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The Universe is AWESOME!

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  • Registered Users Posts: 24,211 ✭✭✭✭lawred2


    JupiterKid wrote: »
    It is indeed OP. That’s why I’ve had an interest in astronomy since I was about 17.

    Just look at this close up image of the atmosphere of the planet Jupiter, taken by the orbiting Juno probe. Surreal!!:cool:

    aHR0cDovL3d3dy5zcGFjZS5jb20vaW1hZ2VzL2kvMDAwLzA3My8xNzgvb3JpZ2luYWwvanVwaXRlcnMtY2xvdWQtdG9wcy5qcGc=

    like something by Edvard Munch


  • Registered Users Posts: 24,211 ✭✭✭✭lawred2


    If the universe is expanding than what is it expanding in to?

    Uranus


  • Closed Accounts Posts: 1,385 ✭✭✭ThunderCat


    Intelligent life on other worlds is not inevitable. After 12 billion years there should be billions of unmanned probes randomly traversing the universe if intelligent life is inevitable.
    Why have none ever crashed into the Moon or Mars.
    Even we have half a dozen floating around in space, a few have already left our solar system. Multiply that by 6 sextillion and some should have come our way after 12 billion years.



    This is easily the best thing I've read on exactly this question. Give it a go:


    https://waitbutwhy.com/2014/05/fermi-paradox.html


    My own personal opinion is that we are currently too primitive to detect intelligent life anywhere else. Taking the analogy that there are more stars in the universe than grains of sand on every beach on Earth, we have yet to visit the nearest grain of sand to us, which in this case would be our nearest star. And we are absolutely nowhere near achieving this either so we really are not as advanced as we think we are. We have barely sent a probe to the edge of our solar system. Speaking of which if we represent the size of our solar system as being a one euro coin then our own galaxy (one of hundreds of billions of galaxies) is the size of North America. And we have barely sent a probe to the edge of the euro coin. Think about that.
    That said we are making strides and I do believe we will find signs of life in our galaxy in the coming decades, not through alien signals or alien probes or anything like that but from our advanced telescopes mapping the atmospheres of exoplanets in an attempt to detect elements in the atmosphere that do not naturally occur. Carbon emissions here in our atmosphere for example.


    As for what the Universe is expanding into, my understanding is that it isn't expanding into anything as the Universe is the creation of space and time itself and those things exist within the universe and not outside it. The expansion of the universe is really more the stretching of spacetime. It is more a stretching than an expansion. Think of it as the stretching of dough with the galaxies being raisins and also stretching with it rather than more dough being constantly added and the raisins remaining static near the centre of the dough. We know this to be the case as the galaxies are moving away from each other due to the stretching of spacetime rather than the other scenario people have in their heads whereby the galaxies remain static but the universe keeps expanding.


  • Closed Accounts Posts: 7,480 ✭✭✭wexie


    ThunderCat wrote: »

    Makes for interesting reading, especially an interesting take on what a discovery of life on Mars would mean for us.

    Seems a lot of this is nearly more philosophy than science though doesn't it?


  • Registered Users Posts: 8,810 ✭✭✭Hector Savage


    valoren wrote: »
    Agreed.

    A photon of light travels at just under 300 million metres per second in a vacuum and it would take that photon 100,000 years to traverse our Milky Way galaxy alone.

    Closer to home in our own solar system, Pluto orbits the Sun at an average distance of 3.7 billions miles.

    Driving at 65 mph non-stop, you would cross continental USA in one week. Taking a 'direct' drive at the same speed, you'd reach Pluto in, give or take a decade or two, 6,293 years. If you instead chose to go by Boeing 777 at it's maximum speed of 590 mph, if you started the trip back in 1338 AD, 680 years ago, you'd reach Pluto in the next day or two.

    Yep!
    Space is big. You just won't believe how vastly, hugely, mind- bogglingly 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.


