Vernor Vinge/David Brin
Patrick Dobson
read his "A Deepness in the Sky". His universe seems very similar to that
of David Brin's Uplift war series; Lots of Ancient Alien races, an enduring
civilisation based on the information in the Net/Library, Humans as a
wolfling race needing to catch up.
Are there any other books set in similar worlds? The other Vernor Vinge and
David Brin books I know of aren't, but do any other authors have similar
books?
Thanks
Patrick
Karl M Syring
Well, that is because they are/were both working in academia,
thus I pull you one Gregory Benford. Now, there is his "Galactic
Center" series. Bingo.
Karl M. Syring
Patrick Dobson
"Karl M Syring" <syr...@email.com> wrote in message
news:bd4mug$p01r7$1...@ID-7529.news.dfncis.de...
Thanks, unfortunately Amazon.co.uk says that it can't offer Great Sky River:
Galactic Centre Book 1 at the moment, as it is out of print. Something to
look for in second hand bookshops whenever I can visit civilisation.
Books 2, 3 and 4 seem available. Is this a Series, or can the books be read
separately. Basically is it worth getting the later books if I can't find
the first?
Thanks
Patrick
Karl M Syring
>
> Thanks, unfortunately Amazon.co.uk says that it can't offer Great Sky River:
> Galactic Centre Book 1 at the moment, as it is out of print. Something to
> look for in second hand bookshops whenever I can visit civilisation.
>
> Books 2, 3 and 4 seem available. Is this a Series, or can the books be read
> separately. Basically is it worth getting the later books if I can't find
> the first?
I would strongly recommend to start with Great Sky River. Note
that there are prequels, which may or may be not to your liking.
Karl M. Syring
Patrick C.
news:bd4nmj$6pp$1...@newsg1.svr.pol.co.uk:
You should definitely start with GSR. Also, #4, _Sailing Bright Eternity_,
was a big letdown IMHO (but then, what #4 book in any series hasn't been
awful?) You should also be aware of a couple/few earlier books that are set
in the same universe/history but a much earlier epoch (the titles escape me
at the moment).
This series is overall very good, and GSR is probably the best part.
Recently I started to re-read the series but found it not quite as
thrilling the 2nd time around; the sections from the p.o.v. of the aliens
in book #2 especially became annoying.
Pat
bananko
David Dyer-Bennet
> (but then, what #4 book in any series hasn't been
> awful?)
_Skylark Duquesne_ (Doc Smith)
_Children of the Lens_ (or, if you start with the prequels, _Gray
Lensman_)
_Field of Dishonor_ (David Weber)
And outside the genre they're legion
_A Taste for Death_ (Peter O'Donnell)
_The Red Box (Rex Stout)
_Hornblower and the Atropos_ (C.S. Forester)
_October Men_ (Anthony Price)
_Nightmare in Pink_ (John D. MacDonald)
_The Memoirs of Sherlock Holmes_ (Arthur Conan Doyle)
_The Mauritius Command_ (Patrick O'Brian)
--
David Dyer-Bennet, <dd...@dd-b.net>, <www.dd-b.net/dd-b/>
RKBA: <noguns-nomoney.com>
Photos: <dd-b.lighthunters.net> Snapshots: <www.dd-b.net/dd-b/SnapshotAlbum/>
Dragaera mailing lists: <dragaera.info/>
Rich Clark
news:bd51mu$pi$1...@sunce.iskon.hr...
> A Deepness in the Sky is a sequel of A fire upon the Deep, or...?
Even though _Deepness_ takes place chronologically before _Fire_ (long
before), IMO they should be read in publishing order (_Fire_ first). There
are things you'll learn about the universe in _Fire_ that enrich the
experience of reading _Deepness_. And I believe such was the author's
intent.
RichC
Mike Schilling
news:m2adc9ua...@gw.dd-b.net...
> "Patrick C." <pat@outer*omittoreply*reaches.com> writes:
>
> > (but then, what #4 book in any series hasn't been
> > awful?)
>
> _Skylark Duquesne_ (Doc Smith)
> _Children of the Lens_ (or, if you start with the prequels, _Gray
> Lensman_)
>
> _Field of Dishonor_ (David Weber)
_Taltos_ (Steven Brust)
_Brothers in Arms_, (Lois Bujold [perhaps _Borders of Infinity_, if you
count differently. Works either way.])
Peter Meilinger
>> (but then, what #4 book in any series hasn't been
>> awful?)
Guards! Guards! was the fourth Discworld book, wasn't it?
That was the first good one, if you ask me.
Plenty of children's series are at least pretty good all
the way through. None are coming to mind right now, of
course.
Aha! What was the fourth book in the Prydain series by
Lloyd Alexander? I liked all of those just fine.
The only other example to come to mind is the Gor series,
believe it or not. The fourth book had awful elements,
definitely, but there was a good story going on if you
ignored the slavery crap.
Well, maybe not a "good" story, but better than the later
books in the series.
Pete
David Silberstein
Peter Meilinger <mell...@bu.edu> wrote:
>Patrick C." <pat@outer*omittoreply*reaches.com> writes:
>
>>> (but then, what #4 book in any series hasn't been
>>> awful?)
>
>Guards! Guards! was the fourth Discworld book, wasn't it?
>That was the first good one, if you ask me.
No, /Mort/ was number four. But that is definitely where
Pratchett began to improve greatly.
/Guards! Guards!/ is number eig... four plus four.
>Plenty of children's series are at least pretty good all
>the way through. None are coming to mind right now, of
>course.
Well, the 4th Oz book was /Dorothy and the Wizard in Oz/,
which was really only so-so.
The 4th Narnia book (publishing order) was /The Silver Chair/,
which was as good as any of them, I suppose.
HP #4 was OK, but I still think #3 was the best so far (I'll
see how HP#5 is in a few months when my turn comes around for
a library copy).
Mike Schilling
"Peter Meilinger" <mell...@bu.edu> wrote in message
news:bd56cc$1or$1...@news3.bu.edu...
> Aha! What was the fourth book in the Prydain series by
> Lloyd Alexander? I liked all of those just fine.
>
_Taran Wanderer_, which was IMHO the best one.
Keith Morrison
> The only other example to come to mind is the Gor series,
> believe it or not. The fourth book had awful elements,
> definitely, but there was a good story going on if you
> ignored the slavery crap.
>
> Well, maybe not a "good" story, but better than the later
> books in the series.
A lobotomy with a two kilo sledge hammer is better than the
later books in the series.
--
Keith
Konrad Gaertner
> "Patrick C." <pat@outer*omittoreply*reaches.com> writes:
>
> > (but then, what #4 book in any series hasn't been
> > awful?)
Discworld started getting good at book four.
_Taltos_ is my favorite Vlad book.
_Shadow Rising_ is my favorite Wheel of Time book.
I haven't read _House of Chains_ yet, but I wouldn't be surprised
to add it to this list.
I've heard lots of people claim _Goblet of Fire_ as best Harry
Potter book.
Can't think of any examples from science fiction...
--KG
David Bilek
>
>Discworld started getting good at book four.
>
>_Taltos_ is my favorite Vlad book.
>
>_Shadow Rising_ is my favorite Wheel of Time book.
>
>I haven't read _House of Chains_ yet, but I wouldn't be surprised
>to add it to this list.
>
>I've heard lots of people claim _Goblet of Fire_ as best Harry
>Potter book.
>
>Can't think of any examples from science fiction...
>
Depending on how you count, _The Vor Game_ is the 4th Vorkosigan book.
Clearly not awful. Hugo winner and all that.
-David
GSV Three Minds in a Can
Patrick Dobson <pj...@oikumene.freeserve.co.uk> said
<snip>
>> Well, that is because they are/were both working in academia,
>> thus I pull you one Gregory Benford. Now, there is his "Galactic
>> Center" series. Bingo.
>>
>> Karl M. Syring
>>
>
>Thanks, unfortunately Amazon.co.uk says that it can't offer Great Sky River:
>Galactic Centre Book 1 at the moment, as it is out of print. Something to
>look for in second hand bookshops whenever I can visit civilisation.
>
>Books 2, 3 and 4 seem available. Is this a Series, or can the books be read
>separately. Basically is it worth getting the later books if I can't find
>the first?
IMO they go downhill sort of logarithmically, and by the time you get to
the later books things are just plain weird, with all sorts of things
made out of (iirc) EssTee (Space Time), and it's more or less a virtual
reality fantasy-fest. YMMV, but I personally think Benford lost the plot
almost as badly as Brin did in _Heaven's Reach_.
--
GSV Three Minds in a Can
Outgoing Msgs are Turing Tested,and indistinguishable from human typing.
Richard Horton
They don't match exactly, but I thought there were some similarities
in both Charles Sheffield's "Heritage Universe" books (_Convergence_
and others), and the shared world _Isaac's Universe_ (three original
anthologies, a novel by Hal Clement (_Fossil_), and a 2003 novel by
Poul Anderson (_For Love and Glory_) that has had the serial numbers
filed off so that it doesn't quite fit the series).
--
Rich Horton | Stable Email: mailto://richard...@sff.net
Home Page: http://www.sff.net/people/richard.horton
Also visit SF Site (http://www.sfsite.com) and Tangent Online (http://www.tangentonline.com)
Daniel Ban
"GSV Three Minds in a Can" <GSV@[127.0.0.1]> wrote in message
news:LoqlYOBI...@from.is.invalid...
> IMO they go downhill sort of logarithmically, and by the time you get to
> the later books things are just plain weird, with all sorts of things
> made out of (iirc) EssTee (Space Time), and it's more or less a virtual
> reality fantasy-fest. YMMV, but I personally think Benford lost the plot
> almost as badly as Brin did in _Heaven's Reach_.
>
> --
> GSV Three Minds in a Can
> Outgoing Msgs are Turing Tested,and indistinguishable from human typing.
Personally, I found the prequels (Across the Sea of Suns and something Night
IIRC) to be better than the Galactic Center stuff. The first half of the
first Gal Center book was OK but then devolved straightaway to science
fantasy, and bad sci-fantasy at that.
