

Interplanetary Superhighway 241
rotenberry writes "The current issue of Caltech's Engineering and Science magizine contains the article "Next Exit 0.5 Million Kilometers - A Caltech/JPL collaboration explores the 'Interplanetary Superhighway.'" which describes "...the Interplanetary Superhighway - 'a vast network of winding tunnels in space' that connects the sun, the planets, their moons, and a
host of other destinations as well. But unlike the wormholes beloved of science-fiction writers, these things are real. In fact, they are already being used." However, it takes a very long time to get there."
Of course it takes a very long time....... (Score:5, Funny)
There's a bulldozer outside my house (Score:5, Funny)
We have one person to thank for this... (Score:5, Funny)
Oh they had better not.... (Score:2, Funny)
Where's my towel?!?!? (Score:1, Funny)
Re:There's a bulldozer outside my house (Score:1, Funny)
Re:There's a bulldozer outside my house (Score:5, Funny)
Re:There's a bulldozer outside my house (Score:2)
Here, have some muscle relaxent.
Re:There's a bulldozer outside my house (Score:2)
Re:There's a bulldozer outside my house (Score:4, Funny)
Re:There's a bulldozer outside my house (Score:2)
Re:There's a bulldozer outside my house (Score:2)
> put mail on satchel
> hang robe on hook
> press button
And I still think I'm missing a step.
Re:There's a bulldozer outside my house (Score:2)
Re:There's a bulldozer outside my house (Score:2)
Re:There's a bulldozer outside my house (Score:2)
> > put mail on satchel
> > hang robe on hook
> > press button
>
> And I still think I'm missing a step.
5. Profit!!!
time for publishers to start... (Score:5, Funny)
Re:time for publishers to start... (Score:2)
Re:time for publishers to start... (Score:2)
Re:time for publishers to start... (Score:2)
(yeah it's been a while since i read them, and i can't recall correctly the time-machine©right jokes around the book)
Seven Rules For Spotting Bogus Science (Score:5, Funny)
Re:Seven Rules For Spotting Bogus Science (Score:2, Interesting)
From the article:
Ideally, a spacecraft at L4 or L5 will remain there indefinitely because when it falls off the cusp, the Coriolis effect--which makes it hard for you to walk on a moving merry-go-round--will swirl it into a long-lived orbit around that point.
IIRC from physics classes, is the force making it hard to walk on a moving merry-go-round not the centripetal force?? I thought Coriolis was only a pseudo-force, not a real one.
Re:Seven Rules For Spotting Bogus Science (Score:5, Informative)
Ehh... you're 3/4 right. Centripetal force is real and coreolis force is "imaginary". Centripital force is force towards the center of rotation, keeping you from traveling in a streight line. Centripital force doesn't make it hard to walk on the merry-go-round; centripital force allows you to stay on the merry-go-round. You're thinking of the "imaginary" centrifugal force that appears to counter-act the centripital force you are applying with your feet.
Centrifugal force and Coreolis force are both imaginary forces used as short hand for taking second time derrivatives (calclating accelerations) in rotating reference frames using polar coordinates . If you're spinning at a constant speed about the merry-go-round, you keep the same polar cooarinates when in fact, a lot of corce is acting on your body to keep it constantly changing direction at a fairly high rate. In the reference frame you ae always at rest, so you don't say that momentum change is balancing out the force you are using to keep yourself "still" in the rotating reference frame, you say that this imaginary "centrifugal" force is acting on you. The two statements are equivalent, but one is a technical gloss.
Now suppose you try moving in relation to the rotating reference frame. You want to travel in a streight line in the polar coordinates. Well, since the frame of reference is rotating, a streight path in non-rotating space is a curved line in the rotating reference frame, and the amount of aparent curvature is dependent on speed of travel relative to the rotating reference frame. So when you try and walk in a streight line on the merry-go-round with out correcting for rotation, you more or less walk in a streight line in the non-rotating reference frame. In the rotating reference frame, your path is curved. The easiest way to do calculations is to make up frorces that would havepushed your path into that curved shape. It's all just short hand so that everything doesn't need to be translated to and from the stationary reference frame.
