Horizon Season 2008 Episode 3 What on Earth is Wrong With Gravity?

In "What on Earth is Wrong With Gravity?" from the 2008 season of Horizon, scientists explore the mysteries surrounding gravity. While it is a fundamental force that shapes our universe, it has perplexed scientists for centuries. The episode follows leading physicists as they attempt to uncover what creates this enigmatic force.

The show begins by exploring the basics of gravity. We learn that gravity is the force that pulls two objects together. For example, it is what keeps the planets in our solar system orbiting around the sun. However, the force of gravity is incredibly weak, and scientists are still trying to understand how it works.

We then meet scientists who are conducting experiments to gain insight into the properties of gravity. For example, we see researchers conducting a "weighty" experiment in which they try to measure the gravitational pull between two objects. To accomplish this, they build a special balance that can measure extremely small forces. The result is a measurement of gravity 100 times more precise than ever before.

The show then delves into a current area of research in physics - the search for a unified theory that can reconcile gravity with the other three fundamental forces of nature - electromagnetism, the weak nuclear force, and the strong nuclear force. Scientists have been trying for years to find a way to explain these forces using a single theory, but so far, they have been unsuccessful.

Next, we learn about some of the oddities of gravity. For example, as we move away from the Earth, gravity becomes weaker. Scientists have discovered that this decay of gravity follows an inverse square law, meaning that the force of gravity decreases as the square of the distance between two objects. However, this law doesn't hold true for incredibly large distances, such as those between galaxies. This has led to the idea that there may be "dark energy" that fills the universe and is pushing everything apart.

One of the most bizarre aspects of gravity is its effect on time. We learn that time passes slower in areas where gravity is stronger. This has been demonstrated through experiments using atomic clocks. The show explores some of the implications of this effect, including the concept of black holes, where gravity is so strong that nothing - not even light - can escape.

The show also looks at some of the ways in which gravity affects our daily lives. For example, we see how gravity affects the growth of plants and how it influences the tides. We also learn about the gravitational interference caused by the Moon and its impact on our planet.

Overall, "What on Earth is Wrong With Gravity?" is a fascinating exploration of one of the most fundamental forces of nature. It covers a wide range of topics, from the basic properties of gravity to cutting-edge research on the search for a unified theory. The show is a must-see for anyone interested in physics, astronomy, or the mysteries of the universe.