If there are UFO's in galaxies millions of lightyears away, then how would they visit us here at earth?
550076
better question is...If UFO's could make it here to earth, Why would they? we would be like the kids that ride the short yellow bus compared to them.
1101732
Yes, there are aliens among us.  It is difficult to spot them because they can hide themselves by reflecting light.  Our human vision is very limited in the spectrum of light.  They utilize the light we do not see to hide themselves like their space crafts.  They are here to help us in our quest to evolve.  Governments and disinformation specialist's have placed fear about space visitors.   That is why they will not show themselves until we are ready to accept them.  They are our cosmic family beyond our planet.  Are we ready to take the next step?
212132
most scientists agree that it is only mere human egocentricism to believe that in the vast expanse of the universe we are the only form of intelligent life, on this microcosm that we like to call Planet Earth.\n\nthe probability of life existing on only one single palnet is unbelievably low..in about 99999999 cases out of 100000000 life evolves in more than one planet, in most case within a few light years of each other on an average.\n\nit is a fair assumption that our universe contains life within a range of a hundred or two hundred light years from here.\n\nas for contacting aliens, it is definitely possible..no civilisation can develop without trampling on common properties of the universe like radio waves,etc. hence we are already concentrating our efforts in this direction since around the '50s , trying to listen for any regularities in the radio wavws that we recieve from the universe..and sending out our own messages in the hope somebody will listen to them \n\nthe difficulty lies in speed..radio waves travel at the speed of light and you can't get faster..but this means that it will take a message sent now from a planet 200 light years away, two more centuries to reach us..but we are still in with a good chance of intercepting such messages..
970441
Well, if they are out there, I don't think they are from the future.  Man would be silly to think that there are no other life forms out in space.  But, I don't think that those life forms are little green men.\n\nI think that we are the only intelligent human race there is.  I don't believe their are space ships abducting people.  You ever notice, its only in Western Civilization that the UFO concept exists?  You think that if China or other communist countries actually saw them they would not have blasted the snot out of them, especially during the cold war?\n\nGo down to South America where they CITI people have been scanning the Sky's for years.... If they haven't found anything, then the conspiracy theory is just that.\n\nUnless your a Sociologist.  Their religion is based on Aliens.  You will have to make your own decision on that one.\n\nGood luck on your search for the truth.
299490
Without a doubt. Seeing all those stars in the sky.. One of them somewhere has to hold some kind of life. But I don't believe they travel to earth. No ET is phoning home LOL
593865
I don't think a credible claim for seeing aliens exists.  Plenty of stories - zero real evidence.  \nDo they exist?  Well, I think the answer is probably.  There are so many zillions of planets in the universe, I would bet that there are others with life.  However, unless the time scale on which that life lives in FAR longer than ours, the laws of physics do not allow them to live nearly long enough to visit us.  It would take many millions of years to go out and visit these other planets - improve rocket technology even 1000x and it would still be thousands of years.  \nHowever - the possibility of us picking up some sort of radio signal from an alien world seems to be real.  No real hits yet - but it may happen.  We have conducted transmissions that have been sent to star clusters (containing millions of planets) which, if any have the same level of technology as us, should be able to pick it up.  Who knows.
1068867
That's a good question.  If everything started from a singularity and we can see some objects from early in the universe, you'd think they'd all be in one area in space.  \n\nBut you've got to remember, where we are now was also in that same area near the original singularity.  Although our sun, or our galaxy, did not exist 13 billion years ago, this point in space did.  This point in space was surrounded by the early galaxies and quasars of the early universe and they were close to us - a lot closer than 13 billion light years.  The light of many of those early galaxies washed over this point in space long ago.  \n\nBut this point in space has been moving away from all the other points in space at a rapid rate.  We've been moving away from the surrounding points in space and the light from those points has to chase us down.  So if we've been moving away from some point in space that once contained a quasar at 9/10ths the speed of light, that light would take 10 times longer to reach us than if we were standing still.  So if that point was really 1.3 billion light years away from us 13 billion years ago, its light would just catch up with us.\n\nYou got to think 4 dimensional now... we've been moving away from points on all sides of us, thus light needs to chase us down from every direction.  So were surrounded by these ancient quasars.\n\nWell, at least the astrophysicists seem to make the math work...
