I made a little Google Trend request, here is a snapshot:
What is striking is the seasonality. People look up science-related terms when they feel compelled to do so, when classes are going to start or restart (September, the very end of December, before going back to school, trying to find a private tutor, a book, a quick answer on wikipedia).
In fact you can even guess the location of class holidays and exams in, say, France, that way
The large down bowl fits the summer vacation and the accentuated peak before is the time of the Baccalauréat (high-school final/college entry exam). The small down trends fit the starts of the various school vacations quite well, the largest and easiest to find being the year-end holidays (usually 15 days, starting a few days before Christmas).
The news volume increase for physique in the lower part is a consequence of the word being used in english for body shape (unfortunately a topic that news media find more interesting or easier to sell than physics).