Abstract: A linear-motion stage that is angularly or radially symmetric or asymmetric, or monolithic may be used as the moving mechanism in a Fourier transform spectrometer. In embodiments, a linear-motion stage includes a base; a first multiple-arm linkage extending from the base to a first carriage attachment piece; and a second multiple-arm linkage extending from the first carriage attachment piece to the base. The first multiple-arm linkage constrains a motion of the first carriage attachment piece to motion in a first plane and the second multiple-arm linkage constrains the first carriage attachment piece to motion in a second plane, the first and second planes intersecting at a plane intersection line. The first and second multiple-arm linkages constrain the motion of the first carriage attachment piece along a carriage motion line.

Abstract: A linear-motion stage that is angularly or radially symmetric or asymmetric, or monolithic may be used as the moving mechanism in a Fourier transform spectrometer. In embodiments, a linear-motion stage includes a base; a first multiple-arm linkage extending from the base to a first carriage attachment piece; and a second multiple-arm linkage extending from the first carriage attachment piece to the base. The first multiple-arm linkage constrains a motion of the first carriage attachment piece to motion in a first plane and the second multiple-arm linkage constrains the first carriage attachment piece to motion in a second plane, the first and second planes intersecting at a plane intersection line. The first and second multiple-arm linkages constrain the motion of the first carriage attachment piece along a carriage motion line.

Abstract: A play strategy erasable screen assembly is provided including a housing and a display mechanism mounted thereon. The display mechanism includes an upper transparent layer, a thin compartment situated thereunder within an interior space of the housing, and a predetermined amount of metallic shavings situated within the compartment. A plurality of stamps are included each having magnets mounted thereon for being placed on the transparent layer of the display mechanism to adhere the metallic shavings on the transparent layer in a configuration similar to that in which the magnets are mounted on the stamps. Next provided is an erasure assembly for selectively removing the metallic shavings from the transparent layer.