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Aliens have never crashed here. Aliens have never even visited our solar system. The truth is more interesting: the galaxy is emptier than it should be.

FredPret 3y ago
I read somewhere that all of our radio signature would fade away to the point that it's indistinguishable from background noise within five lightyears. Plus, we've been around for ages and only briefly let out a bunch of radio waves. I image we might not even generate that many anymore. By that logic, you could easily image that the universe is teeming with intelligent life that happens to not have sent a powerful radio signal out here, or whose tech development timeline never included wide public radio signal broadcasting.
- baja_blast 3y ago
  Yep radio waves degradation is due to the inverse square law. The strength of the signal is determined by the inverse of the distance squared. So the drop off is pretty extreme.
  - mclightning 3y ago
    I used to be greatly tempted by the fermi paradox, but upon learning about limitations we have observing the skies.... I believe the entire fermi paradox talk, is just steeming from the fact that we think too highly of ourselves as a civilisation and the efford we put into observing the skies. Most people, including myself until recently, don't realise that most of our astrophysics/space science is very limited to our immediate close promixity in the cosmological scale. Correct me if I am wrong but we are only able to do science around the other stars in the Milky way (e.g. exoplanet observations) Beyond Milky way, all the light from the stars are collapsed into a single blob along with the rests of the stars in their home galaxy.
    - baja_blast 3y ago
      > Correct me if I am wrong but we are only able to do science around the other stars in the Milky way (e.g. exoplanet observations) Oh yeah and on top of that the way we detect planets around stars creates a extreme bias on dwarf stars since a positive detection needs a few transits before confirmation of a planet can be made. And since dwarf planets transit within days/weeks sun like stars take around a year so it would take 3 years of observation to find an Earth around a sun-like star. But I have heard science communicators imply that what we have detected so far is representative of what is out there which is absurd. If FTL is impossible(which I doubt since it's only "impossible" in some capacity in Special Relativity. But Special Relativity does not describe our universe, General Relativity does and even that has limits),then not seeing Aliens is not a paradox at all considering radio waves only go out a few light years, and the distances are just too great. And if there are any Alien probes in our solar system sitting on IO or some moon we'd have no idea since we have only done flybys and never truly scanned the surfaces.
      - mclightning 3y ago
        I thought on this for a few days. The nature of scientific process, forces us to maintain absolute emphasis on our observation, to an extent which we are willfully ignoring the limitations and scope of our observations. I wonder who is to blame, is this the current state of scientific studies? or they are actually considering these limitations in the papers, but it is ignored by public? then, is it the science communication to the public that's failing? I feel shy even bringing up such topics among friends, because it is so far out of the common understanding that it will sound like flat-earth conspiracy to most. People don't like to hear anything that goes like "we don't know some things at all". There is a comfort in knowing somewhere, some scientist are %100 accurate and know it all.
merpnderp 3y ago
If you look at all the crazy coincidences that were required for life to develop on Earth, it starts to make sense that we're alone. Single star in the system, need a big Jupiter to block space rocks, our target is a rocky planet close to star, but needs to be hit by an abnormally large moon right as the lithosphere is cooling, ripping out 1/3rd of it so that the planet can have giant continents barely covered with water part of the time, then submerged the rest of the time to the cadence of this moon, oh and has to be the right star type, and etc etc etc. If it takes something like all that for life to spontaneously erupt, we're likely alone.
- baja_blast 3y ago
  Jupiter directs more rocks towards earth than deflects. But life on earth appeared immediately after it cooled suggesting that the process to start life is relatively straight forward. And life by default adapts and evolves based on it's environment, so how crucial the moon is for life says more about how life on earth adapted than how it can possibly form.
- eBombzor 3y ago
  That's one example of how life is formed. By someone's definition on wiki, life could be defined as > self-sustained chemical system capable of undergoing Darwinian evolution Meaning in a different environments with different moons, stars, temperatures, as long as the environment could support abiogenesis (could be different from what we currently know), life would be able to be sustained but it might be a hell of a lot different. I don't really know what I'm talking about but surely a different life form would've existed at some point somewhere... Right?
- 7thaccount 3y ago
  We may only think that because we evolved here and thus think you must need all of that as we can't think of it any other way. On another note, you probably are absolutely right and we do need at least some of that. Not too hot or cold. No massive asteroids to destroy everything...etc. I think some of the rest may be negotiable though. Like do you need water? I think yes, buuut maybe some other liquid could work?
- 3y ago
misterprime 3y ago
Beefman, could you tell us more about how you know this?
- soVeryTired 3y ago
  The Drake equation? We can see the stars, we can see the planets (and there are lots of them). We can infer the number of earth-like planets. So where's all the intelligent life?
  - orwin 3y ago
    Does the drake equation takes into account the timeline earth-like planet have to be inhabitable to carbon-based lifeforms?
  - distortionfield 3y ago
    It could all still be at a relatively early stage like us. Grabby aliens hypothesis predicts this and models it quite well actually. 1. https://grabbyaliens.com/ https://grabbyaliens.com/
bostonwalker 3y ago
I wouldn’t go so far as to claim that we have hard evidence of aliens crashing here or visiting our solar system, but you’re going completely the other way and making an extraordinary claim without evidence. Absence of evidence is not evidence of absence.
detrites 3y ago
Maybe it's emptier than it should be because that's how the universe is always made to appear to emergent civilisations at the dangerous and volatile point of evolution we presently find ourselves at?
syndacks 3y ago
Praise the lord!
ryanmercer 3y ago
> the galaxy is emptier than it should be. It really isn't. Do the math, I did (scroll about halfway down): https://www.ryanmercer.com/ryansthoughts/2014/11/30/this-just-in-you-dont-matter https://www.ryanmercer.com/ryansthoughts/2014/11/30/this-jus... Being very generous, in my opinion, and assuming 1 in 2 systems has a planet/moon that is inhabitable by life as we know it, and that 1 in 2 of those has tool-building life at some point, in our galaxy you get something like 1 tool-building civilization per 600,000 square light-years spread out over 12 billion years.
nonethewiser 3y ago
Ill bite. > The truth is more interesting: the galaxy is emptier than it should be. Why should it be less empty and what are the implications that its emptier than it should be?
Tepix 3y ago
That would be depressing. Now if it were less empty than average, that would be more interesting.

