By Jonny Lupsha, News Writer

A joke about raiding Area 51 this year has two million citizens pledging to visit the military site, Time reported. Area 51 has long been rumored to house government and military secrets about aliens, UFOs, and other wonders of outer space. If they follow through in late summer, what could they see—besides jail time?

According to Time, the Facebook event “Storm Area 51: They Can’t Stop All of Us” was created on June 27 as a joke. However, hundreds of thousands of “likes” later, along with 1.9 million people vowing to go to the mysterious site and an additional 1.5 million “interested” in the event, the U.S. Air Force felt compelled to act. In a response issued to several media outlets, they said that such an act is not only illegal but dangerous. Assuming at least some interested parties are taking the event seriously, what has led them to believe intelligent life from other planets has made it to Earth by now?

Where Is Everybody?

“On June 24, 1947, Kenneth Arnold claimed to have seen what we would now call UFOs,” Dr. Don Lincoln, Senior Scientist at Fermi National Accelerator Laboratory, said. “The newspapers caught wind of it and soon it was on everyone’s mind, with many people making UFO reports. The Roswell Incident was just a few weeks later—for several years, UFO mania was a real thing.”

Dr. Lincoln said that in 1950, Italian physicist Enrico Fermi was listening to a discussion between colleagues about UFOs when he suddenly asked where all the aliens are. “He had thought it through and realized that if faster-than-light travel were possible, the galaxy should already be thoroughly teeming with species who evolved before we did—Earth should be deluged with visitors,” he said.

Even if faster-than-light travel isn’t possible, Dr. Lincoln said, someone should have been here by now if they evolved before us; and even if they merely sent probes instead of lifeforms—much as we do, around our solar system—something clearly detectable should have zoomed by or landed here to take samples, by now. So where is everybody, if they’re exploring the Milky Way? We may not have a definite answer, but on a similar subject, what would a devoted plan to spread across the galaxy look like?

How Fast Could the Galaxy Be Colonized?

Dr. Lincoln proposed an eye-opening hypothetical situation based on the idea that we develop technology capable of traveling 1 percent of the speed of light. “If the stars are about five light years apart, it would take 500 years to get to the next star,” he said. “This is a long time, but not all that long. Say it takes 500 years on the planet around the new star to build enough industry to launch two ships, and they repeat the process—so it’s about 1,000 years between launching two ships, but those colonies then make four ships, then eight, then 16, and so on.”

Dr. Lincoln said that based on this model, the entire galaxy could be colonized in about a million years, or 10 million at the very least. “A million years is a long time, but remember that the Milky Way is over 10 billion years old—that is to say, 10,000 times longer than that,” he said. “Even our own sun is 4.5 billion years old.”

If even one species evolved 10 million years before we did, they would have colonized the entire galaxy by now. Or, looking at it from our end, if we develop the same tech in the next few decades, we could colonize the galaxy in the same amount of time. Clearly, however, neither situation has happened yet.

Anyone who shows up to storm Area 51 likely faces a grim future. Getting arrested is far from the worst that could happen to a person who illegally rushes a private military installation. However, looking at a galaxy colonization model and the obvious fact that it hasn’t come to fruition yet, it’s reasonable to assume they won’t be met by little green men.

Dr. Don Lincoln contributed to this article. Dr. Lincoln is a Senior Scientist at Fermi National Accelerator Laboratory (Fermilab). He is also a Guest Professor of High Energy Physics at the University of Notre Dame. He received his Ph.D. in Experimental Particle Physics from Rice University.