How Far would they have to go?

2

242 9999

Registered Member
Astronomically, it isn't prudent to use common measurements like kilometers or miles, because the distances in the universe are so incredibly huge. Instead, we use the term light year, which refers to the distance light traverses in one Earth year. Light travels at a rate of 300,000 km/second (or 9,460,800,000,000 km/year).

That is 9 TRILLION, 460 BILLION, 800 MIllion kilometers (roughly 5,913,000,000,000 miles) in ONE LIGHT YEAR.

The light year is not a small distance by any stretch of the imagination. For all intents and purposes, we have no means by which a human can traverse that distance in his/her lifespan (relative to our planet or any point on it).

According to a web site which I visited, I found out that there is a star in the Centaurus constellation (visible from Earth) called Rigil Kent; it is 4 light years away from Earth. It was the closest star I could find a distance for, although I have heard varying reports of the proximity of Alpha Centauri.

Some other stars we can see; Rigel (in the Orion Constellation)- 850 light years away. Deneb (in the Cygnus constellation) - 1500 light years away.
Spica (in the Virgo constellation) is 220 light years away.

According to encyclopedia.com:

"galaxy: large aggregation of gas, dust, and typically billions of stars...A typical spiral galaxy is shaped like a flat disk, about 100,000 light-years in diameter, with a central bulge, or nucleus, containing old stars; winding through the disk are the characteristic spiral arms of dust, gas, and young stars...Gravitation also holds clusters of galaxies together; the Local Group cluster includes the MILKY WAY (containing the sun and solar system) and the ANDROMEDA GALAXY, both spirals, and the irregular MAGELLANIC CLOUDS."
(http://aj.encyclopedia.com/articles/04860.html)

So, we can say that aliens from our own galaxy would only have to travel a maximim of a mere 1000 light years to get to Earth, and a minimum of 4. All things being equal we can take the mean of these two numbers and estimate that on average, 502 light years would be the average distance. Without difinitive proof about the frequency of life in our galaxy, I would be willing to give a 400 light year margin of error and say that alien life would need to travel at least 4, but on average 102 light years to get to our planet (considering the 400 light year margin for error).

When we consider light speed as an option, it is important to note that according to modern human physics, this cannot be achieved by anything BUT light. However, if we are in a generous mood, we can even give the technological benefit of the doubt and say that aliens can travel 2 times this speed. This would mean that traveling from the closest star (Rigil Kent) would still take 2 solid years of travel at 2c.

Does this still seem feasable?

-242
 
Well, yes it does all depend on how much time one has to work with i.e. their lifespan and also if the laws of time are the same throughout space i.e. the space-time continuum. Our species is confined to a maximum lifespan of roughly 100 years give or take 10. The average drosophila (fruit fly)lives for just 2 weeks. Who's to say that our species isn't the drosophila of the universe in terms of lifespan. We are a relatively young species in both a biological and technological sense. Given another century or more of technological development as well as biological development, space travel or rather the means of accomplishing it may well be achieved.
 
Hello Peter.

I do agree that aliens might have a much longer lifespan than do humans. Seeing how little we know about alien biology, it would be unsuprising to learn that they may outlive us 10 or 100 times over.

However, this may be more counterproductive than one might imagine. Their adolescence and rate of maturation (not to mention their rate of deduction) might take centuries. Assuming what we know about terrestrial biology applies, longer life spans change alot of parameters. Patience would no doubt differ between our species, so why not metabolism? What if it takes 30 hours for this alien species to make a simple decision? Would their longer lives imply slower movement? All speculation, I'll admit.

Longer life spans seem to be the only way around the very real restrictions imposed on us. If you can't travel faster than light, you have to live so long that you don't mind the trip. I don't readily accept the theory; it seems born out of backward rationalization. But, I'll admit I don't know for sure.

Any other thoughts?

-242
 
Well, yes what about the space-time continuum? Is time the same in space as it is on Earth? Was Einstein correct in stating that time dilation and length contraction occur in regard to space travel at such high speed?
 
