At the time I purchased this version of the Radiometer, the Amazon price was $10.95, with free Super-Saver shipping available. I have seen the identical model retailing in science gift shops and catalogs for $12.95 to $15.95, so I was quite happy with the Amazon price.
The device is sturdily constructed, for what it is. Keep in mind, this is a thin glass bulb similar to a light bulb; it will shatter when dropped. The rotating vanes inside, while intricately crafted, are delicate and not designed to withstand heavy shaking or jarring. It is not a "toy," particularly not for young children. Rather, it is an interesting scientific novelty, or a "curio," not intended for frequent handling.
The bulb is securely affixed to the black plastic base. I appreciate the "retro" appearance of the base, reminiscent of antique bakelite. It is much more attractive and sturdy than the version I remember from my childhood, which had a piece of gaudy colored paper glued to the bottom of the glass bulb. The vanes are nicely painted and well-balanced. The unit will begin to spin when exposed to even muted sunlight. The one I received will spin quite rapidly under bright light without any rattling or shaking, unlike those I remember from years ago.
I am quite pleased with this version of the Radiometer: The Sphere Powered By the Sun (I miss the phrase "Space-Age Sphere," which no longer appears on the packaging), and am ordering several more for demonstrations in my elementary school science classes... and for myself, because... what can I say... it's really cool!
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This fascinating little gadget has been around for years. It is the approximate size and shape of a clear, standard incandescent lightbulb, with a base to stand on. Inside, instead of a filament, there is a small structure of four square vanes held atop a sharp needle, allowing the apparatus to spin. The vanes are colored white on one side and black on the other. Through action of direct sunlight, the vanes spin; the brighter and clearer the light, the faster they spin. The physics of it are explained on an insert. No batteries required, just put it on a sunny windowsill and watch it go!
This really is a terrific and fascinating demonstration of the power of the sun. No matter that now that I am older I understand the physics of it, it is still a remarkable and awesome thing. Fun for young and old, it is probably more suitable for older children who are beginning to express interest in the workings of the world around them and for grownups who still retain a measure of wonderment of natural processes like solar power.
But for its durability, I would easily have given this five stars on coolness and educational merit alone. There is no denying that this is a delicate item, unable to withstand the rigors of a toddler's attention; mine was immediately put on a sunny windowsill where, after spinning smartly for two weeks, it quit. It seems another factor of physics, that of friction, led to its demise. Whether the cap that rests on top of the needle wasn't made of tough enough stuff or whether an initial dab of graphite lubrication manufactured-in would have helped, I don't know. (I'll not leave the question begging: Yes, it was perfectly sunny when it stopped) The vanes are not stuck, as the device does wobble and spin through physical action of rotating the unit, but they can no longer move solely through solar power.
I thought the cost reasonable initially, for such a cool device. But it's no value for a lifespan of two weeks and far more than I would have wanted to spend on a paperweight.
I am reluctant to give what really should be an excellent little scientific experiment three stars. Maybe mine was a dud I really hope so, because like so many others I rely on ratings on Amazon to help with my purchasing decision and I would hate to think some would not be able to experience this based on ratings. Caveat emptor, then, for those who want to go for it: I think you'll love it, but it may not last.
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This is more of an adult's toy than a child's toy due to it is essentially a sealed glass light bulb on a base.
It makes a great conversation piece on my office window sill, especially when the sun is shining and it's spinning.
The unit is well made and small enough to securely sit anywhere it can get sunlight.
As long as you remember to treat it with the caution something made out of thin glass should be treated with it's a nice conversational and educational nicknack.
Honest reviews on Radiometer
My wife bought me the radiometer knowing my love of great innovation and design. I find as I work at my computer I turn into "Rain Man" in a desire to keep uo with the sun's movement. My two year old grandson actually stayed in one spot for over a half hour after I gave him a high intensity flaslight to aim at the vanes. He was enthralled by the fact that he could control something simply by turning the light on and off. I loved this piece of science so much that I ordered four more for my other grandchildren. It is definetly a must buy.
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This product is an excellent example for students to observe and use in laboratory projects. The Radiometer is durable and can be used as a discovery toy when placed in naturally occuring as well as contrived weather & enviornmental conditions. Shadowing with dust or an object that partially shades the solar power can demonstrate the effects caused by the annual, seasonal changes of Earth and the thinning of our ozone layer. Effects of smog can be discovered if you fail to dust or if you breath on the glass when it is cooler than your breath. The novelty & reasonable price of this item makes it an appealing learning tool in the home and school.
