Why does object look larger in water relative to air?

In physics, refraction is normally the change in the path of a wave moving from one medium to a different or from a progressive change in the medium. Refraction of light may be the most commonly observed trend, but other waves for example sound waves and water waves also experience refraction. Just how much the wave is generally refracted is dependent upon the actual shift in wave speed and also the preliminary path associated with wave propagation relative to the path associated with alter in speed.

Light refraction follows Snell's law, which says that, for a given set of media, the ratio of the sines of the angle of incidence θ1 as well as angle of refraction θ2 is equivalent to the ratio of phase velocities (v1 / v2) in both media, or, the ratio of the indices of refraction (n2 / n1) of the two media. The refractive index or index of refraction of the material is a dimensionless quantity in optics that describes how fast light propagates within the material. The index of refraction indicates just how much the path of light is bent, or refracted, whenever entering a material.

Since air possesses a refractive index of essentially 1 and water comes with an index of refraction of just 1.33 the angle that the rays of light reach your eyes is bigger than the angle they might in air. This causes the angular size much larger for your eyes which makes the item appears larger compared to that they would likely appear in the air.

What is Nanotechnology?

Nanoscience and nanotechnology are the review and use of extremely small things and can be used across other science fields, such as chemistry, biology, physics, materials science, and engineering. Nanotechnology is taken as the scale range 1 to 100 nm following the definition used by the National Nanotechnology Initiative in the US. One nanometer (nm) is one billionth, or 10−9, of a meter. Nanotechnology is the adjustment and production of materials and devices on the scale of atoms or small groups of atoms. Nanotechnology makes it possible to manufacture lighter, more robust, and programmable materials that require less energy to produce than conventional materials, that produce less waste than with conventional manufacturing, and that promise greater fuel efficiency in land transportation, ships, aircraft, and space vehicles. Nanotechnology may be able to make current medical applications less expensive and a lot easier to use in places like the general practitioner's office and at home. Researchers at the University of Toronto have demonstrated the use of nanoparticles designed to concentrate on a tumor and generate oxygen can increase the efficiency of the chemotherapy drug doxorubicin. Researchers have successfully used DNA origami-based nanobots capable of carrying out logic functions to achieve specific drug delivery in cockroaches. Cars are being manufactured with nanomaterials so they may need fewer metals and less fuel to function in the future. Scientists are now turning to nanotechnology in an attempt to develop diesel engines with cleaner exhaust gases. Nanotechnology also has a prominent role in the fast developing field of Tissue Engineering. Scientists currently debate the future implications of nanotechnology. Nanotechnology may be able to develop many new materials and devices with a vast range of applications, such as in nanomedicine, nanoelectronics, biomaterials energy production, and consumer products. On the other hand, nanotechnology raises many of the same issues as any new technology, including issues about the toxicity and environmental effect of nanomaterials and their potential issues on global economics, as well as questions about various doomsday scenarios. These concerns have led to a controversy among advocacy groups and governments on whether special rules of nanotechnology is called for.