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Nomad Planets: Stepping Stones To Interstellar Space?
An anonymous reader writes "Ian O'Neill suggests in an opinion piece at Al Jazeera that brown dwarves and nomad planets (planets not orbiting any star) could be a much needed stepping stone on our way to foreign stars. Quoting the article: 'In February, a fascinating paper was published in the Monthly Notices of the Royal Astronomical Society detailing calculations on how many "nomad planets" the Milky Way must contain after estimating our galaxy's mass from how much gravity it exerts on surrounding space. Scientists from the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) had uncovered something surprising — there are likely many more planets in the Milky Way than stars. ... Louis Strigari and his Kavli team calculated that there must be 100,000 planets for every star in the Milky Way (PDF). That's a lot of planets! But how can this be? Every star can't have tens of thousands of planets ranging from Pluto-sized to Jupiter-sized. This planetary "excess" actually suggests the existence of planets that were born without a star — nomad planets. ... we need all the help we can get if we are to venture to another star, so these ultracool brown dwarfs could become much-needed "stepping stones" for future starships to refuel on their light-years of journey time. There may be the possibility that these sub-stellar objects may even become more desirable targets for interstellar travellers. After all, there may be dozens of these invisible objects between here and Proxima just waiting to be uncovered by the sophisticated infrared telescopes of the future; they'd certainly make for more accessible scientific curiosities.'"
Sounds like they're hypothesising that all the "dark matter" is actually made of planets, or did i miss something...
Also - frist prost!!!
Al Jazeera that brown dwarves and nomad planets
I see what you did there.
A most unusual planet...One million stars for the location...
When did a light year become a unit of time?
I don't think I'd want to stop at some random dwarf star. What is it you don't want on a long trip? Yes, to slow down and enter another gravity well. Doing so would make for a hell of a long trip. The time spent accelerating back along your path (people used to call it decelerating, but apparently that isn't a correct term), the fuel used escaping from the new gravity well, and the time and fuel used accelerating again. Worth it? Maybe if your design requires all that refueling. But the time involved is going to be the killer. It would probably triple (or more) the duration of the trip.
Galaxies having a gravity apparently bigger than their visible mass is not news, but that this effect is caused entirely by planets is unlikely. The extraordinary numbers they got are not "surprising results", but rather proof that their initial assumption was wrong. There ratio of heavy elements is too low for that many planets to form.
Scientists from the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) had uncovered something surprising — there are likely many more planets in the Milky Way than stars.
Why is that surprising? Our own solar system contains at least 8 times more planets than stars.
"Our two-party system is like a bowl of shit looking at itself in a mirror." - Lewis Black
Sounds like they're hypothesising that all the "dark matter" is actually made of planets, or did i miss something...
DM cannot be made of planets because it cannot be made of atoms (it was not part of the plasma which filled the universe ~380k years after the Big Bang) nor does it have the same distribution as matter in a galaxy (rather than a disc it forms a spherical halo). The "gravitational effect" the summary misleading refers to is not the gravitational field of the galaxy but the local gravitational field of the object which bends light creating a lens effect. If the object passes between us and a distant star then the field will bend more light towards us causing the star to get brighter which is how you can detect them without seeing them.
I don't have the essay collection on hand, but Freeman Dyson suggested something like this a long time ago. He imagined space-adapted life spreading through archipelagos of interstellar objects.
It might have been in the essay "The Greening of the Galaxy," in his collection Disturbing the Universe.
Well, another possibility is that you have your high-mass ark-ship aimed at the nomad planet and it passes on a slingshot maneuver to point it towards a rendezvous with the next nomad in a travel chain.
Yes, it's slower than a direct-line trip (due to the zig-zag path) but there are some advantages:
1. You get a chance to send small nimble craft ahead to mine or siphon off a few things before rendezvousing with the main ship. Or even top off reserves from a permanent robotic installation. An "interestellar gas station", if you will.
2. Depending on the speeds gravitational gradient, and atmosphere and the tolerances of your equipment, it might even serve as a useful way to reverse course in an emergency. (Haven't done the math, might be improbable.)
Well, the paper actually claims that there are between 2x and 100000x the number of nomad planets as there are stars. This kind of conservative claim is almost certainly right! Their ability to count on the press to distort their claims by citing only the upper bound and not the lower bound is canny and borderline unethical. Kudos to them for an excellent piece of press-release science!