On the topic of more authors who write good space opera like the Brin/Vinge
titles listed, I also like that sub-genre quite a bit. I've been looking
for more authors who can deliver. A lot of people like Alistair Reynold's
stuff although it didn't quite work for me. I also enjoyed the first book
in a new series by Scott Westerfel, The Risen Empire. I also read the first
book in a new series, Wasteland of Flint, which I found promising.
Unfortunately the first books in a series feeling of both titles left me
feeling extremely incomplete.
When is the next Vinge due out anyhow?
Dan
Scott Fluhrer
"Daniel Ban" <dan...@pacbell.net> wrote in message
news:B4uJa.2876$gI4....@newssvr19.news.prodigy.com...
Let me see -- the last one was published in 1999, so we've only got about 6
more years for the next one...
--
poncho
David Dyer-Bennet
> "Daniel Ban" <dan...@pacbell.net> wrote in message
> news:B4uJa.2876$gI4....@newssvr19.news.prodigy.com...
> > When is the next Vinge due out anyhow?
>
> Let me see -- the last one was published in 1999, so we've only got about 6
> more years for the next one...
I thought it was about 6 years per book *before* he went to writing
full time. So we should have something new somewhat *before* 2005, if
that's true.
Norville
<dan...@pacbell.net> wrote:
> I also read the first
> book in a new series, Wasteland of Flint, which I found promising.
> Unfortunately the first books in a series feeling of both titles left me
> feeling extremely incomplete.
_Wasteland of Flint_ did seem promising. It's always fascinated me to
study Aztec culture/history. However, I was left feeling as if Thomas
Harlan could've written so much more background; this first book just
dumps one into his alternate universe, and I felt that I'd missed
something somewhere, though this was the first in a series. Naturally, if
he'd gone into great detail about *how* the Aztecs managed to control
Earth and develop space flight, it would've been a vast book, and at 430
pages, it's long enough as it is. <g>
--
"...To strive, to seek, to find, and not to yield."
<*> "Ulysses" by Tennyson <*>
Salute Space Shuttle COLUMBIA, 1981-2003
Michael Grosberg
They aren't so similar actually - Brin's galaxy has is monocultural,
ritualistic and basically static, while Vinge's Galaxy is chaotic,
ever changing and decentralized.
But if you're looking for other works with plenty of alien races, big
ideas and galaxy-wide setting I can recommend Iain Banks' "Culture"
books. You can begin with almost any of them, But the recommended ones
are _Consider Phlebas_ or _Use of Weapons_.
Julie d'Aubigny
>
> They aren't so similar actually - Brin's galaxy has is monocultural,
> ritualistic and basically static, while Vinge's Galaxy is chaotic,
> ever changing and decentralized.
> But if you're looking for other works with plenty of alien races, big
> ideas and galaxy-wide setting I can recommend Iain Banks' "Culture"
> books. You can begin with almost any of them, But the recommended ones
> are _Consider Phlebas_ or _Use of Weapons_.
I was so hoping that someone wouldn't suggest this before I could. But
I'll second it - The Culture certainly has more of what you (Patrick)
might be looking for.
--
Elizabeth D. Brooks | kalima...@attbi.com | US2002021724
Listowner: Aberrants_Worldwide, Fading_Suns_Games, TrinityRPG
AeonAdventure | "Why, in my day, we used to fight the Lord of
Terror with nothing but a sharp stick!" -- www.reallifecomics.com
Niall McAuley
> I can recommend Iain Banks' "Culture"
> books. You can begin with almost any of them, But the recommended ones
> are _Consider Phlebas_ or _Use of Weapons_.
I'd recommend _Consider Phlebas_ or _The Player of Games
as the best introduction. Even if you don't like whichever
one of those you find first, try _Use of Weapons_ anyhow.
--
Niall [real address ends in se, not es.invalid]
Doom & Gloom Dave
IMHO too.
Peter D. Tillman
"Patrick Dobson" <pj...@oikumene.freeserve.co.uk> wrote:
If you'd like to see the roots of some of these, you might check out a
few of Andre Norton's Forerunner juveniles, from the 50's & 60's.
Forerunner Foray comes to mind, as does Sargasso of Space (the
mysterious planet Limbo) and Galactic Derelict (I think). Hmm, is there
a canonical list of the Forerunner books somewhere? ISFDB has them
scattered among several series.
Be aware that these were pretty simplistic even then, and the characters
are purest cardboard. But there are haunting images of the Forerunner
relics, and they're short.
Cheers -- Pete Tillman
Book Reviews: http://www.silcom.com/~manatee/reviewer.html#tillman
http://www.amazon.com/exec/obidos/tg/cm/member-reviews/-/A3GHSD9VY8XS4Q/
http://www.users.zetnet.co.uk/iplus/nonfiction/index.htm#reviews
http://www.sfsite.com/revwho.htm
Christopher J. Henrich
Patrick C. <pat@outer*omittoreply*reaches.com> wrote:
> (but then, what #4 book in any series hasn't been
> awful?)
_The_ _Citadel_ _of_ _the_ _Autarch_ was OK (at least).
You do have to go through Wolfe's entire oeuvre a fews time to be sure
you know what the hell's really happening...
... but that is not such a bad reading experience.
--
Chris Henrich
The wonderful thing about not planning,
is that failure comes as a complete surprise,
and is not preceded by a period of worry or
depression.
-- "Kiltannen"
Taki Kogoma
to rec.arts.sf.written decree...
>"Patrick C." <pat@outer*omittoreply*reaches.com> writes:
>> (but then, what #4 book in any series hasn't been
>> awful?)
>
>_Skylark Duquesne_ (Doc Smith)
>_Children of the Lens_ (or, if you start with the prequels, _Gray
> Lensman_)
>
>_Field of Dishonor_ (David Weber)
YMMV. I found this one rather disappointing and the seeds of the "St.
Honor of Grayson-Manticore Syndrome" (Gee. She's *that* good with
slugthrowers?) appear.
(Or maybe it's just the "Michael Jackson" cover art on the 1st
edition...)
OTOH, _Dragonsinger_ (4th published Pern book) remains a sentimental
favorite of mine.
>_Hornblower and the Atropos_ (C.S. Forester)
In publication order, doesn't this one come along rather later? ISTR
that the 4th published Hornblower was the _Mr. Midshipman Hornblower_
collection.
--
Capt. Gym Z. Quirk | /"\ ASCII RIBBON
(Known to some as Taki Kogoma) | \ / CAMPAIGN
quirk @ swcp.com | X AGAINST HTML MAIL
Veteran of the '91 sf-lovers re-org. | / \ AND POSTINGS
Patrick Dobson
"Michael Grosberg" <preac...@hotmail.com> wrote in message
news:c21d3ba0.03062...@posting.google.com...
news:<bd4kjt$eqk$1...@news7.svr.pol.co.uk>...
> > I am currently reading "A fire upon the Deep" by Vernor Vinge, having
just
> > read his "A Deepness in the Sky". His universe seems very similar to
that
> > of David Brin's Uplift war series; Lots of Ancient Alien races, an
enduring
> > civilisation based on the information in the Net/Library, Humans as a
> > wolfling race needing to catch up.
> >
> > Are there any other books set in similar worlds? The other Vernor Vinge
and
> > David Brin books I know of aren't, but do any other authors have similar
> > books?
> >
> >
> > Thanks
> >
> > Patrick
>
> They aren't so similar actually - Brin's galaxy has is monocultural,
> ritualistic and basically static, while Vinge's Galaxy is chaotic,
> ever changing and decentralized.
I'm not so sure. In "Fire upon the Deep" places like Relay or Harmonious
Repose are several hundred thousand, or even millions, of years old. The
old races gradually making way for the new, that seems as static as the
Uplift series. True there is no ritual element like the uplift
Patron-client chains, but it (Vinge's Universe) seems quite static in parts.
And there are chaotic and revolutionary times in Brin's, when one client
race is considering a rising by all clients it is mentioned that this has
happened five (I think), times before.
Anyway it was the "feel" of the worlds that I thought was similar, not any
obvious facts which jumped out.
> But if you're looking for other works with plenty of alien races, big
> ideas and galaxy-wide setting I can recommend Iain Banks' "Culture"
> books. You can begin with almost any of them, But the recommended ones
> are _Consider Phlebas_ or _Use of Weapons_.
Yes I have read those, liked them too.
Unfortunately I hadn't read "Consider Phlebas", only "The Wasp Factory",
when Iain Banks came to give a talk at St. Andrews, so the identity of the
victors when I subsequently read it wasn't such a surprise as it may have
been coming to it cold.
I preferred "Player of Games" to "Use of Weapons", but liked most of them,
except, for some reason, "Inversions".
(Hmm, overuse of commas!)
Patrick
GSV Three Minds in a Can
wonderful person Daniel Ban <dan...@pacbell.net> said
>
>"GSV Three Minds in a Can" <GSV@[127.0.0.1]> wrote in message
>news:LoqlYOBI...@from.is.invalid...
>> IMO they go downhill sort of logarithmically, and by the time you get to
>> the later books things are just plain weird, with all sorts of things
>> made out of (iirc) EssTee (Space Time), and it's more or less a virtual
>> reality fantasy-fest. YMMV, but I personally think Benford lost the plot
>> almost as badly as Brin did in _Heaven's Reach_.
>
>IIRC) to be better than the Galactic Center stuff. The first half of the
>first Gal Center book was OK but then devolved straightaway to science
>fantasy, and bad sci-fantasy at that.
>
>On the topic of more authors who write good space opera like the Brin/Vinge
>titles listed, I also like that sub-genre quite a bit. I've been looking
>for more authors who can deliver. A lot of people like Alistair Reynold's
>stuff although it didn't quite work for me.
Reynolds works 'fairly well' for me, but I don't think he's hit
perfection yet. You might want to try Neal Asher (_The Skinner_,
_Gridlinked_ .. actualyl in the other order, sorry ..) since he does it
for me at least as well as Reynolds.