Even at the equator, you experience the coreolis effect, it's just that your axis of rotation is parallel to the ground. At the equtor, running East appears to make you lighter, running West appears to make you heavier, jumping up appears to push you West, and dropping off a ledge appears to push you East. One explination of why thy always launch spacecraft in an eastwardly-traveling orbit is that that way the coreolis force helps, rather than hinders the spaceflight. In a non-rotating reference frame this is equivalent to saying that it already has a lot of speed in an easterly direction, so blasting off to the west actually means sloing down a lot rather than using the speed it already has due to traveling at the same speed as the ground.
It's all equivalent, sometimes it's jsut easier to do the math one way. If nobody has done the math to figure out how the imaginary forces get added in in your situation, then you need to translate everything into a non-rotaing, non-accelerating frame of reference and do the calculatins and translate them back into your rotating frame of reference.
It's kinda like special relativity. If you forget the formulas, you can re-derrive them by looking at everyhting in a stationary reference frame and looking at a photon clock and a photon yardstick and figuring out what apears to happen to one secodn and what appearsto happen to one meter and what appears to happen to one kg being acted upon by 1 Newton. It's just a lot easier if you remember the formulas Einstein derrived for you instead of having to transate everything to and from the stationary reference frame.
Re:Seven Rules For Spotting Bogus Science (Score:2)
One, neither "centripetal" or "coriolis" are actual forces; they're better understood as virtual forces or pseudo forces. That is, they are an easier way for some people to compartmentalize the pragmatic effects of real forces [both are due to the interaction between radial acceleration and linear momentum].
Two, toilets do not spin in the opposite direction in the southern hemisphere as they do on in the northern hemisphere for any reason related to this physics; they spin in a certain direction because of several facts - 1, water is shot in at an angle into the bowl to better catch material stuck to the wall, 2, the toilet bowl is shaped a certain way to cause water to twirl, again to catch materiel.
Re:Seven Rules For Spotting Bogus Science (Score:3, Informative)
The myth about no centrifugal or coriolis forces exists because it's easier to say that to freshman than to try to teach them to analyze forces within a rotating frame of reference.
Re:Seven Rules For Spotting Bogus Science (Score:3, Interesting)
Believe it or not, basic celestial mechanics still has several unsolved problems.
For instance noone knows exactly how to model the formation of ring structures like the Kuiper Belt [harvard.edu](a ring of asteroids orbiting the sun), or Saturn's rings.
If you don't believe me check out this link. [arizona.edu]
huh? (Score:2, Interesting)
The structures aren't fixed (Score:5, Informative)
The thing about the wormholes is, though, that they're governed by non-linear dynamics, and are therefore extremely convoluted and difficult to calculate. But that doesn't imply that they're static, just that they're usually not the shortest distance between points A and B.
Re:The structures aren't fixed (Score:1)
Re:The structures aren't fixed (Score:5, Informative)
NASA's been taking advantage of such "gravity assist" trajectories for a while. How do you get to Jupiter? Slingshot around Venus, flyby Earth twice, then you're on your way. It seems roundabout, but sometimes, paths like that are the easiest way.
Re:The structures aren't fixed (Score:2, Informative)
Re:Sorry, I stills don't understand: (Score:2)
That's true in a 2 body scenario. But there are more options in a 3 body situation.
You write: "least energy" - so, where does this energy come from?
You arrange for the energy to be dumped/removed from some other body.
For example, if a satellite was reentering the earth-moon system, it can arrange for the moon's gravity to suck away some of the kinetic energy it has by going behind the moon; relative to the earth the satellite would have lost energy- and the moon would have gained energy.
Re:The structures aren't fixed (Score:5, Informative)
These are even often refered to as "Highways on the Sea," and calling these "Interplanetary Superhighways" is no doubt derived from this.
Of course there is no actual structure.
The only real difference is that in space the "continents" are in continuous and *rapid* movement as well, and thus the "currents" and "winds" are in a constant state of flux.
