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Comment Re:Garbage what? (Score 2) 70

Without really knowing the answers

Without knowing the answers one conducts research to find out the details to know the answers. There already have been some studies about how plastic trash accumulates metals, although not of the ocean's more valuable metals. In the above-linked articles, some very rough calculations are run for different potential recovery rates of different metals and what their market value would be. There's lots of caveats, though.

Comment Re:Comparison? (Score 4, Interesting) 230

It's interesting nonetheless seeing what studies come up as bunk and which get confirmed. For example, I opened up their data file and started pulling up random entries about gender differences for fun:

"Sex differences in mate preferences revisited: Do people know what they initially desire in a romantic partner?" - The original study claimed that while men often self-report having their selection criteria for a partner being a lot more hinged around appearance than women do, that in practice this isn't the case, and more to the point, people's self-reporting for what they want most in a partner has little bearing on what they actually find most important in partner selection in practice.

The re-analysis confirmed this study.

"Perceptual mechanisms that characterize gender differences in decoding women's sexual intent" - This was a followup study to an earlier study that claimed that women often perceive men's sexual interest as friendliness while men often perceive women's friendliness as sexual interest. This study found, by contrast, that while men often misperceive friendliness as sexual interest, they also often misperceive sexual interest as friendliness - that they're just worse in general than reading sexual interest than women.

The re-analaysis was thus in a way responding to both the original and the followup. And found neither to be true. They found no difference between men and women in ability to read sexual interest vs. friendliness.

"Loving those who justify inequality: the effects of system threat on attraction to women who embody benevolent sexist ideals." - this study was to test - and reported confirmation - of the hypothesis that men who don't trust the government will also tend to find attractive women who embody "benevolent sexist" stereotypes - that is, that women are vulnerable, need to be saved, belong in the house, are there to complete men, etc, vs. women who have interest in careers or activities outside of the family, expect to be seen as equals, etc.

The reanalysis showed no correlation at all.

"The Best Men Are (Not Always) Already Taken: Female Preference for Single Versus Attached Males Depends on Conception Risk" - this study claimed that women in relationships find single men more attractive when they're ovulating and partnered men when they're not, but that single women show no preference. They argued that this result is expected given selective factors.

The reanalysis showed no correlation at all in any of the above cases.

Comment Re:Architect != sysadmin (Score 4, Interesting) 182

Agreed. The architect should not be touching the operational system except for acquiring profiling data and layout information, which they should be able to work with the system administrator to get. They should not have "full access" like the person wants. The architect should be working in a testbed with simulated data or a copy of the live data, depending on the task at hand. Just the same as how an actual architect doesn't go onside and start welding things, they work in simulated models.

Comment Re:Garbage what? (Score 4, Interesting) 70

Ironically, there's the possibility that removing the trash could pay for itself and then some. Plastics floating in the ocean tend to slowly intercalate metals - the types and quantities depending on the plastic and the rate depending on the surface area to volume ratio (very high for most pacific garbage patch trash). Plastic trash that's been floating around for a long time tends to become quite contaminated by these metals (as well as some types of persistent biological toxins), making it much more toxic to sea life than new plastic. But these same metal "contamination" problems could make the waste a potential resource back on land. Intercalated metals can be stripped out by a soak in a strong acid bath. And the ratios of metals found in the oceans are very different than those found on land, with some, such as uranium and lithium, being orders of magnitude more common than they are on land.

Comment Re:Fixed it for you. (Score 2, Funny) 436

When a woman gets married and has children, her whole life changes. Her husband is no longer the focus of her life, her children are. She loses interest in sex, and doesn't see why she should have to do it any more. If she wants another child, sure, but otherwise not. To her, it's just one more person who wants something from her at the end of a long day at work, and this one she can actually say "no" to. So, she does.

Meanwhile, the husband, cut completely off from one source of sex he is allowed to have, grows increasingly desperate and unhappy.

Okay, sorry for the tangent, but: how on Earth are people from the year 1958 managing to make posts on Slashdot that show up today? How are they even getting a bloody net connection back then?

Comment Re:So... (Score 1) 176

Child molesters: If someone calls in a report of a known child molester or a person acting suspiciously, you need police out there to investigate, not a drone zapping people from the air. If someone is running away with a kidnapped child, my "car chase, fast response" example above applies. Now, if you're talking about trying to keep drones in the sky 24-7 tracking the movements of all known child molesters, that's something that should be mandated by a court, not police officers just going off and doing. That's as intrusive as a court-ordered ankle tracking bracelet, and should be treated with no less seriousness.

Drunk drivers attacking police officers: I can't even envision how your mind is factoring drones into this situation. Are you proposing that drones make traffic stops instead of police officers?

Or maybe I'm misreading your post. Was that sarcasm? I can't even tell anymore.

Comment So... (Score 4, Interesting) 176

... So we're talking about poorly regulated government officials using flying robots to spy on and electro-paralyze people from the air.

How exactly is this not a dystopian sci-fi novel come to life?

Don't get me wrong, I think civil use of drones can be a great thing. Even police use of drones - tracking vehicles during a car chase, fast response to a breakin or robbery, etc. But this is just ridiculous.

Comment Re:Use RTGs for ion propulsion then comm. (Score 1) 77

First off, you say "dust lodged in the lungs" as if that's a good thing. It's an intensive alpha emitter. Check out how miniscule of quantities of radon (another alpha emitter) it takes to pose a health threat. But yes, most plutonium dioxide ingested in that form passes through (not without irradiating the digestive tract first, of course); the ingestion route is more hazardous for more soluble forms of plutonium.

Comment Re:And the timeframe for getting another probe (Score 1) 77

Venus has an incredibly hospitable environment... in the cloudtops. Vastly more hospitable than the surface of Mars. And with how little we know about Venus, even something that doesn't land could completely revolutionize our understanding of the planet.

