Saturday, June 24, 2017

Exoplanets, waterworlds and asteroids

After three postings about politics and winning this phase of the Civil War... how about some space stuff?  Proof that we are members of a dynamic, bold, competent scientific civilization.

A planetary system similar to our own: Epsilon Eridani, at 10.5 light years, is one of the nearest solitary stars roughly similar to our sun, and hence was inspected by Frank Drake, in the 1960s, for possible SETI signals. Now, as well reported on the SETI Institute’s site, new infrared observations reveal a system very similar to ours, with a Jovian planet riding herd just outside a silicate-dominated asteroid ring and an outermost ring much like our Kuiper Belt… but with a third debris field also orbiting where we would have Uranus.  

It appears that most habitable planets may be waterworlds: On Gizmodo, George Dvorsky reports on a new study published in The Monthly Notices of the Royal Astronomical Society suggests that most habitable planets are wet. “Like, extremely wet. Using computer models, astronomer Fergus Simpson from the Institute of Cosmos Science at the University of Barcelona found that habitable exoplanets, at least simulated ones, tend to be overrun by water, in most cases accounting for 90 percent or more of the total surface area,” unlike Earth’s relatively dry 70%.  Here’s the original paper’s abstract.

In fact, the authors’ inferences are a bit weak. Still, I have been saying that Earth is likely to be dry, for a water world, for 30 years.  Going back to this classic paper in the 1983 Quarterly Journal of  Royal Astronomical Society.
Or in this way fun youtube riff you’ll enjoy, I promise!

In fact, this is the safest and best "soft landing" to the Fermi Paradox.That the universe is filled with life-rich water worlds, but our Earth, skating the inner edge of the Sun's CHZ or Goldilocks Zone, has unusually more land surface. Hence hands-and-fire races like us are the rare thing.  When we build starships, we'll find lots of other folks out there... with flippers and such. Interesting to talk to, but not competitors.  

Of course there's another aspect to us skating the inner edge of the Sun's CHZ or Goldilocks Zone.  It explains why Earth has to shed heat so efficiently and even a little bit of greenhouse gas excess can be lethal.  But then, members of the Denialist Cult don't read my blog. And you science lovers don't need to be convinced.

== Again, the case for asteroids ==

A question asker over on Quora someone asked: “Is space mining sci-fi or a legitimate concept?

In fact, some of the smartest people on the planet have studied the material properties of meteorites, which are bits of asteroids or comets that have fallen to Earth. Back in the 1980s, John Lewis's book Mining the Sky (or his more recent Asteroid Mining 101) made clear that simple estimates of the various types of asteroids and their relative abundance reveal what’s out there…

…and what’s out there is a bonanza. Just one 1-km asteroid of the right type — if melted and cast using solar concentrators — would produce:
  • the entire Earth’s iron/steel/nickel production for a year.
  • Earth’s gold and silver production for 100 years.
  • Earth’s platinum group production for 1000 years. And that’s one such asteroid, and there are millions

Do we yet know how to “melt and cast using solar concentrators” in space? Only in computer models. But a different kind of asteroid is rich in water, so we’d harvest that resource much sooner, just by throwing a baggie around one and siphoning the evaporated volatiles.

Is all this guaranteed? Of course not. Do the payoffs seem to warrant some capital investment? Um, duh?

Oh, about “bringing asteroids to Earth”… the answer is you don’t do that! You bring them to lunar orbit and process them there. Which means that a lunar orbit station would be valuable in all sorts of ways. Including the profitable selling of services to all the wannabe nations — China, Russia, India, Europe and billionaires — who want to plant their own footprints on that sterile and (for now) utterly useless surface.

(If you meet a “back to the moon!” zealot inside the US, it will always be a republican, whose other mantra is “screw science!”)

I have been cataloguing answers to the “Fermi Paradox” - the question of why we see no blatant signs of other sapient species - since 1983, before it was even called the “Fermi Paradox”! In all that time, I have found that the brightest people — e.g. Hawking — tend to leap to declare “Aha! I know the reason!” 

