We all have played with toys in our childhood,these toys were generally action figures,barbie dolls,racing cars and as we reached adolescense the toys that we used to get also matured a bit from mere action figures to scientific toys teaching us something new.However my first experience to such a toy was when i visited an eye specialist.
Yes,it was Newton’s Cradle.I know its fun to look at these toys with all the science stuff that gets taged onto your mind as soon as you see one which makes you want to learn all about it. This post is for one of such toys. To understand all about Xiralback lets first look at rattleback.
What’s a Rattleback?
Well, rattleback is a desk toy that looks like a pebble which on being rotated on a surface such as a table top would continue to spin in one direction which could be either clockwise or anti-clockwise while when rotated in the other direction would resist its movement and then try to go back in its preferred direction.
The video would have helped you get a feel of this toy its unique rotating property makes it all the more interesting.In the above rattle back the toy is stable in anti clockwise while unstable in clockwise direction this is because the portion of the toy in contact with the table top is not a half cut ellipsoid but an S like surface which makes the toy behave in this manner.
Now lets get to Xiralback…
The χiralback is a variation of a rattleback, it has a strong preference for which direction it spins. If spun in the reverse direction, it converts its energy into a rattle, and then spins back in the preferred direction. This behavior seems to defy the physical law requiring the conservation of angular momentum. The strength of the effect varies on the surface on which it is spun.
Older explanations of rattlebacks have focussed on surface asymmetries near the place where the bottom of the rattleback rests.But the surface of this one is a symmetrical ellipsoid given by the equation x^2/a^2 + y^2/b^2 + z^2/c^2 = 1.
It also has the property that if it is turned upside down, then the preferred direction of spin is reversed! So we call it a χiralback.
A Demonstration and Production video of the toy
The man resposible for this toy is Mr.Tadashi François Tokieda a Japanese mathematician, specializing in mathematical physics,Director of Studies in Mathematics at Trinity Hall, Cambridge