Enough has been spent focusing on finding life outside out planet. Let's colonize space already! We can look for life once we get there.
Is that something to do with completing the Kessel Run in less than twelve parsecs?
UNIX? They're not even circumcised! Savages!
"...brown dwarfs could become much-needed "stepping stones" for future starships to refuel on their light-years of journey time.
Finally! I can stop dragging along all those spare fuel cells when I try to make the Kessel Run in under 2 parsecs!
One can imagine that the 'dust' between us and the center of the Milky Way (as well as the arms of all other galaxies) is in fact made up of hundreds of millions of billions of planets.
I hate to keep repeating this in every space forum or thread I visit. Starships are not going to happen. Von Neumann or self-replicating robotic space probes are the closest will ever get to "real" space travel. Humans who want to hop from star to star will have to leave behind their bodies. Instead only their consciousness is "emailed" between space "stations" built by these robotic probes.
I don't use the word "email" simply as a figure of speech. Email happens to be the most efficient way of sending written documents from one side of the planet to another. Imagine if 3D printing were a widespread and much improved reality. We'd no longer thinking of sending our gifts by DHL or Fedex. We'll just email them.
Printing out human bodies is still in the realm of science fantasy. But i'ts clearly cheaper than building an entire starship with the necessary life support and propulsion systems.
<pedantry>In relativistic terms, what we call "deceleration" is simply "acceleration" with the opposite vector (i.e. the other direction).</pedantry>
It's absurd to say it's an "incorrect" term, though; we are allowed to have words for opposites, after all.
But yeah: stopping at a brown dwarf or other nomad planet on an interstellar journey makes even less sense than pulling off the expressway and stopping at a gas station to walk around, when you were going 80mph and had a full tank of fuel (i.e. momentum). If they were in the right place and massive enough, they could be worth targeting for a little gravity assist to accelerate a bit more, but what else could they possibly have that would be worth the huge expense in time and energy to stop at one? I'm sure they'd be fascinating enough to warrant exploration in their own right, but for interstellar travel, they'd be "speed bumps" not "stepping stones".
http://alternatives.rzero.com/
So it's grab a ride if it's heading your way which seems pretty bad since it's completely unsteerable and would be epically cold from no heat source. Plus the delta-V to land and take off from it.
Flamebait
Serious inquiries only.
Here's the best starship concept I have come up with, based upon the assumption that there are no major undiscovered principles of physics. (aka no way to cheat basic material science or travel faster than light or cheat conservation of momentum, and relativity holds)
Technology needed : with a form of nanotechnology known as "molecular manufacturing", you can produce anything of any size with control over every atomic bond. The only limits are materials and energy. You can also deconstruct any frozen object and determine it's molecular structure.
For departing Sol, use mass drivers. Either build a gigantic mass driver that can accelerate the entire starship in one go, or give the starship a mass driver that can "catch" pellets of iron fired from a smaller one you leave back at Sol.
Either way, you want to accelerate to the desired speed as rapidly as possible. This means hundreds or thousands of Gs of acceleration. The ship is mostly solid state at this point.
At 90% of the speed of the light, the ship cruises until it gets close enough to the destination star. At this point, it reconfigures the matter about the ship into a bussard ramscoop and uses this as a brake to slow down. This way, you use free floating interstellar particles as the reaction mass instead of mass carried aboard the ship. Antimatter is used as a power source, the antimatter being burned inside a power reactor inside the ship. (antimatter does not work very well as a direct source of propulsion)
The same nanotechnology used to construct the ship can also conduct perfect repairs and quickly respond to damage (given sufficient materials and energy). That way, during the many years of travel time when the ship is cruising through the space between the stars, you can repair damage from particle impacts. Also, the ship splits into dozens of pieces separated by thousands of kilometers, enough spacing so that if part of the ship collides with a large mass at 90% of the speed of light, the rest of the ship survives.
Once at the destination star and decelerated to rest relative to the star, the ship finds a small asteroid or comet near the star. It docks with it and uses the asteroid/comet as raw materials to begin expanding infrastructure. The star provides an energy source. With exponential growth, each asteroid or comet consumed increases the infrastructure (aka a swarm of various types of robots) available, allowing bigger objects to be consumed. Eventually, there would be enough equipment built to start tearing down moons for raw materials, and eventually even planets.