It seems an immature habit, given this is a topic that has no known subject matter! ;-)

Seriously, the best we can do is catalogue and maybe rank-order these notions by plausibility. In my novel Existence, for example, I go through more than a dozen hypothetical reasons why interstellar AI probes might sit in the Asteroid Belt, tune in to our Internet, yet refrain from making themselves known.
Among the 100 or so “Fermi” explanations, a few seem plausible (e.g. we may have anomalous-fluke intelligence), some are optimistic (e.g. Earth happens to be “dry” compared to most Water Worlds, and hence, most other bright races have fins, not hands.) And a fair number are pessimistic or dangerous, (I go through more than a few of those, in Existence.)

The dangerous ones aren’t totally compelling - though they worry folks like Nicholas Bostrom and Lord Martin Rees. And Hawking. But they seem plausible enough to put a burden of proof on those silly radio astronomers who eagerly seek to beam “yoohoo!” messages into space. I am among the SETI scholars who object to this foolishness called METI or Messaging to ExtraTerrestrial Intelligences.

This is not a place to go into detail, but you can find a very biting rundown of why so many of us object to this stunt on my website.

== The Politics of SETI ==

Stranger danger: Extraterrestrial first contact as a political problem, by John Hickman and Koby Boatwright offers an interesting essay on political decisions whether to respond to a SETI detection and the difficulties of communications with aliens.

Just released: Aliens: The World's Leading Scientists on the Search for Extraterrestrial Life, edited by Jim Al-Khalili, with contributions from Martin Rees, Paul Davies and others.

And consider this: Nuclear explosions and submarine comms distort space weather near the earth: Very-low-frequency (VLF) signals are emitted by ground stations "at huge powers" so they can reach submarines deep below the ocean's surface. Now comes a (still controversial) finding that these VLF signals can affect the Van Allen radiation belts above the Earth.  Satellites report that the inner boundary of the inner VAB has shifted over time. Measurements from the 1960s, when VLF transmissions were more limited, suggest that the inner edge of the Van Allen belts was closer to Earth then than it is today, according to NASA. It's possible that the inner boundary of the Van Allen belts is an "impenetrable barrier" and that, if humans did not send out VLF signals, the boundary would stretch closer to our planet.  

Gawrsh. There’s a sci fi premise that writes itself.  

 == Cartoons re SETI & METI! == 

Fom: SMBC Comics: 

From: XKCD Comics:

Brewster Rockit on METI and REGRETI


A.F. Rey said...

Way off topic, but did you hear "This American Life" this week, "A Not-So-Simple Majority?" An enraging story of democracy gone wrong, where the conservative Hasidic and ultra-Orthodox Jewish majority in East Ramapo, NY, decided they shouldn't have to pay taxes for public schools their children did not attend. So they took over the school board and gutted the schools, leaving all the other children in the community in the lurch.

Admittedly, this may be a one-side account, but from the little I heard last night, this is the kind of abuse between peoples and classes that you rail against.

TheMadLibrarian said...

A couple of decades ago, I read a delightful YA novel by Charles Sheffield, called Higher Education. It read like a Heinlein juvenile, and was about training some of the teen 'dross' for asteroid mining, with of course the appropriate amount of conspiracy theory and general teen silliness. Sheffield was very good at the physics and nuts and bolts of SF, and this one was no exception.

Tony Fisk said...

On YA novels in space, I have fond memories of Arthur C Clarke's "Islands in the Sky", which was set on a space station. It had some amusing anecdotal tales, like how they managed to deal with a mouse plague using owls (that one was a leg-puller). Other topics were treated more seriously, like a movie crew making the first film in zero G (way before "Gravity"), and the gang setting up a club house in a nearby hulk (given surreptitious safety checks by the adult crew from time to time.)

It recently occurred to me that David's basic premise of Existence was sort of covered by Patrick Farley's weird, freaky, and droll tale "Don't Look Back".

Finally, a more serious contribution to space stuff. The WFIRST coronagraph will allow space telescopes to view objects in star systems that are a billion times fainter than their primaries. With an accompanying Starshade, that figure goes down to 10 billion: sufficient for viewing earth-like planets directly.

David Brin said...

