# What would have to be true for "UFO" aliens to be real? **URL:** \ **Category:** Great Debates\ **Created:** [May 27, 2013, 12:35pm UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459 "2013-05-27T12:35:19Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [May 29, 2013, 3:53pm UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/41 "2013-05-29T15:53:10Z")
[QUOTE=kaylasdad99] Voyager 1 was launched in 1977, and is presently the farthest man-made object from Earth. In 36 years it has traveled 124.34 AU (at 93,000,000 miles per AU, that’s 11.56 billion miles). One light-year is roughly 5.87 trillion miles. [/QUOTE] Right, but it hasn’t been under thrust in over 35 years. It’s gotten a few sling shot boosts from gravity assists from other planets, but it hasn’t been under thrust since it left the earths atmosphere and started it’s journey. Any sort of realistic interstellar scenario is going to include a rocket that uses a continuous thrust system (such as the fission/fusion rockets NASA is currently looking into, or maybe an Orion augmented by something else like a large solar sail). > [@](#): > > Just out of curiosity, how does that work with a non-FTL ship making it in three generations? Because you can’t extrapolate from Voyager 1, since it isn’t a continuous thrust system. I’ve seen estimates of a hundred to a few hundred years to get to the nearest stars with some of the theoretical technology that’s being looked at today. So, maybe 2-4 generations. ---
**Author:** ![aNewLeaf](https://avatars.discourse-cdn.com/v4/letter/a/ac91a4/32.png) [@aNewLeaf](https://boards.straightdope.com/u/aNewLeaf)\ **Post date:** [May 29, 2013, 3:53pm UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/42 "2013-05-29T15:53:52Z")
> [@Czarcasm](#): > > What percentage of lightspeed are you assuming for this generational ship? A small one. Although again, if somehow we manage to come up with a constant-boost drive, it all changes. Heinlein worked out the numbers a long time ago, there’s a chart in Expanded Universe. If we could accelerate constantly at even 0.01G, we’d get there in a hurry. I don’t think that’s feasible for the first ship, but maybe. But the overall operational possibility of the concept is 100%- a generation ship certainly could be built by some species somewhere. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [May 29, 2013, 3:59pm UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/43 "2013-05-29T15:59:55Z")
> [@aNewLeaf](#): > > A small one. > > Although again, if somehow we manage to come up with a constant-boost drive, it all changes. > Heinlein worked out the numbers a long time ago, there’s a chart in Expanded Universe. > If we could accelerate constantly at even 0.01G, we’d get there in a hurry. > > I don’t think that’s feasible for the first ship, but maybe. > But the overall operational possibility of the concept is 100%- a generation ship certainly could be built by some species somewhere. A constant boost ship is a stupid idea, unless you’ve plotted a course where absolutely nothing can get in your way between here and there. Rough guess please on the _average_ speed between here and there. I’m not asking about the type of engine, acceleration or deceleration technics-just the average speed between here and there. ---
**Author:** ![Buck\_Godot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/buck_godot/32/6573_2.png) [@Buck\_Godot](https://boards.straightdope.com/u/Buck_Godot)\ **Post date:** [May 29, 2013, 4:17pm UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/44 "2013-05-29T16:17:43Z")
> [@Lumpy](#): > > [li]These craft are the vessels of diminutive humanoid figures[/li] This is a big one. The only three possibilities that I can come up with are 1. There is some serious convergent evolution going on between our two planets such that there is a strong association between being a bipedal humanoid, and having advanced intelligence/technology. I don’t see any reason why this would be true. 2. Someone has been tinkering with our evolution to make us look humanoid and have advanced intelligence. It could be the aliens making man in their own image or another being that affected both our evolution and the alien evolution. This would have to be done in gradual way over millions of years in such a way that it appeared to occur naturally. This also seems hard to imagine 3. The aliens have modified their bodies from their original shape into something that more closely resembles our species. On the other hand if you think they would bother with this, you think they would do a better job. Although it is possible that what we see now is a transitional stage and that in a few generations they will look like us. But again, why bother. In terms of the government conspiracy the only possibility that I can see is if the government is in direct contact with the aliens and has been instructed by them to hide their presence. The government is kept in compliance either through threat of force, or by being bribed, possibly with advanced technology. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [May 29, 2013, 4:21pm UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/45 "2013-05-29T16:21:28Z")
