Heisenberg's uncertainty principle explains single slit diffraction1 where maximum is always at the centre. The same
experiment has been conducted but with transparent walls i.e. the material present on either side of the slit, instead of
opaque material. The observed result is a minimum at the centre in between two maximum. It is intuitive that atleast
some photons passed through the slit must end up at the centre of the diffraction pattern but the result is different. The
diffraction pattern occurs as the photons interact with the material around the slit. While uncertainty principle cannot
give quantitative explanation as the photons confined in gap between slits still occupy the same space whether it is
passing through a slit or not. This paper discusses various experiments and results by examining the interactions between
photons and the material of the wall which makes the slit for better understanding of properties of light.
This is the study of relation between thermal and magnetic properties of permanent magnets. The concept of adiabatic demagnetization gives the basic idea on variation in temperature of paramagnetic substances due to the application of magnetic field. With the understanding of adiabatic demagnetization the variations in temperature of ferromagnetic materials can be explained. In both cases, adiabatic demagnetization tells us about conservation of energy. The study on thermal properties of ferromagnetic materials at cryogenic temperatures gives the amount of thermal energy being transferred from or to the surroundings and hence gives the variations in magnetic fields due to temperature changes. As samarium cobalt rare earth permanent magnet do quite well at cryogenic temperatures, this study is much useful in future applications of permanent magnets in space for a renewable energy source. This will enable us to look into the design and working of a device that can convert thermal energy to mechanical energy which leads to thinking of energy conversion without causing harm to our environment. Numerous research works report the successful use of samarium cobalt to temperatures as low as 2 K.