for the tiger mauling [sfgate.com].
But people will believe whatever they want to believe, right?
Re:Never mind the physics (Score:4, Informative)
THERE WAS NO TAUNTING (Score:3, Informative)
Re:the tiger had superior knowledge of the situati (Score:3, Informative)
House cats can easily jump a 6-foot wall. I see it all the time here in Phoenix, where all our back yards are separated by 6-foot block walls, and it's common to see cats running around on top of them. This is for a cat which stands less than 12" at the shoulder and weighs 10 pounds or less. A Siberian tiger weighs 300-450 pounds. These animals are huge, and they're at least as well-muscled as a housecat. It makes perfect sense that they could jump over the wall at this zoo, given sufficient motivation.
If you've ever had the privilege of being very close to a large cat, you'd have a better appreciation of their size and musculature. I got to sit next to a cage with a mountain lion at a zoo once (one of the zookeepers let me in the back to see it); mountain lions aren't anywhere near as large as tigers, maybe about the size of a large dog, except that they have FAR more muscle than any dog of that height and length. I wouldn't ever want to tangle with a mountain lion; it's possible to fight one off if you have to, but many people have been killed by them in the wild, and many others severely injured. Tigers are much bigger than this; fighting with a tiger is like fighting with a bear. You're probably going to lose.
Re:They DID NOT have slingshots. (Score:3, Informative)
Here's from the initial article. If the cage was built properly, Tatiana would not have been able to stick her paws through the bars and grab the zookeeper.
From an article last month [sfgate.info] (emphasis mine):
The feeding enclosure was not designed and/or built properly. This was not Lori Komejan's fault. Lori was properly doing her job.
Design Problem was known for 40 years (Score:3, Informative)
The real reason the wall worked that long is that none of the tigers had previously felt motivated enough to jump at it. Apparently Siberians are more aggressive than Bengals, and maybe the two drunk kids pissed her off or just acted enough like prey or cat toys that she went for them. My cats sit on the couch looking out the window at Bird TV, and when one of them sees a laser pointer red dot he has to jump for it without thinking about it first (the other one says "Hey, stop wavin' that thing around".) And I've seen zoo leopards looking at the crowds, intensely tracking the smaller ones that get separated a bit from their herds; I'd feel much safer around tigers.