A higher budget mission could use a ballooning lander that makes repeated descents to the surface, then rises to recharge its batteries and let its coolant chill back down. Wherein it would be far more of a "rover" than anything we have ever sent to Mars - it could explore the whole planet.

Comment Re:And the timeframe for getting another probe (Score 1) 77

Excuse me, I shouldn't have laughed. Ahem. Mercury has the highest delta-v requirement amongst the planets.

Which would have been a great response, had I written:

Venus and Mercury have the lowest delta-V requirements

Which is, of course, NOT what I wrote. What I actually wrote was:

Venus and Mercury have more frequent launch windows.

Moving on...

With Mercury you can't save energy by aerocapture, but you can make very frequent flybys of Venus and Mercury to lose velocity - and making observations of both Venus and Mercury during each flyby. Messenger, for example, was launched in August 2004. It did an Earth flyby 1 year later, a Venus flyby 12 months later, then a Mercury flyby 15 months later, then 3 years later, orbital insertion. Now, that was a long time to orbital insertion, but not a long time before the collection of first data - it did minor data collection at Earth, more at Venus, and more during its first Mercury flyby. But more to the point, it was done with a tiny delta-V budget: 316m/s from Earth escape to Mercury insertion and 862m/s for the orbital insertion itself. Mars takes about 390 m/s from Earth escape to Mars transfer, 670 m/s for Mars transfer to Mars capture (if you can't aerocapture), and entering a similar orbit on Mars would take somewhere in the ballpark of 2000 m/s (5000 m/s to low orbit) (again, possibly reduced if you can aerobrake). While it's technically possible to use an Earth gravity assist to Mars, it takes much longer.

Now, of course, one could have used a more Mars-like delta-V to get to Mercury much faster, although due to the complexities of gravitational assists I can't work out readily here just how long it would take. But for Venus it's easy: 280 m/s from Earth to Venus transfer and then... well, aerocapture is pretty much a given if you want to (far easier than on Mars), but if you don't want to do it, then it's another 360 m/s to high orbit, then 2900 m/s to low orbit. But of course, Venus is a very easy body to aerocapture at, so it should be expected. Short transfer times to Venus, little energy to get there, easy to brake at, and frequent launch windows. How is that not more "probe-able"?

Comment Re:Use RTGs for ion propulsion then comm. (Score 1) 77

1) There's nothing to make staging any harder for ion craft than for chemically-fuelled craft

2) Dawn's ISP has a max of 3100sec. There's plenty of room to be improved.

3) A probe at a gas giant (or moon with an atmosphere, such as Titan) could potentially orbit through the exosphere, scooping up new propellant. While that would be no insignificant engineering work, there's nothing making it impossible. The relative velocity of the ions it'd be scooping are far lower than the exhaust velocity of a good ion engine, meaning that it could compensate for the drag by thrusting with only a small fraction of the propellant that it collects. And most ion engines are very propellant-choice flexible - they don't have to use xenon, and it's not a huge penalty to use other gases. So such a probe could leave orbit and even return to Earth. As a bonus, any leftover propellant upon arriving at Earth would be a sample return.

My personal dream mission is something akin to #3 for Titan, with a VTOL rotary-nacelle lander carried along for the ride - the orbiter being its "tugboat" and communications relay. A one-year mission at Titan with realistic flight speeds and recharge times should allow such a lander to go to pretty much everywhere interesting on the moon. If the probe's payload was sufficient, the VTOL lander could be supplemented by an ascent stage (my calculations show that something like a scaled down Pegasus upper stage should be sufficient, and its propellant mix appears to tolerate cryogenic conditions), so you'd get small surface samples from all over Titan returned as well. And if you have a probe in the Saturnian system with an atmospheric scoop, you might as well do a Stardust-style aerogel flyby of Enceladus and scoop a bit of Saturn's exosphere on the way back - the mass penalty required for adding both to the mission is trivial. An Enceladus flyby needs a sheet of carbon aerogel with a closable shield (if desired, the impact velocity could be kept low if desired by entering into a Molniya-style Enceladus orbit, having near zero velocity high over the plumes). A Saturn scoop needs a tiny additional tank and valve so that its sample doesn't get mixed in with the bulk gas taken from Titan.

Seriously, the potential scientific value of all of those sample returns would be almost unimaginable. We don't even know what tholins are as things stand, and yet they may have been the progenitor to life on Earth. And there's always the chance that signs of actual life, past or present, would be found in Titan or Enceladus samples.

There's of course a lot of engineering work (which means unknowns, which means risk) in such a mission. So it would be wonderful if they could retire part of those unknowns by testing out propellant scooping at Uranus or Neptune.

Comment Re:Use RTGs for ion propulsion then comm. (Score 3, Informative) 77

1) RTGs are not being "phased out". They're actually going to become more common in the coming years, now that 238Pu production has restarted.
2) Computer power consumption has dropped, not increased.
3) For outer planetary missions, there is literally no better solution to produce X number of watts, whatever number X may be (up until you get into the many-dozens-of-kilowatts range, where it probably pays to start developing an outright fission reactor)
4) Few people would consider 238Pu to have a "long half life". There are certainly things that it's long in comparison to, but as far as "long lived radioactive" products are considered, it's not even close to being considered one.
5) Plutonium is not "rejected by the human body", it's accumulated in the bones, and alpha radiation inside the body has 20 times the destructive power of beta and gamma per MeV (also, with beta decay, 2/3rds of the energy is usually lost as a muon antineutrino)

Note: Please don't misinterpret this, I'm pro-RTGs. I just wanted to correct the facts.

Work expands to fill the time available. -- Cyril Northcote Parkinson, "The Economist", 1955

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