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Friday, January 20, 2017

How much force does it take to break a bone?

We couldn’t find any clear answers to this question, because a lot of factors need to be taken into account. Even though according to The Handy Anatomy Answer Book by Patricia Barnes-Svarney and Thomas E. Svarney, one cubic inch of bone can theoretically withstand the weight of around five pickup trucks, and is ounce-for-ounce stronger than reinforced concrete, most of us know someone who has broken a bone, because bone will still break on impact. Charles Q. Choi, writing for LiveScience, says that this is because force is generally delivered quickly, and David Biello, writing for Scientific American, adds that the angle of the force affects whether the bone will break, and what kind of fracture it will be.

On UC Santa Barbara’s Science Line, the writers explain that bones are designed to withstand certain types of stress – arm and leg bones, for instance, have curves to them. This makes them able to resist force from certain directions, but vulnerable from the others.

According to DK’s Human Body, a transverse fracture, where the bone breaks straight across the width, is usually caused by a direct or angled force, whereas a comminuted fracture, where the bone breaks into several fragments, is caused by direct impact. A greenstick fracture, where a bone bends and cracks but does not break all the way across, is most common in children, whose bones are still relatively flexible. As we age, our bones become more porous and fragile, and fractures become more likely.

Friday, January 6, 2017

Why does my cat drop his toys in his water dish?

Drowning toys in the water bowl isn’t uncommon behavior in cats, but we couldn’t find one definite explanation for it. Arnold Plotnick, a veterinarian blogging at, and S. Hartwell, a writer for, both offer some guesses.

Our patron’s cat may be trying to store the toy in a safe place. If the toy is a particular favorite or if they’ve just finished with it, they could be “putting it away” in their food-and-water area, which they may see as a safe and central part of their territory. Wild cats will take their prey back to their nest, and the indoor cat dropping its toy in its dish could be following the same instinct.

Some cats like to play in water. Hartwell relates stories of cats that liked to pat the water with their feet and then pop the bubbles or watch the ripples, or a cat that would drop catnip in the water and watch the leaves float around. Our patron’s cat could be playing at fishing, or they could just like the texture of the wet toy.

According to John Bradshaw and Sarah Ellis in the books Cat Sense and The Trainable Cat, cats treat their toys like prey. They often like toys that resemble creatures they would hunt, and treat them differently depending on the size. They will be more cautious, for instance, with rat-sized toys, and tend to hold them at arm’s length rather than close in their front paws, as rats are more likely to fight back. Cats also tend to get bored with a toy unless they can damage it – a resilient toy that doesn’t show any sign of being “killed” indicates that it’s not really prey, or, if it is, that it’s too hard to subdue. As Bradshaw believes that cats think they are hunting when they play with toys, he would probably put the water-bowl behavior down to some kind of hunting instinct.