Once all the mass in the star system is consumed and converted into more robots, processors, etc more ships are built and sent off like seeds to more stars to continue the process.
In principle, the entire galaxy would be nothing but dyson spheres within a million years or so.
The ultimate Fermi paradox is why has this not happened yet. We are nearing the technological capability to do this. I think we will have molecular manufacturing within 100 years. Once we find a way to copy the complexity of human brains to far faster solid state circuitry, we will create super-intelligent beings who would have the ability to solve all the engineering problems within a matter of years. If the Singularity happens, then after that event this kind of expansion would be expected to start right away. Worst case scenario, within 1000 years this should start happening.
Gravitational microlensing surveys have been looking for brown dwarfs and dim stars (sufficiently low luminosity they are not visible from Earth) in the galactic halo, but not enough were found to explain the mass difference (between luminous and non luminous galactic matter) to explain the observed galactic rotation curves. Planets around such low mass stars can also be seen (and have been seen, see the results by Microlensing Observations in Astrophyics [MOA] Project and associated collaborators - disclaimer I'm a former member). Depending on how small the planets are, they also could be detected (if you get very very lucky, due to the optical alignment required between observer, missing mass, and background luminous object). Given the constraints of the proportions of baryonic matter during the primordial nucleosynthesis (Big Bang/early universe) and the observed microlensing rate brown dwarfs are unlikely to account for the dark matter (AFAIK, I've been out of the game for a while). The baryonic constraints eliminated small rocks and gas clouds etc too. (I'm no expert on the nucleosynthesis calculations, however).
It would not be unusual for someone to come up with a theory that didn't take into account the known observations. For example, during the 1990's the early gravitational microlensing surveys 'rediscovered' the fact that our Galaxy is a 'barred spiral' - something the search teams were not aware of at the start of their studies (although astronomers, a different type of scientist, did know this). So it would not be unusual for someone to be missing key observations that invalidate this 'many planet theory'. Fortunately for the microlensing surveys their observations and results lead them to the correct conclusion (barred spiral galaxy), which instilled confidence in their methods and results. It doesn't take away from the fact that what was already known by astronomers was not at the time commonly known amongst the astrophysicists/particle physicists who designed the early microlensing surveys. It wouldn't surprise me if this was also the case in the paper /theory being discussed in this thread.
Interesting idea (not sure it's necessarily a *good* idea, but nevertheless worth consideration), but there's one issue I can foresee:
How do you *find* the things?
Planets don't emit light. They don't really do much of anything to draw our attention. It can be difficult to spot planets even in our own solar system - Neptune, far from the smallest planet, is invisible to the naked eye, and Pluto (a dwarf planet, I know) is extremely tricky for the amateur astronomer to observe due to its distance and, more importantly, its dimness.
All our current methods for finding exoplanets depend on measuring the star it orbits - even direct imaging relies on the planets being illuminated by their star.
What I'm wondering is, how do they propose to even find these things?
I was taught in school, and thus assume to be the gospel truth, that planets are formed by a spinning disk of excess matter being thrown off by a young star. So where do nomad planets come from? And are they actually solid, or just mini-gas giants? After all, the galaxy is composed primarily of gas, with all the higher numbered elements being created exclusively within stars, right?
I'm having trouble seeing how these planets could form at all, let alone be so ubiquitous.
If human of Planet Earth can think of nomad planets being vehicles to cruise the universe, you think sentient aliens from other planets wouldn't think of he same thing?
Perhaps they already are doing that
Muchas Gracias, Señor Edward Snowden !
n/t
Too bad anyone attempting to reach them would go blind given the time it would take to traverse the distance and the rate at which human eyeballs deform in space.
finding a pink colored pebble shaped like a heart on the ocean floor
Politics is Treachery, Religion is Brainwashing
...use the planets as the ships. Supposing a random distribution sunless planets, there should be plenty nearby. It would require less of a human built ship to reach. The planet itself could then be slowly pushed out of its orbit with its own huge mass drivers that use the mass of the planet itself as propulsion mass. If enough waste heat is generated in this process, it could bu used to power living areas and agricultural areas. Then speed no longer matters. You are on your new planet and simply park it in an appropriate orbit at the target star and begin terraforming it.
