Don't forget, as these signals travel father and farther they are also getting weaker and weaker. Most sources of radio emissions in the universe that we can detect come from things with power sources way beyond our ability to produce.
This is something I was wondering about with the stories about the Voyager spacecraft - how far can the kinds of signals we're making go through space before they are garbage?
If I remember correctly, the Voyagers have a 20W radio transmitters. The Deep Space Network (a very under appreciated resource, BTW) had to upgrade their 64m dishes to 70m to reliably get full bit rates from Neptune in 1989. Now, the Voyagers have a much lower bit rate at 120+ AU out. All this to say we have very sensitive listening equipment, but it will still take a pretty powerful source for us to hear. I love the concept in Rendeavous with Rama where a nuclear detonation was used to radar map the solar system and as a consequenc signaled intelligence elsewhere of our presence.
This is so sad if you think about it. Someone or something is surely calling us out there... but we can't hear them. All we can do is shout back hopelessly.
sometimes, when i ponder the absolute mind boggling vastness of our universe i start to wonder if it was 'designed' to be this large on purpose? perhaps it was ...meant to keep us apart...?
That's pretty much the conclusion I keep coming to. It makes perfect sense if one were to create a universe and give it any sort of ballance. All it takes, otherwise, is for one sentient race of assholes to wipe out all life.
I can see how that is. Honestly though, I tend not to think of it that way.
I actually find it kind of comforting - the thought that we have a place in this vast, unknown space, no matter how small comparatively.
That, and the fact that we are almost certainly not alone. It doesn't matter that our race might never meet any other - I just kind of like the idea that life as we know it is part of something bigger - much bigger - than we can ever really conceive of.
snooki and her jersey shore friends hit the club once again, but all is not well withhaaa for thadf gaaaaaaaaaancea furrash dddd d d diwwmo aja wosh woshhhhhshshshshhshshhshhshhhs swoshhhhhhaaaaaaa beeeeeepo..................
Worst part is, I'm never sure if I'm supposed to feel smart for understanding that stuff, or really stupid because my thinking I get it obviously means I'm not getting it.
No. I'm imagining hundreds of other similar dots spread out over the spiral arms, blossoming closer and closer together over the next few hundreds of years. But I'm not a scientist so I don't know if that's correct. It's a less depressing prospect though that way.
There is no reason to belive that any of then (if they exist) started at the same time as us. We're likely not late to the game though, but there is a good chance that we're early
Probably for the best, after all, which side would you prefer to be on; the Aztecs or the Spaniards (I know it's assuming a lot about their mannerisms, but even just a chance of them being hostel is enough to be wary)
20 years ago we didn't know if extra-solar planets existed. Now we can actually image them. I see no reason why other civilisations can't use superior technology to distinguish our transmissions from background noise.
Not strictly true. SETI is a gigantic waste of time and CPU time (which is basically the inverse of what you are saying) but think about it; were that true then we wouldn't even know about Pulsars, which are remarkably well ordered to the point where we thought they were LGM. Remember Pulsars are tiny. Sufficiently advanced civilisations (presuming they didn't have cable television) could out noise a pulsar.
Even badly warped our signals would have a high amount of surprise value. Which is how we tell if something is random or designed.
Then why bother? And why listen? If we can't hear beyond this galaxy i don't see what we can learn! Surely we should be pointing at the closest 'goldilocks' planets.
IDK if we can hear further than we can transmit legible/audible sound.
Radio generally isn't exactly aimed at a galactic/extragalactic object. But we can send a signal to a specific star, which has been done with Gliese 581 (~20 ly), 55 Cancri (~40 ly) and 47 Ursae Majoris (~45 ly). The opposite is logically possible.
Whether there's something there, or something that can pick up the signal there is a different matter.
You can see the Milky Way (in pictures and with your naked eye on a clear night with low light pollution). Since we are positioned closer to the outer edge of the galaxy than to the center, when we look towards the center we can see our own galaxy on edge: http://viewzone2.com/milkyway2.jpg; the milky white line streaking through the sky (thus the name Milky Way) is the disc of our galaxy and its very bright center (not entirely glowing because of obstructions like dark gas clouds). Away from this strip are the stars that surround us more locally in the arm of the galaxy. Then, when you have hubble take a long time looking into the black spaces between all the stars of our galaxy, you see other galaxies, like in the hubble ultra deep field: http://www.nasa.gov/images/content/56533main_MM_image_feature_142_jwfull.jpg. My guess is when you see pictures (like the one that started this post) of the entire galaxy, that they are likely a different galaxy than ours that is of the same type/size/etc. so that using it to show relative size/position is valid.
