henrietta leavitt first showed the relationship between the mass and luminosity of cepheids and their period of pulsation; the brighter, the longer this period.

Why does lightning travel from clouds to the ground?

Mackinzie walks 4 blocks west, then 2 blocks south, then 4 blocks east, and,finally, 1 block south. what is the magnitude of her total displacement duringthis walk (in blocks)?

Geologists get to play with chemistry, physics, and history! and what a history you will meet as youwork your way through the course. starting at the beginning, the textbook provides the scientifically acceptedstart of the and promises that you'll get to explore some of the evidence for that scientific view, later inthe semester. meanwhile, which is more nearly correct of the scientifically accepted view? a) the earth formed when the big bang caused older materials to fall together, about 14 billion years ago.b) the earth formed from the falling together of older materials, about 4.6 billion years ago.c) the earth formed in the big bang, about 6000 years ago.d) the earth is eternal, having been here forever and promising to be here forever.e) the earth was assembled by gigantic space beavers, which gnawed down the primordial tree of life andpiled its branches together to form the planet.