Striking view of 'Milky Way twin'

[Hum]

Astronomers have released what they say is the best-yet picture of NGC 6744, a spiral galaxy described as a "sibling" of our own Milky Way.

The image was snapped by the European Southern Observatory's MPG/ESO 2.2-metre telescope in Chile.

The galaxy lies 30 million light-years away, in the constellation Pavo.

While it is almost twice as large as the Milky Way, it exhibits the same sharply-defined spiral arms and stretched central region.

There is even a small companion galaxy, visible at the lower right of the image, which is analogous to our own galactic neighbours the Magellanic Clouds.

Those arms host many star-forming regions; the glow coming from hydrogen gas in these active regions shows up as red in the image.

source

[DocM]

This is a model of the Milky Way's barred spiral based on star surveys -

Link....

[Klownicle]

Hard to even believe the possibility that we could be alone. With soo much out there. It feels like it should be fact we're not.

[neoadorable]

we are not alone. most definitely. but it is odd we're not getting any radio, TV and data from other civs. it would seem either people capable of such technology are rare and spread out, or that we've lucked out and are among the very first to have achieved these feats.

[Growled Member]

Amazing how similiar the two galaxies are.

[guru]

we are not alone. most definitely. but it is odd we're not getting any radio, TV and data from other civs. it would seem either people capable of such technology are rare and spread out, or that we've lucked out and are among the very first to have achieved these feats.

yeah. i think its odd too.

[Growled Member]

we are not alone. most definitely. but it is odd we're not getting any radio, TV and data from other civs. it would seem either people capable of such technology are rare and spread out, or that we've lucked out and are among the very first to have achieved these feats.

It probably not that odd when you consider the size of the galazy.

[ViZioN]

yeah. i think its odd too.

I don't think it's that odd at all. We've only had radio for around a 100 or so years? So radio waves that have leaked into space are only around 100 light years from us right now which in space terms, isn't very far at all. For all we know, there's radio/TV waves currently on their way to us from another galaxy but they might not arrive for another decade, century, millennium :p

[Nagisan]

It probably not that odd when you consider the size of the galazy.

Yeah, the amount of time it takes radio and other communication wavelengths to travel through that amount of empty space, I would be surprised if we had gotten anything from another civilization by now. Honestly....this galaxy is 30 million light years away....that means it takes light alone 30 million years to travel from there to Earth. We are seeing that particular galaxy how it was 30 million years ago. In other words, that galaxy at this very moment could have life as advanced (or more so) than our own, we just cannot see it in its current state.

The sheer distance between habitable planets (without technological changes to the planet) is vast enough that we are unlikely to discover any advanced life on them until our technology advances hundreds of years (maybe even more) past what we have right now.

I have no doubt that there is other advanced life in our universe, but I do doubt anyone alive today will live long enough to discover any advanced life beyond our own.

[DocM]

As far as communications go there are likely 3 levels of civilization -

Pre-radio: our world before Maxwell, Hertz, Tesla and Marconi. voice, hand/smoke signals, writing, telegraph.

Modern: TV, radio, microwave etc. What you're talking about. This era's only been around <150 out of our civilizations 5,000+ years, yet possible replacements are on the horizon -

Post-radio: based on other technologies. One already under test is quantum communications, which transferrs data as qbits encode on very low intensity laser beams. Another possibility is a communication based on quantum entanglement. Paired particles so entangled will reflect their partners state instantly, no matter if they're 1 meter apart or halfway across the universe. Not working yet, but it's being worked on. Yet another would require the development of efficient, controllable neutrino detectors and generators.

Before the radio era we most certainly were not detectable beyond our solar system, and none of those post-radio techs would be detectable with the gear we're using for SETI or anything else. That leaves a pretty narrow window of development where other civilizations at out current state could be detected by us. More likely is that anyone "out there" is at a different stage than us.

[4CxbqFxVnstmA Veteran]

This is really cool!

I know you are all talking about other civilisations. But how old is the universe? Why would civilisations all have to start when our own did?

I mean, 30 million years is nothing in terms of the age of the universe. Aliens in our sister galaxy could have created radio waves 100 million years ago, or a billion. They don't have to follow our time line.

[DocM]

Our current state of understanding is that the universe is about 13 billion years old, our sun is about 4.57 billion years old, and Earth is about 4.53 billion years old. Life appeared at about 3.5 billion years ago. Stars like the sun live for about 10 billion years, but smaller stars called red dwarfs could live, and support life, for thousands of times longer. IMO they're the best bet fot earlier-than-us civilizations that are still around.

[Nagisan]

Post-radio: based on other technologies. One already under test is quantum communications, which transferrs data as qbits encode on very low intensity laser beams. Another possibility is a communication based on quantum entanglement. Paired particles so entangled will reflect their partners state instantly, no matter if they're 1 meter apart or halfway across the universe. Not working yet, but it's being worked on. Yet another would require the development of efficient, controllable neutrino detectors and generators.

Last I heard, they have entangled particles working over a short distance (a mile or so is the max distance currently), and like you said, it is instant communication over any distance. Another problem with them though, is they are only point to point communication. For each system you wish to communicate with, you need to have an entangled particle on each side. So if you have a central area communicating with 50 remote areas, you need to have 50 entangled particles on the central location, then each of the 50 particles partners in each respective remote location. The problem is a single entangled particle ONLY affects its partner particle, so each of the 50 particles would be its own individual connection from all the others. You can at best (currently at least) communicate from 1 point to another, there is no such thing as 1 to many or many to 1 when it comes to entangled particles (at least that's the way I understand it).

This is really cool!

I know you are all talking about other civilisations. But how old is the universe? Why would civilisations all have to start when our own did?

