Peering into the Mind of God: Are we built to venture beyond the Heliosphere? With a look at the physics of 0.71c

The following story was written by Dan Teodor, originally for use here on the ISA website.  It's a bit outside our pure informational fare so I'm posting it as a blog entry for Dan.  It is amusing, but also has good information about some of the physics involved in interstellar travel and survival in space.  Dan has also posted this on his oil & gas investing blog, since we were slow to put it on here.  Enjoy! - and check out his blog at hydrocarboninvester.blogspot.com.  - garyb

Peering into the Mind of God:

Are we built to venture beyond the Heliosphere?

An essay by Dan Teodor

 

Introduction

So, on exhibit, we have a rough seven billion hairless upright apes scampering around somewhat aimlessly on a random rock, mostly covered by dihydrogen oxide enveloped in a thin cocoon of nitrogen, feeding on energy spewed out into the cosmos by a middle-aged, mid-sized, unexceptional star. Looking more closely at these ungainly apes, the observer realizes they are absolutely unfit for the cosmic environment: They consume fully one-third of their energy intake doing nothing but feeding their enormous brains, they can only store enough energy to feed those brains for one solar day and, therefore, they must constantly gorge themselves non-stop on complex hydrocarbons just to stay alive. Beyond this, things get even worse because in their natural silly hairless state, they wither away at temperatures below 283°K or above 311°K and would die within a tiny fraction of a solar day without continuous access to van der Waals paired (i.e. warm porridge-like unexcited low-energy state) free oxygen. Now, dear reader, I know you’re smirking inwardly because such a hypothetical lifeform wouldn’t last for very long in this galaxy of ours and therefore is either a complete fabrication of this author’s imagination or was wiped out eons ago, if it ever existed. However, let’s just assume, for the sake of this discussion, that, once upon a time, such a ridiculous thing could have existed. Let’s call these sad and unlikely creatures ‘helios’.

We’re going to explore the likelihood of whether these helios are in a position to ever venture beyond the confines of their star’s sphere before a billion of their years pass by and their star engulfs them in its collapse.

 

The Environment

These helios evolved in a gravity well on a middling size rock of about 6×1024kg with a silicate outer shell and a molten nickel-iron core, dragged into it at a rough constant 10m/sec2. They live in a hydrocarbon soup, constantly renewed by the energy from their star that happens to be held together by hybridizing covalent bonds – a constant and abundant source of chemical energy for them. These helios are so tiny and insignificant that you could fly right by that rock and never know they completely infested every corner of it, had you not read this.

The helios lead, if nothing else, a very sheltered existence. First, the orbit of their rock around that star exhibits almost no eccentricity and it sits almost perfectly within the orbital plane of that star. So there is very little variation in temperature on the rock throughout its year. As if that weren’t enough, the rock has an absolutely massive natural satellite that completely stabilizes the spin of that rock so that every point on the rock maintains an almost constant attitude with respect to its star. What more could one ask for, it’s just a Shangri-la! In fact, the surface of their rock is such a wonderful place that the helios would be completely incapable to surviving on the surface of any of the other rough five dozen planets and satellites that also orbit their start.

Yes, living in the Garden of Eden made these helios awfully soft. So soft, in fact, that setting foot on any of the other bodies orbiting their star would likely kill them in a matter of seconds without some very specialized equipment.

 

The Helios’ Habits

The helios realized early on in their evolution that access to the stuff they needed was in limited supply and, thus, they began competing with one another very early in their evolution. That’s where those ridiculous brains become key, because they have the remarkable ability to conceive and carry out long-term multi-generational projects designed to exterminate their competition, thereby ensuring more access to what they really need (and also, strangely enough, also causing the winners of those competitions to breed and multiply uncontrollably). And because of the decentralized environment in which they lived, whoever succeeded in building the most destructive offensive devices in the shortest amount of time pretty much won all of the resources. Throughout the first forty thousand generations or so, they became really good at this and everything was fine in paradise.