AFR the ability of the Hassid to ignore the blatant theological lessons f the last century are depressing.

MadLibrarian... I SO miss Charles Sheffield.

Tony, your taste for Farley lifted my already high opinion of you.

Yeah, we at NIAC funded the first Starshade work! But you can only use each one a few times.

Troutwaxer said...

Maybe the problem is that we're made of meat. (Sorry, couldn't resist.)

David Brin said...

WFIRST is being built from one of the two obsolete KH-11s that the NRO suddenly plopped on NASA's lap, one day. Two whole Hubbles! It took hard work and tens of millions to even find a plan for one of them and then several hundred millions to prepare and launch.

Sue Bursztynski said...

I read an interview with Michael Collins the astronaut, who was asked, would he go to the moon now if he could, seeing he missed out on the landing last time. And he said, no, but he'd go to Mars tomorrow. He's up to date.

LarryHart said...

My teenage daughter and her best friend went to see "The Martian" three times in the space of about a month. She's up to date too. :)

Sue Bursztynski said...

I'd hope so! ;-) But your daughter should be. This gentleman is old enough to be her great grandad. He lived in the era of "let's all go to the moon." He went there, though he didn't land. To be honest, he's my favourite of the three.

DP said...

Speaking of pessimistic/scary explanations for the Fermi paradox (hostile aliens), may I direct you (and toot my own horn) to a series of articles I wrote for a game site where I do a technical analysis of HG Wells War of the Worlds?

I reverse engineer a Martian heat ray (minimum 200 MW power plant required, probably from the equivalent of a small nuclear reactor), determine the power-to-weight ration of a Martian tripod, compare Martian weapons systems to Victorian and Modern armaments (spoiler: the Martians can still kick our ass), estimate the energy costs of a Martian interplanetary invasion, and analysis Martian strategy and operational goals. Let me know what you think:

As rare as it would be, what is the outcome of 2 intelligent species evolving in a single solar system?

Robert said...

One reason for METI would be to let the UFO flyers' parents know what they're up to. the Mother Thing would arrest them right away.

More in the political thread. Today's On the Media on NPR covered gerrymandering and census sabotage through deliberate underfunding.

Bob Pfeiffer

Tony Fisk said...

@daniel, John Christopher reworked Wells' martians in his Tripod series.
He got lambasted by Aldiss for proposing a hostile alien takeover of a heavily militarised planet with weapons as pathetic as high profile three legged shooting targets (at least Star War's AT-ATs have four).
Christopher tartly responded that he had addressed the problem with a paragraph in the second book, but decided to give it a proper airing with a prequel.

"The Coming of the Tripods" is just a reworking of "The White Mountains" set in the present day. Silly in many ways. And yet, America now has Fox News, and Cambridge Analytica, and MAGA caps, and a resident whose ways seem as alien as Harold Saxon... and "Hail the Tripod" is easily modified to "Heil the Trumpod".

Sorry, politics intrudes.

duncan cairncross said...

Hi Daniel

If you used a 200 Mw beam a foot across it would take some time to penetrate a 4 inch thick plate
The problem is that the surface of the steel will vaporise and then effectively block the beam with the vapour cloud

I suspect that with thicker armour the heat transfer would make it even less effective

Now assume that you could penetrate the armour of Dreadnaught - what would happen? - you would destroy a turret?

As the ship moved a new piece of the main armour would block the beam and have to be burned through

Meanwhile the battleship is throwing shells at you - even if you could hit a shell with your heat ray you would only vaporise a small amount of it and the tripod would then be hit by a very hot two tonne projectile traveling at twice the speed of sound

When I first read War of the Worlds I thought that it was silly - the idea of lobbing shells at targets over the effective horizon was well known by then (late 1800's) - a battery of howitzers on the other side of the hill with a few signalers - vulnerable but hidden - would have been able to land quite a few salvos on a war machine before it managed to walk up the hill and return fire - and if a low speed ramming destroyed a war machine a few shells would have done the same

DP said...


