Note: Corrections have been made to the original story published on Jan. 30.

LEWISTON — Talk about a timely message.

As Laura Grego spoke to a group of Bates College students about the many dangers of nuclear arms, news was coming across the wires.

“North Korea has followed through on its threat to advance its nuclear weapons program,” according to The Associated Press, “while a research institute pointed to signs the communist country is preparing to launch bigger rockets.”

That will come as no surprise to Grego, a senior scientist in the Union of Concerned Scientists Global Security Program. As an expert on space security issues, she knows how precarious things have become in the world of nuclear weapons.

Things have vastly improved since the hysteria of the Cold War, Grego said, but there still is some way to go.

Thousands of nuclear weapons are deployed and in reserve, and so the odds of a catastrophic mishap or misunderstanding involving nuclear weapons is much greater than the odds that those weapons will be used in a conflict.

It happens more often than most people might believe.

“The list of accidents,” Grego said, “is incredibly long.”

Grego is soft-spoken for one who speaks of such explosive matters. Before the group at Carnegie Science Hall on Wednesday, she let the figures provide the drama.

Although, she did give one grim demonstration.

Before her on a desk sat a tall jar. She dropped a single metal pellet into it. The pellet rattled around for a few seconds and then was silent. That pellet, Grego said, represented 100 kilotons of TNT, capable of a blast roughly six times greater than the one dropped on Hiroshima.

She scooped a small handful of pellets out of a container and dropped them into the jar.

“This is enough to destroy pretty much any country,” Grego told the audience.

She poured more pellets into the jar, attempting to get a visual representation of the United States’ nuclear arsenal.

“I want you to raise your hand when you think I should stop,” she said.

When the jar was half full, a few hands went up.

“Enough?” Grego asked them.

Nope. Not quite there.

When it was two-thirds full, a few students tentatively lifted their hands. But the visual was not complete. When the jar was full of bright green pellets, Grego said it was still not enough to represent the nuclear weapons the government has at the ready.

As she spoke, Grego was mindful of a few pertinent anniversaries. Thursday was the 50th anniversary of the release of the movie “Dr. Strangelove,” a dark comedy that satirized the nuclear scare that gripped the world.

“It doesn’t end well,” she said of the cult classic film.

It was also near the anniversary of a close call in January 1995, when Russian military officials detected missles that appeared to be coming toward them. At the time, Grego said, Moscow went on high alert. Submarines were sent to their ready positions. Military leaders prepared to launch a defense.

Before the command was given, they learned that the projectile was a scientific rocket sent up to study the northern lights. Russia halted its defense.

Some scientists called it one of the closest calls in human history. And that happened at a time well after the end of the Cold War, which began in 1945 and ended in 1991 with the breakup of the Soviet Union.

“What if this had happened during a time of high tension?” Grego asked the group.

Today, Russia and the U.S. still have massive stockpiles of nuclear weapons, Grego said, but now there are other countries to worry about. Pakistan, North Korea, Israel and others all have nuclear capabilities. Grego wondered whether the people who supervise the weapons of all nuclear arsenals are experienced  and disciplined enough to keep them under control.

Grego, among many others, passionately believes that the U.S. is spending untold billions of dollars on a missile defense system that might not even work properly. Given some thought, the idea of using one missile to shoot another out of the sky doesn’t sound all that practical. The last three tests have been failures, she said, which doesn’t inspire confidence.

“There’s been no test that tells us how well it would work in a real-world situation,” she said.

There was a time when the U.S. and Russia were talking in earnest about a massive downscaling of their weaponry, Grego said. And while the United States and Russia have a nearly 30-year history of reducing the total number of nuclear weapons in their inventories, weapons remain.

Now, a $30 million study is underway to determine whether a new missile defense site should be constructed. And if so, where it should be located.

“Guess what?” Grego said. “Maine is on the short list.”

Some Maine representatives have already come out in favor of the plan. After all, it would create jobs and perhaps boost the economy. Grego pointed out that studies have consistently shown that education is a better way to stimulate an economy.

Although she and others regard the country’s defense system as one that provides a false sense of security, “it’s challenging,” Grego said, “to be the person who comes out against defense.”

The students who attended the lecture asked many questions of Grego. How would the waste be disposed of if all of those weapons were dismantled? How much would it cost and how much time would it take?

It could be done, she said. The first step is convincing people that it’s a step that should be taken.

“Write your senators and tell them we don’t need this number of nuclear weapons,” she said.