Why not? with countless stars in countless galaxies, does anyone really believe that life doesn't exist anywhere else?
I'm still looking for intelligent life on Earth. Seems hard to find these days.
Its the Vex.
Grtechguy said:Why not? with countless stars in countless galaxies, does anyone really believe that life doesn't exist anywhere else?
Actually, most of the physicists believe that because there ARE so many potential planets and we can't find any sort of non natural signal from anywhere, that it proves we probably ARE alone.
Radio waves can go a LOONNGG way in space.
They're trying to contact us about our cars expiring warranty.
In reply to wvumtnbkr :
well, life in our dimension and sphere of understanding. We might be the only type of carbon based life in the galaxy but that is likely not the only defining type of life.
Now, I'm waiting for this to happen.
In reply to wvumtnbkr :
They also take a loooong time to get anywhere.
Our second closest planetary neighbor, Mars, has an 8 minute delay.
From our nearest solar neighbor at alpha centauri? 4.5 years at light speed, and radio waves don't move at light speed.
That's where physics get really interesting though, as just the things we're able to see and record from further out are how things were millions or billions of years ago. A LOT can happen in that span of time, especially when homo sapiens as a species are barely 300,000 years old.
Phosphine gas on Venus though is an intriguing development. It will be nice when we finally get more probes and observations of the planet available. The videos are still out there from I believe a Russian probe that made it to planet surface before being crushed by pressure back in the 90s, very interesting compared to earth or Mars from a terrain perspective.
An astronomer on Reddit made this excellent post about what was found and why it's significant:
Astronomer here! Here is what is going on!
For many years, astronomers have speculated that the most likely way to find evidence of extraterrestrial life is via biosignatures, which are basically substances that provide evidence of life. Probably the most famous example of this would be oxygen- it rapidly oxidizes in just a few thousand years, so to have large quantities of oxygen in an atmosphere you need something to constantly be putting it there (in Earth's case, from photoplankton and trees). Another one that's been suggested as a great biosignature is phosphine- a gas we can only make on Earth in the lab, or via organic matter decomposing (typically in a water-rich environment, which Venus is not). So, to be abundantly clear, the argument here is to the best of our knowledge you should only get this concentration of phosphine if there is life.
What did this group discover? Is the signal legit? These scientists basically pointed a submillimeter radio telescope towards Venus to look for a signature of phosphine, which was not even a very technologically advanced radio telescope for this sort of thing, but they just wanted to get a good benchmark for future observations. And... they found a phosphine signature. They then pointed another, better radio telescope at it (ALMA- hands down best in the world for this kind of observation) and measured this signal even better. I am a radio astronomer myself, and looking at the paper, I have no reason to think this is not the signature from phosphine they say it is. They spend a lot of time estimating other contaminants they might be picking up, such as sulfur dioxide, but honestly those are really small compared to the phosphine signal. There's also a lot on the instrumentation, but they do seem to understand and have considered all possible effects there.
Can this phosphine be created by non-life? The authors also basically spend half the paper going through allllll the different possible ways to get phosphine in the atmosphere of Venus. If you go check "extended data Figure 10" in the paper they go through all of the options, from potential volcanic activity to being brought in from meteorites to lightning... and all those methods are either impossible in this case, or would not produce you the concentration levels needed to explain the signature by several orders of magnitude (like, literally a million times too little). As I said, these guys were very thorough, and brought on a lot of experts in other fields to do this legwork to rule options out! And the only thing they have not been able to rule out so far is the most fantastic option. :) The point is, either we don’t get something basic about rocky planets, or life is putting this up there.
(Mind, the way science goes I am sure by end of the week someone will have thought up an idea on how to explain phosphine in Venus's atmosphere. Whether that idea is a good one remains to be seen.)
To give one example, It should be noted at this point that phosphine has apparently been detected in comets- specifically, it’s thought to be behind in the comet 67P/Churyumov-Gerasimenko by the Rosetta mission- paper link. Comets have long been known to have a ton of organic compounds and are water rich- some suggest life on Earth was seeded by comets a long time ago- but it’s also present in the coma of comets as they are near the sun, which are very different conditions than the Venusian atmosphere. (It’s basically water ice sublimating as it warms up in a comet, so an active process is occurring in a water-rich environment to create phosphine.) However, the amounts created are nowhere near what is needed for the amounts of phosphine seen in Venus, we do not have water anywhere near the levels on Venus to make these amounts of phosphine, and we have detailed radar mapping to show us there was no recent cometary impact of Venus. As such, it appears highly unlikely that what puts phospine into Venus’s atmosphere is the same as what puts it into a comet’s coma. Research into this also indicates that, surprise surprise, cometary environments are very different than rocky ones, and only life can put it in the atmosphere of a rocky planet.
