By MICHIO KAKU

Champagne bottles were popped Tuesday in Geneva where the largest science machine ever built finally began to smash subatomic particles together. After 16 years—and an accident that crippled the machine a year and a half ago—the Large Hadron Collider successfully smashed two beams of protons at the astounding energy of 3.5 trillion electron volts apiece. This act produced temperatures not seen since the Big Bang occurred 13.7 billions years ago.

The LHC is colossal. It is a gigantic doughnut, 17 miles in circumference, in which two beams of protons will eventually create energies of 14 trillion electron volts. Yet by nature’s standards the LHC is a pea shooter. For billions of years the earth has been bathed in cosmic rays much more powerful than those created by the LHC.

Despite this great achievement, European taxpayers are asking if this 10 billion euro machine is a waste of money, particularly given the current financial crisis. These skeptics would do well to remember that the LHC could help us understand not only the instant of genesis, but will help unify the four fundamental forces that rule the universe. Each time one of these forces was deciphered it changed the course of human history.

When Sir Isaac Newton worked out the theory of the first force—gravity—in the 17th century, he created the mechanics that laid the groundwork for steam engines and the Industrial Revolution. The Machine Age unleashed humanity from the bondage of subsistence farming, lifting untold numbers from grinding poverty.

When Thomas Edison, James C. Maxwell and Michael Faraday helped to decipher and harness the second force—electromagnetism—it eventually gave us TV, radio, radar, computers and the Internet.

When Albert Einstein wrote down E=mc2, it helped to unlock the secret of the two nuclear forces (weak and strong), which unraveled the secret of the stars and unleashed nuclear power.

Today the LHC may have the potential to explain the origin of all four fundamental forces—gravity, electromagnetism, and the strong and weak nuclear forces. Physicists believe that at the beginning of time there was a single superforce which unified these fundamental forces. Finding it could be the crowning achievement in the history of science, ending 2,000 years of speculation since the Greeks first wondered what the world is made of. It could answer some of the deepest questions facing us, such as: What happened before the Big Bang? Are there parallel universes? Is time travel possible? And are there other dimensions?

In addition to helping us unlock the mysteries of the universe, the LHC may also create a new scientific elite. These scientists will likely spearhead new industries, creating jobs and perhaps significant wealth in Europe.

It’s sobering to remember that this could have happened in the U.S. Back in the 1980s, President Ronald Reagan pushed to create a Superconducting Supercollider just outside Dallas, Texas. This machine would have been three times larger than the LHC and would have maintained U.S. leadership in advanced science for at least a generation. Congress allotted $1 billion to dig the hole for the Supercollider. Then it got cold feet and cancelled the plans in 1993, spending another $1 billion to fill up the hole. U.S. high-energy physics was set back an entire generation and has never recovered. So today the Europeans can brag about being the world’s leader in advanced physics.

Remember that because of World War II, the cream of European science, perhaps no more than a few hundred people, fled Europe for America. They unleashed the greatest explosion in science the world has ever seen. These Europeans trained new generations of American scientists, people that went on to create radar, microwaves, nuclear power, computers, the Internet, the laser and the space program. They created a scientific establishment that is the envy of the world, a source of profound wealth, and a magnet for young scientists world-wide. U.S. technological superiority and all the high-tech wonders of today can, in some sense, be traced back to this exodus. But such leadership is not a given.

I extend my congratulations to the Europeans; the LHC is their well-earned prize. I only hope that U.S. policy makers are paying close attention to Geneva.

Mr. Kaku, a professor of theoretical physics at City College of New York, is the author of “Physics of the Impossible” (Doubleday, 2008) and host of “Sci Fi Science: Physics of the Impossible,” on the Science Channel.