Rattleback - Plastic Assorted Colors - Pack of 10 with Teacher's Guide

EXCELLENT! I BUY THESE NIFTY SCIENCE TOYS TO SHOW AND THEN GIVE AWAY TO INTERESTED MIDDLE SCHOOL KIDS. DEFINITELY ***** (5 STAR)

Simple plastic shapes, that appear to defy common rules. They rotate freely counter-clockwise, as fast and as long as you'd like. Challenge kids (and adults) to spin them clockwise! They slow, rattle back & forth, and reverse direction. They simply will not spin clockwise for any length of time.They are pure plastic. No electronics, no batteries. Led to interesting discussions about physics with a teenager. Several hours of entertainment (shhh: and education) for very little cost.Tip: spin on a hard smooth surface, like a mirror, or a smooth table top.Do not spin on a friction surface such as paper, tablecloth,Tip: when giving it a spin, keep it in the same place. Too easy to spin it off the table.Tip: when motionless, tip one end vertically. The energy is converted to a rotary spin.Have fun!

Wish they were assorted; they all were the same color of blue. Don't know it that will be good or bad for a boys' birthday party; I thought different colors would be easier to keep track of for the partygoers, but perhaps they won't care.

These are great for teaching a principle of physics. It comes with a small pamphlet that describes the principles and some simple experiments. Frankly, I purchased them an inexpensive fidget toy. I find that when I’m having a mental block playing with something like this is helpful.

Best puchase ever. I have this on my desk at work. It amuses the crap out if everyine. Its nice to have extras. I give one to coworkers who have kids. Best purchase ever! To confuse person spinning, i rub my hands to throw them off. Thus they think its static electricity causing reverse spin. They laugh their butts iff when they try it w/o rubbing hands abd it still reverses. Really great item. And all ten worked! Very excellent mind teaser!

My first introduction to this type of device was a custom, hand carved wooden sculpture in someone's home. They had a parable about Noah's Ark (it looks ship-ish) and faith pointing you in the right direction. Fast forward years later to discovering these, and thinking they would be an interesting stress-toy type of item.The Rattlebacks are well made - basically a solid piece of plastic, with no seams, burrs, or sharp edges. The colors are clear and crisp - I have the translucent ones and they look great. The size is good too, about 3-14/16" long. I appreciate that they are not cheap crappy molds.The Rattlebacks spin nicely and easily on smooth surfaces, and indeed they do reverse direction. You spin them clockwise, and they start to wobble then spin a little in the opposite direction. It's cool to watch and demonstrate to someone. I wish that they would spin longer in the reverse direction, but that's not the toy's fault, that's just a limitation of the physics.The Rattleback also slightly magnifies writing, so I suppose it is also useful to have on my desk.I would have rated it higher in fun & education, except that I think a lot of people will lose interest fairly quickly.

A toy, but it provides a valuable object to use for a lesson. There is no logo nor marking...perfect for putting a sticker with a short lesson reminder that you wish to convey.

This toy entertains everyone young and old, without the internet or batteries.