How can life exist on Venus? I thought it was a hell hole! The surface of Venus is indeed not a nice place to live- a runaway greenhouse effect means the surface is hot enough to melt lead, it rains sulfuric acid, and the Russian probes that landed there in didn't last more than a few hours. (No one has bothered since the 1980s.) However, if you go about 50 km up Venus's atmosphere is the most Earth-like there is in the Solar System, and this is where this signal is located. What's more, unlike the crushing pressure and hot temperatures on the surface, you have the same atmospheric pressure as on Earth, temps varying from 0-50 C, and pretty similar gravity to here. People have suggested we could even build cloud cities there. And this is the region this biosignature is coming from- not the surface, but tens of km up in the pretty darn nice area to float around in.
Plus, honestly, you know what I’m happy about that will come out of this? More space exploration of Venus! It is a fascinating planet that is criminally under-studied despite arguably some of the most interesting geology and atmosphere there is that we know of. (My favorite- Venus’s day is longer than its year, and it rotates “backwards” compared to all the other planets. But we think that’s not because of the way it formed, but because some gigantic planet-sized object hit it in the early days and basically flipped it upside down and slowed its spin. Isn’t that so cool?!) But we just wrote it off because the surface is really tough with old Soviet technology, and NASA hasn’t even sent a dedicated mission in over 30 years despite it being literally the closest planet to us. I imagine that is going to change fast and I am really excited for it- bring on the Venus drones!
So, aliens? I mean, personally if you're asking my opinion as a scientist... I think I will always remember this discovery as the first step in learning how common life is in the universe. :) To be clear, the "problem" with a biosignature is it does not tell you what is putting that phosphine into the Venusian atmosphere- something microbial seems a good bet (we have great radar mapping of Venus and there are def no cloud cities or large artificial structures), but as to what, your guess is as good as mine. We do know that billions of microbes live high up in the Earth's atmosphere, feeding as they pass through clouds and found as high as 10km up. So I see no reason the same can't be happening on Venus! (It would be life still pretty darn ok with sulfuric acid clouds everywhere, mind, but we have extremophiles on Earth in crazy environments too so I can’t think of a good reason why it’s impossible).
If you want to know where the smoking gun is, well here's the thing... Hollywood has well trained you to think otherwise, but I have always argued that discovering life elsewhere in the universe was going to be like discovering water on Mars. Where, as you might recall, first there were some signatures that there was water on Mars but that wasn't conclusive on its own that it existed, then a little more evidence came in, and some more... and finally today, everyone knows there is water on Mars. There was no reason to think the discovery of life wouldn't play out the same, because that's how science operates. (This is also why I always thought people were far too simplistic in assuming we would all just drop everything and unite as one just because life was discovered elsewhere- there'd be no smoking gun, and we'd all do what we all are doing now, get on social media to chat about it.) But put it this way- today we have taken a really big first step. And I think it is so amazing that this was first discovered not only next door, but on a planet not really thought of as great for life- it shows there's a good chance life in some for is ubiquitous! And I for one cannot wait until we can get a drone of some sort into the Venusian atmosphere to measure this better- provided, of course, we can do it in a way that ensures our own microbes don't hitch a ride.
RevRico said:That's where physics get really interesting though, as just the things we're able to see and record from further out are how things were millions or billions of years ago. A LOT can happen in that span of time, especially when homo sapiens as a species are barely 300,000 years old.
Reminds me of Seth Green's character's line from Mass Effect 2: "You know what I hate about deep space? Crap radio stations from two hundred years back. My gosh, we were idiots."
RevRico said:radio waves don't move at light speed.
Source?
Further complicating the radio wave issue is that if a species did manage to create radio waves, what are the chances they exist in such a timeframe that their emitted radio waves happen to pass through our solar system during a time when our species has the ability to detect them? Time dilation can complicate all of this as well.
^That isn't covered in the typical drake equation.
There is a really strong likelyhood that there is life in many places in the universe, but we will never see evidence of it.
wvumtnbkr said:Grtechguy said:Why not? with countless stars in countless galaxies, does anyone really believe that life doesn't exist anywhere else?
Actually, most of the physicists believe that because there ARE so many potential planets and we can't find any sort of non natural signal from anywhere, that it proves we probably ARE alone.
Radio waves can go a LOONNGG way in space.
To me, the issue is that the likelihood that we are both "intelligent" within the same itty bitty sliver of time and happen to be close enough together to communicate is extremely small. earth has had life for like 1 trillion years or so, and we have been able to communicate with outsiders for maybe 50 of them? What are the chances that someone close enough to us also shares the same 50/1,000,000,000,000 year window?
In reply to ProDarwin :
Slightly misremembering.
In a pure vacuum, they can approach light speed.
I don't know that I would consider interstellar space as a pure vacuum though, based on interstellar dust, effects from gravity and changes of density of the medium, but I'm not a physicist, just a big science fiction fan and bit of a space nerd.