FredPret 3y ago

I read somewhere that all of our radio signature would fade away to the point that it's indistinguishable from background noise within five lightyears. Plus, we've been around for ages and only briefly let out a bunch of radio waves. I image we might not even generate that many anymore. By that logic, you could easily image that the universe is teeming with intelligent life that happens to not have sent a powerful radio signal out here, or whose tech development timeline never included wide public radio signal broadcasting.

baja_blast 3y ago
Yep radio waves degradation is due to the inverse square law. The strength of the signal is determined by the inverse of the distance squared. So the drop off is pretty extreme.
- mclightning 3y ago
  I used to be greatly tempted by the fermi paradox, but upon learning about limitations we have observing the skies.... I believe the entire fermi paradox talk, is just steeming from the fact that we think too highly of ourselves as a civilisation and the efford we put into observing the skies. Most people, including myself until recently, don't realise that most of our astrophysics/space science is very limited to our immediate close promixity in the cosmological scale. Correct me if I am wrong but we are only able to do science around the other stars in the Milky way (e.g. exoplanet observations) Beyond Milky way, all the light from the stars are collapsed into a single blob along with the rests of the stars in their home galaxy.
  - baja_blast 3y ago
    > Correct me if I am wrong but we are only able to do science around the other stars in the Milky way (e.g. exoplanet observations) Oh yeah and on top of that the way we detect planets around stars creates a extreme bias on dwarf stars since a positive detection needs a few transits before confirmation of a planet can be made. And since dwarf planets transit within days/weeks sun like stars take around a year so it would take 3 years of observation to find an Earth around a sun-like star. But I have heard science communicators imply that what we have detected so far is representative of what is out there which is absurd. If FTL is impossible(which I doubt since it's only "impossible" in some capacity in Special Relativity. But Special Relativity does not describe our universe, General Relativity does and even that has limits),then not seeing Aliens is not a paradox at all considering radio waves only go out a few light years, and the distances are just too great. And if there are any Alien probes in our solar system sitting on IO or some moon we'd have no idea since we have only done flybys and never truly scanned the surfaces.
    - mclightning 3y ago
      I thought on this for a few days. The nature of scientific process, forces us to maintain absolute emphasis on our observation, to an extent which we are willfully ignoring the limitations and scope of our observations. I wonder who is to blame, is this the current state of scientific studies? or they are actually considering these limitations in the papers, but it is ignored by public? then, is it the science communication to the public that's failing? I feel shy even bringing up such topics among friends, because it is so far out of the common understanding that it will sound like flat-earth conspiracy to most. People don't like to hear anything that goes like "we don't know some things at all". There is a comfort in knowing somewhere, some scientist are %100 accurate and know it all.