Craig Richardson
wrote:
>"Patrick C." <pat@outer*omittoreply*reaches.com> writes:
>
>> (but then, what #4 book in any series hasn't been
>> awful?)
>
>_Skylark Duquesne_ (Doc Smith)
>_Children of the Lens_ (or, if you start with the prequels, _Gray
> Lensman_)
>
>_Field of Dishonor_ (David Weber)
Glen Cook, <Old Tin Sorrows>. Arguably the best Garrett book.
Pratchett, <Jingo>, <Maskerade>, and <Hogfather>. While the former
two are IMO weak for their series, they're still far from awful.
--Craig
--
Managing the Devil Rays is something like competing on "Iron Chef",
and having Chairman Kaga reveal a huge ziggurat of lint.
Gary Huckabay, Baseball Prospectus Online, August 21, 2002
how...@brazee.net
On 22-Jun-2003, "Patrick Dobson" <pj...@oikumene.freeserve.co.uk> wrote:
> I am currently reading "A fire upon the Deep" by Vernor Vinge, having just
> read his "A Deepness in the Sky". His universe seems very similar to that
> of David Brin's Uplift war series; Lots of Ancient Alien races, an
> enduring
> civilisation based on the information in the Net/Library, Humans as a
> wolfling race needing to catch up.
>
> Are there any other books set in similar worlds? The other Vernor Vinge
> and
> David Brin books I know of aren't, but do any other authors have similar
> books?
It seems that there superficial similarities put them in a large category of
SF. Maybe I'm missing some other point of commonality.
Richard Horton
<til...@aztec.asu.edu> wrote:
>If you'd like to see the roots of some of these, you might check out a
>few of Andre Norton's Forerunner juveniles, from the 50's & 60's.
>Forerunner Foray comes to mind, as does Sargasso of Space (the
>mysterious planet Limbo) and Galactic Derelict (I think). Hmm, is there
>a canonical list of the Forerunner books somewhere? ISFDB has them
>scattered among several series.
Good call -- the Forerunner books seem definitely early examples of
this sort of thing. (Anderson uses the term Forerunner in _For Love
and Glory_ in what I take to be an hommage to Norton.)
I don't think _Galactic Derelict_ is a Forerunner book, though. I
think it's a Time Trader book.
James Nicoll
I am a few hundred pages into _Line of Polity_ [1] and he
managed to top the anti-photons thing: they have orbiting mirrors
that can concentrate sunlight to the point of *inducing fusion*
in the target. Generally, thermodynamics frowns on a heat source
being used to heat another object up to a higher temperature but
I suppose these are *special* mirrors.
James Nicoll
1: Americans need not envy me, as the US edition is coming---in late 2004.
--
"About this time, I started getting depressed. Probably the late
hour and the silence. I decided to put on some music.
Boy, that Billie Holiday can sing."
_Why I Hate Saturn_, Kyle Baker
J.B. Moreno
> what #4 book in any series hasn't been awful?
Recently there's been a thread on Tamora Pierce, who seems to specialize
in 4 book series -- all of which have been fairly good to wonderful.
--
JBM
"Everything is futile." -- Marvin of Borg
Myrnag2555
>this sort of thing. (Anderson uses the term Forerunner in _For Love
>and Glory_ in what I take to be an hommage to Norton.)
He also refers to Voortrekkers and has a
a long lived species of reptilians with great
intellectual capacities.
Incidentally, one of his characters spouts one of the silliest ideas I've ever
heard, that the lack of understanding between alien minds would lead to a lack
of serious animosity between them. Yeah, right.
Olivier Travers
ISFDB has them scattered among several series.
We have an entry for this series, though I'm not sure it's
"canonical":
http://www.scifan.com/series/series.asp?SR_seriesid=742
Olivier Travers
http://www.scifan.com
Karl M Syring
Basically, the common theme is that humans are an endangered species.
Karl M. Syring
--
Harry Potter is a sexist neo-conservative autocrat.
- Pierre Bruno, Liberation (cf. ISBN 1-85984-666-1)
JJ Karhu
Moreno) wrote:
>Patrick C. <pat@outer*omittoreply*reaches.com> wrote:
>
>> what #4 book in any series hasn't been awful?
>
>Recently there's been a thread on Tamora Pierce, who seems to specialize
>in 4 book series -- all of which have been fairly good to wonderful.
Steven Erikson's Malazan series. Book 4 is great. The 4th Harry Potter
was the best so far in that series. I'm sure there are other examples
as well :)
// JJ
Matthew T. Carpenter
> On Mon, 23 Jun 2003 23:42:32 -0400, pl...@newsreaders.com (J.B.
> Moreno) wrote:
> >Patrick C. <pat@outer*omittoreply*reaches.com> wrote:
> >
> >> what #4 book in any series hasn't been awful?
The Shadow Rising was the best book in Robert Jordan's Wheel of
Time....unfortunately his brain was devoured by weevils and books have
sucked progressively worse after the sixth one. If you stop at #6 you
can still say to yourself, wow can't wait for the next one.
Matt
Andrew Plotkin
> I am a few hundred pages into _Line of Polity_ [1] and he
> managed to top the anti-photons thing: they have orbiting mirrors
> that can concentrate sunlight to the point of *inducing fusion*
> in the target. Generally, thermodynamics frowns on a heat source
> being used to heat another object up to a higher temperature but
> I suppose these are *special* mirrors.
Karl Schroeder's _Permanence_, which I mentioned a few weeks ago,
makes the same mistake. Star system where the sun is a
barely-red-glowing dwarf; solar mirrors heating a metal sphere up to
white heat. Oops.
> 1: Americans need not envy me, as the US edition is coming---in late 2004.
--Z
"And Aholibamah bare Jeush, and Jaalam, and Korah: these were the borogoves..."
*
* Make your vote count. Get your vote counted.
Mark Sidarous
The 4th book in the Darksword Trilogy, _Legacy of the Darksword_, was
really good. Oh wait, nevermind. I meant really bad.
--
Mark
Daniel Speyer
> Patrick C. <pat@outer*omittoreply*reaches.com> wrote:
>
> > what #4 book in any series hasn't been awful?
>
> Recently there's been a thread on Tamora Pierce, who seems to specialize
> in 4 book series -- all of which have been fairly good to wonderful.
Is _Men_at_Arms_ the fourth in its series? That's a truly great book.
I suppose SW:ANH doesn't count ;-)
How about _Return_of_the_King_ though?
I thought _Alvin_Journeyman_ was pretty good, though not as good as
the first three.
I haven't finished _Fortune's_Stroke_, but it looks pretty good so far
(not that any of the series has been truly brilliant)
_Robots_and_Empire_ was good, count that as you like.
So there are many good fourth books, even if some of them rather
straing the definition. The reason there are disproportianately few
of them, I suspect, is that the trilogy is such an established form.
A fourth book often means an author is returning to a story that's
already been told (_Foundation's_Edge_), or stretching to fit a story
that's out of control (_Children_of_the_Mind_). To support this
hypothosis, I point out that fourth books that were planned from the
beginning (Harry Potter) tend to turn out a lot better.
James Nicoll
Andrew Plotkin <erky...@eblong.com> wrote:
>Here, James Nicoll <jdni...@panix.com> wrote:
>> I am a few hundred pages into _Line of Polity_ [1] and he
>> managed to top the anti-photons thing: they have orbiting mirrors
>> that can concentrate sunlight to the point of *inducing fusion*
>> in the target. Generally, thermodynamics frowns on a heat source
>> being used to heat another object up to a higher temperature but
>> I suppose these are *special* mirrors.
>
>Karl Schroeder's _Permanence_, which I mentioned a few weeks ago,
>makes the same mistake. Star system where the sun is a
>barely-red-glowing dwarf; solar mirrors heating a metal sphere up to
>white heat. Oops.
>
stuff involving stitches or the phrase 'When I regained consciousness')
but one of the positive aspects of my father was that from time to
time he'd toss questions like 'why can't you run a car by turning
liquid water to ice, and using the liberated energy?' at us. And
then explain, thermo being one of his fields of specialty. So I
would never make the mirror heating something up hotter than the
sun mistake because that was drummed into me at age ten [1].
Of course, teaching a course in heat transfer didn't stop
him from pointing the spout of a kettle at a window on a cold winter's
night, although as I recall he only did that the once.
1: Arguably, I would have derived more use from 'never feed an animal
you don't know is a domestic species'.
Taki Kogoma
to rec.arts.sf.written decree...
>pl...@newsreaders.com (J.B. Moreno) wrote in message
>news:<1fx0nzm.1mgijt81dwigdhN%pl...@newsreaders.com>...
>> Patrick C. <pat@outer*omittoreply*reaches.com> wrote:
>> > what #4 book in any series hasn't been awful?
>>
>> Recently there's been a thread on Tamora Pierce, who seems to specialize
>> in 4 book series -- all of which have been fairly good to wonderful.
>
>Is _Men_at_Arms_ the fourth in its series? That's a truly great book.
Second of the "City Watch" sub-series, 15th Discworld book overall.
(4th "City Watch" would be _Jingo_.)
>How about _Return_of_the_King_ though?
3rd segment of the 2nd book. Sorry.
GSV Three Minds in a Can
James Nicoll <jdni...@panix.com> said
<snip>
>>Reynolds works 'fairly well' for me, but I don't think he's hit
>>perfection yet. You might want to try Neal Asher (_The Skinner_,
>>_Gridlinked_ .. actualyl in the other order, sorry ..) since he does it
>>for me at least as well as Reynolds.
>
> I am a few hundred pages into _Line of Polity_ [1] and he
>managed to top the anti-photons thing: they have orbiting mirrors
>that can concentrate sunlight to the point of *inducing fusion*
>in the target. Generally, thermodynamics frowns on a heat source
>being used to heat another object up to a higher temperature but
>I suppose these are *special* mirrors.
