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Are we visible to advanced alien civilizations?
- tetrisgm 3y agoThe answer is yes. Simply because the question is flawed. The premise of the question is advanced alien civilizations exist. It asks are we visible to them. We don't have a definition of what advanced here, so for any answer that's no yes, let's just assume they could get more advanced. So the question is just: are we visible? (Assuming infinity advancement and that there are alien civilizations). Yes we are visible.
- deleted 3y ago[deleted]
- samstave 3y agoOrcas. If we are being observed by Aliens, I hope they focus on animals, specifically Elephants, Dolphins, Orca and Penguins.
- bemusedthrow75 3y agoOh yeah. Orcas. The other highly intelligent, highly social apex predators that haven't graduated from sexual violence for domination and torturing lesser creatures for fun.
- samstave 3y agoThey dont destroy. You are fun at BDSM parties.
- bemusedthrow75 3y agoOrcas kill other creatures and discard them without eating them. They are highly capable, intelligent and enjoy violence for the sake of it. Give them limbs and opposable thumbs and they would be just like us. There's absolutely no reason to project any kind of higher, more connected, more honest natural wisdom onto them.
- samstave 3y agoSeriously, you have converted me. put this internet point in your trophy cabinet. (i mean that, im not being rude)
- deleted 3y ago[deleted]
- zelphirkalt 3y agoIs it a reference to Star Trek? Otherwise, why would they focus on animals, when mankind is the most visible and most affecting the planet?
- samstave 3y agoI guess it would be based on level of intelligence of their environ.. Who actively destroys their environ? Humans. these animals master their environment without destruction. Humans destroy.
- etaioinshrdlu 3y agoIs it because these animals are smarter and wiser than people or because they're literally not able to?
- samstave 3y agoYes
- bemusedthrow75 3y agoHaha OK this is a good answer. :-)
- nozzlegear 3y agoHow do we know aliens don’t destroy their environs too? Maybe it’s the mark of an “intelligent” species.
- dylan604 3y agoHow do you get to the point of observing orcas before you've noticed everything else on the surface?
- A_D_E_P_T 3y agoSo the pyramids are visible out to 3000 light years away if the aliens have extremely powerful optical telescopes. More recent developments, like satellites, might be visible out to 60ly. It is basically a signal travel speed issue. So, the paper doesn't mention this, but if -- and only if -- they're looking for pyramids, we're visible to about 0.1% of the galaxy.
- bemusedthrow75 3y ago> So the pyramids are visible out to 3000 light years away if the aliens have extremely powerful optical telescopes. Is such a telescope (resolving power etc.) actually possible? At the level of basic physics, could anyone build it, hypothetically? I don't know, because I am an idiot who has spent 30 years building websites of various complexity and pretending that is advanced knowledge.
- boomboomsubban 3y agoIt seems to involve building a telescope with a diameter of several million kilometers. As a reminder, the circumference of the earth is about 40,000km. So several hundred times bigger than the earth. It's hard to imagine, but the baseline mentioned is being able to utilize all the energy of their star.
- jandrese 3y agoAnybody who starts off their paper with mentions of the Kardashev scale is already pretty far out there. It has never been clear to me if even a Level 1 civilization is practical, there could well be physical (as in physics based, like thermodynamics) limits that prevent you from reaching that point. And the scale goes dramatically up from there. Level 2 is building Dyson Spheres. It always felt like the whole thing was made by someone who didn't really have a good grasp of scale. Maybe it's a failure of imagination on my part, but I tend to think that projects on scales like that are just too impractical for real life. It's like if you decided to make up a scale for land speed records, and made type 1 100,000 kph, level 2 100,000,000 kph, and level 3 100,000,000,000 kph.
- crispyambulance 3y agoI certainly hope so. It might take a few years, or hundreds, or thousands to finally receive a tentative "hello?" transmission from them, however. I struggle to even imagine how Earth's civilizations would react to such a "phone call."
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- Joeri 3y agoThey would write “wow!” on top of the printout and call it a day. Somewhat more seriously, I have my doubts we would even pick up or recognize the hello today.
- Brajeshwar 3y agoFor those wondering about “wow” - https://en.wikipedia.org/wiki/Wow!_signal https://en.wikipedia.org/wiki/Wow!_signal I learnt about this about a decade ago and was a nice read.
- ta8645 3y agoWe'd have to return the greeting, including our preferred pronouns.
