segment 1, Top of Mind–Obama points us to Mars (0:00): This week saw some developments in subjects we’ve discussed in each of our earlier episodes. from episode 3: global climate change — Cornell scientists predict a significant increase in the odds of...

segment 1, Top of Mind–Carbon Tipping Point (0:00): Earth’s atmospheric carbon-dioxide concentration is now above 400ppm.  Is there any way we’ll ever get back below that number?  Scientists are pretty sure that for the immediate future,

segment 1, Top of Mind–False Memories (0:00): A researcher has demonstrated that she can elicit from people memories of things that never happened.  She has managed to convince everyday people that they committed a petty crime in their childhood.

segment 1, Top of Mind–Driverless Cars (0:00): Uber is experimenting with driverless cars in Pittsburgh, with the goal of “making self-driving Ubers a reality.”  We discuss Uber’s pilot program, Tesla’s first fatality,