> [@Czarcasm](#): > > A constant boost ship is a stupid idea, unless you’ve plotted a course where absolutely nothing can get in your way between here and there. Rough guess please on the _average_ speed between here and there. I’m not asking about the type of engine, acceleration or deceleration technics-just the average speed between here and there. You should probably tell the folks at NASA (and others working on the same thing) that it’s a stupid idea…save them the trouble of working on the thing. 😛 I don’t think it would be a problem…space is pretty empty, you don’t go in a straight line regardless, and you can always maneuver if something unexpected gets in your way…and, even if you are coasting the exact same problem would crop up (i.e. if something unexpected was going to get in your way, it would whether you were coasting or under acceleration). As to how fast you could go, that’s hard to say. It will depend on what technology they finally come up with. I know NASA is working on a constant acceleration fission system atm (not an Orion) that could put out low thrust for months or years. As for average speed, my WAG would be something like [this](http://www.popularmechanics.com/science/space/deep/how-to-build-a-starship#slide-1)…or about 90+ years to do 4.24 light years. Pure fantasy at this point, of course, but that would be 39,900,000,000,000 km in, say, 100 years, or 399,000,000,000 km/year, 12,653 km/sec on average for the entire journey, which is admittedly pretty damn fast. Of course, you’d have to be accelerating for half the trip and decelerating for the other half the journey if you actually wanted to stop off at Proxima Centauri and look around a bit, so your top speed would actually be faster to average out. ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [May 29, 2013, 4:42pm UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/46 "2013-05-29T16:42:44Z")
> [@aNewLeaf](#): > > Heinlein worked out the numbers a long time ago, there’s a chart in Expanded Universe. > If we could accelerate constantly at even 0.01G, we’d get there in a hurry. Science fiction isn’t science. Even using fusion or fission or even antimatter, an interstellar ship would need to carry an impossible amount of mass with it. The only “continuous” system I’ve heard that might be plausible is using a powerful earth-based laser to push a giant sail. Not really sure how they would stop it at it’s destination. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [May 29, 2013, 4:55pm UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/47 "2013-05-29T16:55:02Z")
> [@XT](#): > > You should probably tell the folks at NASA (and others working on the same thing) that it’s a stupid idea…save them the trouble of working on the thing. :p. Let me know when they work out that problem where you have to start the process all over again every time the vehicle has to stop, o.k.? ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [May 29, 2013, 4:59pm UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/48 "2013-05-29T16:59:37Z")
> [@Czarcasm](#): > > Let me know when they work out that problem where you have to start the process all over again every time the vehicle has to stop, o.k.? There is some disconnect here, because frankly I’m not seeing the ‘problem’. Why would the vehicle have to ‘stop’? Relative to what? Are you talking about going into orbit? If that’s the case, the vehicle doesn’t ‘stop’. I seriously have no idea what you are getting at here or why you think it’s a problem…or why you think that a continuous thrust ship is ‘stupid’ or why you don’t understand that it’s not fantasy, and that NASA as well as other groups are working on these things right now. Whether they are ever practical or not, or whether we can ever use them for an interstellar (or even within our solar system) trip is questionable, but not because they would have to ‘stop’, or because they might run into something. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [May 29, 2013, 6:18pm UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/49 "2013-05-29T18:18:45Z")
> [@XT](#): > > There is some disconnect here, because frankly I’m not seeing the ‘problem’. Why would the vehicle have to ‘stop’? Relative to what? Are you talking about going into orbit? If that’s the case, the vehicle doesn’t ‘stop’. > > I seriously have no idea what you are getting at here or why you think it’s a problem…or why you think that a continuous thrust ship is ‘stupid’ or why you don’t understand that it’s not fantasy, and that NASA as well as other groups are working on these things right now. Whether they are ever practical or not, or whether we can ever use them for an interstellar (or even within our solar system) trip is questionable, but not because they would have to ‘stop’, or because they might run into something. Well, rather than hijack this thread, I’m going to read more on the subject. Speaking of the subject of generational ships, [I’ve started this thread in IMHO.](http://boards.straightdope.com/sdmb/showthread.php?t=692347)😃 ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [May 29, 2013, 9:36pm UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/50 "2013-05-29T21:36:22Z")
> [@aNewLeaf](#): > > We’re assuming a fusion-powered drive, not a chemical rocket. But when you mentioned two generations, you were positing thrust-and-drift, which does assume a chemical rocket, AFAICT. But let’s say it’s a fusion-powered rocket. and let’s say 50-100 years between stops. You’re still talking about traveling 5.5ly in fifty years (because you have to start braking at the halfway point). This means a specific level of constant acceleration, and a specific percentage of lightspeed at the turn-around point. I don’t have the calculus chops to figure those numbers out. Anybody? ---