Other than *that* Mrs. Lincoln. .
KFG
Trade winds and currents (Score:2)
WRT sailing routes from England to NYC, it really depends on your boat. Multi-hulls pioneered the southern passage because they are much faster on a reach or broad reach, and not quite as good to windward. Some modern overpowerd monohulls might be faster on the southern route, but it is more of a toss up.
They don't really go into the details of the actual paths because of how hard it is to picture the multi-dimensional spaces that would make it clear. It is remarkable how everything changes with the third body in what seems like a simple system at first glance. I think I get some of the fundamentals intuitively. The "stable" manifold leading to L1 would be a group of orbits that tend to pump the spacecraft into more and more excentric orbits, while the "unstable" manifold leading to L2 does the oposite. On the other hand, the physics is reversible, so there are trajectories taking you toward the unstable L2 state and away from the stable L1.
When they start talking about orbit transfers, you are trying to find where the systems from neighboring planets link together. This involves considering seperate 3-body problems of Sun-Spaceship-Planet for each planet where the manifolds of each system are rotating with the planets, and are only synchronized at certain times. They don't really say why the link ups are harder to find (or longer to wait for) for Earth/Mars than the outer planets. If I had to guess, it is probably related more to the scaling the the orbit distances and the planet masses. The Earth and Mars aren't that massive, but it still might be more related to the closer orbital periods.
To me, it is just fascinating that there can be so much to investigate and study in the pure mathematics of a few simple equations. Most of this was just about the near equilibrium equations for uncontrolled objects. The slingshot trajectories represent another group of solutions that have some special characteristics. Very cool stuff. It really points the way for a lot of robotic missions over the coming centuries. With solar power, the fact that it take a long time to get there doesn't matter as much as the fact that you can keep manuvering for new missions long after the initial mission planning.
Re:Trade winds and currents (Score:2)
By "Bolger sqare boats", you mean scows, right? I'm from the Midwest where they are (or at least were) very popular on the small lakes. They have most of the advantages of multihulls as long as you don't have any waves. I am partial to cats, although tris seem to be in vougue these days. I try to follow what's going on with the "maxi-multis" built for The Race a few years back. I know Playstation II set a new trans-atlantic record, but broke gear and dropped out early in the big one. There's something to be said for not pushing the envelope too much in size (105' x 60' is just huge), nobody had experience with sails of that size, particularly with the higher rig loadings that multihulls produce. If they can make it reliable, it will be unbeatable.
To get a little more on-topic ... It's amazing what Poincare did on the problem before computers. He really started Chaos theory before it had a name, but the complexity was so great it was difficult to go much further until the computer came along.
Re:The structures aren't fixed (Score:2)
Re:The structures aren't fixed (Score:2)
Unfortunately, when they introduced words like "superhighway" and "wormhole", it just added hype, while making the subject only more confusing.
Did you read the whole article? (Score:2)
A set of five of these balance points, called Lagrange or libration points, exist between every pair of massive bodies--the sun and its planets, the planets and their moons, and so on. -- from the article.
Calculations are much easier than you think (Score:2)
The original method was published in Neural Computing.
Re:huh? (Score:2)
Re:huh? (Score:5, Informative)
It's not. You have to constantly calculate where the low energy paths will be and and then choose one that will take you where you want to.
When the planets move around these paths will change and to get to the same place you may have to take a different 'route' for journeys that start at different times.
Calling it a 'network of tunnels' is a poor simile, lets see if I can do any better. It's more like a set of deep valleys connected to each other over a small rise. The valleys are formed by the gravity of the planets and moons, and the layout of the valleys change as the planets move around.
To get from point A to point B, you can either use lots of energy to go in a straight line up and down the deep sides of the valley or if you follow the bottoms of the valleys and aim carefully at the connection between different valleys you can use less energy to move.