I *assume* gravitational distortion from black holes, neutron stars, galactic structures and their associated gravity wells would have an affect on electromagnetic waves, let alone interference from similar objects and wave producing objects, but that's so far above my pay grade I wouldn't even know how to ask the only person I know sort of in the field the questions about it. (He works at CERN, not remotely the same but not entirely different)
There's still the distances to take into account, by the time any of our neighboring galaxies start picking up our radio waves, we could easily have killed ourselves off, so it's not a stretch to say the same with waves coming into our own galaxy from parts unknown.
Tom_Spangler (Forum Supporter) said:An astronomer on Reddit made this excellent post about what was found and why it's significant:
... However, if you go about 50 km up Venus's atmosphere is the most Earth-like there is in the Solar System, and this is where this signal is located. What's more, unlike the crushing pressure and hot temperatures on the surface, you have the same atmospheric pressure as on Earth, temps varying from 0-50 C, and pretty similar gravity to here. People have suggested we could even build cloud cities there. And this is the region this biosignature is coming from- not the surface, but tens of km up in the pretty darn nice area to float around in. ...
Book me a room, I'm in:
Robbie (Forum Supporter) said:To me, the issue is that the likelihood that we are both "intelligent" within the same itty bitty sliver of time and happen to be close enough together to communicate is extremely small. earth has had life for like 1 trillion years or so, and we have been able to communicate with outsiders for maybe 50 of them? What are the chances that someone close enough to us also shares the same 50/1,000,000,000,000 year window?
This is what I was trying to say, but your number is a bit off :)
Earth has had life for ~3.7billion years
The accepted age of the universe is 13.8 billion years.
Figure the human species lasts another 1 million years somehow. Lets say we are the first in the university to gain the ability to communicate, and the next species to do so comes along 50 million years from now. We will never know. Another species could detect those radio waves far in the future, but by the time such a species could come over to Earth to check things out, we will be long extinct.
In reply to ProDarwin :
I never said I was intelligent! I thought I remembered the earth to be about 4 something years old and I guessed life was around for the last 1/4 of that.
But really I'm only 3 orders of magnitude off which is pretty good in astrophysics.
This news was discussed during an astronomy live discussion last night. The host said he was finishing up a short video about the discovery. One comment is the initial discovery happened about 3 years ago and the researchers have been spending the time since trying to figure out all of the other possible explanations.
It will be fun to see how this all develops.
wvumtnbkr said:Radio waves can go a LOONNGG way in space.
Yes, but if they aren't directed- i.e. laser focused- they disseminate too quickly to be detected against the cosmic backdrop. Remember analogue TV static? It's literally leftover energy from the big bang that you're seeing and hearing; the channels only occur on specific wavelengths, and it's easy to change your channels just enough to warp them back to the static. I believe it was back in the late 80s/early 90s that Arthur Clarke and some astronomer tested how "far" something could see and hear our TV and radio using Voyager 2 when it was at Neptune- I think it's about 3 light years for the highest-energy stuff before cosmic background just overpowers it.
Radio waves travel at light speed in vacuum and get affected/twisted by all the same things.
Like that reddit poster stated, I'm very excited and Venus is criminally under-rated for exploration (as if America would ever properly fund NASA) but going to Venus is harder than Mars. Venus orbits around the sun faster, and to get a probe into orbit around it for these types of experiments you both have to get it into a position to intercept but also slow it down enough so it doesn't overshoot. I think the Mariner probes had to loop around Mercury to be in position, and the Japanese Akatsuki probe failed it's first insertion and had to orbit the sun for several years before it could reattempt.
Ian F (Forum Supporter) said:This news was discussed during an astronomy live discussion last night. The host said he was finishing up a short video about the discovery. One comment is the initial discovery happened about 3 years ago and the researchers have been spending the time since trying to figure out all of the other possible explanations.
It will be fun to see how this all develops.
That is one thing that is somewhat surprising about this. They actually waited until they had a pretty solid analysis of it before releasing. Big contrast to the standard "OMG, huge scientific breakthrough, tune in at 9 for details", to find out it's some super prelimnary finding that may result in nothing after 10 more years of needed research.
I still want to know whatever happened with that pulse of energy that came out of the black hole a couple years back. That one really threw a bunch of astronomers for a loop. I remember the consensus being "Well, that's not supposed to happen."
The more you learn the more you know how much there is you don't know.
Space is cool. This is fascinating. That's my only real input.
Don49 (Forum Supporter) said:I'm still looking for intelligent life on Earth. Seems hard to find these days.
i quote Calvin and Hobbes
"sometimes i think the only sign that there is intelligent life elsewhere in the universe is the fact that none of it has tried to contact us" (something to that effect)
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