    :P


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  • Registered Users Posts: 4,741 ✭✭✭10000maniacs


    H3llR4iser wrote: »
    It's actually very simple - the vast majority of people can't appreciate the sheer scale of just our galaxy, let alone the Universe.

    Let's put it this way - Earth's oceans are brimming with fish. We know it, we've seen them and...came up with delicious recipes using them :D

    But let's say there's a guy who has never seen a fish; Just heard stories about these creatures. He goes to the coast and takes a look for himself by scooping up a drinking glass of water from the sea. There are no fish in it.

    We, as a species and civilization, are the guy staring at a glass of sea water with no fish in it - would it be reasonable to assume the ocean to be a barren expanse based on that observation?

    (I *might* have lifted that example out of Neil DeGrasse Tyson's "Star Talk" podcast!)

    To use your analogy with my hypothesis if I may, if your guy who has never seen a fish places a glass ball in a fixed position in the sea, eventually a fish will crash into the glass ball.


  • Registered Users Posts: 934 ✭✭✭OneOfThem Stumbled


    ThunderCat wrote: »
    As for what the Universe is expanding into, my understanding is that it isn't expanding into anything as the Universe is the creation of space and time itself and those things exist within the universe and not outside it. The expansion of the universe is really more the stretching of spacetime. It is more a stretching than an expansion.

    If the universe is the extent of the laws of physics, how can things happen without the existence of time? As far as I'm aware, conventional wisdom says it can't (depending on how you define "it")! As such nothing could exist before the big bang, because there wasn't a time within which for anything to exist, and as such the big bang occurring when it did makes sense, as there was no time in which it could occur before there was a time for it to occur in.

    Aaah. And it still makes no sense as something can't come from nothing, much less everything! And where did all the energy come from in the first place? Some people say that there are many universes, like bubbles in a river - and while this idea is interesting, it is also alarming. Are these bubbles popping out of existence? Also, while it may explain where the "bubble" came from, an explanation for everything else (the "river") would still be required.

    We know so little. We are like ancient Greeks with a little bit of knowledge - capacities in the sciences and the arts, but outside of our own little world; the underpinnings of everything and the dark universe around us are obscure, unreachable and unknown.


  • Closed Accounts Posts: 7,480 ✭✭✭wexie


    If the universe is the extent of the laws of physics, how can things happen without the existence of time? As far as I'm aware, conventional wisdom says it can't (depending on how you define "it")! As such nothing could exist before the big bang, because there wasn't a time within which for anything to exist, and as such the big bang occurring when it did makes sense, as there was no time in which it could occur before there was a time for it to occur in.

    Aaah. And it still makes no sense as something can't come from nothing, much less everything! And where did all the energy come from in the first place? Some people say that there are many universes, like bubbles in a river - and while this idea is interesting, it is also alarming. Are these bubbles popping out of existence? Also, while it may explain where the "bubble" came from, an explanation for everything else (the "river") would still be required.

    We know so little. We are like ancient Greeks with a little bit of knowledge - capacities in the sciences and the arts, but outside of our own little world; the underpinnings of everything and the dark universe around us are obscure, unreachable and unknown.

    Can't for the life of me remember where I read it but apparently (if I remember correctly) physics as we know it is pretty accurate right up till just after the BigBang. During and before the big bang it all gets a bit screwy. Partly no doubt, because of some of the things you mentioned there.


  • Registered Users Posts: 1,017 ✭✭✭Four Phucs Ache


    From what I understand just after the big bang as in millionths of a second, all that existed was pure energy that expanded instantly to infinity.

    What I don't understand and probably never will is how does matter currently exist if dark matter doesn't?

    If dark/anti matter neutrons collide with positive neutrons they destroy each other so just moments after the big bang with everything nice and tight they should have canceled each other out?

    Feckin brain is melted now.


  • Moderators, Social & Fun Moderators Posts: 12,467 Mod ✭✭✭✭JupiterKid


    The Andromeda Galaxy, about 2 million light years away. The closest large spiral galaxy to our own, the Milky Way.