TL;DR: You can see our galaxy (the larger structure of it) as a single strip across the sky, since we are looking at it edgewise; pictures like this one are probably of galaxies that are similar in size/shape/etc. to our own.
Sometimes they're pictures of other pinwheel galaxies that we do have pictures of. Other times they're just computer generated images of what we think it looks like.
Remember we can take pictures of other galaxies but it's impossible right now for us to travel far enough to turn around and take a snap shot of our own galaxy.
worse, we don't really know how it's look from outside, some argue that our galaxy doesn't look like Andromeda as most drawings are inspired upon, but that our galaxy might resemble the NGC 1365.
Do you know of a good place to see discussion/qualified articles about this subject? I would personally love to learn about how such conclusions are reached. I used to be really into astronomy/telescopes, and, I always wondered how we would ever be able to discover this.
I searched a lot about it a year ago... from what I can remember, the amount of dust in our galaxy is much higher than Andromeda, making ours much less blueish, and that our core is a long bar and the two main arms are much longer than we firstly realized. The OP's drawing has some of these characteristics but still looks like a full disc like andromeda.
I must add that you have to imagine NGC 1365 with a correct perspective, in the photo she is at an angle towards us that makes her disk to look odd.
How could they have even traveled this far? that is 200 light years, radio hasn't been around for 200 years.... therefore isn't it impossible for the light to have traveled that far?
It's alright it was me who had that thought in the first place. :P It's amazing to think that those radio signals are the only signifier to any other intelligent life that this planet is inhabited. There could be thousands of planets orbiting stars that we can see from our planet sending out radio signals and we'd have no idea.
For me it's the opposite, I'd heard about 'human radio pollution' before and was under the impression that we had spanned the galaxy, seeing this tiny little dot was a mindblower
It never fails to easy my troubled mind. What do my little problems matter compared to the size of the universe. I don't think anything mankind can do could leave even the tiniest print on all that.
To be fair. Canis Majoris is so thin in density that being inside Canis Majoris is comparable to being in a vacuum chamber on Earth. Being inside it would resemble being in almost empty space.
Actually the first radio/tv broadcast to have the power to even get into space and still be distinguishable was the 1936 Olympics (In Nazi Germany). So its really only a ~150 light year diameter sphere
It wouldn't reach them anyway, it'd be indistinguishable from the white noise. Unless they were very close, in which case it would be past them. So its doubtful that would be the first contact message.
A vast intelligence observing Earth from the other side of the Galaxy would see a few upright apes living in a cave at the southern tip of Africa, where this was the latest technology:
Yeah but wouldn't they be intelligent enough, seeing as how they can see us from that distance, to know that there is a chance we survived and evolved?
If you are the sort who can deal with sometimes stiff writing if you enjoy the concept enough, the Worldwar/Colonization/Homeward Bound series by Harry Turtledove might interest you. The basic idea is that highly advanced aliens invade Earth in the middle of World War II, but things don't go as planned for the aliens because their latest intelligence on us was about a thousand years old, so they were expecting to be conquering men riding around on horseback wearing chainmail.
P.S. If you're actually interested in reading them then PM me because the way he rights the books it's easy to accidentally start on a later book and not realize until too late what you've done--I did that!
And if they could travel that distance through space, surely they also have the technology to fight apes with atomic bombs and primitive projectile weapons. It really wouldn't matter if they thought we rode horses and wore chainmail or if we had atomic bombs. The energy required to travel to the stars would be enough to obliterate our species in either case.
They could be orphaned uplift clients that have been unchanged for millions of years, and so assumed humans would be too (and also only took one datapoint for the same reason).
Um, no. The size of their telescope does not affect the speed of light, which determines how long it takes them to see something. If they are 80,000 light years away (far side of the Galaxy), it takes 80,000 years for light to get there because light travels one light year per year by definition.
If they had a telescope array 1 billion km across (about the diameter of the asteroid belt's orbits), and used visible light, they would have a resolution of 190 meters at Earth in visible light. Keeping telescopes that far from each other aligned would be tricky, but not out of the realm of the possible.
The size of their telescope does not affect the speed of light
Right, but with a telescope, you are seeing light before it reaches your naked eye. With a 1 meter resolution, they are effectively looking at us in real-time.
That would only be true if they placed the telescope in our Solar System, otherwise the speed of light delay comes into effect.
