Over the last few decades, numerous experiments have been operated to search for dark matter, the mysterious component of the universe. The dark matter is unseen and only known by its gravitational effect, but it greatly outnumbers the normal matter concluded from a wide variety of evidence. Since the dark matter only interacts weakly with normal substance, the experiment to search for it is preferred to be located deeply underground and surrounded by layers of shielding materials, which is to diminish the influence of background radiations. One has to have a quantitative idea of the radiation level and the effectiveness of the proposed shielding strategy in order to operate an experiment with a desired sensitivity. This work is to list the background radiations presented at SNOLAB and to examine the water tank shield of the detector testing facility for SuperCDMS experiment by means of Monte Carlo simulation. It is found that the goal of

Metamaterials have attracted enormous interests from both physics and engineering communities in the past 20 years, owing to their powerful ability in manipulating electromagnetic waves. However, the functionalities of traditional metamaterials are fixed at the time of fabrication. To control the EM waves dynamically, active components are introduced to the meta-atoms, yielding active metamaterials. Recently, a special kind of active metamaterials, digital coding and programmable metamaterials, are proposed, which can achieve dynamically controllable functionalities using field programmable gate array (FPGA). Most importantly, the digital coding representations of metamaterials set up a bridge between the digital world and physical world, and allow metamaterials to process digital information directly, leading to information metamaterials. In this Element, we review the evolution of information metamaterials, mainly focusing on their basic concepts, design principles, fabrication techniques, experimental measurement and potential applications. Future developments of information metamaterials are also envisioned.