**Author:** ![outlierrn](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/outlierrn/32/3005_2.png) [@outlierrn](https://boards.straightdope.com/u/outlierrn)\ **Post date:** [May 29, 2013, 10:06pm UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/51 "2013-05-29T22:06:06Z")
> [@Shodan](#): > > I’ve never understood why the government would do this. Why would they cover up such a thing? People aren’t going to panic in the streets. And as mentioned above, the knowledge that antigravity and inertialess movement are possible would be a major scientific advance. I would think the government would want every scientist in the world to jump on it and try to figure it out. I especially don’t get it over time. I could, maybe, see the point of trickling the information out over a few months, or a couple of years, getting a little stronger each time to let people get used to it. Maybe. But perpetually? Ok, it’s a conspiracy theory, I get that, but just like the holocaust or 9/11, the consequences of getting caught outweigh whatever you hoped to gain. ---
**Author:** ![nickak2003](https://avatars.discourse-cdn.com/v4/letter/n/ea666f/32.png) [@nickak2003](https://boards.straightdope.com/u/nickak2003)\ **Post date:** [June 8, 2013, 7:48am UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/52 "2013-06-08T07:48:04Z")
There is an incredible amount of alien and ufo like stuff in art history, so the phenomena of spotting or at least believing in extraterrestrials goes back really far. check out this page: [http://www.in5d.com/ufos-in-art-history.html](http://www.in5d.com/ufos-in-art-history.html) I think ancient art is really the most compelling evidence of alien visitation. There are ancient egyptian glyphs that seem to feature aircraft, ancient cave drawings that clearly feature flying discs, and there is a whole lot of OMG could that be an alien. Maybe the idea of the sky being associated with living beings ( afterlife, etc ), has to do with alien spottings. That said, the technology to make it all possible is really unfathomable. ---
**Author:** ![FuzzyOgre](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@FuzzyOgre](https://boards.straightdope.com/u/FuzzyOgre)\ **Post date:** [June 8, 2013, 8:09am UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/53 "2013-06-08T08:09:06Z")
Little grey aliens are just the elves of long ago, and the angels of even further back. ---
**Author:** ![Miller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/miller/32/481_2.png) [@Miller](https://boards.straightdope.com/u/Miller)\ **Post date:** [June 8, 2013, 8:35am UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/54 "2013-06-08T08:35:32Z")
> [@nickak2003](#): > > I think ancient art is really the most compelling evidence of alien visitation. There are ancient egyptian glyphs that seem to feature aircraft, ancient cave drawings that clearly feature flying discs, and there is a whole lot of OMG could that be an alien. If modern UFO sightings can be explained by unusual atmospheric phenomena, then we should absolutely expect to find similar sightings throughout history. Excepting a few cases of weather balloons or experimental aircraft, all the conditions that lead to false UFO sightings today, existed five thousand years ago, too. ---
**Author:** ![nickak2003](https://avatars.discourse-cdn.com/v4/letter/n/ea666f/32.png) [@nickak2003](https://boards.straightdope.com/u/nickak2003)\ **Post date:** [June 8, 2013, 9:00am UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/55 "2013-06-08T09:00:44Z")
unusual atmospheric phenomena? That is super uncompelling. Exactly what sort of phenomena are we referring to? ---
**Author:** ![nickak2003](https://avatars.discourse-cdn.com/v4/letter/n/ea666f/32.png) [@nickak2003](https://boards.straightdope.com/u/nickak2003)\ **Post date:** [June 8, 2013, 9:29am UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/56 "2013-06-08T09:29:11Z")
Furthermore, why would ancient people interpret “atmospheric phenomena” as “intelligent beings that are flying around”, why would they even comprehend that? I don’t think they would make that association. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [June 8, 2013, 9:37am UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/57 "2013-06-08T09:37:36Z")
> [@nickak2003](#): > > unusual atmospheric phenomena? That is super uncompelling. Exactly what sort of phenomena are we referring to? For starters, unless nature was different in the past, Ball lightning. Also classics like comets and meteors. ---
**Author:** ![GIGObuster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gigobuster/32/421_2.png) [@GIGObuster](https://boards.straightdope.com/u/GIGObuster)\ **Post date:** [June 8, 2013, 9:39am UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/58 "2013-06-08T09:39:52Z")
> [@nickak2003](#): > > Furthermore, why would ancient people interpret “atmospheric phenomena” as “intelligent beings that are flying around”, why would they even comprehend that? I don’t think they would make that association. Most of the pictorial examples you linked at have humans or “spirits” of humans inside those unexplained sightings. ---
**Author:** ![aNewLeaf](https://avatars.discourse-cdn.com/v4/letter/a/ac91a4/32.png) [@aNewLeaf](https://boards.straightdope.com/u/aNewLeaf)\ **Post date:** [June 8, 2013, 10:14am UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/59 "2013-06-08T10:14:15Z")
> [@GIGObuster](#): > > For starters, unless nature was different in the past, Ball lightning. > > Also classics like comets and meteors. The ancients knew of comets and meteors, and drew pictures of them. ---
**Author:** ![nickak2003](https://avatars.discourse-cdn.com/v4/letter/n/ea666f/32.png) [@nickak2003](https://boards.straightdope.com/u/nickak2003)\ **Post date:** [June 8, 2013, 10:18am UTC](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459/60 "2013-06-08T10:18:59Z")
> [@GIGObuster](#): > > Most of the pictorial examples you linked at have humans or “spirits” of humans inside those unexplained sightings. exactly, and why would they think to make those connections? [Previous page](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459.md?page=2) [Next page](https://boards.straightdope.com/t/what-would-have-to-be-true-for-ufo-aliens-to-be-real/659459.md?page=4)