Prosthetics, eyeglasses, and other aids were once seen as less-than-ideal substitutes for normal human abilities. But now technology can enhance us well beyond what's considered normal. Examine the superhuman traits currently available and those on the drawing board. Has the era of the cyborg arrived?

Follow the history of the universe from just after the big bang to the far future, when the universe will consist of virtually empty space at maximum entropy. Learn what is well founded and what is less certain about this picture of a universe winding down.

From routine childhood vaccinations to the experimental vaccines given to Ebola patients in Africa and the United States, vaccines have a powerful effect on public health. Learn the facts about the four different types of vaccines and their components, and discover why the concept of herd immunity is critical to public health.

Probe one of the most fascinating phenomena in all of physics, electromagnetic induction, which shows the direct relationship between electric and magnetic fields. In a demonstration with moving magnets, see how the relative motion of a magnet and an electric conductor induces current in the conductor.

In this episode, investigate cosmic antigravity, starting with cosmic inflation, a phenomenon that exponentially increased the size of the universe during the big bang. Then, learn why dark matter cannot be made of ordinary protons and neutrons, and explore the recent discovery that the expansion of the universe is accelerating, powered by a mysterious dark energy inherent in space itself.

The Rock of Gibraltar marks the gateway from the Mediterranean Sea into the Atlantic Ocean, a connection that has been closed on and off through recent geologic time. Explore the currents, catastrophic floods, and drastic sea-level changes that have occurred at the strait of Gibraltar and throughout the Mediterranean basin.

Embark on the final section of the course, which covers the revolutionary theories that superseded classical physics. Why did classical physics need to be replaced? Discover that by the late 19th century, inexplicable cracks were beginning to appear in its explanatory power.

Take a quick trip from the subatomic to the galactic realm as an introduction to physics, the science that explains physical reality at all scales. Professor Wolfson shows how physics is the fundamental science that underlies all the natural sciences. He also describes phenomena that are still beyond its explanatory power.

Fiction writers have led the way in exploring the prospects of life beyond Earth. See how scientists are catching up, looking for extraterrestrial organisms using a variety of ingenious techniques. Learn how they are narrowing the search and which tantalizing clues have already turned up.

Learn what happens when you or others are in a bad mood by exploring some theories about emotion; explore the role of facial expressions in emotional feedback; and change the way you think about tense arguments.