>
I don't think Neal is a physics major, although his bio says he worked
in mechanical/production engineering, so maybe we should expect better.
Personally I'm willing to cut some slack for interesting grand-scale
space opera .. I don't find miscalculated 'centrifugal' G (_redemption
Ark_) or
unlikely mirrors interrupting my reading pleasure nearly as much as
E-Space (Brin), EssTee wierdities (Benford), or even sub-atomic quantum
simulated human beings (Egan's last effort).
btw, since you are reading _LoP_ (I'm awaiting thr MMPB .. lack of
space) I assume you read at least _G_ and _tS_ .. what did you make of
them?
--
GSV Three Minds in a Can
Patrick Dobson
"Karl M Syring" <syr...@email.com> wrote in message
news:bd98s8$pmba2$1...@ID-7529.news.dfncis.de...
> how...@brazee.net wrote on Tue, 24 Jun 2003 01:00:29 GMT:
> >
> > On 22-Jun-2003, "Patrick Dobson" <pj...@oikumene.freeserve.co.uk> wrote:
> >
> >> I am currently reading "A fire upon the Deep" by Vernor Vinge, having
just
> >> read his "A Deepness in the Sky". His universe seems very similar to
that
> >> of David Brin's Uplift war series; Lots of Ancient Alien races, an
> >> enduring
> >> civilisation based on the information in the Net/Library, Humans as a
> >> wolfling race needing to catch up.
> >>
> >> Are there any other books set in similar worlds? The other Vernor
Vinge
> >> and
> >> David Brin books I know of aren't, but do any other authors have
similar
> >> books?
> >
> > It seems that there superficial similarities put them in a large
category of
> > SF. Maybe I'm missing some other point of commonality.
>
> Basically, the common theme is that humans are an endangered species.
>
Or the Universe is a Vast Old Culture, and Humans are a barely noticed part
by the other races, and when they are it is a Bad Thing for the Humans. The
culture being longer lasting than currently active races is another
similarity.
Anyway, it was a general similarity of feel I was really commenting on.
Patrick
James Nicoll
I thought _Gridlinked_ had fewer Unfortunate Science Moments
than _The Skinner_ and since the tS depends on one of the USMs (the
biology of the planet and why it is that way) I liked G more than tS.
They're a guilty pleasure, sort of Summer Movie Space Operas. The plots
may not make a lot of sense, the science is dubious but there are a
pleasing number of large explosions.
I suspect some of the background details of the Polity will
not appeal to readers of a particular tendency. The Polity puts AIs
in charge because AIs are better at running things than humans[1] and
it spreads because in general the lives of people in the Polity are
happier than outside it: it takes a supermajority to vote for membership
in the Polity but the Polity gets it time after time. People inside
the Polity who oppose it in a way that gets onto the page are generally
swine and the people outside it who oppose it are generally evil
bastards who don't want their boots taken off the throats of their
subjects.
James Nicoll
1: Although it is pointed out in TLoP that the dividing line is getting very
fuzzy.
Michael Stemper
>I am currently reading "A fire upon the Deep" by Vernor Vinge, having just
>read his "A Deepness in the Sky". His universe seems very similar to that
>of David Brin's Uplift war series; Lots of Ancient Alien races, an enduring
>civilisation based on the information in the Net/Library, Humans as a
>wolfling race needing to catch up.
>
>Are there any other books set in similar worlds? The other Vernor Vinge and
>David Brin books I know of aren't, but do any other authors have similar
>books?
You might try the books of the Galactic Mileu, by Julian May. In fact,
the background is quite similar to early Uplift, with Earth being considered
for membership in the wide-spread galactic civilization.
--
Michael F. Stemper
#include <Standard_Disclaimer>
Time flies like an arrow.
Fruit flies like a banana.
GSV Three Minds in a Can
>>space) I assume you read at least _G_ and _tS_ .. what did you make of
>>them?
>
> I thought _Gridlinked_ had fewer Unfortunate Science Moments
>than _The Skinner_ and since the tS depends on one of the USMs (the
>biology of the planet and why it is that way) I liked G more than tS.
Me too. There's apparently another one called _The Engineer_ out there
somewhere, but I haven't found it yet. I do have the print-on-demand (?)
collection _Runcible Tales_, but some of the best bits are sort of
already covered in _Gridlinked_ (_Runcible Tales is a =very= small book
- 5 short stories, 66pages)
>They're a guilty pleasure, sort of Summer Movie Space Operas. The plots
>may not make a lot of sense, the science is dubious but there are a
>pleasing number of large explosions.
>
> I suspect some of the background details of the Polity will
>not appeal to readers of a particular tendency. The Polity puts AIs
>in charge because AIs are better at running things than humans[1]
But of course we are, even IMB has worked that out. 8>. I figure it the
lack or hormones (ObJoke: What's the difference between a Vitamin and a
Hormone?##), unlimited data storage, and not conking out after a few
hundred years, give AIs the edge.
> and
>it spreads because in general the lives of people in the Polity are
>happier than outside it: it takes a supermajority to vote for membership
>in the Polity but the Polity gets it time after time. People inside
>the Polity who oppose it in a way that gets onto the page are generally
>swine and the people outside it who oppose it are generally evil
>bastards who don't want their boots taken off the throats of their
>subjects.
That didn't bother me too much .. after all if it works, (and it doesn't
appear to be particularly oppressive) the folks who oppose it are
clearly somewhat unhinged. It's not like the AIs were coming out with
policies like 'we need to cut number of humans by 25% ... you, you and
you go and get euthanased', is it?
> James Nicoll
>1: Although it is pointed out in TLoP that the dividing line is getting very
>fuzzy.
There are at least a few immortal humans wandering around the polity,
keeping the AIs in check, iirc.
(##. You can't hear a vitamin. Ah, the old ones are best. 8>.)
--
GSV Three Minds in a Can
David Cowie
> On the topic of more authors who write good space opera like the
> Brin/Vinge titles listed, I also like that sub-genre quite a bit. I've
> been looking for more authors who can deliver. A lot of people like
> Alistair Reynold's stuff although it didn't quite work for me.
I like the Alistair Reynolds books, but they're not quite what the OP
wanted. He seemed to want novels about humans being a junior race in a
wider galactic community full of intelligent life, but Reynolds has us
being all alone in a silent galaxy. There is a lot of archaeological
evidence of sentient races, but they all seemed to meet some kind of
disaster round about the time they developed starflight. Hmmm, why might
that be?
--
David Cowie david_cowie at lineone dot net
Joseph Michael Bay
>"Karl M Syring" <syr...@email.com> wrote in message
>> > It seems that there superficial similarities put them in a large
>category of
>> > SF. Maybe I'm missing some other point of commonality.
>> Basically, the common theme is that humans are an endangered species.
>Or the Universe is a Vast Old Culture, and Humans are a barely noticed part
>by the other races, and when they are it is a Bad Thing for the Humans. The
>culture being longer lasting than currently active races is another
>similarity.
It reminds me a bit of HP Lovecraft, actually.
--
Joseph M. Bay Lamont Sanford Junior University
www.stanford.edu/~jmbay/ Program in Cancer Biology
The white zone is for loading and unloading only. If you have to load
or unload, go to the white zone. You'll love it. It's a way of life.
Michael Grosberg
<some heavy snippage...>
> > > I am currently reading "A fire upon the Deep" by Vernor Vinge, having
> just
> > > read his "A Deepness in the Sky".
>
_Consider Phlebas_ or _Use of Weapons_.
>
> Yes I have read those, liked them too.
Can I suggest something that has sort of the same feel but not on a
galactic scale?
I just finished John C. Wright's _The Golden Age_ and I was simply
blown away. A truly superb work. How to explain it... take the ideas
from the books of Vinge, Bear, Sterling and Banks, the protagonist
from Van-Vogt or Bester, the writing style of Cordwainer Smith, mix
greek tragedy and some humor and what you'll get is something close
enough to _The Golden Age_. I know I'm raving here but the guy
deserves it. Wright dreams big, and has all the authorial skill to
pull it off.
Patrick Dobson
"Michael Grosberg" <preac...@hotmail.com> wrote in message
news:c21d3ba0.03062...@posting.google.com...
I will have a look, at least this one is available from Amazon.
Patrick
Karl M Syring
> "Patrick Dobson" <pj...@oikumene.freeserve.co.uk> writes:
>
>
>>"Karl M Syring" <syr...@email.com> wrote in message
>
>>> > It seems that there superficial similarities put them in a large
>>category of
>>> > SF. Maybe I'm missing some other point of commonality.
>
>>> Basically, the common theme is that humans are an endangered species.
>
>
>>Or the Universe is a Vast Old Culture, and Humans are a barely noticed part
>>by the other races, and when they are it is a Bad Thing for the Humans. The
>>culture being longer lasting than currently active races is another
>>similarity.
>
> It reminds me a bit of HP Lovecraft, actually.
Hmmh, meating the upper mech echelons may be not be
much better than to encounter ... you know whom.
Karl M. Syring
Del Cotter
Andrew Plotkin <erky...@eblong.com> said:
>Here, James Nicoll <jdni...@panix.com> wrote:
>> I am a few hundred pages into _Line of Polity_ [1] and he
>> managed to top the anti-photons thing: they have orbiting mirrors
>> that can concentrate sunlight to the point of *inducing fusion*
>> in the target. Generally, thermodynamics frowns on a heat source
>> being used to heat another object up to a higher temperature but
>> I suppose these are *special* mirrors.
>
>Karl Schroeder's _Permanence_, which I mentioned a few weeks ago,
>makes the same mistake. Star system where the sun is a
>barely-red-glowing dwarf; solar mirrors heating a metal sphere up to
>white heat. Oops.
Well, hold on a minute. Schroeder probably doesn't know it, but that
could actually work, because many "red" dwarfs actually *are* white, and
I think even the cooler ones are yellow. Genuinely red-coloured stars
are *brown* dwarfs.