merpnderp 3y ago

If you look at all the crazy coincidences that were required for life to develop on Earth, it starts to make sense that we're alone. Single star in the system, need a big Jupiter to block space rocks, our target is a rocky planet close to star, but needs to be hit by an abnormally large moon right as the lithosphere is cooling, ripping out 1/3rd of it so that the planet can have giant continents barely covered with water part of the time, then submerged the rest of the time to the cadence of this moon, oh and has to be the right star type, and etc etc etc. If it takes something like all that for life to spontaneously erupt, we're likely alone.

baja_blast 3y ago
Jupiter directs more rocks towards earth than deflects. But life on earth appeared immediately after it cooled suggesting that the process to start life is relatively straight forward. And life by default adapts and evolves based on it's environment, so how crucial the moon is for life says more about how life on earth adapted than how it can possibly form.
eBombzor 3y ago
That's one example of how life is formed. By someone's definition on wiki, life could be defined as > self-sustained chemical system capable of undergoing Darwinian evolution Meaning in a different environments with different moons, stars, temperatures, as long as the environment could support abiogenesis (could be different from what we currently know), life would be able to be sustained but it might be a hell of a lot different. I don't really know what I'm talking about but surely a different life form would've existed at some point somewhere... Right?
7thaccount 3y ago
We may only think that because we evolved here and thus think you must need all of that as we can't think of it any other way. On another note, you probably are absolutely right and we do need at least some of that. Not too hot or cold. No massive asteroids to destroy everything...etc. I think some of the rest may be negotiable though. Like do you need water? I think yes, buuut maybe some other liquid could work?
3y ago

misterprime 3y ago

Beefman, could you tell us more about how you know this?

soVeryTired 3y ago
The Drake equation? We can see the stars, we can see the planets (and there are lots of them). We can infer the number of earth-like planets. So where's all the intelligent life?
- orwin 3y ago
  Does the drake equation takes into account the timeline earth-like planet have to be inhabitable to carbon-based lifeforms?
- distortionfield 3y ago
  It could all still be at a relatively early stage like us. Grabby aliens hypothesis predicts this and models it quite well actually. 1. https://grabbyaliens.com/ https://grabbyaliens.com/

bostonwalker 3y ago

I wouldn’t go so far as to claim that we have hard evidence of aliens crashing here or visiting our solar system, but you’re going completely the other way and making an extraordinary claim without evidence. Absence of evidence is not evidence of absence.

detrites 3y ago

Maybe it's emptier than it should be because that's how the universe is always made to appear to emergent civilisations at the dangerous and volatile point of evolution we presently find ourselves at?

syndacks 3y ago

Praise the lord!

ryanmercer 3y ago

> the galaxy is emptier than it should be. It really isn't. Do the math, I did (scroll about halfway down): https://www.ryanmercer.com/ryansthoughts/2014/11/30/this-just-in-you-dont-matter https://www.ryanmercer.com/ryansthoughts/2014/11/30/this-jus... Being very generous, in my opinion, and assuming 1 in 2 systems has a planet/moon that is inhabitable by life as we know it, and that 1 in 2 of those has tool-building life at some point, in our galaxy you get something like 1 tool-building civilization per 600,000 square light-years spread out over 12 billion years.

nonethewiser 3y ago

Ill bite. > The truth is more interesting: the galaxy is emptier than it should be. Why should it be less empty and what are the implications that its emptier than it should be?

Tepix 3y ago

That would be depressing. Now if it were less empty than average, that would be more interesting.