Turkish Kurds watch smoke rises over Syrian town of Kobani after an airstrike, as seen from the Mursitpinar border crossing ...

Imagine tossing a pebble into a pond, and then watching as the ripples spread outward, their effects radiating through the ...

If you throw a pebble into a pond, ripples spread out from where it went in. These ripples are waves travelling through the water. Like ocean waves, these ripples are transverse waves because the ...