Concerning Dreadnought v. Martians:

"Its 12-inch guns on the other hand had a maximum range of 16,450 yards (9.3 miles or almost 15 km). This gives HMS Dreadnaught the chance to fire one or more broadsides against the Martians. However, at an elevation of approximately 30 meters (10 stories), the horizon to a Martian observer would extend 19.6 km (12.2 miles). Again, the unfortunate HMS Dreadnaught could not hide beyond the horizon out of reach of a line of sight weapon like the Martian heat ray. But being a larger ship firing at a greater distance, HMS Dreadnaught could conceivably take out several Martian tripods before its demise."

David Brin said...

Okay! A real nerd sci fi discussion!
Daniel, creative stuff! Fun too. Spielberg enhanced the Martians not with the clich├ęd sci fi “shields” but with the ability to detonate any explosive that approach their craft. In fact, Marian tactics suck, as they depend utterly upon preventing us from setting powerful land mines.

Want to see a weird martian invasion? See my story: “Mars Opposition.”

Ilithi Dragon said...

I'll have to read through your articles to get all the juicy details (I love nerding out over this kind of stuff... Don't get me started on Trek tech, combat, and military capabilities), but a quick point on the Thunder Child battle.

The HMS Thunder Child managed to destroy one tripod by ramming, and managed to kill a second when her boilers (and presumably, her magazines) went up while colliding with with said tripod. It is left unclear by the book, but it possible that the third tripod may have been destroyed, as well. It was not specified what the Thunder Child fired at the third tripod, but given that her primary armament was actually underwater torpedoes, its likely she fired a salvo of those at the third tripod, and I'd say it's not unreasonable to assume that one or more of those struck the legs of the third tripod, bringing it down.

The success of the Thunder Child is no doubt due in part to her Captain's brilliant, and daring order to hold fire until they had closed to ramming range. Because the Thunder Child was not actively firing at the Martians, they did not immediately recognize it as a warship, and so only launched a gas attack initially, only bringing their heat rays to bear belatedly. While they were able to inflict severe damage to the Thunder Child, and ultimately penetrate to her boilers, the Thunder Child would not have been a heavily armored warship, and more substantial warships would likely have fared much better against the Martians' conventional attack.

It is their unconventional attack, however, that is of particular note. At the time the story takes place, chemical weapons weren't really a thing. There were no defenses against it. Even warships would have had only limited defense against it (the Thunder Child survived the gas attack only because she steamed through it at flank speed - there wasn't enough time for it to be circulated through the ship before they were clear of it). The heat rays would have been devastating against any Earth forces in line-of-sight, but the gas attack would have been one of the most effective weapons against surface ships and bunkers.

I think the navies of the world, particularly the heavily industrialized nations, would have been able to put up a substantial fight and hold their own, but without careful maneuvering or favorable weather conditions, that gas attack would have done them in.

donzelion said...

"If you meet a “back to the moon!” zealot inside the US, it will always be a republican, whose other mantra is “screw science!”

I'm no 'back to the moon' zealot, nor am I a Republican with a 'screw science' mantra, but is it really certain that it would be so worthless? For mining, I should think some number of those rich asteroids may have already crashed into the moon; they may not be readily visible from surface exploration, any more than the richest veins on Earth are so easily discovered. I cannot easily imagine what conditions might render it cheaper to harvest asteroids that hit the moon relative to those still out there, but I'm sure there would be some value in more thoroughly exploring the moon, if only to test and establish systems for Mars. Certainly, if raw materials could be mined and refined by robots on the Moon, getting it from there into orbit ought to be much cheaper/easier than getting it to them from Earth.

Does that have to be human boots walking on the Moon? Can't see why. But a great testing ground for robot rovers, at the very least.

David Brin said...

donzwlion I am fine with continuing lunar science. I am fine with setting up a US station in lunar orbit to sell services to dusty footprint wannabes, while that finances asteroid prospecting.

I am nOT fine with wasting the only known (for now) lunar resource - polar ice -- when future lunies will need it! Plenty of ice in ... asteroids.

DP said...

@Ilithi Dragon

Never refer to one of Her Majesty's warships with "the". It is always simply "HMS Thunder Child", never "the Thunder Child" or "the HMS Thunder Child".

