May 21, 2013 — As it roared through the Oklahoma City suburb of Moore, packing winds of up to 200 mph, the twister flattened buildings. Searchers continue to look for survivors and those who were killed.

May 21, 2013 — Under Douglas Shulman's watch, IRS personnel singled out some conservative groups for extra scrutiny. That, he conceded Tuesday, has "justifiably led to questions" about the tax agency's motivation.

May 21, 2013 — In the aftermath of horrible acts of violence, whose faces stick in our memory? Whose faces should?

May 21, 2013 — Engineers have figured out a way to get crystals to form rose and tulip sculptures, each smaller than a strand of hair. The gardens sprout up on a penny dipped in a salt solution. The technique is similar to 3-D printing and could one day be used to make any complex shape.

May 21, 2013 — Religion is often organized in terms of a god, or gods. It's a system of beliefs embodied in a being or beings. But that's not always the case. It can mean more, a lot more, says Adam Frank after finding inspiration in the writing of Ronald Dworkin.