Subject:
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Re: The "geography" of local space
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Newsgroups:
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lugnet.space
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Date:
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Fri, 5 Nov 1999 17:45:36 GMT
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Viewed:
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410 times
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"John J. Ladasky Jr." wrote:
> Hello again,
>
> I''m glad I generated some interest here! I hope, however, that we do not
> stray too far from discussing LEGO -- I have noticed complaints in at least one
> other LUGNET newsgroup.
It's in the context of creating a datsville, so I don't know how anyone can be *angry*.
> > Astronomy is an armchair hobby? Well, I'm a historian (not done with the
> > PhD just yet, but give me just a couple more years) who started out as a
> > palaeontologist and astronomer
>
> Both quite rewarding, but difficult fields in which to find work -- I
> sympathize!
Yeah--my girlfriend's father got his PhD in palaeobotany; not exactly a field in demand, so he ended
up being a groundskeeper and specialist for many businesses and golf courses in Maine. Odd that, but
it paid very well.
History's not that bad--I study African history as well as British and Global/Comparative, so I'm
marketable. We've got a strong program here (I know, no British historians quite like Peter Stansky
there at Stanford, but they're pretty good).
> Actually, your background is interesting. What kind of a dissertation could
> you write? How about "The use of 'dragon bones' and astrology for divination
> in the Shang Dynasty"?
I'm doing colonialism and the imposition of technocracy in Africa during the late 19th century. I
would cry too much thinking about all the specimens lost to posterity by such practices. :(
> The position of a star on the globe of the sky is pretty easy to determine.
> The best way to measure the DISTANCE to a star is by triangulation. You
> measure the position of the star, relative to more distant background stars, on
> a given night. Then, six months later, you measure again. The Earth is on the
> opposite side of its orbit from where you took the first measurement. The
> closer a star is to the Sun, the more it will appear to move against the
> background.
I think I mentioned it somewhere else--the parallax method of measurement. I've been a bad armchair
astronomer in the last few years, since I didn't realize Hipparcos had come to fruition. But I'll be
checking that site; there's got to be *some* way to figure out all the near stars!
> Turbulence in Earth's atmosphere limits this method. It turns pictures of
> stars from pinpricks into blobs. At ten parsecs, trigonometry is only accurate
> to ten percent. Objects beyond this distance are pretty hopeless. The errors
> begin to exceed the average distance between the stars.
Parallax ends up being "very long baseline" trigonometry. What about the suggestion of
interferometry handled that way? The observations could get much, much better, and minor libration
or proper motion could be accounted for more quickly. No six-month wait; stick a telescope on the
other side of the sun in Earth orbit, have a repeater at the 90-degree points, and start cataloguing!
> Hipparcos measured distances accurate to 10% at 100 parsecs. Distances to 10
> parsecs are accurate to one percent! The only shortcoming of the data is that
> the dimmest stars, below a visual magnitude of 12, were not observed. So many
> of those nearby red dwarfs that I mentioned in my first post are not in the
> data set.
Darn those astronomers who don't realise that proximity is more important to some of them! What do
they think our tax money...oh, wait, these are Europeans. ;) Okay, the tax money I paid on my food
in Leiden!
> ESA has placed the Hipparcos data on-line. However, the search program that
> they have provided only allows you to look up stars by name or by position on
> the sky -- not by distance. So it's no easy matter to make a 3D map of local
> space.
Nice of the Europeans to do that. It's not searchable data?
> At this point, then, the material in both the Sky Catalogue and Burnham's are
> probably out of date. And I don't think that the Traveller game had anything
> more than these catalogs.
Distance material in the Sky Catalogue has always seemed a bit suspect. But I'm not sure where GDW
got their material--at least they have about 200 of them. There was no "free and clear" added
population, though. I'm sure that we'd have to posit extra sub-18 magnitude bodies just to make the
population "smooth".
