Forgot your password?

Comment: Re:Klemperer rosette (Score 1) 86

by RockDoctor (#47551639) Attached to: Nightfall: Can Kalgash Exist?
Configuring the Nightfall system as a Klemperer rosette would be one way of achieving the result - but the symmetry would still be broken by the orbiting moon that gives the eclipse.

You'd have to have the various stars in more-or-less concentric orbits of different periods. Then, at some point, they'd all get lined up in one (small angle of direction) from which they could all be simultaneously eclipsed. Ah, no, I see my error ; you only need to get them into one half of the sky for the other half to experience darkness.

But again, that wouldn't work for a Klemperer rosette configuration, either from the central location (not necessarily occupied) or from any of the rosette objects in a rosette of more than three objects (here there are 6 objects).

Comment: Re:But it's the cloud... (Score 3, Insightful) 25

by turbidostato (#47551023) Attached to: Attackers Install DDoS Bots On Amazon Cloud

"If you choose a cloud offering which does that for you then yes, you don't have to worry about things like software updates and patching."

Well, yes, you need to worry anyway.

If it's not done, because it's not done. But if it's done, because of what the update/patching breaks on your own apps.

Comment: Re:But what IS the point they're making? (Score 1) 338

You've gotten less that half-way through your last mammoth before it's no longer safe to eat, so now you gotta kill another.

Actually, you do have a point. So people don't do that.

Mammoths (and bison, and caribou/elk, and horses - to name some of the other usual suspects) are quite dangerous animals when they're full grown. And they are very protective of their young, until they get to a certain age.

So, going from the actual skeletal evidence, what it seems happened, repeatedly, was that hunting would target the yearling (or two-year) youngsters, separate them from the adults, kill and eat them. Getting to the infants through the adults is too dangerous, and getting the adults is too dangerous too. So you take out the middling ones.

Take out 50% of the yearlings (two-yearlings) every year for one generation, and you have halved the population. After five generations, the herds become small enough that they can't protect their infants so effectively ... and you get a populations crash.

Quoth the hunter : "But we never took out too many. We were hunting sustainably!"

Fishermen say the same. And they believe it's true. Population dynamics are not intuitive.

Comment: Simple answer : protection. (Score 1) 547

by RockDoctor (#47546355) Attached to: Laser Eye Surgery, Revisited 10 Years Later

So my question is: what is holding everyone else back from freeing themselves from contacts and glasses?

I've had to, in the past, pull steel splinters (from a rock-hammer, a day-to-day tool at the time) from embedded in the surface of my prescription lenses. When I go out of my office and into the workspace in which I work, I am required by company site policy to wear protective spectacles, even if of no optical effect. So I wear my prescription safety spectacles.

Lasik eye surgery would do nothing to remove the obligation to use that PPE (Personal Protective Equipment).

Dissent on this point is taken as a resignation. You're escourted off the site, with your belongings, never to return and never to work for that client again, anywhere in the world, in any position.

Comment: Re:Correction (Score 1) 97

by RockDoctor (#47531469) Attached to: UEA Research Shows Oceans Vital For Possibility of Alien Life

that carpenter gets special moral authority from his claimed relation to God, and there's only a handful of individuals in history who've been credited with such significance.

There's no shortage of people claiming such a relationship with the FSM. On my friend's locked hospital ward the last time he had one of his episodes, there were 4 claimants.

The number who have actually had such a relationship remains the same as the number of gods - zero.

Or are you hoping to grow in legend until your distant descendents come to worship you as well?

Well, It's not impossible for my legend to grow. Does that mean I'd need to log into FaceSpace and MyBook more than every few months? But it's absolutely impossible for my descendants to worship me, absent one of (1) The Plastic Hippy having had a 15 month pregnancy after we broke up, or (2) someone microsurgically repairs my vasa deferens then anally rapes my corpse with a cattle prod to get a semen sample (the latter has happened, and Diane Blood seems proud to have raped her husband's corpse so. I would hope the necessary repair work would suggest to the courts my strong desire to not have descendants ; since it would require the work of lawyers, I'm not going to bet on it never happening.)

