Source: Derek Wilson, Asantha Cooray, PhD, Department of Physics & Astronomy, School of Physical Sciences, University of California, Irvine, CA
Light travels at different speeds depending on the material through which it is propagating. When light travels from one material to another, it will either slow down or speed up. In order to conserve energy and momentum, the light must change the direction in which it propagates. This bending of light is known as refraction. Some fraction of...

Drosophila melanogaster, commonly known as fruit flies, are a frequently used model organism for life science research. Although starting a collection of these critters may seem as easy as leaving a banana on your kitchen counter for too long, a productive fly colony in the lab requires careful husbandry and maintenance.
This video demonstrates the necessary steps for maintaining a healthy fly stock. The overview begins with the preparation and storage of the yeast and sugar-containing media on...

When a wave travels from one medium to another, it gets reflected at the boundary of the second medium. A common example of this is when a person yells at a distance from a cliff and hears the echo of their voice. The sound waves (longitudinal waves) traveling in the air are reflected from the bounding cliff. Similarly, flipping one end of a string whose other end is tied to a wall causes a pulse (transverse wave) to travel through the string, which gets reflected upon reaching the wall. In...

According to Charles Cooley, we base our image on what we think other people see (Cooley 1902). We imagine how we must appear to others, then react to this speculation. We don certain clothes, prepare our hair in a particular manner, wear makeup, use cologne, and the like—all with the notion that our presentation of ourselves is going to affect how others perceive us. We expect a certain reaction, and, if lucky, we get the one we desire and feel good about it. But more than that, Cooley...

Ceanorhabditis elegans has been, and is still, used to great success as a model organism for studying a variety of developmental, genetic, molecular and even physical phenomena. In order to use C. elegans to its full potential, proper care and attention to the basic maintenance of this powerful organism is essential.
In this video you will learn the basic housing and feeding requirements of C. elegans, how to correctly handle and manipulate worms using a worm pick and how to freeze and recover...

The cells of the blastocyst inner cell mass only remain pluripotent for a short time. This state of pluripotency and self-renewal can be maintained in embryonic stem (ES) cell culture by adding specific chemicals or growth factors to ensure the cells can continue dividing and later differentiate into different cell types. In some cases, the cells are grown on a feeder layer of differentiated cells, which provides the growth factors and extracellular matrix components necessary for stem cell...