> > Yes, but even "hard" sci-fi fans (like you and I) who dislike superluminal
> > travel can still deal with space-folding, wormholing, and the like--there
> > are ways around it. ;) But I believe that beyond 200ly you begin to get
> > "weird." See below.
>
> Even if FTL travel is possible, by any means, current theories say that the
> amount of energy that would be required to make it work are enormous -- a lot
> more than what we would need to send a ship somewhere at sub-light speeds.
Yes, but when has that stopped the military? It's more part of a dream--a possibility. Fission
power works, why do we keep working on fusion research? Because of the promise of greater return--it
would be hard to have a strong feeling of anything other than wistful memory on sleeper ships. If
you wanted to send an 80-year slowboat to RK, what's the chance of any of them ever making it back
home? What's the likelihood of a disaster preventing them from ever contacting Earth?
> My professional calling is biology. I see biological progress as being faster
> than progress in the mechanics of space travel. I believe that we will triple
> human life span, and/or figure out how to place a human body in suspended
> animation, centuries before we harness the energies needed to break the
> light-speed barrier. Oh yes, and we will have a colony on Mars, which might
> make an interesting LEGO setting. If we have not found any indigenous life
> there, we will also be well on our way to terraforming the Red Planet, before
> that first interstellar spacecraft sets sail.
I noticed that you're an immunologist. I actually live here in a house with two of them--both are
postdocs at Merck, and one just landed a tenure-track job at U-Minn (he's from Wisconsin, so this is
a great stroke of luck). I agree that biological advance will proceed ahead of bending the laws of
physics--but the latter will happen, or at the very least people will make inordinate efforts to
*make* it happen. I've always liked the very evenhanded approach of Eugene Mallove and Gregory
Matloff, who are also not in favor of superluminal flight. Their book is "The Starflight Handbook,"
and it's a good read even ten years after its release.
> The LEGO mothership that is a gleam in my eye is full of little high-tech
> sarcophagi, in which the minifigs will spend decades in hibernation on their
> way to the stars. Think of the spacecraft "Nostromo", from the movie _Alien_.
> Periodically, some of the crew may be awakened to check on the condition of the
> ship, and perform any needed maintenance before going back to "sleep." If
> there's a place in the Datsville-in-space future timeline for a millennium or
> so of slower-than-light, interstellar exploration of local stars, there might
> be a place for my models. I like the idea of interstellar space travel being
> really expensive and difficult at first. That's how travel to Earth's orbit is
> right now, and that's how it will remain for the foreseeable future.
Maybe we can make our datsville temporally open as well as physically open? :) I tried to make
cryogenic capsules; someone here had more luck than me, and it's a thread from General from last year
sometime.
> Will the people of the LEGO universe discover extraterrestrial life before or
> after the hyperdrive? It matters. We didn't send the Pathfinder to Mars armed
> to the teeth, because we assumed that there's nothing out there to harm it. My
> hypothetical LEGO mothership is actually quite lightly armed -- and if it
> should have a chance encounter with a hostile ET, it might well get its butt
> kicked! And when the video transmission of the encounter makes it back to
> Earth, the engineers will begin redesigning the fleet...
...with the hope that the ETs haven't returned with the transmission. =:o If we end up with a
hyperdrive, who's to say that it won't happen in a "Galaxy Rangers" sort of manner, with one alien
ship providing the technology and then we master it?
> My best guess on this matter is that we will greet ET by radio, even before we
> leave the solar system. What happens next? Do they have FTL travel? Will
> they see us as friend or foe? Are we too pathetic to worry about, or are we
> immediately threatening? Will we become threatening ONLY when we start
> travelling to other stars? Will they come to subdue us, or take our pretty
> planet from us?
Isaac Asimov raised the spectre of aliens whose transmissions we receive, but regarding whom we just
kept our mouth shut--because they were found to be hostile. Making noise would attract them, and
possibly end life on Earth.
> Last time I checked through my minifigs, I didn't see any non-human life forms.