Silence is a state of mime.
it's called Fleet of Worlds
after a while technical civilizations start noticing that a star is more of a liability than an asset, so they just... get rid of the star.
Wait for nomad planet, red darf, to pass nearby. Settle on or near it Use nomad planet/red darf materials to survive (may need special technology) Wait until a new interesting place is near enough. Move to it or send some settlers and continue travel. May consider change from nomad planet/red darf on the way if materials and/or direction is more convenient. Slow but safer
With all the resources that only a civilisation like Magrathea might have, we could build our own Rama cylinder! w00t!
Step One: Find a big chunk of floating planet.
Step Two: Reconfigure the resources
Step Three: ???
Step Four: Profit
Step Five: Let your next generation prodigy meet the humans who got to whichever star or another in two weeks.
Step Six: What? You're probably dead now anyhow. Great time to be a joke.
Step Seven: This step intentionally left blank.
"Yeah...it was the numbers that were irrational, not the murderous cult of vegetarians...." -- Hippasus of Metapontum
You are imperfect! You know what you must do.
"Yeah...it was the numbers that were irrational, not the murderous cult of vegetarians...." -- Hippasus of Metapontum
Wake me up
When they find the 'Fleet of Worlds'
Traveling between stars requires a lot of speed. The best (known) way is gravitational slingshot maneuvers around a large object. And stopping at the other end requires the same. So you Can't stop at some rock, you literally don't have the fuel to manage it.
all this talk of space travel is nice but it aint going to work. you'll get brave men & women going in these starships & the plan is to have successive generations born in space while in flight to the destination. I think as soon as the second generation becomes aware of what they're missing out on here on earth they'll mutiny against the older first generation & head back to earth.
The full sky data release from the wise missions is due this month. It can detect any unbound juptier sized planet out to 1ly. So we will soon know if there is anything like that near us.
I'm writing a book on that subject. There are way more than gravity slingshots. That's #73 out of 83 on the list so far, and I'm only 1/3 of the way to a first draft:
http://en.wikibooks.org/wiki/Space_Transport_and_Engineering_Methods
"... 100,000 planets for every star in the Milky Way ..."
And we've never happened to notice any star blinking out as something dark drifts by, relatively close to us, eclipsing it for a while?
Or has nobody looked for this in the pictures taken over the years?
It'd be sad if it turns out this has been documented as random dust spots on the film for all this time.
"What do you think, Helena?"
"Oh John, those poor aliens need our help!"
"So be it. Victor, can you reprogram Computer to land this planet on a planet?"
"Oh I don't know, John. Maybe we should go down in an Eagle instead?"
"Good thinking. Alan, lift-off in 5 minutes!"
Plus the delta-V to land and take off from it.
If you can match speed with the planet then you don't really need to land on it. You are already moving as fast as the planet, and in the same direction. The only benefit of bothering to land would be in order to mine it for energy and for shelter.
However what are your chances of finding convenient supplies of fissible or fusible elements on a random piece of rock? These are largely iron - which is the end of the line, not very usable for production of energy. If your rock-hopping trip requires several planets and you can be stuck on any of them for that reason, your chances of successful arrival drop exponentially.
You would be better off not landing at all. First, you will be living in a prebuilt ship that already has everything that you need to survive the trip (such as hibernation facilities.) Second, the ship is steerable at any time (as long as you have the energy.)
I'll volunteer to look for these planets but only if my co-pilot was Wilma. No, not that That wilma.
Sooooo if there are 10s of thousands of rouge planets per sun does that mean that thousands could show up at once and the earth could be bombarded to death by rouge planets? If there are so many why have we never seen one?
...we still have warring governments, political corruption, rampant diseases, including self inflicted ones like morbid obesity, the virulent stupidity and deliberate ignorance that is religion, and racism/sexism/classism, etc. and so forth.
What the fuck makes any of you think we're going to be ready to travel to stars besides our own... ever?
