Radiometer

by Tedco

Product Features

• Vanes in the Radiometer are alternately dark and light in color
• Vanes transfer heat to each one but not at the same degree
• Lighter vane reflects the rays and the darker vane absorbs the rays
• For ages 7 and above
• Recommened Age 6 thru adult

Product Details

• Shipping Weight: 2.9 ounces (View shipping rates and policies)
• Shipping: This item is also available for shipping to select countries outside the U.S.
• ASIN: B0007YFJI2
• Item model number: 01800
• Manufacturer recommended age: 5 - 10 years
• Amazon Best Sellers Rank: #1,219 in Toys & Games (See Top 100 in Toys & Games)
  • #6 in Toys & Games > Learning & Education > Science > Physics
• Average Customer Review: 4.4 out of 5 stars  See all reviews (49 customer reviews)
• Discontinued by manufacturer: Yes

Product Description

From the Manufacturer

It's the spear powered by the sun! When light strikes the diamond wings it tranfers heat to each one, but not to the same degree. The light wing reflect the rays and the darker wing absorbs the rays. The stronger the light the more energy there is to heat up the darker side causing the wings to spin faster.

Product Description

Experience this sphere powered by the sun! The vanes in the Radiometer are alternately dark and light in color. When the light strikes these vanes it transfers heat to each one - but not at the same degree. The lighter vane reflects the rays and the darker vane absorbs the rays. The stronger the light, the more energy there is causing the vanes to spin faster.

Customer Reviews

Most Helpful Customer Reviews

63 of 64 people found the following review helpful:

5.0 out of 5 stars Well Constructed, Good Price, August 24, 2008

By 

David W. Dellinger "PuuikiBeach" (North Shore of Oahu) - See all my reviews
(REAL NAME)   

= Durability:2.0 out of 5 stars  = Fun:5.0 out of 5 stars  = Educational:5.0 out of 5 stars 

Amazon Verified Purchase

This review is from: Radiometer (Toy)

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!

38 of 38 people found the following review helpful:

3.0 out of 5 stars Fascinating, But Does Not Last, January 7, 2011

By 

M. Ross "Bacchuskitty" (Orange, CA USA) - See all my reviews
(VINE VOICE)    (TOP 500 REVIEWER)    (REAL NAME)   

= Durability:1.0 out of 5 stars  = Fun:4.0 out of 5 stars  = Educational:5.0 out of 5 stars 

Amazon Verified Purchase

This review is from: Radiometer (Toy)

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.

17 of 18 people found the following review helpful:

5.0 out of 5 stars Nice Radiometer, March 25, 2010

By 

Ok2bclever (Michigan, USA) - See all my reviews

= Durability:3.0 out of 5 stars  = Fun:5.0 out of 5 stars  = Educational:5.0 out of 5 stars 

Amazon Verified Purchase

This review is from: Radiometer (Toy)

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.