This is related to that other classic hard-sf booboo, the "bloody red
light of the dwarf (or giant) sun". Red dwarfs and red giants have a
considerably higher temperature than a 100W incandescent bulb. They
appear red when seen as tiny points of light by our dark-adapted eyes,
especially if placed next to even hotter stars.
--
Del Cotter
Thanks to the recent increase in UBE, I will soon be ignoring email
sent to d...@branta.demon.co.uk. Please send your email to del2 instead.
Del Cotter
>James Nicoll <jdni...@panix.com> said
>>>Reynolds works 'fairly well' for me, but I don't think he's hit
>>>perfection yet. You might want to try Neal Asher (_The Skinner_,
>>>_Gridlinked_ .. actualyl in the other order, sorry ..) since he does it
>>>for me at least as well as Reynolds.
>>
>> I am a few hundred pages into _Line of Polity_ [1] and he
>>managed to top the anti-photons thing: they have orbiting mirrors
>>that can concentrate sunlight to the point of *inducing fusion*
>>in the target. Generally, thermodynamics frowns on a heat source
>>being used to heat another object up to a higher temperature but
>>I suppose these are *special* mirrors.
>>
>>1: Americans need not envy me, as the US edition is coming---in late 2004.
>
>I don't think Neal is a physics major, although his bio says he worked
>in mechanical/production engineering, so maybe we should expect better.
I could be wrong, but I *think* I remember hearing that's in the same
sense that Glen Cook and Peter F Hamilton were in mechanical/production
engineering: i.e. he worked in a factory.
This is not to dis any of them; I worked as a turner for years before I
went to college, and I was a pretty keen amateur physics student if I
say so myself.
Andrew Plotkin
> On Tue, 24 Jun 2003, in rec.arts.sf.written,
> Andrew Plotkin <erky...@eblong.com> said:
>>Here, James Nicoll <jdni...@panix.com> wrote:
>>> I am a few hundred pages into _Line of Polity_ [1] and he
>>> managed to top the anti-photons thing: they have orbiting mirrors
>>> that can concentrate sunlight to the point of *inducing fusion*
>>> in the target. Generally, thermodynamics frowns on a heat source
>>> being used to heat another object up to a higher temperature but
>>> I suppose these are *special* mirrors.
>>
>>Karl Schroeder's _Permanence_, which I mentioned a few weeks ago,
>>makes the same mistake. Star system where the sun is a
>>barely-red-glowing dwarf; solar mirrors heating a metal sphere up to
>>white heat. Oops.
> Well, hold on a minute. Schroeder probably doesn't know it, but that
> could actually work, because many "red" dwarfs actually *are* white, and
> I think even the cooler ones are yellow. Genuinely red-coloured stars
> are *brown* dwarfs.
I'm afraid he knows it, and he does refer to the thing as a "brown
dwarf". There's a whole background spiel about how humanity colonized
the dim, red-or-IR brown dwarf systems. Populations living in
near-darkness, etc. The metal sphere is supposed to be an artificial
daylight source for one of these non-lit planet.
David Bilek
I didn't like the sequel, _The Phoenix Exultant_ quite as much, but
I'm still going to buy the third book in hardcover. Too much time in
the second volume spent in a setting I found rather boring.
-David
Thomas Lindgren
David Bilek <dbi...@attbi.com> writes:
> I didn't like the sequel, _The Phoenix Exultant_ quite as much, but
> I'm still going to buy the third book in hardcover. Too much time in
> the second volume spent in a setting I found rather boring.
This was basically my conclusion as well.
MILD SPOILERS
On the plus side, I thought the parts with Daphne were funny, which
was a bit unexpected, and that the brief vision of the Silent Oecumene
was nicely chilling.
Best,
Thomas
--
Thomas Lindgren
"It's becoming popular? It must be in decline." -- Isaiah Berlin
David Bilek
>David Bilek <dbi...@attbi.com> writes:
>
>> I didn't like the sequel, _The Phoenix Exultant_ quite as much, but
>> I'm still going to buy the third book in hardcover. Too much time in
>> the second volume spent in a setting I found rather boring.
>
>This was basically my conclusion as well.
>
>MILD SPOILERS
>
>On the plus side, I thought the parts with Daphne were funny, which
>was a bit unexpected, and that the brief vision of the Silent Oecumene
>was nicely chilling.
>
Yes, The Silent Oecumene was quite well done.
Daphne was charming..
Atkins is great.
The bits with Phaethon while he was ostracized in (mumble.. Ceylon?)
sucked.
-David
James Nicoll
GSV Three Minds in a Can <G...@quik.clara.co.uk> wrote:
>Bitstring <bda2ci$hqv$1...@panix1.panix.com>, from the wonderful person
>James Nicoll <jdni...@panix.com> said
><snip>
>
>>not appeal to readers of a particular tendency. The Polity puts AIs
>>in charge because AIs are better at running things than humans[1]
>
>But of course we are, even IMB has worked that out. 8>. I figure it the
>lack or hormones (ObJoke: What's the difference between a Vitamin and a
>Hormone?##), unlimited data storage, and not conking out after a few
>hundred years, give AIs the edge.
Human/machine interfaces are getting good enough that
telling where the human ends and the AI begins is starting to be
difficult to determine. In a few decades, the entities running
worlds in the Polity might well have large human fractions.
Unfortunately the AI/Drone interactions lead me to think
lesser minds (as measure in bytes) often find themselves as files
in larger minds and the larger minds are not always as polite about
it as they might be. I will admit that one lesson of tS is that which
is the larger and which the smaller is not always obvious.
snip
>
>There are at least a few immortal humans wandering around the polity,
>keeping the AIs in check, iirc.
>
Exactly what the immortals are isn't obvious: one of them
in LoP claims to have been watching the A-Bombing of Hiroshima
in 1945 from ground zero. His parents were human, though.
James Nicoll
Jon Leech
>> I am a few hundred pages into _Line of Polity_ [1] and he
>> managed to top the anti-photons thing: they have orbiting mirrors
>> that can concentrate sunlight to the point of *inducing fusion*
>> in the target. Generally, thermodynamics frowns on a heat source
>> being used to heat another object up to a higher temperature but
>> I suppose these are *special* mirrors.
>
>Karl Schroeder's _Permanence_, which I mentioned a few weeks ago,
>makes the same mistake. Star system where the sun is a
>barely-red-glowing dwarf; solar mirrors heating a metal sphere up to
>white heat. Oops.
"White hot" metal is much cooler than the surface of a red dwarf,
and not much hotter than a brown dwarf.
But I'm not following the problem here even were that not the case.
Are you thinking there's some limit on the amount of solar energy that
could be concentrated on the sphere?
Jon
__@/
Andrew Plotkin
> In article <bd9r2t$n67$1...@reader1.panix.com>,
> Andrew Plotkin <erky...@eblong.com> wrote:
>>Here, James Nicoll <jdni...@panix.com> wrote:
>>> I am a few hundred pages into _Line of Polity_ [1] and he
>>> managed to top the anti-photons thing: they have orbiting mirrors
>>> that can concentrate sunlight to the point of *inducing fusion*
>>> in the target. Generally, thermodynamics frowns on a heat source
>>> being used to heat another object up to a higher temperature but
>>> I suppose these are *special* mirrors.
>>
>>Karl Schroeder's _Permanence_, which I mentioned a few weeks ago,
>>makes the same mistake. Star system where the sun is a
>>barely-red-glowing dwarf; solar mirrors heating a metal sphere up to
>>white heat. Oops.
> "White hot" metal is much cooler than the surface of a red dwarf,
> and not much hotter than a brown dwarf.
See my other post -- I *was* being precise with my language! A dwarf
star which is barely glowing red -- therefore being a brown dwarf star
-- *not* a barely-glowing red dwarf star!
> But I'm not following the problem here even were that not the case.
> Are you thinking there's some limit on the amount of solar energy that
> could be concentrated on the sphere?
Yes.
Mirrors (and lenses) are passive optical devices. Heat cannot of
itself pass from one body to a hotter body.
Even if you arranged mirrors so that every ray leaving the star
impinged on the metal sphere, and vice versa, you'd just be creating a
closed system. The two objects would come into thermal equilibrium.
(If you strike the "and vice versa" clause, you're punching a hole for
the sphere to cool off through, thus lowering its temperature
further.)
how...@brazee.net
how...@brazee.net
On 24-Jun-2003, Karl M Syring <syr...@email.com> wrote:
> > It seems that there superficial similarities put them in a large
> > category of
> > SF. Maybe I'm missing some other point of commonality.
>
> Basically, the common theme is that humans are an endangered species.
I don't believe it. There are big and powerful species out there, but the
galaxy/galaxies are big, and the powers that be aren't all powerful.
Jon Leech
Andrew Plotkin <erky...@eblong.com> wrote:
>Mirrors (and lenses) are passive optical devices. Heat cannot of
>itself pass from one body to a hotter body.
>
>Even if you arranged mirrors so that every ray leaving the star
>impinged on the metal sphere, and vice versa, you'd just be creating a
>closed system. The two objects would come into thermal equilibrium.
Are you saying that, although the smaller object would be radiating
the same total amount of energy as the larger one in this case, their
surface temperature would be the same?
Jon
__@/
GSV Three Minds in a Can
Andrew Plotkin <erky...@eblong.com> said
<snip>
>Mirrors (and lenses) are passive optical devices. Heat cannot of
>itself pass from one body to a hotter body.
>
>Even if you arranged mirrors so that every ray leaving the star
>impinged on the metal sphere, and vice versa, you'd just be creating a
>closed system. The two objects would come into thermal equilibrium.
Hmm, I think the closed system would get rather hot under those
conditions, since you've stopped the heat leaking out into the rest of
the universe .. I expect you'd achieve fusion in your metal sphere
rather quickly .. just somewhat after your star went 'boom' on you.
(You'd need rather high quality mirrors too). 8>.
--
GSV Three Minds in a Can
Carl Dershem
> Patrick C. <pat@outer*omittoreply*reaches.com> wrote:
>
>> what #4 book in any series hasn't been awful?