You may use "the" in referring to American warships, such as "the USS Enterprise", but for British ships it is always simply "HMS Hood", "HMS Ajax", "HMS Dreadnought", etc.

By adding "the", you in effect are saying "the Her Majesty's Ship (name)" which is garbled syntax and poor English.

Tony Fisk said...

To move to another alien invasion, I haven't read much of Harry Turtledove's account of aliens turning up in the middle of World War 2, but was amused by the incident where the Germans use a siege gun to bombard the alien landing site. It didn't last long, but it gave the aliens something to think about when these puny 'missiles' with no avoidance systems could carry on through their sophisticated air defences as if they weren't there (half a tonne of supersonic armour-clad ordinance having a substantial momentum)

duncan cairncross said...

Hi Tony

half a tonne?

The HE shell was 4.8 Tonnes and the AP shell was 7.1 Tonnes - defensive missiles designed to kill other soft skinned missiles would not have a chance

A.F. Rey said...

My teenage daughter and her best friend went to see "The Martian" three times in the space of about a month. She's up to date too. :)

Say, Larry is it that your daughter is up-to-date, or up-to-dating? ;)

Robert said...

Maybe David Frum should join David Brooks on the Good Conservatives List.
Of course maybe it's in the name - I'm sure David (ahem) would agree.

Davids are good.
Georges are bad.
Bobs are still better,
and Donald is mad.

A coworker sent me a lame dinosaur joke, but "Tyrannochorus" sounds like a perfect description of last week's Cabinet meeting.

Bob Pfeiffer.

raito said...

Like donzelion, I am neother a Republican nor a 'screw science' guy, but I do see value in returning to the moon. But not for mining. I've given my reasons before.

Re: asteroid mining:
One thing I've always though (and never seen addressed) about as far as mass space mining goes is how do we decide what to >export< from earth as we import those materials (or even bring them into the earth-moon system).

Yes, all the numbers are (currently) very small compared to the mass of the earth. But I imagine that doing it wrong (like changing the velocity of the earth-moon system) could be deterimental. And yes, the mass of the system is chaning all the time anyway (with gas loss, energy changing, etc.) And I suppose those ships we send into the belt could be offset.

Possibly of slightly more concern is changing the rotational period of the earth.

As Dr. Brin points out, we're on the edge of the zone, and I sure wouldn't like to upset that balanace.

I bring these things up because I'm pretty sure the first blacksmiths in Britain thought that their own making of charcoal wouldn't have much effect of their country, or the world as a whole, for example.

As for Fermi,
No mention of Liu's 'dark forest'? (Apologies if that's already in Existence. I haven't managed to read it.) Quite chilling.

LarryHart said...

A. F. Rey:

Say, Larry is it that your daughter is up-to-date, or up-to-dating? ;)

Actually, she was the first of her friends to have a boyfriend, and they gave her all kinds of s### about it until they started discovering the joys of dating. It's not like they admit they were wrong, though--they just stopped giving s###.

LarryHart said...

@Robert (Pfeiifer) :

I like your poem, but I would rhyme "Georges are horrible" with "And Donald's deplorable".


David Brin said...

raito, you would enjoy my YouTube riff on lifting the Earth:

Tony Fisk said...

re: lifting the Earth. I wonder how much the change in solar mass due to fusion and solar weather would alter the Earth's orbit over time (an idle thought: I suspect the effect is miniscule.)

Tim H. said...

Mostly waterworlds? Alan Dean Foster's "Cachalot", or the planet described in Arthur C. Clarke's "The Songs of Distant Earth" being a possibility seems a good thing.

donzelion said...

All this talk of a Mars invasion overlooks my all-time favorite must be "The Sirens of Titan" - the most hilarious, hopeless, idiotic, dogmatic invasion of all-time.

His Martian invasion offers a Cervantesian treatment of a children's crusade (a recurring motif in his later writings), which ultimately serves no purpose whatsoever but to slaughter a massive Martian invading force using antiquated arms so that the Earth might unite to build proper spare parts for an observing interloper. Sheer brilliance.

donzelion said...

Dr. Brin: Hmmm...I don't like politicians setting the priority schedule for Mars, the Moon, or anywhere else - but without political backing for a grand vision, what will defend science funding long-term? What vision is worth insisting upon?

