Oh, they know we're here. They avoid us for the same reason we'd leave if we could.
Posted on 09/28/2022 7:39:15 PM PDT by LibWhacker
Earth is “well-hidden” to extraterrestrial observers using photometric microlensing to hunt for habitable planets that might support life, an international team of researchers has concluded. The findings could also help to narrow down the best areas of the galaxy to target in our own searches for extraterrestrial intelligence (SETI).
When looking for potentially inhabited planets beyond the solar system, astronomers have a variety of tools at their disposal. As it stands, by far the most successful of these has been the transit technique, which has made about 75% of all the exoplanet discoveries so far. This approach involves watching for the periodic dimming of a star’s light as a planet passes between the star and an observer on Earth.
The transit method, however, has its weaknesses; the principal one being that transits only occur for the small fraction of planets whose orbital planes are almost exactly edge-on to Earth. An alternative approach lies in photometric microlensing, which involves the gravitational lens effect that occurs when one star passes in front of another, temporarily magnifying the light from the more distant, “source” star. If the nearer star has a planet orbiting it, this can further perturb the light, leading to characteristic spikes in the observed light.
Long-distance technique A particular advantage of the microlensing technique is that it works at relatively long distances. While other exoplanet detection methods have typically only yielded planets up to one kiloparsec (about 3200 light–years) away from Earth, the majority of the 130 exoplanets detected to date using microlensing are up to seven times that distance from Earth. Accordingly, with the Milky Way being around 30 kiloparsecs across, it is conceivable that the microlensing method might be used by other technological civilizations to detect the Earth across galactic distances.
It has long been considered that those locations from which Earth could be detectable via the transit method are themselves good candidates for targeted SETI searches – following a game theoretic, “Schelling Point” cooperation strategy for two parties looking for each other who have no means of communicating. Applying the same logic to the microlensing technique has, therefore, the potential to identify new and more distant targets for the search for extraterrestrial intelligence.
In their new study, astronomer Eamonn Kerins of the University of Manchester and his colleagues considered the photometric microlensing signal of the Earth as it would appear to other potential technologically-advanced civilizations.
Defining the EMZ “[We] dub the regions of our galaxy from which Earth’s photometric microlensing signal is most readily observable as the ‘Earth microlensing zone’ (EMZ),” the researchers explain, adding: “The EMZ can be thought of as the microlensing analogue of the Earth Transit Zone (ETZ) from where observers see Earth transit the Sun”.
The team used data from the European Space Agency’s Gaia telescope — specifically, the instrument’s second data release (DR2), which includes information on more than 1.1 billion stars. Dividing the sky up into small areas, the team mapped out from where Earth’s microlensing signature would be visible. Even if technologically advanced alien civilizations were located around every star they studied, the team found that the total Earth discovery rate is only 14.7 observers per year across the entire sky — meaning that, assuming technological life is actually relative rare, it is “very doubtful” anyone has spotted us using microlensing.
“Earth would be a challenging target,” Kerins told Physics World, in part because it is rather too close to the Sun to give a strong lensing signal for most potential observers. Furthermore, he said, “our location 27,000 light-years from the [Milky Way’s] galactic centre is something of a blind spot for any observer using microlensing.”
Background stars needed To have a good shot at spotting us, Kerins explained, an alien civilization would need to be positioned such that there were a lot of background stars behind us, as to give the Earth a good chance of deflecting the light from one. “The best position for an observer to be is right at the edge of our galaxy with us on a line of sight towards the galactic centre,” he noted, adding: “But there are very few stars at the edge of our galaxy and so presumably few observers.”
Defining EMZs as those areas containing the top 1% of discovery rates, optimal regions for detection appear in the Large and Small Magellanic Clouds, as well as at low galactic latitudes near the galactic centre — where there is some overlap with ETZs.
The researchers note that the direction from Earth in which potential alien civilizations would have the highest chance of detecting Earth is towards the Milky Way’s Orion–Cygnus arm, in the galactic plane. There, Earth’s microlensing probability and discovery rate values are 3.28×10−10 and 2.35×10−2 observer per year per square degree respectively.
The researchers conclude, “Overall, it seems the Earth is very dark to photometric microlensing discovery by other observers, unless they have sensitivity well beyond our own present capabilities.”
Martin Dominik, an astrophysicist from the University of St Andrews who was not involved in the present study, comments, “Clever aliens might want to use gravitational microlensing for finding candidate planets to search for other civilizations.” He adds, “It appears intriguing that they won’t be able to detect Earth transiting in front of the Sun unless they are in a narrow strip close to the ecliptic plane, which does not make it a good option to get to know each other!”
I agree. We are too crazy and not developed or mature enough.
We do not have own stuff together as a world. Still fighting among ourselves.
Society will freak out if aliens show up today.
LOL. Loved Hitchhiker’s.
Well, they ARE in trouble if they think any of God’s commands are insignificant. If He tells you how to comb your hair, you’d BETTER do it that way!
And once those Raquel Welch movies from the 60’s arrived, they headed this way, warp factor 9.
Sort of like Homo habilis asking what humans of the 21st Century could possibly have that they don’t.
One thing I found amazing about the trilogy (especially the first book).