>
> Recently there's been a thread on Tamora Pierce, who seems to specialize
> in 4 book series -- all of which have been fairly good to wonderful.
I haven't found any of Brust's Taltos series to be a stinker. Heck, I've
thoroughly enjoyed them all.
cd
Paul F. Dietz
> Are you thinking there's some limit on the amount of solar energy that
> could be concentrated on the sphere?
There is a well-known limit from theromdynamics. Mirrors and other
optical devices cannot increase the power/steradian of sunlight(*),
they only make more of the solid angle around the target appear to be
from the sun.
(*) If the target is immersed in a material of higher refractive
index n you get an additional factor of n^2, but the argument is not
fundamentally changed.
Paul
Niall McAuley
news:bdaq4d$55r$2...@reader1.panix.com...
> Heat cannot of itself pass from one body to a hotter body.
and that's a natural law!
--
Niall [real address ends in net, not ten.invalid]
Sea Wasp
>> But I'm not following the problem here even were that not the case.
>>Are you thinking there's some limit on the amount of solar energy that
>>could be concentrated on the sphere?
>
>
> Yes.
>
> Mirrors (and lenses) are passive optical devices. Heat cannot of
> itself pass from one body to a hotter body.
>
> Even if you arranged mirrors so that every ray leaving the star
> impinged on the metal sphere, and vice versa, you'd just be creating a
> closed system. The two objects would come into thermal equilibrium.
Ummm... And how does this prevent a white-hot sphere?
Answer: it doesn't.
It only prevents heating a sphere that's the SAME SIZE as the star
to anything hotter than the star.
If I intercept all the rays of the sun and concentrate them on a
point the size of my hand, I assure you, that point is going to be a
LOT hotter than the surface of the sun. It will, in fact, be hotter
than the CENTER of the sun. It will be hot enough to induce fusion.
If you don't believe me, think about all the powersat suggestions.
If I can get enough electricity from the sun to light up Denver, and I
channel all that electricity into a set of lasers, I can induce
fusion. And that's a FAR more inefficient route than just taking the
sunlight and concentrating it directly.
--
Sea Wasp
/^\
;;;
http://www.wizvax.net/seawasp/index.htm
Paul F. Dietz
> If I intercept all the rays of the sun and concentrate them on a
> point the size of my hand, I assure you, that point is going to be a LOT
> hotter than the surface of the sun.
I assure you that you are completely mistaken. For extra credit, assume
that what you just said was true, and show how it can be used to build
a perpetual motion machine of the second kind.
Paul
Paul F. Dietz
> I assure you that you are completely mistaken. For extra credit, assume
> that what you just said was true, and show how it can be used to build
> a perpetual motion machine of the second kind.
I'll add that I was assuming you were doing this with lenses and mirrors.
There's a limit to how much these can concentrate light.
Paul
don't spam me]@slater.net Joe Slater
<erky...@eblong.com> wrote:
>Karl Schroeder's _Permanence_, which I mentioned a few weeks ago,
>makes the same mistake. Star system where the sun is a
>barely-red-glowing dwarf; solar mirrors heating a metal sphere up to
>white heat. Oops.
I don't understand why that won't work. Surely when you hit something with
a photon you're adding energy to it, and if you throw enough photons at
something you'll get it arbitrarily hot?
jds
David Bilek
Damn you! My patent is still pending!
-David
Richard Horton
wrote:
>I like the Alistair Reynolds books, but they're not quite what the OP
>wanted. He seemed to want novels about humans being a junior race in a
>wider galactic community full of intelligent life, but Reynolds has us
>being all alone in a silent galaxy. There is a lot of archaeological
>evidence of sentient races, but they all seemed to meet some kind of
>disaster round about the time they developed starflight. Hmmm, why might
>that be?
Well, maybe it's a bit of a spoiler, but not quite all alone.
--
Rich Horton | Stable Email: mailto://richard...@sff.net
Home Page: http://www.sff.net/people/richard.horton
Also visit SF Site (http://www.sfsite.com) and Tangent Online (http://www.tangentonline.com)
Andrew Plotkin
> Bitstring <bdaq4d$55r$2...@reader1.panix.com>, from the wonderful
person
> Andrew Plotkin <erky...@eblong.com> said
>>Mirrors (and lenses) are passive optical devices. Heat cannot of
>>itself pass from one body to a hotter body.
>>
>>Even if you arranged mirrors so that every ray leaving the star
>>impinged on the metal sphere, and vice versa, you'd just be creating
>>a closed system. The two objects would come into thermal equilibrium.
> Hmm, I think the closed system would get rather hot under those
> conditions, since you've stopped the heat leaking out into the rest
> of the universe ..
Okay, I admit that -- if you wrap a star in mirrors, it will change
state in some very impressive manner. :)
Here, Jon Leech <nos...@oddhack.engr.sgi.com> wrote:
> Are you saying that, although the smaller object would be
> radiating the same total amount of energy as the larger one in this
> case, their surface temperature would be the same?
Ignoring the problem of what a mirror-wrapped star would *look* like
once it settled down... (I suspect it would look like a larger
star...)
Short answer: yes.
Actual answer: I think my thought experiment is ill-stated. I think
what actually happens, *no matter how you arrange your mirrors*, is
that most of the star's light bounces back to the star (since it's
larger). Result: Equilibrium, where the energy intercepted (and
radiated) by each object is proportional to its area.
Okay, forget the closed-star problem. Back to the "standard"
solar-mirror case, where your mirror budget isn't in the Dyson-sphere
class.
Here, Sea Wasp <sea...@wizvax.net> wrote:
> If I intercept all the rays of the sun and concentrate them on a
> point the size of my hand, I assure you, that point is going to be a
> LOT hotter than the surface of the sun.
But mirrors (even curved ones) won't do that. Not unless the *sun* is
*itself* the size of your hand. (And if that's true, then, obviously,
the sun and the hand will wind up the same temperature.)
> If you don't believe me, think about all the powersat suggestions.
> If I can get enough electricity from the sun to light up Denver, and I
> channel all that electricity into a set of lasers, I can induce
> fusion.
Lasers aren't passive. Thermodynamically, they're heat pumps. Energy
is necessarily wasted in creating that little hot-spot.
You don't have to plug in a mirror to make it reflect; this is a clue
about how much energy concentration you can do with mirrors.
If Schroeder had said he was heating his metal sphere with lasers
pumped by photoelectric powersats, it would have been fine.
Ray Blaak
> Here, James Nicoll <jdni...@panix.com> wrote:
> > I am a few hundred pages into _Line of Polity_ [1] and he
> > managed to top the anti-photons thing: they have orbiting mirrors
> > that can concentrate sunlight to the point of *inducing fusion*
> > in the target. Generally, thermodynamics frowns on a heat source
> > being used to heat another object up to a higher temperature but
> > I suppose these are *special* mirrors.
>
> makes the same mistake. Star system where the sun is a
> barely-red-glowing dwarf; solar mirrors heating a metal sphere up to
> white heat. Oops.
Now call me uneducated, but a larger body has a larger total heat energy, no?
Even if at a lower average temperature. If concentrated to such a small
space, why can it not indeed heat something to a higher temperature?
The laws of termodynamics say nothing about temperature, only about total
entropy in a closed system.
Are there not houses heated by heat pumps "pumping" warmth from colder air
outside?
--
Cheers, The Rhythm is around me,
The Rhythm has control.
Ray Blaak The Rhythm is inside me,
rAYb...@STRIPCAPStelus.net The Rhythm has my soul.
Michael Grosberg
> In article <bd9r2t$n67$1...@reader1.panix.com>,
> Andrew Plotkin <erky...@eblong.com> wrote:
> >Here, James Nicoll <jdni...@panix.com> wrote:
> >> I am a few hundred pages into _Line of Polity_ [1] and he
> >> managed to top the anti-photons thing: they have orbiting mirrors
> >> that can concentrate sunlight to the point of *inducing fusion*
> >> in the target. Generally, thermodynamics frowns on a heat source
> >> being used to heat another object up to a higher temperature but
> >> I suppose these are *special* mirrors.
OK. I'm no expert on this, but in university I studied about air
conditioning systems. An air condition unit uses an X amount of energy
to transfer an amount of about 5x (IIRC) from one place to the other,
and do it in the reverse direction from the "natural" flow of heat -
basically they syphon heat from inside the cold room to the hotter
outside. Now, The above paragraph would seem to imply that said air
condition system cannot exist. Nevertheless, I'm using one of them
right now.
Paul Colquhoun
| But mirrors (even curved ones) won't do that. Not unless the *sun* is
| *itself* the size of your hand. (And if that's true, then, obviously,
| the sun and the hand will wind up the same temperature.)
So those astronomical photographs where telescope mirrors are used to concentrate
the light from a star down to a small point on the film/detector must all
be fakes then, since the mirrors cannot possibly focus the light down to an
image smaller than the actual star.
|> If you don't believe me, think about all the powersat suggestions.
|> If I can get enough electricity from the sun to light up Denver, and I
|> channel all that electricity into a set of lasers, I can induce
|> fusion.
|
| Lasers aren't passive. Thermodynamically, they're heat pumps. Energy
| is necessarily wasted in creating that little hot-spot.
|
| You don't have to plug in a mirror to make it reflect; this is a clue
| about how much energy concentration you can do with mirrors.
|
| If Schroeder had said he was heating his metal sphere with lasers
| pumped by photoelectric powersats, it would have been fine.
--
Reverend Paul Colquhoun, ULC. http://andor.dropbear.id.au/~paulcol
Asking for technical help in newsgroups? Read this first:
http://www.tuxedo.org/~esr/faqs/smart-questions.html
Thomas Lindgren
David Bilek <dbi...@attbi.com> writes:
> Atkins is great.
I particularly liked that scene where they detect and deal with the
double agent, come to think of it.
> The bits with Phaethon while he was ostracized in (mumble.. Ceylon?)
> sucked.