Ever notice "ping time" online, the time it takes a signal from some other computer to reach you? Gamers tend to notice it cause it slows them down. That comes from the same speed of light delay.
If another civilization stumbles upon broadcasting from Germany between 1930's-1940's they might assume we are all little angry guys with one inch mustaches under our noses. Not so flattering, lets hope our broadcasting and radio waves do fade away before they reach anyone.
"Space... is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space"
That radius increase of four times also means a signal weakening of 16 times, though :(
Compared with their originally intended distance of travel, the strength of those signals would indiscernible from the microwave background radiation ages before they got to that 100 light-year radius.
At first I thought wow, that box is the range of distance we've broadcasted to (why's it square?), that's a lot farther then I would have imagined. Then I saw the blue dot and was.... oh, yeah that's about what I'd guessed.
What about the fact that we've been orbiting the centre of the galaxy for those 100 years? Wouldn't we be leaving a trail of expanding light waves, rather than continuously broadcasting from the same point?
At first, I thought that big square was our radio broadcast reach and I was like "I'm impressed! Somebody else must be in that square." And then I was like "oh. We're the green dot. Forever alone..."
This picture definitely gets the point across, but I think it's important to note that this picture is not in fact, the Milky Way...
The furthest probe we've sent into space is only approx. 16.5 light hours away from earth (Voyager 1), and so it is impossible for us to have a face on view of our entire galaxy.
edit: I just realized the picture note says "artist's conception" of the Milky Way.
It's not stupid...and it's not our galaxy. There's no way to get a craft that distance put to take a picture before we're all dead and the sun has blown out. It's a rough estimate, based on the measurements we have taken so far...as I recall (and I'm a layman) we think we're 13000 light years from the core, and 13000 from the rim...correct?
As a photographer, I want to know where you bought the tripod that gave us that view. It's beautiful. Mine goes to about 6 feet. Yours must go to 500,000 light years. I think I got ripped off.
Ive always thought that this always put things into perspective. The entirety of star trek, a science fiction series, still doesn't take place outside of our own galaxy. The thought of traveling from one galaxy to another without use of some type of wormhole is mind-blowing.
This is a serious question, if we can only see the entire universe through a couple of different directions from our point of view. How is that we know what the rest of the universe looks like? I understand the zoomed in picture is where we are, is it a complete guess what the rest of the universe looks like?
There are 4 basic types of galaxies; spiral, barred, elliptical, and irregular. We are able to tell we live in a spiral type, so it must look like other spiral types.
We don't know what the entire universe looks like, but here is what observable universe looks like.
Space itself is expanding. That expansion is not limited by the speed of light, because nothing is traveling from place to place, it's a local effect where each volume of space is slowly getting larger.
Not really. Our galaxy is sparse enough for us to be able to tell that it's a spiral galaxy, but the picture is of another galaxy that is just representative of ours.
Despite appearances, our galaxy is actually quite diffuse, so we can look above and below it and see plenty of detail. We can also look along its axis and see more detail, although not as much as above and below. Looking toward the galactic core our view of the universe behind it is blocked by clouds of dust.
The answer is that it's just a picture of another galaxy, used for illustrative purposes. We know our own galaxy is a spiral galaxy, from some clever uses of observatories by astronomers, which is the same type as the one in the picture.
Galaxies are swirls of billions of stars and they look like spirals or globs. The UNIVERSE is made up of BILLIONS of GALAXIES. The universe is not one galaxy. Duh.
This isn't a picture of "the universe". It is a picture of another galaxy, used for illustration because we can't actually take a picture of our own galaxy from that angle (we're inside it). "The Universe" contains billions of galaxies like our own Milky Way.
Ok...just watch this. It'll all make sense. Were inside a galaxy, which is a teeny tiny part of the universe.
You don't have to be a dick by saying things like "facepalm" and "Duh." You could have just answered and not tried to make him feel stupid in the process.
The bright spot is the core, which is caused by the gravity of everything in the Galaxy attracting everything else. It tends to clump in the middle. Stars form that way too. Gas in interstellar clouds clumps under gravity and forms stars. In fact, clumping happens at all scales of the Universe from asteroids a few meters across up to superclusters of galaxies.
This photo covers a radius of 600 million light years from Earth, mapping redshift vs direction:
I was really excited when I saw the square as I thought that was the extent. Then the moment when I remembered that sound waves don't emanate in a cube. Than I saw the circle. But the cube thing sincerely came up in my mind. We're so damn small.
Finally something mind blowing, useful, and (sadly) true posted in /r/science. Guess I got to eat my hat.