The chinese author wrote about the communist take over of china. I was thinking...they let him write about this? Because he doesn’t make it sound good. And also in the book he talks about a political officer in the military. Something as a USAF Officer is completely foreign to me and he had no clue most militaries don’t have this.
But that’s just an aside from the great sci-fi in the trilogy. It’s hardcore sci-fi too. Quantum Physics, entanglement, life outside of our planet issues, etc... Amazing.
Thank you for the tip. Sounds just like the kind of sci-fi I love.
So you people actually think Biden, Obama, Gates, Soros and Schwab are homo sapiens of this earth? Interesting theory.
(ha ha right?)
Maybe they are aliens like Kim Jong-Il in Team America
I was sent from planet Gyron to conquer the Earth
I had a terrific plan
I thought it would work
Tried to get the earthlings all to kill each other
You see
But it all went wrong and now I must decree
You are worthless, Alec Baldwin
You are worthless, Alec Baldwin
You failed in every way and now my stock in you has fallen.
Your career is stalling’ and you’re worthless, Alec Baldwin
That’s why I blew your head off
And your children are all Balwin
Planet Gyron is inhabited with Zypods like me
But also with Balmacks who are giant bees
The Zypods and the Balmacks are at constant war
So we wanted a new home and that’s what Earth was for
But you are worthless, Alec Baldwin
You are worthless, Alec Baldwin
You f**ked up my whole plan
And now Gyron is smeared with Balmack Pollen
Your garbage needs some hauling’
And you’re worthless, Alec Baldwin
Now I must return home a failure
I’m afraid the pit of Kryrock is calling
Oh, they know we're here. They avoid us for the same reason we'd leave if we could.
There is no hiding, there is no advanced alien civilization out there “looking” for us, at this very late stage.
The age of the galaxy is about 13 BILLION years. That is long enough for a single space-faring civilization with only sub-light travel, to probe and possibly colonize every planet in this galaxy, THOUSANDS OF TIMES OVER.
Any sense of isolation we have on Earth is almost certainly artificial and intentional.
It’s not that they don’t know about us.
We are just a quarantined planet.
—
This is far more likely. Aliens probably see the inhabitants of this planet as extremely dangerous. The way we might see a tribe of primitive headhunters.
For me, it’s the sin issue. The natural consequences of sin must become undeniable, which may include the conditions to which we might extinguish ourselves.
If God were to allow advanced races to make an appearances, they could save us from continuing down the path of sin. If we were saved from our sins, then man would not face the full consequences of sin. If that were to happen, we would have an out as to why sin cannot be considered that bad and we might continue.
However, if we were allowed to continue down the path of sin until we have extinguished ourselves. Whether because of AI or a too polluted environment or disease from bad chocies, then it becomes undeniable and we will be more ready to be completely obedient even on the smallest of sins because we know what might happen now.
What I mean is that the fruit from the Tree of Knowledge was the smallest possible sin, in the overall scheme of things, that man could commit. If Adam and Even had refrained from touching and eating the fruit, we would have maintained a sinless world because we wouldn’t do other sins that are worse than that. It’s a gateway sin, so to speak.
I don’t think that we will be the last creation in a deathless and future sinless universe. If there are other creations, they will have their own tests of their smallest possible sins that, if avoided, will help maintain their world to be a sinless one.
You and I, having intimate knowledge of just how things can get in a world of sin, we would be well qualified to teach new creations why they should resist their gateway sins.
I think it was C.S. Lewis that said something like the following, but I can’t find the actual quote. He supposed that it would be no stretch for other beings to exist in the universe. He also figured that they may live in their own paradise untouched by sin. But then he brings up his mixed feelings about that. While it would be great to live in paradise (and in constant relationship with God), then one would never know the grace and forgiveness and redemption of God.
I wish I could find the quote. I did find another interesting conversation:
Wirt: Do you think there will be widespread travel in space?
Lewis: “I look forward with horror to contact with the other inhabited planets, if there are such. We would only transport to them all of our sin and our acquisitiveness, and establish a new colonialism. I can’t bear to think of it. But if we on earth were to get right with God, of course, all would be changed. Once we find ourselves spiritually awakened, we can go to outer space and take the good things with us. That is quite a different matter.”
In that same article it said that Lewis and Tolkein were discussing space travel and time travel one evening. After much discussion they each agreed to write about one of the topics. They flipped a coin to see who would get which topic, and Lewis got space travel. He ended up writing much about it - Tolkein never got around to his writing about time travel! (Or at least that is what the article said.)
My understanding is that Lewis had to write about being in another space we’ve never been to,never been to, which resulted in the Space Trilogy. Tolkien had to write about a time we’ve never had, which resulted in the LOTR.
Thank you - that would make sense, as the LOTR sure seems like a sort of “time travel”. (Like Star Wars?)
Years ago I had the evening to myself, no kids around, wife was out of town and I had no evening work. I had planned it for a few days to make a special meal, popcorn, etc. and sit down and watch the epic LOTR. I was full of anticipation.
I found it to be pretty boring. I watched the entire thing, but I can’t say it did much for me. I think I watched some of the later ones with my kids and those seemed to be more enjoyable.
> Need to read the Three body problem trilogy. It deals with this issue. Best Sci-Fi book ever.
I finally went through that one a couple of years back. Great science in there, but it had a depressing Chinese world view.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.