As space is frictionless, not only do you have to spend a lot of energy to get up the side of the valley (ie getting the spaceship up to speed for the journey), you also have to spend a lot of energy to stop from rolling on past where you want to go to (ie slow the spaceship down once it there). This is a problem if you want to send a probe to go and look at several planet/moons in a mission and spend a reasonable amount of time around each one. If you just accelerate/decelerate to get to and from each orbit you'll need a lot of fuel.
What's cool about this is that if you want to, you can bounce around within the valley so long as you don't roll at the low connection to another valley. This means that the spaceship/satellite could stay in one orbit around a moon for a while, and then when the time comes to move on, it can fire its rocket for a very short time just to aim at the low connection to the next valley. This will then make the ship move into orbit around the next planet/moon and it will be in a stable orbit around that until it decides to move on again.
Re:huh? (Score:2, Interesting)
(Of course, the manifolds do not just have coordinates in space but have required velocities at those coordinates. But once you are "on" the manifold in the sense of being in the right place with the right velocity, then it works exactly like a tunnel connecting you to somewhere else because you simply "fall" there without having to do anything else.)
Three words: read the article. (Score:1)
Re:huh? (Score:2)
Wrong, hotshot. The earth doesn't rotate. The sun revolves around the earth. Just as G-d intended.
Uh yeah... (Score:1, Funny)
Gravity Hitchhiking, Pure and Simple (Score:4, Funny)
Now if only I could get a free ride to the Midwest or East Coast this way.
yes, it takes a long time. (Score:5, Funny)
Ok... it's a friday night... I'm sitting at home, with nothing better to do than try and be a smartass on slashdot... Oh lord, I've wasted my life...
Bend space (Score:1, Funny)
Space-folding technology is still a work in progress, though.
Re:yes, it takes a long time. (Score:1, Informative)
Re:yes, it takes a long time. (Score:2)
But it seems the path of least resistance is curved... Following gravity ripples where it cancels.
Re:yes, it takes a long time. (Score:3, Informative)
Mod up parent if you grok General Relativity (Score:2)
The above statement is fundamentally the way the universe works. There is gravity (modulo quantum gravity :-) because both of these statements are basically true.
You move towards a mass because it distorts spacetime so that the "straight line" you're travelling in actually goes towards the mass.
Re:yes, it takes a long time. (Score:3, Interesting)
Re:yes, it takes a long time. (Score:1)
It'll Never Pan Out... (Score:5, Funny)
Re:It'll Never Pan Out... (Score:2, Funny)
Re:It'll Never Pan Out... (Score:2)
This Reminds me of Doug Adams (Score:3, Funny)
how this works (Score:2, Informative)
for those who didn't read the article... (Score:4, Informative)
for those who didn't understand the article ... (Score:5, Insightful)
This isn't just a way to get from planet to planet using less fuel -- it's a way to get around using no more than a shove in the right direction, starting from between the Earth and Moon and ending up anywhere you want. That's not your father's rocket science, and it's bloody cool -- flashy language or not.
Re:for those who didn't understand the article ... (Score:2)
Re:for those who didn't understand the article ... (Score:2, Interesting)
Although I guess I am in some sense a "rocket scientist," I think the truly cool aspect of the work is the light that it sheds on the mechanisms of "interplanetary cross-fertilization." This understanding contributes to fields such as astrobiology, for example, where comet impact rates are key for determining the delivery of water to the Earth and impact ejecta exchange rates are important for investigating the transportation of microbes between Mars and Earth.
By the way, the fastest that a piece of impact ejecta has been able to get between Earth and Mars in any simulation is 10,000 years. This would be a piece of debris which, due to nonlinear effects, repeately encountered Mars and Earth with just the right geometry that it made the trip in the fastest time. The average transit time for bits of debries is a few million years.
You are so full of crap (Score:5, Informative)
They have discovered a new type of route throughout the solar system, besides the conic sections typically used today, requiring orders of magnitude less energy. They can also predict up to 100 orbits into the future, with multiple ports of call on the itinerary, which is much more sophisticated than the simple slingshot method you're alluding to.
They are using chaos theory and orbital instability to their advantage. That is something most certainly not done in traditional conic orbital maneuvers, which are of such a short duration and simple nature that chaos and instability don't enter into it.