Much too long a detour, I thought.
Niall McAuley
> Now call me uneducated, but a larger body has a larger total heat energy, no?
> Even if at a lower average temperature. If concentrated to such a small
> space, why can it not indeed heat something to a higher temperature?
If the small space is the hottest part of the system, it will radiate heat
and warm up the sun until they are at equilibrium.
> The laws of termodynamics say nothing about temperature, only about total
> entropy in a closed system.
Not so, the Zeroth Law is about temperature.
> Are there not houses heated by heat pumps "pumping" warmth from colder air
> outside?
You can pump heat, as shown by the ordinary fridge, but you have to work at it.
If a system is closed, (like the sun/mirrors/ball system) it will just settle
at equilibrium.
--
Niall [real address ends in se, not es.invalid]
Karl M Syring
In Benford's "Galactic Center" series the mechs are powerful
enough, and they are bent on extermination of all other kingdoms
of life. That is were the Wedge comes into the game.
Karl M. Syring
Niall McAuley
> So those astronomical photographs where telescope mirrors are used to concentrate
> the light from a star down to a small point on the film/detector must all
> be fakes then, since the mirrors cannot possibly focus the light down to an
> image smaller than the actual star.
That's not what was stated. The telescope can focus to as small an image as you
like. What it can't do is heat the photo to a temperature higher than that of
the imaged star.
The star radiates because it is hot. It heats the plate. As the plate is heated,
it too will radiate. When it is at the same temperature as the star, it will
radiate as much heat as it receives from the star, and equilibrium is reached.
If you heat it further (with your trusty Bunsen burner), it will radiate more
heat, and warm up the star. There will obviously be some delay before a new
equilibrium is reached.
Niall McAuley
The hitch is that as it heats up, it starts radiating too. If it
could get hotter than the source, heat would start flowing the
the other way.
Now, if you built a big heat pump, you could do it. The goof is
trying to do it with mirrors.
Jani Jaakkola
> Reynolds works 'fairly well' for me, but I don't think he's hit
> perfection yet. You might want to try Neal Asher (_The Skinner_,
> _Gridlinked_ .. actualyl in the other order, sorry ..) since he does it
> for me at least as well as Reynolds.
ME2. Reynolds is fun to read, but sometimes boring with lots and lots of
storyarcs to be used in later books.. (at least in Redemption Ark).
However, Neal Ashers Skinner is best space opera which I have read in a very
long time. Spaceships, rayguns, monsters, aliens, robots, horrors and
heroes to match them, you name it!. And with lots of action. And still, the
plot isn't stupid (even when the science is far from hard SF).
And Gridlinked and Line of Polity are both very good too.
- Jani
rex luscus
Yup. With passive optical devices you cannot heat the target to a
higher temperature than the source. If tou put a _bigger_ mirror you
do it faster, but that's all.
Active optical devices are a differet thing, though. You can pass the
star's light through a frequency doubler (nonlinear optical medium)
and get a target hotter than the star. But the nonlinear crystal will
heat up too, and generate lower frequency harmonics, etc. It
effectively will behave as a heat pump, with all the limitations of
the second law.
Bruce Hollebone
> Here, James Nicoll <jdni...@panix.com> wrote:
>> I am a few hundred pages into _Line of Polity_ [1]
>> and he
>> managed to top the anti-photons thing: they have orbiting
>> mirrors that can concentrate sunlight to the point of
>> *inducing fusion* in the target. Generally, thermodynamics
>> frowns on a heat source being used to heat another object
>> up to a higher temperature but I suppose these are
>> *special* mirrors.
>
> Karl Schroeder's _Permanence_, which I mentioned a few
> weeks ago, makes the same mistake. Star system where the
> sun is a barely-red-glowing dwarf; solar mirrors heating a
> metal sphere up to white heat. Oops.
That's true as long as the Born-Oppenheimer approximation holds.
In fields of high photon flux, coupling, frequency-doubling and
-tripling can occur. This allows higher excitation states to be
reached. UV/Vis states decay via vibrational or plasmon modes
and voila, white-hot metal. Thermodynamics is not avoided;
energy is conserserved and entropy increases (rather a lot---
coupling isn't efficent).
--
Kind Regards,
Bruce.
Schrodinger's Cat
Hi there, I don't post here often, but I would like to shed some light
(pardon the pun) on your discussion. (The subject caught my
attention, I am an avid lover of the laws of thermodynamics, and
consider them to be the most important of the physical laws.)
Anyway, here goes. Consider a star, with a certain radius, and is
radiating with a particular temperature. (By temperature, I mean
energy, when you are speaking about thermodynamics you are talking
about energy.)
You have a certain amount of energy leaving a star per second (the
luminosity, which we will call L). So we will look at one second, and
then we are talking about energy again. There is a law called
Stefan-Boltzman law, which says that
L = A*<sigma>*T^4
where <sigma> is just a constant, it doesn't matter what it is,
because it is gong to go away in a second, and T is the temperature,
and A is the surface are of the star.
In one second we have an amount of energy (E) released that is given
by
E = A_star*<sigma>*T_star^4
We can stop all the nonsense talk of mirros and lenses, and just
simplify things by saying that all of this energy is incident ona
target (our target will be a sphere of material, 1m in radius). If
all of the energy is absorbed, and none of it is reflected, the
temperature of the sphere is given by the same equation, ie
E = A_tar*<sigma>*T_tar^4.
We say that E is the same in both. It is. Thats what all that talk
about reflected sunlight, and the like was for. We will just assume
that it is, and ignore the partical impossibility of focusing all the
light radiated by a star on a target 1 m in radius.
Anyway, we equate the two equations, and we get
(A_star)*(T_star^4) = (A_tar)*(T_tar^4)
(R_star^2)*(T_star^4) = (R_tar^2)*(T_tar^4) (the 4*pi terms cancel in
the area)
T_tar = SQRT[(R_star)/(R_tar)] * T_star
Here, R is the radius. R_star, the radius of the star, and R_tar the
radius of the target. We see here that in the square root term, the
star radius is graeter then that of the target, whihc means that the
target temperature will be greater then the star temperature. (tada)
Keep in mind that this is the case if we take one seconds output worth
of star output, and put it into a target sphere, the sphere will have
this temerture.
The problem is that the sphere will want to radiate this energy
outward, to the cold dark exterior that is space. I haven't really
taken any of that stuff into account, but I think that this will
answer your question. You don't have to think about how the star will
deform if you reflect light onto it, or anything like that.
SO in conclusion, the temperature will change, dependin on the ration
of the two radii of the two objects. If the target is bigger then the
star, then the temperature will decrease. If the target is smaller,
then it will have a higher temperature.
I'm not saying anything about the praticallity of doing any of this, I
am just outlining the energy exchange. (1st law of thermodynamics,
energy is always conserved.)
Any question, just leave a message. This is also my first time
posting to this particular group, so excuse me if I have broken some
ettiqute that I am ignorant of.
Sincerly,
Schrodinger's Kat
Daniel Speyer
> On Sun, 22 Jun 2003 17:14:01 +0100, "Patrick Dobson"
> <pj...@oikumene.freeserve.co.uk> wrote:
>
> >I am currently reading "A fire upon the Deep" by Vernor Vinge, having just
> >read his "A Deepness in the Sky". His universe seems very similar to that
> >of David Brin's Uplift war series; Lots of Ancient Alien races, an enduring
> >civilisation based on the information in the Net/Library, Humans as a
> >wolfling race needing to catch up.
> >
> >Are there any other books set in similar worlds? The other Vernor Vinge and
> >David Brin books I know of aren't, but do any other authors have similar
> >books?
>
> They don't match exactly, but I thought there were some similarities
> in both Charles Sheffield's "Heritage Universe" books (_Convergence_
> and others), and the shared world _Isaac's Universe_ (three original
> anthologies, a novel by Hal Clement (_Fossil_), and a 2003 novel by
> Poul Anderson (_For Love and Glory_) that has had the serial numbers
> filed off so that it doesn't quite fit the series).
For a fun turn-around on this, check out VV's _Original_Sin_. It's
funny to see humans as the mature, long-lived, quiescent (however
that's spelled) ones who feal a need to tyraniccally clamp down on a
younger race. It's also very interesting to see such a short-lived
intelligent species.
In the foreward, he makes it clear that humans as the upstarts is an
overly-established motif which he is quite familiar with. Of course,
the opposite of a cliche is a fascinating new idea!
Del Cotter
Andrew Plotkin <erky...@eblong.com> said:
>Del Cotter <d...@branta.demon.co.uk> wrote:
>>>Karl Schroeder's _Permanence_, which I mentioned a few weeks ago,
>>>makes the same mistake. Star system where the sun is a
>>>barely-red-glowing dwarf; solar mirrors heating a metal sphere up to
>>>white heat. Oops.
>
>> Well, hold on a minute. Schroeder probably doesn't know it, but that
>> could actually work, because many "red" dwarfs actually *are* white, and
>> I think even the cooler ones are yellow. Genuinely red-coloured stars
>> are *brown* dwarfs.
>
>I'm afraid he knows it, and he does refer to the thing as a "brown
>dwarf".
Oh. That is an "oops", then.
--
Del Cotter
Thanks to the recent increase in UBE, I will soon be ignoring email
sent to d...@branta.demon.co.uk. Please send your email to del2 instead.
David Dyer-Bennet
> "Andrew Plotkin" <erky...@eblong.com> wrote in message
> news:bdaq4d$55r$2...@reader1.panix.com...
> > Heat cannot of itself pass from one body to a hotter body.
>
> and that's a natural law!
Physical, at least in the recording I have.
--
David Dyer-Bennet, <dd...@dd-b.net>, <www.dd-b.net/dd-b/>
RKBA: <noguns-nomoney.com>
Photos: <dd-b.lighthunters.net> Snapshots: <www.dd-b.net/dd-b/SnapshotAlbum/>
Dragaera mailing lists: <dragaera.info/>
David Dyer-Bennet
> Here, Sea Wasp <sea...@wizvax.net> wrote:
>
> > If I intercept all the rays of the sun and concentrate them on a
> > point the size of my hand, I assure you, that point is going to be a
> > LOT hotter than the surface of the sun.
