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How come your reflection in the bowl of a spoon is upside down? asks reader Matthew Wiegert.
An ordinary mirror is made by coating one surface of a piece of glass with a thin layer of metal, like silver or aluminum. It’s this shiny metal that reflects your image. So a shiny, scratch-free metal spoon, such as one made from stainless steel or polished silver, makes a good mirror, too.
When you stand in front of an ordinary flat mirror, light zooming through the room bounces off your body and hits the mirror. The mirror obediently reflects the light back to you, in neat, parallel rays. So you see an image of yourself. But think about it, and you’ll realize there’s something strange about the image. Since a flat mirror reflects exactly what is put in front of it, the mirror image reverses your right and left sides.
Something even stranger happens with the reflection from a spoon. Your image may be distorted in a number of ways, from size to shape. And you may even find that you’ve been flipped upside down. That’s because the bowl of a spoon is curved rather than flat, like a funhouse mirror, or the rear-view mirror mounted on the side of your car.
Mirrors that curve away from the viewer, like the inside bowl of a spoon, are called “concave.” Depending on an object’s distance from the mirror, a concave mirror can make objects look bigger, wider, and shorter. A shaving or makeup mirror is slightly concave, showing you an enlarged image of your face when you’re close to the surface.
Mirrors that bulge toward you, like the back of a spoon, are called “convex.” They make objects look smaller, taller, and skinnier. Rearview mirrors on cars are convex. Because of the way they shrink images, convex mirrors allow the driver to see more of what’s on either side of the car.
Why all the distortion? Look at yourself from in front of in a curved mirror, and the light that reaches your eyes is coming from many angles. Curved mirrors reflect light at odd angles. Look at the bulging back of a spoon, and light from the top bounces up, while light from the bottom reflects down. This means that light from the top of your head will bounce up, while light from the bottom of your face will bounce down. The result: Your face is right-side up, but it looks longer and skinnier.
But the caved-in side of the spoon is another story. Light bounces upward from the bottom of your face as it hits the bowl’s curved bottom. And light from the top of your face reflects downward from the curved top. The result is an inverted image: You, upside down.
By varying the distance of the spoon, you can play with its special effects. From far way, your face will be small and upside down. Get closer to the spoon, and you’ll be upside-down, but normal- sized. A bit closer, and your inverted face will look larger. Finally, come very close to the reflective surface, and your face will appear enormous–but right side up!
I heard that if a bee dies, its stinger is still active. Is that true? asks reader Tim Younquist.
Luckily for us, most bees have a live-and-let-live attitude. It takes a lot to provoke the average bee, like stepping on a worker bee on a blade of grass, or — especially — threatening her home. Most bee species are solitary, with female bees laying eggs in individual nests. But honeybees (and bumblebees) live in complex tribes. In the hive, a single queen does all the egg-laying. Thousands of female workers clean, tend to baby bees (aka larvae), and make nectar runs. The only job of the hundreds of male bees, called drones, is to mate with the queen.
 Bee collecting pollen Some bee species are stingless, defending themselves by simple biting. But most species do sting, and only female bees–the workers and the queen–have stingers. The stinger, with its load of toxic venom, is a worker bee’s last-resort way of defending her nest or hive.
While bumblebees, the gentle giants of the bee world, rarely sting, they live to tell the tale if they do. A bumblebee’s stinger is smooth; the bee easily withdraws it and goes on her buzzing way. In honeybee clans, the queens are likewise armed with smooth stingers, the better to kill off rival queens and reign another day.
Worker honeybees aren’t so lucky. Their stingers are barbed, like tiny harpoons. When a honeybee worker stings a threatening insect, the barbed stinger can be pulled from the victim’s squishy body, and the bee resumes her life. (The stung insect isn’t as lucky; the venom is lethal to it.)
But when a worker honeybee stings an animal like a bird or a bear or a human being, it’s the end of the bee. Like a fish hook, the stinger firmly embeds in the target’s skin. When the bee pulls away, the stinger organ rips from her abdomen, and the bee soon dies of her injury.
But even when the bee drops off the wound, the stinger’s work isn’t done. Tiny muscles in the venom sac continue contracting, squeezing bee venom into the skin. In fact, the firmly hooked stinger can continue to pulse out poison for several minutes. Meanwhile, like a tiny splinter of wood, the barbed ends of the stinger work their way deeper into the skin. The result? The spot where you were stung becomes more and more painful.
The tiny amount of bee venom delivered in a single sting isn’t enough to sicken or kill a human being. But in the approximately 2 percent of people who are especially sensitive to the venom’s proteins, the body’s own allergic reaction can be life-threatening. So to minimize pain and an allergic reaction, it’s important to remove the stinger as quickly as possible. Pulling out with tweezers may compress the venom sac, squeezing out more poison. A better method is to scrape the stinger off from the side, using your fingernail, a credit card, or the dull edge of a knife. Once the stinger is out, clean the wound with soap and water or rubbing alcohol, and apply ice to reduce pain and inflammation.
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