The hydrogen atoms in a star are also moving at high velocity because of the random motions caused by their high temperature. as a result, each atom is doppler shifted a little bit differently, leading to a finite width of each spectral line, such as the 656.46-nm line we were just discussing. for a star like our sun, this leads to a finite width of the spectral lines of roughly δλ=0.04nm. if our instruments can only resolve to this accuracy, what is the lowest speed v, greater than 0, that we can measure a star to be moving?

a high pressure system is a dense air mass that is usually cooler and drier than the surrounding air. a low pressure system is a less dense air mass that is usually wetter and warmer than the surrounding air.

in general, areas that experience high atmospheric pressure also experience fair weather. low pressure systems can cause the formation of clouds and storms. air usually flows from areas of high pressure to areas of low pressure..

radiation warms things up temp rises convection currents air circ windy weather

this would be about 43%