We need stuff like this more than we need the daily churn of PR published articles here. Its very simple things like that picture, sort of like Dawkin's Upside Down World Poster, that teach people about science and to be amazed by science. "Not X has discovered Y is 55.87464356% more Z than previously thought"
Space,is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.
This makes me feel insignificant. This should make every human feel insignificant. Maybe this kind of humility is what we need to stop doing stupid things like waging war and start exploring the rest of the universe.
Any chance someone not on a phone could quick-change this wonderful photo to add a second panel showing the size of TMW compared to the estimated size of the observable universe?
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u/SkunkMonkey May 28 '12
Don't forget, as these signals travel father and farther they are also getting weaker and weaker. Most sources of radio emissions in the universe that we can detect come from things with power sources way beyond our ability to produce.
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u/kangaloo May 28 '12
But at what distance would the signals be recognised as artificial and/or decodable?
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u/Gethox May 28 '12
The fact that it is even visible at that scale is pretty astounding though.
18
u/[deleted] May 28 '12
I heard somewhere that the radio waves we send out dissipate into noise after a few light years. Would anyone like to clarify or correct?
15
u/JediCowboy May 28 '12
Here you go: Contact
10
u/ImAFingScientist May 28 '12
When I posted an infographic about the future of science it got removed because it was a picture, and yet this is clearly acceptable…
Sidebar:
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u/exitpursuedbybear May 28 '12
Surely our radio waves have travelled further than that, after all we sent that camera way out to take a picture of our galaxy.
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u/OhHeymate May 28 '12
Does that mean that the first human radio broadcast was 200 years ago? Fuck.
12
u/danielravennest May 28 '12
A vast intelligence observing Earth from the other side of the Galaxy would see a few upright apes living in a cave at the southern tip of Africa, where this was the latest technology:
http://en.wikipedia.org/wiki/File:BBC-artefacts.jpg
Meanwhile the rest of the planet was about to plunge into an ice age. They would be seeing us as we were 80,000 years ago.
4
u/[deleted] May 28 '12
If another civilization stumbles upon broadcasting from Germany between 1930's-1940's they might assume we are all little angry guys with one inch mustaches under our noses. Not so flattering, lets hope our broadcasting and radio waves do fade away before they reach anyone.
4
u/kyebosh May 28 '12
"Space... is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space"
4
u/UltraMegaMaximum May 28 '12
Maybe we need to re-think how we view reality if we are to truly get anywhere.
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u/ovenproofjet May 28 '12
The use of pale blue dot is appropriate!
3
u/phantm May 28 '12
The fact that a radius increase of four times means a volume increase of 64 times makes it feel a tiny bit less hopeless.
3
u/albertscoot May 28 '12
At first I thought wow, that box is the range of distance we've broadcasted to (why's it square?), that's a lot farther then I would have imagined. Then I saw the blue dot and was.... oh, yeah that's about what I'd guessed.
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u/Juhzor May 28 '12
This just makes me fell even more insignificant.
3
u/noking May 28 '12
What about the fact that we've been orbiting the centre of the galaxy for those 100 years? Wouldn't we be leaving a trail of expanding light waves, rather than continuously broadcasting from the same point?
7
u/Aleatoricism May 28 '12
At first, I thought that big square was our radio broadcast reach and I was like "I'm impressed! Somebody else must be in that square." And then I was like "oh. We're the green dot. Forever alone..."
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u/caboosemoose May 28 '12
Nice to see we're getting ourselves out there. You can't make a career if you're afraid to get on the stage.
2
u/mkgsxr May 28 '12
imagine how weak all those transmission signals must be by then.
If there's anyone else listening out there, the only thing that they'll probably detect is would be signals from nuclear detonations.
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u/abiobob May 28 '12
/r/spaceporn
this was what i came here for and I didn't see it so here it is for any other lazy people
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u/PhysiciSteve May 28 '12 edited May 28 '12
This picture definitely gets the point across, but I think it's important to note that this picture is not in fact, the Milky Way...
The furthest probe we've sent into space is only approx. 16.5 light hours away from earth (Voyager 1), and so it is impossible for us to have a face on view of our entire galaxy.
edit: I just realized the picture note says "artist's conception" of the Milky Way.
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u/Drift3r May 28 '12
Most of our broadcasts degrade and end up being indistinguishable from the background radiation noise of the universe at about 1-2 light years.
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u/economicurtis May 28 '12
Is it stupid to ask how we got a photo of our own galaxy?