From what I understand, actually traveling in a ship at certain speeds isn't what these aliens are doing. They are actually picking a point in space and time and in effect bending space and time together so that they can reach that point in space and time without actually travelling anywhere. In other words, it doesn't matter if they are 10 trillion light years away, they can get here in an instance if they wanted to. They bend space and time relative to their ship, so that their ship all of a sudden appears just outside the earth, and then they decend into our airspace. Because this theory doesn't jive with current physics, most mainstream scientists refuse to believe that any aliens are visiting our planet because it would technically be impossible according to our current physics model. Of course, if we find out that they aren't actually travelling in a way that we would concieve as travelling, and that they are simply taking a point in space and bending it, to their current location and then just moving over to that point, rather than travelling like we would to the moon or whatever, then we might realize that our current physics models are flawed and incorrect. Has anybody here ever heard of string theory?
 
242,

I do believe you are off in your maximal distance of travel estimate. Given a diameter of 100,000 ly, and the fact that we are about 2/3 of the way from the galactic center, the longest distance from us to another system in the Milky Way would be something like 5/6*100,000 =~ 83,000 ly. It's also a bit tricky to define average distance when we talk of travel within (roughly) a disk. You'd have to integrate all distances from us to all points in the disk, and then divide by the disk's area... But either way, it'll come out to a bit more than 500 ly, I believe. :)

But I do agree that interstellar travel is insane. Just the energies required to reach anywhere near lightspeed or to bend spacetime are way beyond what we have available in the Solar system (even for one measley trip!) Maybe our theories or methods are not refined enough...

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I am; therefore I think.
 
Boris, you are indeed correct. Off by a decimal, indeed. Without reposting the corrected parts, it is still far beyond human comprehension. Nice to meet you.

Commander X, I have heard the notion of bending space to allow instantaneous travel to any part of the known universe. Seems to me that this is increasingly difficult, as we have no true way in which we can grip space (other than high concentrations of matter). Besides, no matter how distorted space becomes, we must remember that we are dealing relatively. While going at near light speed, you notice no difference whatsoever with your dimensions; this would be mirrored if space was bent by some other means. I could very well be wrong here, but I see no practical way to do this.

Some other points, Commander, if they can truly bend space to their whim, then we must take every precaution not to anger them in any fashion. Imagine them bending space so that Earth is within a few feet of 12 suns. Or, what if they touched a singularity with our sun? Bad things.

Greetings to all. I am 242.

-242
 
242,

Nice to meet you too. One thing: supposing for a moment that better propulsion technologies allow us to achieve speeds approaching 1c using reasonable amounts of energy -- interstellar travel indeed becomes possible (though not routine). It would take over 4 years Earth-time to get to the nearest star (actually, a lot more than 4 years, considering time wasted accelerating and decelerating) -- so let's say it's 6 years for a 1-way trip. At cruising speed of 0.9c, the time elapsed on the vessel is "only" (very crudely) about 3 years (due to time dilation.) It's definitely within human limits, but it's no picknick either...unless the crew is in some kind of biostasis during the trip.

Though still, cruising at such a high speed even the interstellar dust becomes deadly shrapnel, not to mention that any collision with a minor-sized meteoroid would spell instant annihilation for the entire mission (and at those speeds, one can't detect small dark bodies well enough in advance to avoid collision.) It seems that for practical interstellar travel (without using any space-warping technologies, that is) we would not only need unheard-of biostasis, energy generation, and propulsion systems, but also some sort of typical sci-fi "deflector shields". So yeah, right now the prospects aren't looking too bright. But there's always the other day... ;)

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I am; therefore I think.
 
Of course the possibility exists that whoever appears to be leading us all a merry dance are not extraterrestrials at all.

Then again, I'm pretty sure that you've all considered this little possibilty before......
 
THANK YOU SPADGE! FOR CRYING OUT LOUD PEOPLE, WAKE UP! THEY'RE SPIRITS!!!!!!!!! FOR CRYING OUT LOUD!!!!!! DUH, DUH, DUH. *banging head on keyboard*

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You may think I'm a nut, but I'm fastened to the strongest bolt in the universe.
 