Can we plausibly mine asteroids within a decade? Kennedy's space race seems to be the model for boldness later president's have sought to follow (or Teddy Roosevelt's use of 'science' as the basis for the Antiquities Act, which in turn gave rise to our National Parks system), or Clinton's support in the 'gene race' (though that one in turn gave rise to an endless stream of gene patents, which have their own patent cliff coming up in the next decade). I struggle to see Obama's grand vision in this field, leaving Trump's 'back to the moon' as a nostalgic embrace of an 'ill-defined era when America was 'great' but for the folks who made it so).

occam's comic said...

Does anyone know if we can get a list of the 1,000 people who will get the biggest tax cuts when the republicans kick millions of Americans off their health insurance?
I think the people who are going to be given a death sentence should know who is going to benefit from their deaths.

Also what do you think about democrats running on a plank of TRUMP TAXES

For income above one million dollars to ten million a simple 40% tax of all income no deductions no exceptions.
For incomes above 10 to 100 million a simple 50% tax of all income no deduction no exceptions.
For incomes above 100 million a simple 60% tax of all income no deductions no exceptions.

a 10% annual wealth tax on all wealth above 100 million.
A 25% annual wealth tax on all wealth above 1 billion dollars.

It is time to start fighting back against the class warfare that has been ongoing sense Reagan.

donzelion said...

A.F. Rey: I heard the piece, and shrugged. This is far more common in rural America, where local public schools get gutted in favor of Christian schools (which now, with Liberty University and other Christian universities on tap, including on-line Christian colleges, have a semi-successful pathway toward a 'college degree' - so long as nobody looks twice). That a Hasidic Community near NYC does it too shouldn't be so surprising (the fact that the community is a 1-hr drive from NYC explains why it was made in the first place).

"This is the kind of abuse between peoples and classes that you rail against."
It is a sad tale, but not exactly 'oligarchs v. everyone.' The oligarchic hand is more typical in the various Charter School movements - owning/operating such a school can be an easy path toward six figure salaries for well-connected insiders only.

That story involves intentionally wrecking a school district (and other community bastions) for a period of several years, wrecking the suburban property values along with it, while buying up cheap - then 'saving the community' (by stopping the quiet, subtle siege) after the big timers have set up their positions - and then 'flipping' it. It's a slow game that works mostly at the 'renewal' stage (when a 'wrecked' community turns to tax subsidies to bring in 'outsiders' - most of whom were already in place, setting the whole thing up).

donzelion said...

Occam: "Does anyone know if we can get a list of the 1,000 people who will get the biggest tax cuts when the republicans kick millions of Americans off their health insurance?"

Wouldn't that pretty much be the same list as the 1,000 biggest taxpayers?

The flip here ought to focus on how many millions of jobs they will create - in China, in Mexico, in all those other countries where they've been creating them. Trump's efforts at 'nationalism posturing' were intended to obscure and block anyone from directly taking note of this fact, since it's ultimately the weakest element (but easily proven one) in the claims about 'tax cuts creating jobs' (they actually do: just not for Americans, except perhaps in bubble professions).

"I think the people who are going to be given a death sentence should know who is going to benefit from their deaths."
I wish I could find a colonel nearby to get behind and fight this, but I'll happily settle for a chemist or a physician and go across the street to help. The 39th in CA is solid red and 'safe' 57% for the incumbent Red Royce in 2016 - but went for Hillary over Trump. It is indeed time to start fighting back and finding any last ship in the harbor for a 'last stand', but the only groups and candidates I've heard from want nothing but my money. I'll give a little if that's what it takes to get their attention and join this fight in earnest.

raito said...

If you really want those sorts of taxes, it's easy.

Elect legislators who won't be affected by them.

Good luck with that.

David Brin said...

Occam's taxes won't work without major international treaties. Companies and individuals will just offshore more than before. None of it will do the slightest good without wealth transparency... demanding that any and all property on Earth be ascribed to and claimed by living human beings -- or governments, NGOs or foundations -- with only three transparent layers of holding companies allowed. If it goes unclaimed, it goes to the state.