    11417_61822946_andromeda-galaxy.jpg

    Astronomers think that our galaxy and Andromeda will merge into a giant elliptical in less than a billion years.


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  • Registered Users Posts: 10,558 ✭✭✭✭Fourier


    To answer a few questions on the thread.

    The Big Bang is not the beginning of the universe, just the earliest point we can reconstruct from observations. The universe could have existed for trillions of years prior to it, or five minutes. We don't know.

    As for why matter and antimatter didn't cancel out, the full explanation is too complicated for a forum post, but essentially the laws of physics are not symmetrical between matter and antimatter. On average, over billions of particle collisions, slightly more matter is produced than antimatter, so they don't perfectly cancel out.


  • Moderators, Social & Fun Moderators Posts: 12,467 Mod ✭✭✭✭JupiterKid


    The ringed gas giant planet Saturn and its largest moon, Titan, seen edge on by the Cassini probe.

    Titan is the only moon in our solar system that has a substantial atmosphere and has seas of liquid ethane. The Huygens probe successfully landed on Titan in 2005.

    60254420_cassini-titan-rings.jpg


  • Registered Users Posts: 11,977 ✭✭✭✭Giblet


    To use your analogy with my hypothesis if I may, if your guy who has never seen a fish places a glass ball in a fixed position in the sea, eventually a fish will crash into the glass ball.

    Firstly how would you know? And secondly who says you can reach the middle, you can barely get the ball wet as it is. If you thinking probes should crash into mars because there are so many of them, then you vastly under estimate the size of the Uinverse and the Distances involved, The speed of light dictates that a civilisation would need be given a hell of a head start, and any civilisation that has such a head start, is going to know how to hide from us idiots.


  • Registered Users Posts: 4,741 ✭✭✭10000maniacs


    Giblet wrote: »
    Firstly how would you know? And secondly who says you can reach the middle, you can barely get the ball wet as it is. If you thinking probes should crash into mars because there are so many of them, then you vastly under estimate the size of the Uinverse and the Distances involved, The speed of light dictates that a civilisation would need be given a hell of a head start, and any civilisation that has such a head start, is going to know how to hide from us idiots.

    You say what about the size of the universe?
    I say what about the amount of time since the first intelligent civilization was formed to the last, maybe 10 billion years if life is inevitable?. And what about the gargantuan amount of civilisations formed since the first one if intelligent life is inevitable?
    What about the 100,000 potential intelligent civilisations formed in our galaxy if intelligent life is inevitable? Where are they? Where are their radio waves, where are their probes?
    I personally think we are a bizarre freak of chemistry that only happened once.


  • Registered Users Posts: 32,802 ✭✭✭✭NIMAN


    Getting back to how amazing the universe/space etc is, I once saw a TV programme with Prof Brian Cox.

    He took a photo of the stars in the sky using an ordinary digital camera. On the screen he showed us a distant universe that he claimed was X number of million light years away (can't remember exact figure), and said the light from it started travelling to us when dinosaurs were walking the earth.

    And it was now this simple camera was capturing it. Now considering we know how fast the speed of light is, the distance to that universe is simply unfathomable if that light has been travelling since dinosaurs were roaming about.

    It really makes you wonder what its all about, how it all came about, what was there before it, where is it all going, etc etc.

    And realise how silly it is to have arguments with strangers on the internet about some TV programme.


  • Closed Accounts Posts: 1,385 ✭✭✭ThunderCat


    You say what about the size of the universe?
    I say what about the amount of time since the first intelligent civilization was formed to the last, maybe 10 billion years if life is inevitable?. And what about the gargantuan amount of civilisations formed since the first one if intelligent life is inevitable?
    What about the 100,000 potential intelligent civilisations formed in our galaxy if intelligent life is inevitable? Where are they? Where are their radio waves, where are their probes?
    I personally think we are a bizarre freak of chemistry that only happened once.



