If you time it just right, tossing a ball in the air as an elevator starts to move, the ball seems to hang in the air for a moment, like gravity had been canceled, says astrophysicist Adam Frank.
The U.S. solar industry is bracing for possible tariffs or quotas on imported solar panels. Such action could have very different consequences on different parts of the industry.
The Trans Mountain pipeline expansion would triple the amount of oil moved from Alberta's tar sands to the coast. Environmental groups and First Nations in the U.S. and Canada oppose the project.
Almost a month after Hurricane Maria made landfall, most of the island is still without electricity. Officials have estimated it could be months before power is restored.
Energy Secretary Rick Perry says subsidizing coal and nuclear power plants would make the grid more reliable. An unlikely array of critics say the move is expensive and unnecessary.
Nearly 90 percent of Puerto Rico is still without power more than two weeks after Hurricane Maria. Authorities say it will take months to restore electricity, as the storm destroyed the power grid.