Cure stupidity, THEN we worry about colonizing the universe. You all are like trainers trying to figure out how your guy is going to take first at the next track meet, and he's on full cardio-respiratory life support, with end stage liver cancer, heart failure, TEN, and Alzheimer's. The human race isn't going to BE at the track meet, friends, let alone run in it. So you can forget about WINNING it, altogether.
We have first to educate the masses, to eliminate these problems before we try to go anywhere. If we try to colonize anywhere off Earth, with humanity as fucked up as it is, we're just taking our problems with us. Look how hard it was for the first British colonists to survive in the new world... they brought the trappings of civilization, (foppish crap,) and few if any thought to bring farming implements, or basic knowledge of how to survive away from hundreds of years of developed society. They didn't expect to have to work with their hands, or get their finery dirty.
If the Indians hadn't taken pity on them, they would have ALL died, instead of just MOST of them. That's how humanity will be going to the stars, if we take all this bullshit with us.
Terribly sorry. It doesn't matter how many brown dwarf stars there are. It doesn't matter at all.
"Every star can't have tens of thousands of planets ranging from Pluto-sized to Jupiter-sized."
Yeah, so in case you haven't heard - a bunch of a$$hats demoted Pluto. It's not a planet anymore.
Slingshots are fine pottering around the solar system, where your ship speeds are comparable to your planet escape velocities. When you're travelling at over 1000 km/s, slingshotting past a 20km/s escape velocity planet does stuff-all for you.
Quattuor res in hoc mundo sanctae sunt: libri, liberi, libertas et liberalitas.
want to play "Spaceward Ho!"
"Don't be a martyr -- BE THE ONE WHO GOT AWAY!"
but they apparently didn't analyze how many rungs of the ladder could be available - that's the difference
Note that they are by definition completely inhospitable without a star, and also have no way for a spaceship to refuel on the way.
They might be a more accessible target and also an incredibly vast source of knowledge for research in their own right. On an actual longer journey, though, it's hard to see them offering much as a waypoint except for an extra gravity well to enter and leave.
Intelligence is not raw processing capability. Take an idiot and double the speed of his brain. What do you have? A faster idiot. It's not how fast you can think, its how you think that defines intelligence.
Other than that, I like the overall vision, other than the uncontrolled replication consuming all matter in the universe part...
The phrase "light-years of journey time" mildly upset me as light-years is a unit of distance not of time. Not the most constructive comment but I felt it needed to be said.
Or even as "vehicles"? How's that supposed to work?
There will be certainly be one of these "nomad planets" available in our vicinity with earth-like gravity plus a not-too-toxic atmosphere plus a magnetic field protecting against cosmic radiation, even such a planet heading in the desired direction like, say, Alpha Centauri.
Fine, so far.
But then, do what? Just sit comfortably on the surface of such a "nomad planet" and wait a million years or two until this "raft to the stars" arrives anywhere near Alpha Centauri?
What's more important than collecting fissible or fusible material is collecting propellant. The only engines* we know how to build are action/reaction engines: You want to go forward? Well, you throw a large amount of mass backwards; and the faster, the better. That mass is propellant. Currently, we tend to use chemical wastes as propellant, accelerated by the very chemical reaction that produced the waste in the first place. The other tech we use is ion thrust: You create an ion by stripping an electron off of an atom. The ion is attracted to a charged screen. The charged screen is likewise attracted to the ion. An electron is returned to the atom to maintain the charge balance, and the ship moves forward. The third class of engine is the nuclear rocket. You create a nuclear reactor, and you use some material to absorb the heat. The material evaporates, and the pressurized vapour is expelled out the back. NERVA used hydrogen as the propellant, but pretty much anything will do. Even iron vapour.
*I guess solar sails are a different class.
When our name is on the back of your car, we're behind you all the way!
My clock has a light year arm too!
Ian O'Neill suggests in an opinion piece at Al Jazeera
I've always had the empression that A-J was a Rant Rag. Now I can read Non-Rant stuff from it? Cool.
I now understand why always having a towel is important.
Do they constantly seem to come up with calculations that seemingly don't make any sense, and then just randomly without any evidence other then their own calculation that doesn't make any sense, explain it away as something else.
Oh that's dark matter... or super fluid... or nomad planets... Maybe there is an invisible bearded magical being out there that needs to go on a diet? Have you thought of that yet?