I mean, 30 million years is nothing in terms of the age of the universe. Aliens in our sister galaxy could have created radio waves 100 million years ago, or a billion. They don't have to follow our time line.

While true, you also have to remember the way we broadcast signals. When we send a signal out from Earth, we usually send it in 1 direction to improve the quality of the signal in that direction. That being said, for another civilization to pick up a radio signal we send, they would have to line up perfectly with our planet and with no major interference in between. The same goes for another civilization sending signals to us.....they would have to send it almost exactly to Earth and in a way that nothing major will interfere with the signal for us to actually receive it.

There's no doubt other civilizations in our universe could be sending out radio waves for the past 100 million years or whatever, but the chances for those radio waves to actually reach Earth and still be strong enough for our technology to receive it properly is extremely slim. It would be like sending a weak signal from the middle of the ocean in the direction of a land mass and hoping someone is there with the proper equipment to pick up that signal.

[guru]

nvm

[guru]

While true, you also have to remember the way we broadcast signals. When we send a signal out from Earth, we usually send it in 1 direction to improve the quality of the signal in that direction. That being said, for another civilization to pick up a radio signal we send, they would have to line up perfectly with our planet and with no major interference in between. The same goes for another civilization sending signals to us.....they would have to send it almost exactly to Earth and in a way that nothing major will interfere with the signal for us to actually receive it.

There's no doubt other civilizations in our universe could be sending out radio waves for the past 100 million years or whatever, but the chances for those radio waves to actually reach Earth and still be strong enough for our technology to receive it properly is extremely slim. It would be like sending a weak signal from the middle of the ocean in the direction of a land mass and hoping someone is there with the proper equipment to pick up that signal.

ok. but assuming there are one million civilizations that can send out radio signals out in our galaxy, there should have been atleast some signals out there that we can detect atleast from the nearby civilizations??

[+Majesticmerc MVC]

ok. but assuming there are one million civilizations that can send out radio signals out in our galaxy, there should have been atleast some signals out there that we can detect atleast from the nearby civilizations??

There are a hundred million reasons why we might not be able to hear other civs though. Anything ranging from the likely (e.g. They're transmitting at a frequency that we can't receive), to the almost impossible (e.g. we really are alone in the universe).

It's even entirely possible that other civilisations are deliberately preventing their signals from reaching outside their world so as to keep themselves hidden, and thus safe from extra-terrestrial invaders. I mean lets face it, as a species we're hardly the most accommodating, we can't even make peace among ourselves.

[xendrome]

I don't think it's that odd at all. We've only had radio for around a 100 or so years? So radio waves that have leaked into space are only around 100 light years from us right now which in space terms, isn't very far at all. For all we know, there's radio/TV waves currently on their way to us from another galaxy but they might not arrive for another decade, century, millennium :p

Pretty sure radio/microwave travels at a much slower speed then light, so when you are talking about 30 million light years away.. I mean just think about it.

Plus I think those signals would lose their strength anyway. Someone correct me if I am wrong please.

[XerXis]

Pretty sure radio/microwave travels at a much slower speed then light, so when you are talking about 30 million light years away.. I mean just think about it.

Plus I think those signals would lose their strength anyway. Someone correct me if I am wrong please.

erm no, they are all electormagnetic waves and they all travel at the same speed ;)

[bjoswald]

Show me an alien, then I'll care. :alien:

[neoadorable]

majesticmerc - for your name you're strangely anti-warfare :laugh: i don't think civs at our level or lower in terms of tech are actively trying to mask signals. i don't think humanity is doing this.

thanks for the always useful explanations Doc, you're talking about a space ansible! again, straight out of Avatar and Le Guin! love it when sci fi becomes reality. this will be awesome, being able to communicate instantly from Mars or even further. only a matter of time we can move well, matter, faster than light.

i don't think the explanation is that we're not getting signals because of physical barriers such as signal degradation or angle of broadcast. i think it's a combination of factors people here mentioned: tech civs are relatively rare and far apart, and they are at wildly different levels. some don't broadbast at all yet, some broadcast in ways most of the others simply can't detect. i think even when human space encompasses a bubble say 50 lightyears in size we still won't know much more about other civs than we do now. all the more reason to take as much of the universe as possible for our own. it's humanity's destiny.

[Hum]

Plus I think those signals would lose their strength anyway. Someone correct me if I am wrong please.

I read somewhere that radio/TV signals disintegrate after X number of lightyears.

I wonder if there are a few parallel Earths in that galaxy .... it's fun to imagine so. :happy:

[DocM]

I read somewhere that radio/TV signals disintegrate after X number of lightyears.

Radio waves go in virtually forever, that's why radio telescopes can see billions of light years away, but cosmic rays do degrade because they are accelerated particles - mostly protons. They run into light, radio and x-ray frequency photons as they travel, losing energy over time until little is left. This is known as the Greisen?Zatsepin?Kuzmin (GZK) limit, and amounts to about 163 million light years.

I wonder if there are a few parallel Earths in that galaxy .... it's fun to imagine so. :happy:

Multiverse theory involve multiple universes of parallel worlds, most with different versions of you. Some died as a child, others have no Hitler while in others he won the war. Remember the old TV series Sliders? They had it pretty much right save for the ability to slide between them.

[neoadorable]

we're talking parallel universes now? can we focus on exploring the one we find ourselves in?

[DocM]

Too late - parallel universe theory is the norm in physics and is used to explain particle-wave duality, gravity's relative weakness vs. the other forces, and other quantum effects.

[Hum]

we're talking parallel universes now? can we focus on exploring the one we find ourselves in?

Don't you wonder what your other Selves are up to ? ;)