    Human Civilization has been around for the blink of an eye in Cosmic terms. And that blink of an eye is far far less if you are just talking about the period of time that we have had clear knowledge of what we are looking at in the nights sky. So we really are only just opening our eyes to what is out there. Our telescopes are becoming more advanced all the time but they too are limited. For example the most numerous type of star in our galaxy is the red dwarf but they are not easily observed individually due to their low luminosity. Even more so for Brown Dwarfs. We don't know how many rogue planets are in our neighbourhood either. So there is plenty of things that we just can't see out there right now. And the things I've listed are Star and Planetary sized bodies. What hope do we have of identifying an alien probe (if such a thing exists) unless it crashed to Earth, without burning up in our atmosphere and without landing in a sea or desert.


    Just think of the Kuiper Belt and Oort Cloud in our own solar system, trillions upon trillions of objects, but how many of them have ever been observed close to Earth or hitting Earth. And these are objects already within our own solar system we are talking about. So the sheer vastness of space is of huge importance when considering all this.


    The other thing is that as we the only form of life we know about, we can only compare what we would expect to see with what we have already seen, in this example probes. It could very well be that another intelligent civilization evolved in such a different way to us that we would not recognise them or their technologies.


    Lastly, using this example, a probe hurtling through space is one of mans greatest achievements however a civilization only a 1000 years more advanced than us would likely use something far far different that we may not be able to even comprehend. And what about a civilisation a million years more advanced than us? They would be so technologically advanced that they could very well observe us without us ever knowing. Surely such a civilization would not deal in something as rudimentary as radio waves. Surely they would use their technology to mask the very fact that they are so technologically advanced.


  • Registered Users Posts: 4,027 ✭✭✭H3llR4iser


    To use your analogy with my hypothesis if I may, if your guy who has never seen a fish places a glass ball in a fixed position in the sea, eventually a fish will crash into the glass ball.
    You say what about the size of the universe?
    I say what about the amount of time since the first intelligent civilization was formed to the last, maybe 10 billion years if life is inevitable?. And what about the gargantuan amount of civilisations formed since the first one if intelligent life is inevitable?
    What about the 100,000 potential intelligent civilisations formed in our galaxy if intelligent life is inevitable? Where are they? Where are their radio waves, where are their probes?
    I personally think we are a bizarre freak of chemistry that only happened once.

    There are a number of faults in this argument.

    First, a fish may indeed eventually come near the "glass ball" - but will you be looking at that exact same moment? The fish comes around, swings in and out, and disappears. You turn up a second later, take a look and...still no fish.

    If you read a bit about the research that has been done in the field, you'll find out that it's been extremely spotty and based on the observations of very small portions of space for short times. Setting up continuous, widespread observation facilities is, in fact, one of the most immediate goals for the SETI program.

    Second, we've only been looking for a very short time with any intent, it's barely been 35 years. Time adds another dimension of enormity to a scale that is already nearly incomprehensible. Remember the story about the seven planets in the Trappist system? There has been a volountary, "is anybody out there?" signal sent by us. It'll take 40 years to reach the system and, IF there is anybody there, and IF they are capable of receiving our signal, and IF they decide to reply, it's going to be another 40 years until we get that. In 80 years time, we might get this "yeah, we're here!" signal back...which we, as humans (I won't be around...) might very well go on miss, because we forgot about the original message, moved on in technological terms...or everyone is just too engrossed watching 2097's version of Netflix while posting cat pictures on 2097's Facebook.

    Which brings to the third argument - "surely if somebody was out there, we'd get signals!". Not necessarily; We've only been broadcasting stuff for about 100 years. Let's say there's a planet, 200 lightyears away, with a civilization more or less on the same level of advancement of our own. They have their equivalent of NASA's Kepler program; They look at the star we call Sol, which is named something like "SPACEPROGRAM-8472" to them, and detect it has at least 4 planets - to big(ish) gas giants, and two smaller ones which probably are ice giants, orbiting far from the star. There MAY be two smaller, rocky worlds somewhere near the inhabitable zone (Venus and Earth, Mercury and Mars are likely too small to be detected) - their scientists get excited; They point their biggest and most powerful radio telescopes, only to be disappointed - nothing coming out to them. These planets, if they exist at all, must be barren.
    And this assuming their tech to be exactly like ours, without going in the more complex realms of species and civilizations using completely different means of communication.