Oh the taxes (Score:5, Funny)
MacDonalds (Score:1)
Interesting prospects for NEAR (Score:1)
Any distributed computing people listening? (Score:5, Interesting)
Massive amounts of numbers to be crunched, tons of routes to be discovered, and all by lowly computers with nothing better to do.
Proving that some ungodly number of ProcHours can figure out a RC-72 bit key is meaningless to me.
This is the sort of science humanity is interested in. Onward to Mars [nw.net]!
-Brett
Re:Any distributed computing people listening? (Score:5, Insightful)
Re:Any distributed computing people listening? (Score:2)
But I have enough problems folding sheets!
Re:Any distributed computing people listening? (Score:2)
Re:Any distributed computing people listening? (Score:2)
Poincare Conjecture (Score:3, Informative)
The Poincare Conjecture [claymath.org]
IIRC, solving this problem should make some major advances in this 'tube-theory'. Can anyone explain how though?
---
Re:Poincare Conjecture (Score:3, Informative)
The article has nothing to do with this. The article is simply discussing searching for trajectories whihc minimize the energy to get from A to B. The tube/wormhole terminology seems awful, if not incorrect (wormholes are very different beasts).
Wait a minute... how long? (Score:3, Funny)
Plus, those gravitational speed ups are slowing down the planet! Eventually, we'll suck up so much momentum to cause the earth to stop revolving around the sun, and we'll burn up!
Act now to fight the destruction of our gravitational resources!
Re:Wait a minute... how long? (Score:2, Interesting)
Hopefully we'll find other ways to explore the space before we slow down so much that we crash into the sun.
Gravity drive (Score:3, Insightful)
Bus, as far I understand, that "highway" must be very dinamic, is like saying that in a year, 6 months and 3 days there should be a "road" to Pluton, but if you try this every other moment it will be very costly or the trip will last 4 months more.
And, well, this "highway" is beloved as well for good hard sci fi writers, taking advantage of gravity to do "impossible" tricks is very used, and is funny to see everyone surprised in the story of that kind of tricks
Lagrange Points (Score:3, Informative)
This technique is used to keep the SOHO [nasa.gov] sun observation satellite at Lagrangian point 1 [montana.edu] in the earth/sun system, so that it keeps a constant view of the sun.
The concept behind this is extended in this instance to reveal tunnels which offer the 'path of least resistance.'
In fact, this has been discussed [slashdot.org] on Slashdot before. Slashdot users have also discussed Lagrangian points in relations to one [slashdot.org] or both [slashdot.org] of Earth's sub-moons.
Re:Lagrange Points (Score:4, Informative)
Evidently the research is more immediately useful for the techniques learned in complex multi-body interacting systems problems, which fluid dynamics guys are also fascinated in.
Re:Lagrange Points (Score:2)
Home? (Score:5, Funny)
Where the space debris always collects,
We possess, so it seems, two of Man's greatest dreams:
Solar power and zero-gee sex.
I am truly sorry for that one...
Where's LTOOL? (Score:3, Funny)
Some day... (Score:3, Insightful)
It'll get nudged this way and land in the back yard of the lucky (corporation, government, fill in the blank) via these EXACT orbital pathways.
When it does, you can tell the grandchildren, "Bah, that's OLD news. We were talking about it on slashdot before your PARENTS were even born."
The problem with nerds... (Score:4, Insightful)
... is that for the most part we have too much information in our heads, but no common sense to use it. This article does a wonderful job of illustrating, in a relitively reasonable manner, how we can do a lot of work traveling between planets without expending much energy!
BRAVO!!!
They have managed to move beyond their meager geekness and actually apply concepts that come from Lagrange, chaos theory, etc... and use them to better mankind and also explain previously unexplained phenomena.
I know way too many nerds who cannot do this for the life of them. They have lots of knowledge, but they are useless!!!
A bit of a rant... I know, but it's frustrating to read all the comments by idiots who can't even read the article before they reply...
