[Abhimanyu Kumar] was watching YouTube videos one day when he came across something called a Polariscope — After learning how it worked, he discovered you can make your own using household items!

If you’re interested in viewing those stresses before they result in damage to the underlying material, take a look at this DIY polariscope which can view internal stresses in glass and other ...

THE following is an interesting combination:—When the polariser and analyser are crossed, insert a concave plate of quartz cut parallel to the axis, with its axis inclined at 45° to that of the ...