    Fourth, we do certainly exist as a civilization and we are technologically advanced enough to shoot various kinds of physical stuff off our planet - from utility satellites to research probes, from scientific stations to human beings. We've been at this for over 60 years and yet...how many of our "space rubbish" has crashed on a planet in another solar system? Absolutely none; Our farthest object has barely made it our of our own neighbourhood.
    Your point is based off the theoretical existence of a Star Trek-like universe with plenty of civilizations possessing ultra-advanced, FTL means of transport, which at least our side of the Galaxy doesn't seem to be the case.


  • Registered Users Posts: 4,741 ✭✭✭10000maniacs


    H3llR4iser wrote: »
    There are a number of faults in this argument.

    First, a fish may indeed eventually come near the "glass ball" - but will you be looking at that exact same moment? The fish comes around, swings in and out, and disappears. You turn up a second later, take a look and...still no fish.

    If you read a bit about the research that has been done in the field, you'll find out that it's been extremely spotty and based on the observations of very small portions of space for short times. Setting up continuous, widespread observation facilities is, in fact, one of the most immediate goals for the SETI program.

    Second, we've only been looking for a very short time with any intent, it's barely been 35 years. Time adds another dimension of enormity to a scale that is already nearly incomprehensible. Remember the story about the seven planets in the Trappist system? There has been a volountary, "is anybody out there?" signal sent by us. It'll take 40 years to reach the system and, IF there is anybody there, and IF they are capable of receiving our signal, and IF they decide to reply, it's going to be another 40 years until we get that. In 80 years time, we might get this "yeah, we're here!" signal back...which we, as humans (I won't be around...) might very well go on miss, because we forgot about the original message, moved on in technological terms...or everyone is just too engrossed watching 2097's version of Netflix while posting cat pictures on 2097's Facebook.

    Which brings to the third argument - "surely if somebody was out there, we'd get signals!". Not necessarily; We've only been broadcasting stuff for about 100 years. Let's say there's a planet, 200 lightyears away, with a civilization more or less on the same level of advancement of our own. They have their equivalent of NASA's Kepler program; They look at the star we call Sol, which is named something like "SPACEPROGRAM-8472" to them, and detect it has at least 4 planets - to big(ish) gas giants, and two smaller ones which probably are ice giants, orbiting far from the star. There MAY be two smaller, rocky worlds somewhere near the inhabitable zone (Venus and Earth, Mercury and Mars are likely too small to be detected) - their scientists get excited; They point their biggest and most powerful radio telescopes, only to be disappointed - nothing coming out to them. These planets, if they exist at all, must be barren.
    And this assuming their tech to be exactly like ours, without going in the more complex realms of species and civilizations using completely different means of communication.

    Fourth, we do certainly exist as a civilization and we are technologically advanced enough to shoot various kinds of physical stuff off our planet - from utility satellites to research probes, from scientific stations to human beings. We've been at this for over 60 years and yet...how many of our "space rubbish" has crashed on a planet in another solar system? Absolutely none; Our farthest object has barely made it our of our own neighbourhood.
    Your point is based off the theoretical existence of a Star Trek-like universe with plenty of civilizations possessing ultra-advanced, FTL means of transport, which at least our side of the Galaxy doesn't seem to be the case.

    We have maybe been looking only for 35 years, well its over 60 years actually, but that does not stop the inevitable probes from the gargantuan number of planets with intelligent life flying towards us over the last 10 billion years and potentially crashing into the Moon or Mars which of course they have not done so far. Both the Moon and Mars are nearly 5 billion years old.
    Yet no evidence of any collisions with alien probes.
    Yes radio waves are different as we have been only seeking them for 60 years. But its crickets and radio silence out there even with the hundreds of thousands of planets potentially with intelligent lifeforms in our galaxy.
    When you say "Our farthest object has barely made it our of our own neighborhood", what does that prove?
    Not all lifeforms were created at the same time as we were. There could have been intelligent species created anytime in the last 10 billion years.
    Yet its crickets.


