Have we waited long enough to send any aliens out there another message?

If extraterrestrials exist, we have no idea whether they are trying to send a message to other extraterrestrials (to them that would be us). Earth tried calling once. No one phoned home. Maybe we should call again — and say something else.

In 1974, the Arecibo Radio Telescope in Puerto Rico beamed a message to the stars that was meant for any other intelligent civilizations that exist. It wasn’t so easy to dial up aliens as a certain iconic creature from another planet thought it would be when he tried to use the phone in E.T.: The Extra-Terrestrial. To reach the star cluster M13, which is 21,000 light years away, Arecibo’s huge antenna needs to beam its megawatt transmitter’s energy into the sky. Turned out that might have not been the ideal place to send it, or the best message to send.

Astrophysicist Jonathan Jiang thinks we’ve waited long enough since Arecibo, so he led a team in creating a message to beam over to anyone who might be out there. He wanted to create something that was potentially easier to understand for an alien civilization than the pictorial Arecibo message. This is why his message was written in binary code, which is more of a universal language than symbols which may leave other intelligent beings confused.

“Any type of intelligent civilization should understand this because binaries are yes and no,” Jiang told SYFY WIRE. “Our intelligence, even our consciousness, is based on so many yeses and nos, which form our communications, so we used binary code to introduce ourselves.”

What should these hypothetical beings know about us? In the message, a series of 0s and 1s are used to explain what humans are and how we think. This includes our size, our mass, our biology, our mathematics, and our physics. There was still one problem left. Wherever there might be life with brains, their concept of time might be totally different depending on how long it takes for the body they live on to orbit their star, so our understanding of time will mean nothing to them. Jiang found a solution for that which goes all the way back to the Big Bang.

Aliens will be able to tell when the message was sent because of a timestamp created from hydrogen. Neutral hydrogen gas was around at the dawn of the universe. Its atoms become high-energy when they crash into electrons or other atoms, which aligns the spin of its electron and proton, but will end up flipping its spin back to its previous state of lower energy after about 10 million years. This is known as the spin-flip transition. With this timestamp, it is possible to understand how long after the Big Bang humans transmitted the message.

“Our timestamp is based on fundamental physics, and the same laws of physics apply anywhere in the galaxy,” said Jiang. “We believe intelligent life should have the same laws of physics that we do and be able to understand astrophysics and quantum mechanics.”

Maybe E.T. was more fascinated by the curiosities in a suburban household, but it would only make sense that an actual intelligent alien civilization would discover physics at some phase in their evolution. The most advanced tech we have on Earth is nothing compared to what a civilization around for millions of years could potentially pull off. Aliens would need knowledge of physics to build a Dyson sphere able to harvest energy from the star they orbit, or travel at the speed of light, or come up with some other form of tech that is beyond imagination.

Humans aren’t all that advanced. We aren’t even able to harness the power of a star yet. Never mind that it will be a while before we have the technology to beam this message to someone...or something.

Though another study tried searching for technosignatures in the galactic center and got no dial tone from E.T., it doesn’t mean we are alone. There are enough exoplanets around that region, around 13,000 to nearly 20,000 light years away, which are within the habitable zones of their stars. Earthlings will have to wait. No one might pick up the proverbial phone for hundreds of years. Jiang thinks that so long as homo sapiens don’t realize the late Stephen Hawking’s worst fear and self-annihilate before our message reaches an extraterrestrial, we have the chance to find out.

“Uncertainty is a huge danger,” he said. “We have to prepare ourselves even if we’re not here; we have to leave a legacy that says the human species was here once, and urge people to think about themselves and our survival.”