>
> But mirrors (even curved ones) won't do that. Not unless the *sun* is
> *itself* the size of your hand. (And if that's true, then, obviously,
> the sun and the hand will wind up the same temperature.)
Why can't mirrors do this? It looks straightforward to me.
One simple way: surround the sun with light-pipes, picking up all the
light it puts out (a light-pipe is a complex mirror, right?). Lead
them over to form another sphere, which will have to be the same
size since the light pipes were packed tight originally. At the
end of each light pipe place a converging lens, to focus the beam down
to the size you need, and point it at the small sphere you want to
heat, at the center of the big sphere of light pipes.
Hey presto, you've got the entire output of the original sun impinging
on the smaller sphere. I see no limits to how small the smaller
sphere can be made.
I introduced lenses as well as mirrors, but both are really acceptable
for this game as I understand the rules.
If you don't like the light pipes you can do a harder to describe but
equivalent set of lenses and mirrors to pick up the light and reflect
it around to the intended target.
Michael Stemper
>> Patrick C. <pat@outer*omittoreply*reaches.com> wrote:
>> > what #4 book in any series hasn't been awful?
>How about _Return_of_the_King_ though?
Nope. _Return of the King_ is books five and six. Book four of Lord of
the Rings is Frodo and Sam's journey from the breaking of the fellowship.
--
Michael F. Stemper
#include <Standard_Disclaimer>
Life's too important to take seriously.
David Tate
> "Andrew Plotkin" <erky...@eblong.com> wrote in message
> news:bdaq4d$55r$2...@reader1.panix.com...
> > Heat cannot of itself pass from one body to a hotter body.
>
> and that's a natural law!
Ah, another Flanders and Swann fan. Nice to know I'm not alone...
(...he said, as he hastened to put out the wine, the cat, his cigar,
and the lamps...)
David Tate
Andrew Plotkin
> "Niall McAuley" <gnmc...@eircom.ten.invalid> wrote in message news:<SU6Ka.19874$pK2....@news.indigo.ie>...
>> "Andrew Plotkin" <erky...@eblong.com> wrote in message
>> news:bdaq4d$55r$2...@reader1.panix.com...
>> > Heat cannot of itself pass from one body to a hotter body.
>>
>> and that's a natural law!
> Ah, another Flanders and Swann fan.
Yes, and it looks like Niall is one also.
--Z (only slightly sardonically)
John Schilling
But, any object at any temperature above absolute zero will also
radiate, i.e. spontaneously throw photons away. These photons remove
energy from the object, and if you let it throw away enough photons
it will get arbitrarily cold.
And the rate at which the object throws away photons increases with
temperature. So you can't get the object arbitrarily hot by throwing
photons at it, you can only heat it to the point at which it is throwing
photons back at you as fast as you are throwing them at it.
At best, this happens when the object is exactly as hot as whatever it
is you are using as a photon source, and that only if the target object
is completely enclosed by either the photon source or by mirrors reflecting
an image of the photon source. You can't get the object to a higher
temperature than the photon source by any trick of mirrors.
You can use photon sources that do not have "temperatures" in the strict
thermodynamic sense of the word, such as lasers. Stars, unfortunately
for this purpose, do have well-defined surface temperatures.
--
*John Schilling * "Anything worth doing, *
*Member:AIAA,NRA,ACLU,SAS,LP * is worth doing for money" *
*Chief Scientist & General Partner * -13th Rule of Acquisition *
*White Elephant Research, LLC * "There is no substitute *
*schi...@spock.usc.edu * for success" *
*661-951-9107 or 661-275-6795 * -58th Rule of Acquisition *
Andrew Plotkin
different (attempted) reductio ad absurdum arguments, all of which are
slightly off-target.
Here, Joe Slater <joe[please don't spam me]@slater.net> wrote:
> On Tue, 24 Jun 2003 15:34:53 +0000 (UTC), Andrew Plotkin
> <erky...@eblong.com> wrote:
>>Karl Schroeder's _Permanence_, which I mentioned a few weeks ago,
>>makes the same mistake. Star system where the sun is a
>>barely-red-glowing dwarf; solar mirrors heating a metal sphere up to
>>white heat. Oops.
> I don't understand why that won't work. Surely when you hit
> something with a photon you're adding energy to it, and if you throw
> enough photons at something you'll get it arbitrarily hot?
Those statements are true, but you have to collect the photons, and
then throw them in the right direction. Concentrating photons is an
act of entropy reduction; it has to be powered by something.
This is why the distinction between passive optics (mirrors and
lenses) and active devices (heat pumps, lasers, refrigerators) is
important.
Here, Ray Blaak <rAYb...@stripcapstelus.net> wrote:
> Now call me uneducated, but a larger body has a larger total heat
> energy, no? Even if at a lower average temperature. If concentrated
> to such a small space, why can it not indeed heat something to a
> higher temperature?
We talk about lenses "concentrating light", and in common experience
that's true. You can put a lens in sunlight (temperature 120 degrees
on the asphalt) and concentrate it enough to burn paper (temperature
451 degrees in the movie). But what you're *not* doing is
concentrating it more than it started out at the Sun's surface
(temperature 10,000 degrees, please use a potholder).
> Are there not houses heated by heat pumps "pumping" warmth from
> colder air outside?
Pumping is exactly right. Lenses aren't pumps.
Here, Paul Colquhoun <postm...@andor.dropbear.id.au> wrote:
> So those astronomical photographs where telescope mirrors are used
> to concentrate the light from a star down to a small point on the
> film/detector must all be fakes then, since the mirrors cannot
> possibly focus the light down to an image smaller than the actual
> star.
I didn't say you can't focus the image of a star smaller than the
star. I said you can't focus *all the energy* radiating from a star
into a smaller area. (A telescope lens obviously doesn't do that,
or astronomers would be vaporized on a regular basis.)
When you focus an image of the Sun, you're sampling light from every
point on the Sun's surface -- well, the near hemisphere. But you're
getting only a tiny fraction of the energy from each point.
Put it another way: say I hang a big lens above my head at high noon.
The lens is a meter away and two meters across. So it spans an angle
of 45 degrees, from my POV.
Now, optically, the best this lens can do is "act like" the Sun's
surface. If I look at any point of the lens, I'll see a point whose
brightness is equal to a point on the Sun.
Clearly my head will catch fire. I'm effectively faced with an object
the temperature of the Sun, whose apparent area is 8100 times that of
the Sun. (Give or take, I'm not arsing with the spherical trig right
now.)
*But*, an object whose effective temp is that of the Sun cannot heat
me *hotter* than the Sun, *no matter how much of my sky it covers*.
Here, David Dyer-Bennet <dd...@dd-b.net> wrote:
> Andrew Plotkin <erky...@eblong.com> writes:
>> Here, Sea Wasp <sea...@wizvax.net> wrote:
>>
>> > If I intercept all the rays of the sun and concentrate them on a
>> > point the size of my hand, I assure you, that point is going to be a
>> > LOT hotter than the surface of the sun.
>>
>> But mirrors (even curved ones) won't do that. Not unless the *sun* is
>> *itself* the size of your hand. (And if that's true, then, obviously,
>> the sun and the hand will wind up the same temperature.)
> Why can't mirrors do this? It looks straightforward to me.
> One simple way: surround the sun with light-pipes, picking up all the
> light it puts out (a light-pipe is a complex mirror, right?).
Yes, that's right.
> Lead them over to form another sphere, which will have to be the
> same size since the light pipes were packed tight originally. At the
> end of each light pipe place a converging lens, to focus the beam
> down to the size you need
I am not an opticker, but I believe here is where your plan slips.
The "beam" coming out of the pipe won't be purely parallel; nor will
it be purely radial (like a point source). It will have as much
dispersion (at each point of its breadth) as the light had on the
input side.
So your lens won't focus all the output onto your smaller target. Some
of it will miss. That fraction will hit light-pipes on the other side,
go back the other way, and hit the original source.
It winds up being equivalent to surrounding the entire two-object
system with perfect mirrors.
(By the way, I've been thinking about what happens if you *do*
surround a brown dwarf with mirrors. It's actually much simpler than a
"lit" star, because brown dwarfs have no fusion going on. I'm pretty
sure that -- long term -- the whole thing just homogenizes to a
constant temperature. I'm not having any luck finding the core
temperature of a brown dwarf, but I think it's safe to say that the
core will get a little cooler and the surface will get a lot hotter.
It'll probably swell up a bit, overall.)
David Argentar
> Here, GSV Three Minds in a Can <GSV@[127.0.0.1]> wrote:
>> Bitstring <bdaq4d$55r$2...@reader1.panix.com>, from the wonderful
> person
>> Andrew Plotkin <erky...@eblong.com> said
>>>Mirrors (and lenses) are passive optical devices. Heat cannot of
>>>itself pass from one body to a hotter body.
>>>
>>>Even if you arranged mirrors so that every ray leaving the star
>>>impinged on the metal sphere, and vice versa, you'd just be creating
>>>a closed system. The two objects would come into thermal equilibrium.
>> Hmm, I think the closed system would get rather hot under those
>> conditions, since you've stopped the heat leaking out into the rest
>> of the universe ..
> Okay, I admit that -- if you wrap a star in mirrors, it will change
> state in some very impressive manner. :)
I believe it goes nova in short order. IIRC, stars sit in equilibrium between
gravity trying to contract them, and their own radiation pressure puffing them
up. Reflect back the star's light, and now radiation pressure from the outside
starts to squash it as well, making it denser, so it gives off more light, is
under more pressure, etc. Pretty soon, it's the size of Jupiter, glows in the
far UV, and rapidly runs out of hydrogen. Pop! I'm not sure what happens
then. :) Containing a nova in an unobtanium sphere is left as an exercise
for the reader.
--dave