If aliens call, what should we do? Scientists want your opinion

If they were so advanced, presumably they would go to the trouble of learning to communicate with us before they arrived or announced themselves. If this were the case, we should probably just listen as we're at a fairly significant disadvantage and we have more to gain from them than them from us. In that case, I'd probably send the Aga Khan, Dalai Lama, a Pope and other religious leaders because they deal with this specific existential problem in a fairly in-depth way, and and billions of people will credibly listen to them.

However, if the aliens just YOLO'd it and showed up, this sounds completely insane, but I'd send the head rider of the Spanish Riding School of Vienna or the Cadre Noir of France, as an advisor/translator because they have spent their entire lives cultivating the ability to listen, empathize, and develop sophisticated communications and relationships with beings that are non-human and completely alien to us, while also necessarily embodying human leadership characteristics people develop, and are therefore probably the only humans trustworthy to represent us to an alien species.

Nuts, but we're way past nuts if this happened.

In my personal opinion we should always answer, because (scientific) curiosity trumps all reasons not to. However, we should carefully analyze the message before replying and be careful about what we say.

As a hobby sci-fi author with a long-term interest in the topic, I'd like to point out one thing in the debate that is often forgotten. When it comes to aliens and their motivations, all bets are off. Even if the aliens were capable of FTL traveling, this does not indicate that they are far more advanced than us, that they are probably benevolent, that they would consider us inferior, or anything like that. They could be like us. They could be totally different. They could be more intelligent than us, but they could also be more stupid than us. Technological advances are unpredictable and on the cosmic scale occur in a ridiculously short time span. So they might just be a hundred years advanced in comparison to us, for example, and judging from our own development this does not indicate any major advance in society or biological evolution.

Unfortunately, that also means that seemingly highly advanced aliens might seek out to destroy all other life in the galaxy for religious reasons, for instance. Or they might want to do the opposite. We don't know. Therefore, unless there were specific reasons to distrust them, we should reply, just as we tend to reply phone calls from unknown numbers.

We answer like adults. Ie hello, what’s your nature? Ignoring them is probably not a sustainable option.

Lightspeed-limited message (eg radio, laser): take a collective breath, agree on a response from the UN GA, then coordinate a broadcast from all possible transmitters globally. We want to show pro-social behavor and also strength in unity (even though they've seen our last hundred years via radio). Also immediately prioritize colonizing nearby systems to reduce our likelihood of extinction.

Relativistic spacecraft entering our solar system: similar to above but we won't have as much time for a response so it's better if it's planned ahead of time. Also they're certain to listen to popular reactions—maybe that's something to just acknowledge in the official message, rather than trying to make Earth go dark. Discretely inform any extra-solar colonies.

FTL message: devote all resources to reverse- engineering the technology, and send as many colony ships away as fast as possible (ideally with that FTL tech). Respond as per below.

FTL spaceship: accept our dramatically inferior position and accept their every demand—including religious conversion and slavery—so they don't annihilate us. Getting that FTL tech is a close second priority. If they begin destroying us, broadcast a wide-spectrum warning to other colonies or species.

Don't answer. You never know who is behind the "phone".

I wanna recommend a book to the Scientists called "Three Body Problem" by Liu CiXin. It's a story about inter-galactic struggle between Mankind and Aliens started off because a scientist answer the call.

I don't know but be prepared that it's just a planet-scanning bot.

We should stay quiet; there's no need to inflict humanity's problems and memes on the poor aliens.

Send them a bunch of sci-fi movies and see which ones they like most. Based on that, we should have a pretty good idea of what to expect next.

Say hi then ask them if they have tech that could stop us from destroying our planet.

Ask if they're free for a hot date on Saturday.

That's what Kirk would do.

"do you have a solution for global warming?"

Thank you for calling Earth Tours! [name] speaking, how may I help?

I think it depends a good deal on what the aliens have to say. If the first word out of their mouths is "ni-hau" I wouldn't be inclined to listen much beyond that.

(Just for the record, that was supposed to be a humorous reference to Chinese robocalls, not a pejorative reference to Chinese speakers in general.)