The Pennsylvanian, for its entire Pittsburgh to Philadelphia run, carried 212,006 passengers, up 2.2 percent over the prior year. Nearly 70 percent of that ridership boarded or disembarked west of Harrisburg, according to Amtrak. think it would be worth it for Amtrak and PennDOT to see if more schedule diversity might make it a more popular travel option, Ms. Katchmar says. â¢ Go to post-gazette.com for a slideshow of photos taken aboard the Pennsylvanian and a video report. Jon Schmitz: jschmitz@post-gazette.com or 412-263-1868.
How light travels. Light travels as waves. These are transverse waves, like the ripples in a tank of water. The direction of vibration in the waves is at 90Â° to the direction that the light travels. Light travels in straight lines, so if you have to represent a ray of light in a drawing, always use a ruler. Unlike sound waves, light waves can travel through a vacuum (empty space).
The key background to this question is the nature of sound waves and light waves. Youâre right in that sound waves are a vibration traveling through an object, including condensed things like solids and liquids. In solids, those waves can consist of either alternating compressed and stretched regions, or regions wiggling sideways, compared to the direction the wave is traveling.