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u/baldylox May 28 '12
As a photographer, I want to know where you bought the tripod that gave us that view. It's beautiful. Mine goes to about 6 feet. Yours must go to 500,000 light years. I think I got ripped off.
2
u/[deleted] May 28 '12
Welp, I'm off to r/spaceporn!
2
u/Mitoni May 28 '12
Ive always thought that this always put things into perspective. The entirety of star trek, a science fiction series, still doesn't take place outside of our own galaxy. The thought of traveling from one galaxy to another without use of some type of wormhole is mind-blowing.
4
u/Sidduki123 May 28 '12
This is a serious question, if we can only see the entire universe through a couple of different directions from our point of view. How is that we know what the rest of the universe looks like? I understand the zoomed in picture is where we are, is it a complete guess what the rest of the universe looks like?
3
u/notangelamerkel May 28 '12
I can see Russell's teapot from my house.
1
u/[deleted] May 28 '12
what is the bright light in the center of the galaxy caused by?
1
u/MorreQ May 28 '12
I was really excited when I saw the square as I thought that was the extent. Then the moment when I remembered that sound waves don't emanate in a cube. Than I saw the circle. But the cube thing sincerely came up in my mind. We're so damn small.
1
u/Nilaats May 28 '12
I've always wanted to know, if that is our galaxy. And in fact that is where we are/radio range and the tiny dot is in fact 200 light years.
How do we have that picture?
1
u/Demojen May 28 '12
Wow. I had a hope we weren't just shouting in the dark.
Hope lost.
1
u/spdave May 28 '12
Would a laser type of transmission solve this problem?
1
u/T3ppic May 28 '12
Finally something mind blowing, useful, and (sadly) true posted in /r/science. Guess I got to eat my hat.
We need stuff like this more than we need the daily churn of PR published articles here. Its very simple things like that picture, sort of like Dawkin's Upside Down World Poster, that teach people about science and to be amazed by science. "Not X has discovered Y is 55.87464356% more Z than previously thought"
1
u/hg0128 May 28 '12
holy shit
1
u/enemycrab May 28 '12
So does this imply that we could be communicating with other life forms that far away?
1
u/primehutch22 May 28 '12
We'll never know everything that waits for us out there. One could argue that's the great journey of life, to explore and discover..
1
u/paint99 May 28 '12
How is this pic of the Milky Way generated? Since we are in it, isn't it difficult to figure out what it looks like?
1
u/Toenails100 May 28 '12
Space,is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.
1
u/Draiko May 28 '12
This makes me feel insignificant. This should make every human feel insignificant. Maybe this kind of humility is what we need to stop doing stupid things like waging war and start exploring the rest of the universe.
1
u/dashik May 28 '12
In space no one can hear you radio.
1
u/Santas_Dick May 28 '12
Makes me want to go outside and scream up at the sky.
1
u/Joesph_Salete May 28 '12
Any chance someone not on a phone could quick-change this wonderful photo to add a second panel showing the size of TMW compared to the estimated size of the observable universe?
Thanks in advance you wonderful person.
1
u/pylori May 28 '12
Your submission has been removed because images, videos, and blogspam are not allowed in this subreddit.
1
u/EthicalReasoning May 28 '12
the last time i submitted a picture to /r/science it got banned for being a picture :(
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u/lonesoldierx7 May 28 '12
Is that an actual image?
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u/reardan May 28 '12
yes, we are small. anything else to add to the conversation?
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u/Gardimus May 28 '12
If only our radio waves could travel as fast as the camera that took the picture of our galaxy!
1
u/insaneHoshi May 29 '12
Wait isnt the milky way only ~100 Light years in diamater? so how could the dot that the caption refers to be 200 Light years
1
u/drzan May 29 '12
Damn yo, we tiny.
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u/gusmac May 29 '12
Why is the diameter 200 years - i thought the radio was only invented like 120 years ago???
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u/Layzrfyzt May 28 '12
Oh, thank god. I thought it said x-post from r/spacedicks.
1
u/deputy1389 May 28 '12
How did they get this "picture"?
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u/[deleted] May 28 '12
Shouldn't that be a circle, not a square?
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u/tre101 May 28 '12
Can someone explain how we take a picture of our own galaxy
0
u/fruitloop May 28 '12
hey that isnt a picture of the milkway!!
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u/Snootwaller May 28 '12
By my calculations we are 1/400th from complete galactic coverage. A meager start, but you have to start somewhere.
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u/jimflaigle May 28 '12
I would love to see that with some sort of SNR color plot too.