Comment: Re:Correction (Score 1) 97

by RockDoctor (#47531337) Attached to: UEA Research Shows Oceans Vital For Possibility of Alien Life
You've plotted three chapters for the compendium "Generation Ship Tales", examining the fates of the generation ships sent out by Earth in the 3000s.

ha, ha, but serious. There's a sea of ideas out there for SF authors to mine, but they don't seem terribly inclined to dip into that particular pond. targeted anthologies ("Dangerous Visions", the Berserker universe) have a decent track record for getting people to play with an idea.

Comment: Re:Time delay (Score 1) 95

by RockDoctor (#47525871) Attached to: Finding Life In Space By Looking For Extraterrestrial Pollution

Then again, if the atmosphere clears up in a year or two, then they either are even more advanced than we are or they destroyed themselves and their planet healed itself.

We've two data points for the cleaning up of atmospheres after a sudden bout of pollution : the ozone hole we created in a few decades is steadily reducing and dispersing since the 1990 ban on producing CFCs ; that looks as if it'll be cleared up in a century or two (large, sulphate-rich volcanic eruptions not occurring, which may put it back by a few years or decades). Whether that was an externally detectable pollution event is more dubious - it was hard enough to detect from here.

The other datum is the decay of the PETM carbon dioide spike of 55 Myr ago. That took between 100,000 and 150,000 years to return to something resembling an equilibrium CO2 content in the atmosphere and reduce temperatures to something approaching their pre-PETM levels.

Combining the two, expect it to take 10s of thousands of years for a major pollution spike to "heal". If you look at it from the other end of the telescope, that's around 10 overturnings of the oceans (our largest and most massive environmental component).

Comment: Re:idiotic (Score 1) 95

by RockDoctor (#47525751) Attached to: Finding Life In Space By Looking For Extraterrestrial Pollution

We can almost create artificial gravity by finding a way to generate Higgs Bosons and attach them to matter.

Do you have a vaguely credible citation for that - an Arxiv paper, or a professor of physics describing a roadmap. I've never heard even a hint of anyone planning to do that. (Besides, for a long, long time, it'll be much easier to mimic gravity with centripetal acceleration of the floor.)

and we're almost done with fusion.

Well, give or take a decade or three. It does appear to be closer now than when I was an optimistic schoolkid hitch-hiking to university.

We already developed algae that can strip CO2 out of the air.

I'll grant you that. It means that when I stop drilling oil wells, I can start drilling wells to dump CO2 into. That's fine by me. (You do realise that we've got gigatonnes of CO2 that need to come out of the atmosphere and back into the ground before we can even start to consider the job done?)

I think you're being highly optimistic on a 20 year timescale. Maybe 20 years once we get the political will together and start to actually address the problem. 50 years being highly optimistic ; well over a century being realistic.

Comment: Re:idiotic (Score 1) 95

by RockDoctor (#47524171) Attached to: Finding Life In Space By Looking For Extraterrestrial Pollution

What kind of moron came up with that? Let's see, life was here for like 500 million years, for about 150 we've been ruining the atmosphere, and 100 years from now we'll have solved it.

OK. And now let's look at the real figures :

There has been life on the planet for approximately 3500 million years (definite fossils to 3.2 billion, more disputed going back to 3800 million).

The first major pollution event - the production of oxygen - started around 2600 million years ago, with oxygen becoming ubiquitous (if at 1/100th of current levels) by about 2300 million.

Multicellular life first left fossils (the Ediacara fauna) about 600 million years ago (what you think was the origin of life?).

Multicellular life came onto land about 420 million years ago.

For about 150 years we've been polluting the atmosphere significantly (NB : there is detectable pollution in the Greenland ice cores dating back to Roman times. If you consider lead dust from Britain under the Romans "significant".), and we're continuing to do it at an accelerating rate. Going on the previous occasion when this happened, it'll take around 100,000 to 150,000 years for the atmospheric perturbation to self-correct. At that scale, it doesn't really matter if we die this year, next year or 1000 years from now.

and 100 years from now we'll have solved it.

Can you cite a source for that? I've never heard that sort of claim, even from pot-smoking AGW-denying oilfield trash. (Actually, working in the oil field, I haven't met AGW-denying trash. We know fine and well what we're doing.)

Life is difficult because it is non-linear.