- bemusedthrow75 3y agoPlease no. At least let us get 2024 over with first. Then maybe we can hold our heads up.
- LuciBb 3y ago[flagged]
- ck2 3y agoPBS Space Time of course https://www.youtube.com/watch?v=Ttwl_zH_DZ8 https://www.youtube.com/watch?v=Ttwl_zH_DZ8 some other great related episodes (but really all are fantastic) https://www.youtube.com/watch?v=uTrFAY3LUNw https://www.youtube.com/watch?v=uTrFAY3LUNw https://www.youtube.com/watch?v=cJONS7sqi0o https://www.youtube.com/watch?v=cJONS7sqi0o https://www.youtube.com/watch?v=uhJ9lJPt09k https://www.youtube.com/watch?v=uhJ9lJPt09k
- dylan604 3y ago> https://www.youtube.com/watch?v=Ttwl_zH_DZ8 https://www.youtube.com/watch?v=Ttwl_zH_DZ8 TRT 17 mins. Actual content 13 mins with the remaining 4 mins about Patreon/subscription/blah. That's just gross.
- dylan604 3y agoby the time they are able to discern features like buildings on the surface, they should have already been able to see what type of atmosphere Earth has. they should have already been able to detect radio signals from Earth.
- pavel_lishin 3y agoIt's neat that it focuses on visible-light observations through a telescope, but I wonder what else is visible at long distances. Would spectroscopy reveal other evidence of our existence? Besides the change in atmospheric co2 levels (which could be explained by natural ebbs and flows caused by, I don't know, volcanoes?), would they see an increase in our use of refrigerants in the late 1900s? Would the effects of nuclear detonations be detectable at all, even in principle? What about things like the use of sodium lamps, and then the switch to more LED lighting?
- marcosdumay 3y agoThe oxygen-rich atmosphere is a dead giveaway, and we can already detect this kind of thing hundreds of light-years away.
- pavel_lishin 3y agoThat doesn't say anything about a civilization, or any life more advanced than single-cells floating in an ocean though, right?
- marcosdumay 3y agoGood luck telling the difference between alien simple life and smart industry, even up close with a microscope. But life on Earth has a strong tendency into aggregating into complex organisms, so we can expect that one step to happen everywhere.
- h2odragon 3y agoThe whole solar system is leaving a scent trail behind it. Just how far does the human flavor in that trail extend? not totally kidding: https://earthobservatory.nasa.gov/images/144386/toward-mapping-the-atmospheres-escape-from-earth https://earthobservatory.nasa.gov/images/144386/toward-mappi...
- spzb 3y agoHang on, I'll ask Professor Farnsworth
- 1970-01-01 3y agoTsar bomba would certainly be visible if they were constantly watching. Anything else would be unlikely. https://en.wikipedia.org/wiki/Tsar_Bomba#Analysis https://en.wikipedia.org/wiki/Tsar_Bomba#Analysis
- hrunt 3y agoTsar Bomba was detonated in October 1961. That means that for any civilization to have seen it, that civilization must be within 63 light years of Earth. In addition, unlike the Pyramids, Tsar Bomba was a momentary flash, so if a civilization within that distance started looking today, they wouldn't see it. They probably wouldn't even see evidence of it, since here on Earth we can detect only traces that it specifically happened. What the paper talks about is constantly visible evidence of human life. Civilizations up to 3000 light-years away can see evidence of the Pyramids because they were built 3000 years ago and have been visible from space ever since.
- graycat 3y agoLet's see: Our galaxy is what, rough ballpark 100,000 light years (LY) in diameter. Soooo, to have a reasonably large collection of aliens to detect us, ask that they be ~50,000 LY or so away. Soooo, by now all they could get from us would be from what we were doing ~50,000 years ago. But we've been radiating from our civilization only in the last ~200 years. Net, the aliens would have to wait ~50,000 years to receive anything very interesting from us. Sooo, have they detected us yet? Likely not. Instead they will have to wait another ~50,000 years. And even if alien ET (extra terrestrial) has found how to travel and signal faster than light, OUR signals, what WE have sent, will still travel only at the speed of light.
- jandrese 3y agoThis paper is very silly. It considers only trying to resolve features with a colossal optical telescope instead of the far easier method of monitoring the chemistry of the atmosphere via spectral absorption lines as it passes in front of the host star to watch for unnaturally rapid changes in carbon dioxide and other chemicals.