709216
Hmmmm, in the future you might be right, but I think the cost of sending anything into space is quite goppingly high at present - and until we can travel SIGNIFICANTLY faster than light, I'm afraid the ex-con would have died a fair few tens of millenia too early to note anything of value.\n\nEven our own galaxy (a teeeeeny spec in the universe) is roughly 100,000 light years wide. At 1000 times the speed of light, an 18 year old criminal would need to live to be 118 year old just to see one side of our galaxy to the other. He would also be going a little fast to make the most accurate of observations.\n\nIt really is awfully big.\n\nInteresting idea though - and with suspended animation / faster than light travel it may one day be a plan.
472738
they could come from other star systems and yes they would have the technology to travel to our world. the universe is estimated to be around 12 billion years old.\n\nhow long have we been on this planet?\nwhat was our technology like 200 years ago?\n...no electricity, cars or planes etc.\nlook how far our technology has advanced in 200 years...\n\ncan you imaging what technology the aliens would have if their world started a million or billion years before ours?
328025
Absolutely! The odds that they exist are overwhelming when you think of how GALAXIES are scattered like specks of dust!\nNow... even though aliens exist, what are the odds that they are on another planet in our galaxy right NOW? Think about it... It took 50 million years for humans to appear on Earth. How long will we be here?... only 50 to 100 thousand years (hopefully)? How many other planets will bring forth intelligent life - not a whole heck of a lot. And of them, when will that life be around? Just a tiny amount of relative time.\n...What I am saying is that EVEN IF other civilizations were, are, or will be... the timeline of the universe is too insanely long for any of us to be co-existing. The reality may very well be that we are currently very alone here in our time and place. I hope this gives you a new, more realistic way of seeing things. Sorry it's such a downer, though!
979405
The question is twofold and most responders missed that. To my knowledge there is no scientific evidence of aliens visiting earth space.\n\nBut there is plenty of independent scientific evidence of UFOs. The UFO phenonena has been studied at great length and there is evidence that something comes and goes and that that something operates intellegently.  But we do not know what they are.  \n\nMy personal opinion is that there is likely life somewhere in the vastness of the cosmos.  But I can not believe that life visits earth regularly each and every day all over the globe. So the UFOs may or may not be alien.  But highly unlikely.
362363
There is, sadly, no evidence of aliens.  I'd love to encounter visitors from another planet (of the peaceful variety, at least, I'm not looking forward to a real-life game of Space Invaders!), but there don't seem to be any.  Maybe we all smell funny.\n\nThe evidence against the so-called alien encounter stories is pretty telling.  Look up "spleep paralysis" for an explanation that covers the "alien abductions".\n\nBut, while I don't beleive earth is being visited, that doesn't mean I believe it isn't happening, just that the people who say they are meeting aliens seem to be wrong.  If aliens are here, they're being very quiet, observing us like biologists behind blinds.\n\nLife seems pretty easy to develop in the right circumstances.  I expect the universe will be full of life, though most of it will be of the bacterial level of complexity, getting no further.  I would be surprised if there weren't other intelligences out there somewhere, though.  It just doesn't seem that difficult to evolve.  Still, I don't know and I won't pretend I do.  Here's hoping!\n\nAs my father says, either there's life out there or there isn't.  Either way, it's amazing.