  • Closed Accounts Posts: 1,385 ✭✭✭ThunderCat


    We have maybe been looking only for 35 years, well its over 60 years actually, but that does not stop the inevitable probes from the gargantuan number of planets with intelligent life flying towards us over the last 10 billion years and potentially crashing into the Moon or Mars which of course they have not done so far. Both the Moon and Mars are nearly 5 billion years old.
    Yet no evidence of any collisions with alien probes.
    Yes radio waves are different as we have been only seeking them for 60 years. But its crickets and radio silence out there even with the hundreds of thousands of planets potentially with intelligent lifeforms in our galaxy.
    When you say "Our farthest object has barely made it our of our own neighborhood", what does that prove?
    Not all lifeforms were created at the same time as we were. There could have been intelligent species created anytime in the last 10 billion years.
    Yet its crickets.



    It shows our technology is still primitive compared to what is potentially out there. As such we cannot hope to detect let alone recognise and understand technologies belonging to more advanced beings than us. There could be signs of intelligent life everywhere we look but just aren't advanced enough to know it.


  • Registered Users Posts: 8,253 ✭✭✭MonkieSocks


    ThunderCat wrote: »
    It shows our technology is still primitive compared to what is potentially out there. As such we cannot hope to detect let alone recognise and understand technologies belonging to more advanced beings than us. There could be signs of intelligent life everywhere we look but just aren't advanced enough to know it.


    Yes, BUT at sometime in their civilization they would have been where we are today, regards space technology.

    If so, they should have sent out probes and radio signals just as we have done.

    No sign of any of em yet

    =(:-) Me? I know who I am. I'm a dude playing a dude disguised as another dude (-:)=



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  • Registered Users Posts: 4,741 ✭✭✭10000maniacs


    ThunderCat wrote: »
    It shows our technology is still primitive compared to what is potentially out there. As such we cannot hope to detect let alone recognise and understand technologies belonging to more advanced beings than us. There could be signs of intelligent life everywhere we look but just aren't advanced enough to know it.

    But surely all potential intelligent civilizations were as primitive as us at some stage. And they sent out their probes to explore their closest planets like we did. And they sent out their radio signals in analogue format like we did before they subsequently moved to digital.


  • Registered Users Posts: 4,741 ✭✭✭10000maniacs


    Yes, BUT at sometime in their civilization they would have been where we are today, regards space technology.

    If so, they should have sent out probes and radio signals just as we have done.

    No sign of any of em yet

    Snap, I didn't see your post. :D


  • Registered Users Posts: 9,847 ✭✭✭py2006


    Triiippppeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeey!

    I thought that said Tipperary


  • Moderators, Recreation & Hobbies Moderators, Science, Health & Environment Moderators, Technology & Internet Moderators Posts: 90,537 Mod ✭✭✭✭Capt'n Midnight


    To use your analogy with my hypothesis if I may, if your guy who has never seen a fish places a glass ball in a fixed position in the sea, eventually a fish will crash into the glass ball.
    If you were to analyse sea water you'd find traces of life.

    Likely to find bacteria or plankton.
    Large organic molecules.
    Dissolved oxygen AND organic molecules co-existing.

    The last one can be seen from very very far away.


  • Registered Users Posts: 32,802 ✭✭✭✭NIMAN


    I saw the Irish documentary 'The Farthest' last year.

    That really makes you realise how small and insignificant we are.


  • Registered Users Posts: 2,913 ✭✭✭SuperTortoise


    Intelligent life on other worlds is not inevitable. After 12 billion years there should be billions of unmanned probes randomly traversing the universe if intelligent life is inevitable.
    Why have none ever crashed into the Moon or Mars.
    Even we have half a dozen floating around in space, a few have already left our solar system. Multiply that by 6 sextillion and some should have come our way after 12 billion years.

