We don’t live in a perfect world, and neither do gases – it would be great if their particles always fulfilled the assumptions of the ideal gas law, and we could use PV=nRT to get the right answer every time. Unfortunately, the ideal gas law (like our culture) has unrealistic expectations when it comes to size and attraction: it assumes that particles do not have size at all and that they never attract each other. So the ideal gas “law” often becomes little more than the ideal gas estimate when it comes to what gases do naturally. But it’s a close enough estimate in enough situations that it’s very valuable to know. In this episode, Hank goes through a bunch of calculations according to the ideal gas law so you can get familiar with it.
Imagine to place New York City on another planet in our solar system. Life of course would cease to exist at least as we know it. You will realize once more that our beautiful blue planet is very rare. The following illustrations were made with the help of Marilyn Vogel.
James May finds out how exactly the internet knows where to send you.
Fran Scott shows us how you can make your own Van de Graaff using household objects. How big a spark can you create?
NASA’s Kepler telescope has lost its ability to precisely point toward stars, putting its exoplanet search in jeopardy. One of the reaction wheels –devices which enable the spacecraft to aim in different directions without firing thrusters – has failed. This is of grave concern because last year reaction wheel #2 failed, and now #4 has failed. Kepler scientists say the spacecraft needs at least three reaction wheels to be able to point precisely enough to hunt for planets orbiting distant stars.
Krista Tippett talks about the beauty and mystery in science and religion and how they go hand-in-hand, not head-to-head.
In the last century humanity has taken gigantic leaps forward in the robotic exploration of the cosmos — not least in the search for habitable worlds and environments that could house life outside of the Earth. The next logical step is for humanity itself to leave the confines of our planet, and take on long-term human exploration of the Solar System. Mars in particular is a key target for future human planetary adventures even though on the face of it, it seems so hostile to human life.
Are sound vibrations and the sounds we hear the same thing? Or are they separate? It depends on your perspective. The tree in the forest may be silent or screaming for some help.
I hypothesize that sound vibrations are separate from what we hear. What we hear is our brains’ interpretation of the information. Sound happens in our minds. As of now there is no evidence to support this idea. But it’s fun to think about. So what do you think? Does the tree make a sound?
You have been predicted — by companies, governments, law enforcement, hospitals, and universities. Their computers say, “I knew you were going to do that!” These institutions are seizing upon the power to predict whether you’re going to click, buy, lie, or die.
In the 1930s journalists from publications like the New York Times and Time magazine would regularly visit Nikola Tesla at his home on the 20th floor of the Hotel Governor Clinton in Manhattan. There the elderly Tesla would regale them with stories of his early days as an inventor and often opined about what was in store for the future.