[htss2013]

>The thought that humans might be the only life in the universe to me seems like the 21st century equivalent of believing earth is the center of the universe.

Or it's an acknowledgment of the posterior data that has arisen over the past 30 years.

Every human has a camera 24/7 now and no one has documented visitors. Countless new missions and sensor arrays have found no evidence of life anywhere.

That doesn't prove no life, but it does make it more likely that the Drake equation is based on assumptions that are fundamentally flawed. Otherwise the Fermi paradox wouldn't still be a paradox.

Maybe it's all a simulation. Maybe it's something from a completely different paradigm. Who knows. But insisting they're out there as more decades pass with none found...that may be the real insistence that the sun revolves around the earth.

[wolfram74]

That there is no complicated life in Sol system besides on earth, or even within 50 light years of Sol system, and that there is complicated life in other parts of the universe are easily mutually compatible facts. Considering our search exhaustive at this point is selling the size of the universe short. We'll likely never interact with extra terrestrials, but it's silly to assume they're not out there.

[IanCal]

There being life somewhere in the universe and something coming to visit here are wildly different things though.

[revscat]

> Every human has a camera 24/7 now and no one has documented visitors.

You are being willfully obtuse. There have been thousands of documented sightings over the past 80 years. Audiovisual recordings abound, not infrequently matched with radar or other secondary corroborating evidence.

The typical response to this is:

1. “They are faked.”

2. “That doesn’t mean it’s aliens.”

3. “It’s a secret government program.”

Fine. Nevertheless some percentage of documented events cannot be explained. There is a non-zero chance that they are caused by things that were not made by humans. They deserve to be scientifically investigated in good faith, without the arrogant dismissiveness that is so frequently encountered.

Something mysterious is going on in our skies.

[akomtu]

A much bigger elephant in the room is the fact that nearly all mass of the universe is made of dark matter and we have no clue what it is.

It seems plausible to me that by the time a civilization can quickly travel to other stars, it becomes so different that it doesn't need to interact or even be visible to advanced monkeys on a distant planet, just like we aren't really striving to talk to exotic monkeys on isolated islands. And the only reason those exotic monkeys and birds haven't become our food, like cows or pigs, is that there is very little protein on their bones (speaking bluntly).

We also wonder why we don't see alien activity in radio spectrum, while at the same time we use encryption to make radio wave communication indistinguishable from noise. More advanced civilization might have learnt that not getting noticed is vital to survival, so they scramble all signals. That background microwave noise might be those signals scrambled.

[dougmwne]

Space is much bigger than you are accounting for and the speed of light much slower. If the nearest spacefaring civilization is in the next galaxy over, we will never meet them. It actually seems rather unlikely any spacecraft could ever reach us unless they evolved right in our backyard, within a few dozen light years.

[polishdude20]

That's also IF the life is space faring. We haven't even found life anywhere that is at least remotely simple let alone one that has built spacecraft.

[dougmwne]

But to be fair, it’s not like we’ve been able to look very many places. We’ve checked a few of the planets in our own solar system and it could be plausible to detect a civilization within a few light years by radio wave if we were very lucky.

https://physics.stackexchange.com/questions/245505/from-how-...

[wruza]

It’s also extremely hostile to anything non-trivial like biology or electronics. We all have that cool space-faring ideas in mind from scifi, but reality is more like swimming in a tiny boat through the storms of Pacific Ocean and it’s acid.

[chongli]

That perspective is a somewhat human-centric one. There’s nothing stopping some aliens from having lifespans in the thousands or even millions of years. For those cultures, a 300 year trip is nothing!

Furthermore, Andromeda galaxy is on a collision course with the Milky Way. If there’s an intelligent alien culture there, they might get here just by waiting.

[dougmwne]

Well we reproduce so it’s really the same difference. The huge limiting factor for getting between stars seems to be the rocket equation. You have to invent magic propulsion to cross the galaxy.

[jimmcslim]

Have a look at the Grabby Aliens model [1] when essentially says:

1. We are likely amongst the earliest of advanced space-faring civilisations that have ever exists, which is why we haven't established evidence of other life,

2. There are 'quiet' civilisations and 'loud' civilisations. We will never see evidence of 'quiet' civilisations, and the other 'loud' civilisations haven't expanded sufficiently to be observable at this point in time.