Re:The problem with nerds... (Score:2)
Duplicate article from July 20, 2002 (Score:5, Informative)
Re:Dupes (Score:2)
Re:Dupes (Score:2)
I know some other sites have comments, but
oh dear (Score:5, Funny)
Hmmm... (Score:3, Funny)
Am I the only one who finds this redundant?!?! =P
The Intergalactic Laxative (Score:2)
I was impressed like everyone when man began to fly
out of earthly regions to planets in the sky
with total media coverage we watched the heroes land
as ceremoniously they disturbed the cosmic sand
I awe with admiration we listened to the talk
such pride felt they, such joy to be upon the moon to walk
my romantic vision shattered when it was explained to me
spacemen wear old diapers in which they shit and pee
chorus:
oh the intergalactic laxative will get you from here to there
relieve you and believe me without a worry or care
if shitting is your problem when you're out there in the stars
the intergalactic laxative will get you from here to mars
they don't partake like you and I of beefy burger mush
their food is specially prepared to dissolve into slush
absorbed my multi-fibres in the super diaper suit
otherwise the slush would trickle down inside the boot
you may well ask now what becomes of liquid they consume
a pipe is led from penis head to a unit in the room
the water is recirculated, filtered for re-use
in case of anti-gravity, pee gets on the loose
wherever man has conquered on the quest for frontiers new
I'm glad he's always had to do the no. one and two
it makes it all so ordinary just like you and me
to know the greatest heroes they had to shit and pee!
Hmm.. who wants to start a project on sourceforge? (Score:5, Interesting)
You know I wonder if this idea opens the thoughts for an interplantary positioning system (IPS)... in order to know where you get off, you'd have to know where you are.
Interplanetary SuperHighway (Score:2, Funny)
Cant we just walk? (Score:3, Funny)
Cant wait (Score:2)
Link to interview at genesismission.org (Score:2)
This link I gleaned and posted on Slashdot the last time we had an article about this. There are actually several interesting papers about this on the net, look for Lo in xarchiv and elsewhere I think. Downloaded a whole bunch last time.
Re:Home On Lagrange (Score:4, Funny)
Where the three-body problem is solved,
Where the microwaves play down at three degrees K,
And the cold virus never evolved.
(chorus)
We eat algea pie, our vacuum is high,
Our ball bearings are perfectly round.
Our horizon is curved, our warheads are MIRVed,
And a kilogram weighs half a pound.
(chorus)
If we run out of space for our burgeoning race
No more Lebensraum left for the Mensch
When we're ready to start, we can take Mars apart,
If we just find a big enough wrench.
(chorus)
I'm sick of this place, it's just McDonald's in space,
And living up here is a bore.
Tell the shiggies, "Don't cry," they can kiss me goodbye
'Cause I'm moving next week to L4!
(chorus)
CHORUS:
Home, home on LaGrange,
Where the space debris always collects,
We possess, so it seems, two of Man's greatest dreams:
Solar power and zero-gee sex.
--Home on Lagrange (The L5 Song)
© 1978 by William S. Higgins and Barry D. Gehm
http://www.jamesoberg.com/humor.html [jamesoberg.com]
(from very bottom of page)
Get it right. (Score:2)
#3 (Score:2)
#4 (Score:2)
Re:Deflect killer astroids, gather comet dust? (Score:2, Informative)
Material typiclly doesn't come from elsewhere in the solar system and get stuck in some system's L4 points (like the Earth-Moon L4 or L5 points). The material that is there, if any, would have existed in that location since the formation of the system, i.e., anything near the Earth-Moon L4 or L5 points was there when the Moon formed [nasa.gov].
Regarding the killer asteroids, you're totally right about deflecting them with small forces. There will be a conference next year, Planetary Defense Conference: Protecting Earth from Asteroids [aero.org], where people will propose technical plans associated with defending Earth from approaching near Earth objects (comets and asteroids). The threat will be approached from three warning levels: short-term (less than ten years warning); medium-term (ten to 30 years warning); and long-term (more than 30 years warning). The more time we have to deflect it, the smaller the force needs to be.