    I think that answer lies in the OP, because the universe is so unimaginably big!

    The fastest man-made object in space is the juni probe, it travels at 265,000km/h at that speed it will take 110 million years for it to reach the edge of our galaxy, and that's just our galaxy.

    An asteroid(big enough to do a bit of damage) passed very close (~150,000km) to earth a few weeks ago, we did'nt detect it until about 24 hours before it passed by, added to the fact we've only really being watching the sky with the sort of technology able to detect such things for a few decades which is a very, very small ammount of time in comparison to 13.7 billion years!


  • Registered Users Posts: 4,741 ✭✭✭10000maniacs


    I think that answer lies in the OP, because the universe is so unimaginably big!

    The fastest man-made object in space is the juni probe, it travels at 265,000km/h at that speed it will take 110 million years for it to reach the edge of our galaxy, and that's just our galaxy.

    An asteroid(big enough to do a bit of damage) passed very close (~150,000km) to earth a few weeks ago, we did'nt detect it until about 24 hours before it passed by, added to the fact we've only really being watching the sky with the sort of technology able to detect such things for a few decades which is a very, very small ammount of time in comparison to 13.7 billion years!

    How far will an aliens version of the Juni probe travel in 10 billion years? What are the chances of one crashing into Mars if there are googol's of them traversing space for the last 10 billion years? I would say the chances are quite high.


  • Registered Users Posts: 246 ✭✭dsaint1


    800px-Hubble_ultra_deep_field_high_rez_edit1.jpg


    In the image above taken by the Hubble Space Telescope there are 10,000 visible galaxies each containing billions and billions of stars.

    If you took a needle out and held it to the night sky and looked through the hole on the end - that is the equivalent portion of space in the picture.

    To cover the whole sky the same techique would have to be used roughly 40,000,000 times.

    :)

    Yes, amazing but, if you count each source of light from this image, it's nowhere near 10,000 individual sources of light....


  • Closed Accounts Posts: 18,268 ✭✭✭✭ Dominik Unkempt Pimple


    H3llR4iser wrote: »
    It's actually very simple - the vast majority of people can't appreciate the sheer scale of just our galaxy, let alone the Universe.

    Let's put it this way - Earth's oceans are brimming with fish. We know it, we've seen them and...came up with delicious recipes using them :D

    But let's say there's a guy who has never seen a fish; Just heard stories about these creatures. He goes to the coast and takes a look for himself by scooping up a drinking glass of water from the sea. There are no fish in it.

    We, as a species and civilization, are the guy staring at a glass of sea water with no fish in it - would it be reasonable to assume the ocean to be a barren expanse based on that observation?

    (I *might* have lifted that example out of Neil DeGrasse Tyson's "Star Talk" podcast!)

    Explains where my aunt Thelma went to....eaten by an alien!


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  • Registered Users Posts: 2,913 ✭✭✭SuperTortoise


    How far will an aliens version of the Juni probe travel in 10 billion years? What are the chances of one crashing into Mars if there are googol's of them traversing space for the last 10 billion years? I would say the chances are quite high.

    The juni probe will travel 23,214,000,000,000,000,000 Km in 10 billion years
    or 2.5 million light years.
    The observable universe is 93 billion light years in diameter so the juni probe will have travelled just 0.003% of the ways across the universe in 10 billion years! and even then that does'nt account for expansion.

    The asteroid belt between jupiter and mars contains millions and millions of asteroids but when NASA launches spacecraft to the outer planets they don't bother trying to negotiate a way through them, because space is so vast and the chances of them hitting one are so small it's not worth their while!
    All this would have had to have happened in the last 50 years for us to see it, so while we cannot absolutely rule out the possibility of humans being the outlier in the universe the chances of us finding alien life in the future i would say is decent enough.


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