Boris, the time dialation is not percieved by the traveler. A 10 light year trip at c would take 10 years (the traveler's time). From the standpoint of the Earth, however, it would take much longer than 10 years (as the ship never really ever seems to be traveling at c (due to time dialation). The distortion is never subjective, instead it is only percieved by comparison with other standpoints.

So, the time elapsed on the vessel would be the distance (in light years) over the speed (in c). Thus;

4 ly / .9c = 4.444 years.

At least, this is the truth as I understand it. I will research a little more to make sure.

However, computing Earth's elapsed time is another story.

Lori, spirits?

-242
 
As for the whole bending space and time thing, I'm not a physicist, but I believe that they aren't exactly bending the entire space, where planets and star systems would be folded, or anything like that, but that they are bending the space that surrounds the ship. I know that doesn't make sense, but a physicist on a tv program was talking about how that would be the only real way that aliens could travel here from trillions of miles away.

Lori- Some beleive that these so called aliens are not alien at all, and that they aren't traveling through space either. Some believe that these so called aliens are actually humans, only humans that could potentially be millions of years ahead of us on the evolutionary curve, and that these humans from millions and millions of years in the future are travelling back in time to our present time, trying to encourage us to make sure that we don't destroy the planet and their future. I know that it sounds crazy, but it is an interesting concept. Also if you look into to String Theory, which is a theory that would correct some of Albert Einsteins mistakes in Relativity, for String Theory to work, there would have to be five dimensions in addition to our current dimension on this planet. Therefore, these creatures could simply be traveling interdimensionally and not through outer space at all. Just something to ponder.
 
Boris, I expected you to get into wormhole theories. Bending space is one analogy, and lets not forget mathematicaly they exist, we just can't make it happen..YET, remember what was said about breaking the speed of sound? I did alot of this crap at Uni, and I'm telling you physists in the last century (it would have been better if I could say this century) believed that it was impossible, fluid dynamics does not allow for compression of fluids...therefore the idea was not widley accepted but here we are a world that has not only supersonic flight its now ultra - sonic...F#$ckin fast. Also lets not forget cryogenics, we can't achieve it but its definetly do able....especialy if you talk about alien biologies, its all possible.......

BTW I recently read an article on wormholes and the theory is looking for exotic matter, anti-matter that sort of stuff to stabilise a wormhole. I believe if it exists in mathematics its only a matter of time until it becomes a usable technology.......Distance is not an issue, we can thank Dr Hawkin for that.

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work to LIVE...don't live to WORK.
 
From a NASA site:

"We used to think that the speed of sound was impassable, isn't the speed of light the same thing? No, because the speed of light
permeats EVERY experiment that physicists have conducted for the last 100 years. Not a single chink in this wall has ever been seen to suggest that matter or energy can travel even so much as 1 micron per second faster than light speed. If there is a way to do it, nature is not telling us by showing a single phenomenon where it naturally happens."
(http://image.gsfc.nasa.gov/poetry/ask/a11133.html)

"...Nature seems to be locked-in to this velocity limit, and there is nothing that we can do to the matter and energy within space-time that can exceed this limit. We can no more exceed the speed of light than we can alter any of the other constants in Nature."
(http://image.gsfc.nasa.gov/poetry/ask/a10807.html)
 
242,
That may very well be the case, in fact I don't really believe that we will evetr travel faster then light. However, wormholes are exactley what was mentioned above with the whole bending of space stuff. You can reduce a journey measured in light years to a few meters.....to my knowledge these exotic "tunnels" exist in mathematics at least. So as I said above if it exist in math its only a matter of time until its real....we'll just have to see. ET may already have that mystery solved.


Another point to consider,
I think Boris mentioned that the amount of energy needed to travel that far is extrodinary...more then we can afford to lose, well there are many alternatives that may not be feasable right now but work in theory at least. Have you heard of solar sailing?, I did a design research project in my final year of Engineering on alternative propulsion systems....a solar sailing vessel could (in theory) be accelerated to 30% the speed of light.....12 years to proxima cent. What about the concept of generation ships...i.e. the generation that begins the journey is long gone by the time the mission is in its final stages? Really a civilisation that is only 100 years ahead of us in technology wouldn't have any problems with distance.