18185
since UFO simply means Unidentified Flying Object, anything you see zipping about in the sky that you can't identidy is a UFO... so yeah, you sorta have to believe in them.  ;)  \n\nas for creatures from another planet finding us, the possibilities of that are slim, due to the vastness of the universe.  travel at or above the speed of light is impossible, as that's when you get complete molecular and atomic disintigration.  the only way life can travel distances is if energic beings exist, or if it's in some primitive seed state, dormant inside some meteor, but that's not all that likely, especially since when simple protein molecules impact at those high speeds known to meteors, they change..  forming amino acids.  this is cool, as such can help form the building blocks of life, but i cannot imagine that such would actually spawn life, but hey, life is a product of environment, so if a species evolved to spread as such, then so be it.\n\nback to sentient beings finding us, let's say they mastered interstellar travel..  at speeds that don't cause their matter to break up, they could travel, but their ships would have to be of some sort of colony-type, so that the decendents of those who set out would be the ones that eventually "got there"...  and then our planet would be little more than a pile of resources they'd just end up taking, than some opportunity for some cool star-trekkish interstellar alliance.  ;)
842008
Yes, it is true that there are stars and galaxies whose light has not yet reached Earth. This is because light travels at a finite speed (about 3.00E8 km/s). It does not lose energy to space either... and the only thing in space that disrupts light's path by any real amount is gravity.\n\nWhen we look into the sky at night we are seeing the past. When we look at our Sun we are looking 8 minutes into the past (light from the Sun takes about 8 minutes to reach us)... The nearest stars to our Solar System are hundreds, even thousands of light-years away (a light-year is the measure of the distance that light travels in a year)... So, when you look at the stars in the sky, you are seeing them as they were 100's, 1000', if not millions or billions of years ago. Scientists, using our most advanced telescopes have looked as far back as when our Universe was only a baby (about 450 million years old). As the Universe is about 15-20 billion years old right now thats very far back in time.\n\nTo answer your question about faster-than-light travel. As we know physics today, that is impossible. Einstein and many other relativistic theortists have shown time and time again that faster-than-light travel has a high probablity of impossibility. Also, light speed and (if possible) faster than light speed travel would affect the traveler's perception of time relative to the inertial frame.\n\nThis is a basic theory in relativity and I really don't want to get into that.
1072373
i also think aliens exist. out of all solar systems all the planets all the galaxies in the universe we can or should never argue that we are alone.
940433
Well, if there are billions of stars in an average galaxies, and there are countless galaxies in the universe, even if there is an odd of 1 to trillion, then the probability of having life forms in other galaxy systems appears to be good. \nHowever, life-forms as we know on earth may not be duplicated elsewhere.  Ours is carbon-based.  It is not improbable for other forms of life to exist.  \nBecause of limitations to speed of light, and hence to travelling speed, we, earthlings, may never be able to encounter alien life, as some galaxies are hundreds of millions of lightyears (a lightyear is the distance travel by light in 1 year) away, that is it takes light hundreds of millions years to reach us from that distant galaxy.\nSo even if the intelligent life-form on the outskirts of our known universe were to evolved a million years before us, and if such intelligent life-forms were to be able to travel at the speed of light, they cannot reach us in another hundreds of million years.\nBy then, our enlarged sun would have scorched our earth into an uninhabitable region, meaning all lives on earth would be wiped out.
540450
well, this really isn't a question about astronomy, but imagine the trip were possible, and you could travel as close to lightspeed, c, as you chose.  special relativity shows that you could choose how long the trip would take by choosing your speed.  the distance of the trip will shrink more and more the faster you choose to go.  if the trip were to cross the galaxy (100 000 ly) and you traveled at:\n0.9999c (9 x 10e-4) the distance would look like 1000 ly and take 1000.10001 years.\n0.999999c (9 x 10e-6) the distance would look like 100 ly and take 100.0001 years\n0.99999999c (9 x 10e-8) the distance would look like 10 ly and take 10.0000001 years\n\nthis is actually observed in nature.  high speed cosmic atomic nuclei are continuously raining down on earth, and sometimes one strikes the nucleus of an atom in the upper atmosphere and produces a muon.  muons are very short-lived and shouldn't have time enough to reach us down here before decaying, but they do.  the muons are traveling so fast that they see the distance between the upper atmosphere where they originated to here as much shorter than we do so they have enough time to travel the short distance before decaying.\n\nlook here:\nhttp://en.wikipedia.org/wiki/Special_relativity