The number of problems that would solve are innumerable. With criminals and tax cheats caught, revenues will go up WITHOUT raising taxes on law-abiding tax payers. In fact, given the amount of wealth that would be abandoned to the state, taxes for the latter should go down! Drug lords would hire local poor folks to launder $10,000 each and the resulting commissions would be a massive blow against poverty. Insurance would go down, if all events could be traced to responsible parties.

Now add a treaty against countries undercutting other countries' taxes and you'll have a system that works WITH current rates left intact.

Sure, at that point taxpayers might also call for some kind of wealth tax... but these should only be applied at most once per decade. Like the biblical Jubilee.

occam's comic said...

Wouldn't that pretty much be the same list as the 1,000 biggest taxpayers?

yes, do you know if there is a list like that?

Maybe people from every city in America could start putting up WANTED posters. With a pic of the local oligarch and some verbiage like this;

in connection to the loss of health care form millions and the preventable deaths of thousands of Americans.

Deuxglass said...

I would prefer to go to Mars and the asteroids but if setting up shop on the Moon happens to be politically necessary to match the Chinese or whatever then I would be for it and hope that mission creep sets in as it inevitably does.

David Brin said...


A.F. Rey said...

A.F. Rey: I heard the piece, and shrugged. This is far more common in rural America, where local public schools get gutted in favor of Christian schools...

I'm not surprised. It has nothing to do with religion, just the concept of taking control when being apart from the others in the community.

I didn't hear the whole piece--I finished walking the dog, and what I heard upset me enough--but a couple of things stood out.

One was where they brought in a negotiator to try to get the two sides to talk. One of the school board members said, why should we negotiate? We have all the power, so we can only lose in any negotiation.

The other was when a someone from the high school brought proof of how there were not enough classes. Seniors were spending an extra year in school because there were not enough classes for them to earn enough credits to graduate. She brought in one kid's schedule, which had three lunch periods and two study halls out of the eight classes. There were only three classes for learning in the day.

She presented it to the school board, and one of members simply dismissed it, saying he didn't believe it was true.

How do you work with people like that? How do you create change when the opposition won't believe what you tell them, has a strong, tightly-knit community to overwhelm your votes, are solely concerned with their group, and has no interest in the institutions because, being apart, they don't participate in them? How can you change that in a democracy?

I get the feeling we may soon be facing a similar dilemma on a national level. :(

Jumper said...

Wonder how common fire would be on a waterworld, one with complete coverage of land and rock by water throughout its history. The answer of "pretty darn rare" is of course correct. Of course, fire is mostly a parasite on life itself, as without life, what's gonna burn? Not counting volcanoes.
Which all leads to a plot on the world of intelligent sea creatures and their floating islands of kelp and various plants evolved to grow out of the floating islands of organic material. Our heroes, the porpoise equivalents, have no hands, but a rich tradition of history, culture, and intricate language. Only a few tiny creatures have evolved to live on the floating islands; certainly not our porpoises who hold the floating islands in some fear and suspicion, having never had a way to explore them except from underneath. Then one night lightning hits and sets an entire floating island on fire - something the porpoises have never seen or conceived of.

David Brin said...

great concept!




David desJardins said...

NYT story says:

‘‘It is possible that within just 50 years, we could create an antimatter rocket that could propel a substantial pellet of several kilograms, at half the speed of light at times to intersect with the orbit of a planet within 10 light-years of us.’’ Even a few kilograms colliding at that speed would make the asteroid that killed off the dinosaurs look like a meteor shower.

I hope you were misquoted/mischaracterized. 1 kg of matter at 0.5 c is only a couple of megatons. The Chicxulub impact was around 100,000,000 megatons.

David desJardins said...

On another point above, there's a billion tons of lunar polar ice. There's no chance we're going to significantly reduce that resource any time soon, at least until we have self-replicating robots.

Anonymous said...

Slight correction-- 1 kg at 0.5 c is 3 megatons. You would have to throw 30, 000 tons at half the speed of light to get a 100 million megaton explosion and we are unlikely to have the capability to launch something the size of a battleship at that speed in 50 years.