251–260 of 353 posts
Earlier quoted context omitted.
No, he was rightly pointing out that your "there probably is" statement was bullshit, not supportable from the evidence.
> bullshit, not supportable from the evidence Two different things. You can't prove there aren't, and I can't prove there are.
The Fermi paradox is good for a nice chat at a party. But it's not a paradox at all. Imagine there's an alien civilization in our galactic neighbor Proxima Centauri. How would we know they are there? To make it more plausible. Let's say we figure out a way to send a space probe to Proxima Centauri. How do we communicate with that probe? Easy, you say, just like we communicate with the Voyagers: they point a reasonabl…
And getting a low power signal doesnt means its impossible to detect, but that the bandwidth is short. Instead of 200 bits per second, you would get 1 bit per hour. But that´s enough.
Earlier quoted context omitted.
BS. Filter 1. If we had no large moon, roughly every 30 million years or so our axial tilt would become too extreme for life. We do not have another example of a planet with a moon to rival ours in relative size. Filter 2. Without Jupiter acting as a cosmic vacuum cleaner, we'd predictably be hit by enough asteroids and comets that we'd never have evolved. In thousands of solar systems that we've found, we've found l…
But it comes back to the number of chances. To wit, there's approximately 200,000,000,000,000,000,000,000 stars in the universe. We might be that one in a 200,000,000,000,000,000,000,000 shot where it all came together to create life but it's rather improbable. Almost certainly is other life out there.
That said, most of the visible universe is now unreachable due to the ongoing expansion of the universe. And life somewhere unreachable, even in theory, is not of that much interest to me.
Earlier quoted context omitted.
Flip the point of view for a moment - what's the absolute best way we could try to say "hey, we're here" to the universe in the hope of detection from far away civilizations? I like the idea of Contact's Prime Number signal but how would you do this on a large scale? I was thinking Dyson Sphere a star as a huge Flag Semaphore to send the message, but then what rate do you flip bits to make it optimal for the receivin…
And what if we broadcast and whomever hears us wants us dead? Maybe it’s so quiet because to be loud results in death of the entire civilization.
You build replicating factories to build relativistic kill missiles and preemptively destroy all the planets in the galaxy.
The Fermi paradox is good for a nice chat at a party. But it's not a paradox at all. Imagine there's an alien civilization in our galactic neighbor Proxima Centauri. How would we know they are there? To make it more plausible. Let's say we figure out a way to send a space probe to Proxima Centauri. How do we communicate with that probe? Easy, you say, just like we communicate with the Voyagers: they point a reasonabl…
> it's just some aliens that are not pointing an antenna straight at us Even worse, don’t modern digital signals look similar to noise, are usually encrypted, use much higher frequencies, and have less gap between bands? Good luck trying to spot a cellphone signal from Proxima Centauri (my phone has trouble getting signal at home!) Many analogue broadcast signals have been replaced by digital, and broadcast as a tech…
That being said, the question is to tell if a signal is man-made or not, which is much easier than to discover what information it conveys. Based on modulation carrier frequency and the transmit (on/off) pattern you can still very much tell if that signal is man-made or not.
The Fermi paradox is good for a nice chat at a party. But it's not a paradox at all. Imagine there's an alien civilization in our galactic neighbor Proxima Centauri. How would we know they are there? To make it more plausible. Let's say we figure out a way to send a space probe to Proxima Centauri. How do we communicate with that probe? Easy, you say, just like we communicate with the Voyagers: they point a reasonabl…
Flip the point of view for a moment - what's the absolute best way we could try to say "hey, we're here" to the universe in the hope of detection from far away civilizations? I like the idea of Contact's Prime Number signal but how would you do this on a large scale? I was thinking Dyson Sphere a star as a huge Flag Semaphore to send the message, but then what rate do you flip bits to make it optimal for the receivin…
The problem is the other way around. An unintentional or broad signal is extremely unlikely to be picked up. However, it would be trivial to send out an intentional signal to a candidate planet that can be picked up without the locals having an equivalent of SETI, and there's no rational* reason not to do it if you decided to send. SETI's useless either way.
* The moment you get to irrational aliens, is the moment you need to consider the option they exterminate anyone who replies, so SETI for listening to irrational signals is also a bad idea.
Earlier quoted context omitted.
Flip the point of view for a moment - what's the absolute best way we could try to say "hey, we're here" to the universe in the hope of detection from far away civilizations? I like the idea of Contact's Prime Number signal but how would you do this on a large scale? I was thinking Dyson Sphere a star as a huge Flag Semaphore to send the message, but then what rate do you flip bits to make it optimal for the receivin…
And what if we broadcast and whomever hears us wants us dead? Maybe it’s so quiet because to be loud results in death of the entire civilization.
This paper seems to explore a question I've had for a while which is: What is the maximum distance an Alien civilisation could eventually detect life signatures from Earth assuming their detection technology matches ours? I know that our current radio signals extend 100 light years or so but at which distance could these eventually be detected? I ask because I've read that in order for the SETI program to make a dete…
Our electromagnetic shell drops below the noise floor around 15 light years out for say 5 MW military radars. For coherent signal decoding into carrier wave and payload waveforms as opposed to being able to point to a signal and say, yep that's not natural, probably around 5 light years out. Some discussion here [1] to get you started. Even assuming super duper alien technology that violates what we know of the physi…
The Curiosity rover communicates with Earth from Mars with an antenna the size of a soda can.
Earlier quoted context omitted.
We might be able to see their drive plumes if they use some of the theoretical high performance reactive drives we know of on big crafy. Eq. various fusion plasma drives, Orion, Nuclear Salt Water Rocket release so ludicrous ammounts of energy that they might be visible over interstellar distances, especially if pointed in our general direction when running. Massive solar sails as well would be very very big and very…
I'm not convinced we would be able to view any of those. The only exoplanets we've been able to directly image are huge gas giants that emit a ton of infrared light. A massive solar sail will likely be much smaller and emit a lot less light. See here for a list with images to understand the level of detail we're getting: https://en.wikipedia.org/wiki/List_of_directly_imaged_exopla... I'd think you can easily have gal…
All occlusion observations require orbital planes which are aligned such that they're viewable from our solar system, further reducing observable planets.
And yes, there are a very few exoplanets which have been directly observed, but those are very much the exception.
Detecting any signals or emissions of a technological alien race would be exceedingly difficult even at near range.
Though mention of possible rocket systems and the fact that these are directional suggests that one of the more likely signals to be detected might be a decelerating ship, or ships, approaching the Solar System directly.
Earlier quoted context omitted.
> bullshit, not supportable from the evidence Two different things. You can't prove there aren't, and I can't prove there are.
"Bullshit", as I use the term, is misrepresentation of the state of your knowledge by confident assertions you can't back up with evidence. The statement is precisely that, bullshit.
No one is getting all oracular here. I have my opinion, you have yours. "Probably" is not a "confident assertion" at all.