3. Assuming we don't die out ourselves and are therefore a 'quiet' civilisation, we should encounter the other 'loud' civilisations sometime in the next hundred million years or so :-)

[1] https://grabbyaliens.com/

[sliken]

Not sure I buy the "we are special/early" explanation.

However I don't think it makes sense for any civilization to be 'loud'. Just seems naive to blunder about and risk your civilization. However monitoring new civilizations for intelligence, fairness, open mindedness, lack of religions that justify killing outside their religion or species, treating the less fortunate of their/other species well and the like. Then once they hit some developmental milestones for compatible civilizations you introduce yourselves. Possible milestones include practical fusion, returning your ecosystem to baseline, practical anti-matter production/use, making a blackhole, traveling to the nearest star that you don't orbit, quantum computing at scale, etc.

Might well be something on the moon, well stealthed, a few meters down, with receivers capable of decryption RF traffic, and sensors to see how quickly we are poisoning ourselves.

If you think about it, if you were an alien watching earth, would you want to meet us? Or terminate us, at least the humans, and wait for something else intelligent to appear.

[Simon_O_Rourke]

> Every human has a camera 24/7 now and no one has documented visitors.

Take a few minutes to listen to Prof. Robin Hanson talk on this very thing.

https://youtu.be/cQq2pKNDgIs

The jist of what he says, is that there's very much weird stuff seen in the sky, like the McMinnville photos [1], but there's nobody as yet landing a craft on the White House lawn and posing for the cameras.

He puts forward a model for this kind of scenario, it's worth a listen, that any visitors would quite rightly be far in advance of the societies we currently live in, and may only show themselves fleetingly so we gain an acceptance of their presence.

[1] https://en.m.wikipedia.org/wiki/McMinnville_UFO_photographs

[GolfPopper]

I don't buy it.

The "weird stuff" is always distant, blurry, shot under terrible conditions, etc. Yet when a research team, or random passer-by snaps a photo of some never-before-seen, or thought-extinct creature, there's no difficulty in getting a quality image, either on the initial sighting or shortly afterward. It's only the "aliens" that are so problematic.

As for the idea that "they" are doing it deliberately (and perfectly)... it reminds me of the TIGHAR folks and Amelia Earhart. TIGHAR knows that Earhart crash-landed on Nikumaroro (Gardner Island), so every piece of information they see is interpreted through the lens of how it fits with that interpretation. But they have no root basis for the conclusion, just that they really want to believe it.

When faced with the question, "Why are pictures of possibly alien UFOs blurry?" two (of many) possible answers are "because if they're not low-quality we can tell they're not aliens" and "because the aliens are carefully arranging circumstances so that pictures of them are always low-quality" I know which one I'm putting my money on.

[cthalupa]

The problem is that "Technology allowing an advanced civilization to travel to Earth, enter the atmosphere, leave, etc." is significantly more complex than "Technology that would allow them to be completely undetectable to us, and also not crash into the planet"

"Only detectable by people with bad gear" is just not a technological state that makes sense in this context.

There is A LOT of stuff recording what's going on in the sky at all times. A lot of stuff that could give us detailed and high resolution images and other readings. Some of it is actively beholden to various governments so I guess you could argue it's being kept from us there - but are all of these governments going to be in lockstep on this issue? And even more aren't - are scientists going to all just keep quiet on this?

We've had all these declassified videos released recently, and they're some of the most obvious not-extraterrestrial-visitors ever. The one recorded on an aircraft carrier through nightvision with the flying triangles? Night vision goggles have triangular apertures. Bokeh takes the shape of the lens aperture - so bokeh lights become triangles. The blinking in and out of existence? Same timing pattern as a commercial jet.

The pill video from the jets? Parallax makes stationary things look like they move fast. The pill only ever looks to rotate/change direction when the actual recording device in it's housing also does. It's all stabilized so it's not readily apparent unless you know to look for it, but it becomes obvious when you do. What is the object itself? It could be a mylar balloon, it could be an IR hot spot from the sun reflecting off the water. Could be other things. What we don't have any reason to believe is that it is some sort of advanced craft with physics-defying maneuverability.

I fully believe that there is intelligent life out there. Probably in our galaxy, but near certainty in the universe. I also believe that the chances we have had intelligent visitors from another place is the barest fraction of a fraction of a percent.