However, there came that fine day when the dominant populations who had exterminated the less fast-with-the-brains populations came to outgrow those resources, at which point, they all turned to each other and said: “We really need to find another rock, because this one just doesn’t have enough resources for all of us anymore”.

At that point, they built more contraptions, at an even faster pace to search the neighborhood of that star for other rocks ripe for infestation. But, to their dismay, they quickly realized that all of the other rocks circling that star were places that were really terrible to live on. So, they kept looking and looking and started cataloging rocks they found circling other stars.

Graph 1: number of exoplanets discovered per year - Dan Teodor
 

Graph 1: Number of rocks orbiting other stars discovered by the helios by year.

However, at that point, the helios realized that, not only were the other stars really really far away, but the rocks that orbited those other stars were also not very nice places to live. The biggest problem for them was one of size because their physical constitution would not allow them to survive on any other rock that was not between a mass of next-to-nothing and about 150% of their own rock. They realized that the acceleration of the gravity at the surface of anything larger than this would kill them. And so they were left with an awfully tiny pond of choices.

Graph 2: Sizes of Known Explanets - NASA Exoplanet Archive
 

Graph 2: Number of rocks orbiting other stars grouped by size.

It was at this point that these ridiculous little helios started to get really big heads… in the figurative sense (as in, over and above their already ridiculous big and unwieldy brains). This was the point where the helios began to realize that maybe, just maybe they weren't completely out of cosmic luck, because there actually were a few (not many, but more than zero) other rocks out there that somewhat matched their long suffering little Garden of Eden.

Table 1: Most habitable planets found to date

Table 1: Most habitable rocks found by the helios.

In fact, the first actual candidate that rose to the level of ‘infestable’, they named ‘Gliese 667 Cc’ (the reader will note here that these helios were of a very small-minded and bureaucratic nature, lacking the imagination of a ‘Helicon the 3rd – Great Gift to the groveling slaves from our almighty god-given emperor’ – but dwelling on these shortcomings in their nature is beyond the scope of this paper). Then, after building a few more gadgets, faster than ever before, they realized that it was potentially a really nice place and was only 23.6 light years away. This was cause for rock-wide celebration and they promptly proceeded to drink themselves into rock-wide stupors for a few of their years.

Image 1: Landscape from Gliese 667 Cc (new rock to be infested).

Then, when the rock-wide hangovers began to abate, they sort of stumbled into their next big shortcoming: Their laughably short lifespans! On the galactic scale, those 23.6 light years are basically pissing contest distance, but, these helios had such short flash-in-the-pan lives that, combined with the effects of special relativity, it made crossing that distance an almost insurmountable challenge. What were these helios to do? They spend about five seconds considering stopping breeding so as to continue to subsist on the resources already available to them on their rock. However, they quickly concluded that it was just a random thought in their hangover induced haze and they could never stop breeding because it was just plain too much fun. So, with that, they all collectively decided that they had better find a way to get to that other rock before all of their resources ran dry.

Solving the Distance Problem

In brief, the helios’ challenge was how to find a way to cross the distance to the other rock while still ensuring there was someone to talk to back home to let them know they had arrived and that all was well. The utterly big deal lay in the problem of the amount of time which the observer on their home rock would see pass, by the time the observer on their ship reached their destination (the Lorentz relation):

Formula 1: Lorentz relation

 
Graph 3: Time dilation factor observed from origin

Graph 3: Time dilation factor observed by a helio on the home rock as a function of the time experience by a helio on a spaceship moving away from the home rock (in speeds measured as a fraction of the speed of light).

The helios’ brains were really working hard now. They didn’t need skillets and stoves to cook their breakfast eggs anymore, they would just crack open eggs, let them drop on their braincases and breakfast would be ready in under a minute. They took a look at how much time would pass for both the helio waiting around on the home rock and the helio on the space ship traveling to the new rock.

Graph 4: Elapsed solar years observed at origin and by traveler

Graph 4: Elapsed solar years observed by a helio on the home rock and a helio on the spaceship traveling to the new rock necessary to cross one light-year at varying speeds (measured as a fraction of the speed of light).