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work to LIVE...don't live to WORK.



[This message has been edited by Rambler (edited March 07, 2000).]
 
242,

You've got it backwards when it comes to time dilation. When an object is travelling at 0.9c <u>as observed from the Earth</u> -- then as far as Earth is concerned it will indeed take the object 4.44... years to travel 4 ly. From the object's own point of view, however, much less time would have elapsed.

<hr>

Everybody,

As far as bending space, the energy required is still far beyond what is available even if we were trying to make a wormhole smaller than an atom. Think about this: the phenomenon of space distortion is just another definition of gravity. Thus, to cause space to bend in extreme ways, we would have to introduce locally extreme amounts of some gravity-causing agent. Gravity is only produced by matter or energy; achieving enormous concentrations of either in a very localized region is correspndingly enormously taxing.

As for other alternatives, such as stasis, generation ships, etc. -- sure, why not? The only thing is that such travel can no longer be casual; given the amount of time and resources it requires it would only be useful for colonization. Or should I say emmigration, since given such means of travel, any interstellar colonies will end up virtually cut off from each other?

Granted, our physical knowledge is not complete, and there might indeed exist phenomena that allow casual interstellar travel. But it doesn't look like we are currently aware of even one such phenomenon.

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I am; therefore I think.

[This message has been edited by Boris (edited March 07, 2000).]
 
Well, I agree that 100 years of technology would be quite an advantage. Also, the notion of generation ships and mechanical colonies is a very real (and feasible) idea. However, I can't ignore all of the data we have concerning relativistic speeds. I don't think it is possible to make the 4-1000 light year trip in a few days traveling conventionally.

Seems more prudent to send out messages into space. Either that or send millions of tiny titanium projectiles etched with information. By gathering just 2 of these projectiles, alien life could get a rough idea of where we are, and perhaps we could establish some sort of communication with them. Of course, there would need to be more than millions to ensure this, but...

-242
 
Point well taken Boris,
So in the context of this thread,the possibilty of ET being a colony looking for a place to settle makes sense. Maybe we are being observed to see if we can coexist in a space where casual travel is going to be a reality.

Boris do you believe Humans are stuck here?

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work to LIVE...don't live to WORK.
 
Rambler,

Are we stuck here? Well, at present we certainly are. In the near future, we will spread all over the solar system, to the very edges of interstellar space. After that, if we do not discover any better means of travel, we'll probably start launching one-way interstellar colonization missions. If, on the other hand, we do discover a means of casual interstellar travel, we'll probably end up with something very reminiscent of the Star Trek or Babylon 5 types of situation.

Could there be a colonizing alien presense in the solar system? Well, why not? It's actually one of the very few explanations for aliens being here that I find even remotely convincing. Though there are a couple of snags to such a theory.

If they didn't know that humans were already here before they set out on their journey, and they find it unethical to simply wipe us out, why don't they just use the resources available in the solar system to re-fuel and/or re-build, and set out to find another (unoccupied) home?

On the other hand, wouldn't it be one heck of a coincidence if the colonizing aliens set out on their mission just in the nick of time, as homo sapiens emerged on Earth? They could have easily colonized the solar system a few million years ago, when there was no sentient life here.

Anyway, such are my thoughts...

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I am; therefore I think.
 
Boris,
"If they didn't know that humans were already here before they set out on their journey, and they find it unethical to simply wipe us out, why don't they just use the resources available in the solar system to re-fuel and/or re-build, and set out to find another (unoccupied) home?"

Maybe that is the plan, but if you found an intelligent life form during the journey to "where ever" wouldn't you hang around and study it? After all if the reported sightings of ET are true then we have a striking resemblence to them....


on a side note:
Have you guys seen the pics of the strange buildings etc that were photographed by acident during the manned lunar missions. Don't get me wrong I'm not convinced its anything more then a fluke of some kind but its very interesting to look at. Also I have looked around on the net a fair bit as to sightings much earlier in history and I gotta tell you guys There are some well known old paintings with strange craft in them....I can e-mail the pics if anyone wants them.




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work to LIVE...don't live to WORK.
 
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