The Science of Stars

The Science of Stars
Crystal Graham
SCI/151
Moses Olade
October 13, 2010

The Science of Stars
      Light is used in many ways, but the rate that light carries energy toward or away from us is what scientists are interested in. Light is a form of energy that can be created, travel through space, and be absorbed. This energy is carried around by waves and is described as spread-out disturbances. Sound waves move through the air and cause molecules to vibrate back and forth, permitting waves to transmit energy from one place to another. Light waves are vibrations of electric and magnetic fields caused by motions of charged particles. Electric and magnetic fields create waves in space when light travels.
      “Because we sometimes describe light as an electromagnetic wave, the complete spectrum of light is usually called the electromagnetic spectrum” (Bennett, Donahue, Schneider, & Voit, 2009). The electromagnetic spectrum is what scientists use to determine the composition, temperature, speed, and rotation rate of distant objects. Spectra consist of three different types: continuous, emission line, and absorption.
      Emission and absorption lines tell us that each type of atom, ion, or molecule possess a unique set of energy levels. Scientists have learned the composition of distant objects in the universe using this method. Every atom has its own unique spectral fingerprint because it has its own unique set of energy levels. If matter is made of hydrogen, it emits and absorbs light at specific wavelengths and makes it possible to detect its presence in distant objects.
      Ions of an element produce fingerprints different from neutral atoms. This difference helps us determine the temperature of hot gas or plasma. This is used to measure the surface temperature of stars. Higher charged ions will be at higher temperatures. Atoms and molecules that we see in our everyday lives cannot be considered independent. It has much more complex sets of energy... [continues]

Read full essay