> Then again, I don't own any UFO or Insectoids sets. Nor do I have any Star
> Wars sets, so no Gungans. Was anyone out there planning to develop their
> corner of Datsville in space with non-humans? That could be cool. (Maybe I
> should buy some of these sets? Are they lame?)
Some are lame, but some are cheap. The SW sets are great for building parts!
> > But what may be even
> > more numerous than red dwarves are *brown* dwarves--stars so small that they
> > "abort"--sort of super-Jupiters, like Van Biesebroeck 8B and the sort. They
> > give off heat, and can have habitable tidally locked moons, but they're
> > really too small to light up like a red star.
>
> Yeah, I didn't want to talk about these, because I have found so little
> information on them. There is no good census of brown dwarfs yet. They have
> seen so few. There might be many, but so far they're just too darn hard to
> see.
I'm convinced that they're probably even more numerous than M-class stars (!). They wouldn't fuse,
they wouldn't die, and they'd just sort of...accumulate. Maybe free brown dwarves would end up
becoming red dwarves by accretion some future day?
> The Nemesis theory comes and goes.
I almost spit out my drink when I read this. Maybe this part of the thread should go to
.off-topic.pun? ;) (Maybe we should all go to .off-topic.geek?) That was a REAL groaner.
> I must warn you that if you do a Web search
> on the subject, you will come up with a lot of crackpot pages. For some
> reason, there are a lot of folks out there who are convinced that the Biblical
> flood and other mythical and historical events are connected to the existence
> of a "dark" companion to the Sun.
Yeah, forgot to mention that little fringe thing. The Creationists don't like to be connected to the
Flat Earthers, which angers the Flat Earthers; the Hoaglands of the world don't want to be connected
to the conspiracy theorists, etc etc ad nauseum. Fringe theories are always ripe for people looking
for some kind of reinforcement--remember "water canopy" theory and the like?
> Do we want Nemesis to exist in the Legoverse? Should it be a small sun instead
> of a big planet? Will it have planets of its own? (Please, no aliens that
> speak ancient Sumerian...)
Who knew that Dr. Cyber's brother was Erich von Daniken? Wow!
> What's VB8B? (Maybe you should answer this question by email?)
Van Biesebroeck 8B, the theorized companion to VB8.
> I think you're mistaken here. Before Hipparcos, the 10% accuracy limit on
> trigonometric (direct parallax) measurements of stellar distance was *ten*
> parsecs. At 300 parsecs, the error by parallax from the ground would be huge.
> Even with Hipparcos, the error at 300 parsecs would be unacceptable -- about
> 33%.
Yes, but if the accepted value is around 1000pc, that still puts it more than 500pc out. ;)
> Now you're trumping me! Above, I said that I was interested in
> slower-than-light travel. But what if another race has FTL before humans?
> Your idea, that there might be many ways to travel faster than light (some
> better than others?), is the logical extension of my thoughts. Actually, I
> seem to recall that the Star Trek series hints at this. Remember the ST III
> movie, and the trans-warp drive? I also had a glimpse at one of the new ST
> technical manuals in a bookstore a while back, and I seem to remember a
> discussion of ship travel speeds that mentioned "warp speed old scale" and
> "warp speed new scale".
And transwarp conduits, wormholes, et cetera...I tend to use shifts in folding space, but I guess
"warp" is a similar idea in general.
> > This is interesting, and worth pursuing--I think a "Space datsville" would
> > be a lot of fun to populate, and I'm convinced we wouldn't be wanting for
> > planets.
>
> So, shall I start the thread on planets and habitability now? :^)
Sure, I'm always game for that. Thank goodness for those Android Base domes!
LFB.
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Message is in Reply To:
 | | Re: The "geography" of local space
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| Hello again, I''m glad I generated some interest here! I hope, however, that we do not stray too far from discussing LEGO -- I have noticed complaints in at least one other LUGNET newsgroup. (...) Both quite rewarding, but difficult fields in which (...) (25 years ago, 5-Nov-99, to lugnet.space)
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