 

It was at this point that the helios that their first of many ‘aha!’ moments. A deathly silence fell over their whole rock and many crawled back into their bottles at the implication of it all. It turned out that, for the helio standing around playing poker on the home rock, it did not matter whether the spaceship traveled away from them at 25.5% the speed of light or at 96.5% the speed of light because, for them, four years would elapse for every light year which the space ship traveled. Likewise, it did not matter whether the spaceship traveled away from them at 35.5% the speed of light or at 93.5% the speed of light because, in both cases, three years would elapse for every light year which the space ship traveled.

When they turned the Lorentz relation around to look for the zero-crossing point for
Formula 2: Lorentz relation, zero crossing point
this is what they found…
 
 Graph 5: Relative change in time observed from origin vs. traveler

Graph 5: Relative change in time experienced by helio on the home rock with respect to the relative change in time experienced by helio on the spaceship traveling to the new rock at different relative speeds (measured as a fraction of the speed of light).

In fact, they concluded, that the optimal travel velocity to minimize time dilation effects on the helios left behind on the home rock was approximately 71% the speed of light. At this point, the reader can imagine what the helios did over the subsequent days (hint: see earlier passage about the time they discovered their first infestable rock).

It was at this point that the helios realized what the basic requirements were for their spaceship. It needed to accelerate at 9.81m/sec2 for about 0.69 of their years (251 days), then it needed to travel at that speed for about 22.8 of their years and, finally, it needed to decelerate at the same rate for another 0.69 of their years. This meant that, from the point of view of the helio on the spaceship, a total of 24.18 of their years had elapsed.

From the point of view of the helio back on the home rock, 33.76 of their years would have elapsed. This meant that within the lifespan of one miserable helio, assuming all went according to plan, the helio on the home rock might be able to receive confirmation of successful arrival by the helios on the new rock in 57.36 years (33.76 years + 23.6 years).

 

Aftermath

It was evident to the helios that they needed to keep up their strength through their voyage if they were to be in a position to successfully infest their new rock (possibly needing to exterminate whatever had the misfortune of having originally evolved there before the arrival of the helios). To that end they built a spaceship large enough to carry a sufficiently diverse genetic population and the necessary room in which to life out a full eventful life full of exercise and long-term social structures. They built it in such a way that, during the 22.8 years in which it would be in interstellar free flight, its main mass would spin to create centrifugal acceleration equivalent to 9.81m/sec2 for the surface on which they would spend the better part of their lives and also raise their offspring.

It was a large undertaking spanning many of their short flash-in-the-pan generations. It was lifted to a launch platform on one of the suitable nearby natural satellites piece by piece and some of it was even constructed on that satellite.

And now, dear reader, we have reached the current state of things. These silly helios have covered a lot of ground. A lot more ground that they should have. In fact, there is a good chance these helios are actually God’s cosmic joke on the galaxy… the little slow turtle and crawls up to you, smiles, pulls out a tiny double barreled shotgun and blows your knees off. Who would have believed it?

The truly frightening fact of this epic is that there is only one last barrier keeping these helios from spreading out from their little heliosphere: Their engines. It looks like their little Garden of Eden made them so fat and soft they didn’t realize they couldn’t rely on harnessing those silly little covalent hydrogen-carbon chemical bonds to reach beyond their heliosphere. Sure, they can generate enough lift for the right acceleration with them, but those engines are so inefficient, they could never carry enough fuel to generate that much lift for a duration of a year or more.

No, dear reader, you should be very afraid, because the only thing keeping those silly hairless upright apes from infesting your garden, your shoe and your cigar is one simple engine design. That’s it! If we have the collective misfortune to have them stumble across its design, we’re going to be spending ourselves silly eradicating them from every corner of our galaxy.

Comments

Mr. Gary Bickford's picture

Most Science Fiction fans will immediately think also of Terry Bisson's story originally published in the late lamented Omni Magazine, "They're Made Out Of Meat". :)