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Comment: Re:Food is not the limiting factor (Score 2) 252

by Rei (#48190491) Attached to: NASA's HI-SEAS Project Results Suggests a Women-Only Mars Crew

That is, of course, for a given radiation dose, which is independent of body cross section - which is relevant in real-world scenarios. If we assume an isotropic radiation exposure profile, an average male height of 174cm, an average female height of 161 cm, and asssume an equivalent profile, then a man presents a 17% higher profile to radiation exposurediation exposure, so if a woman has a 50% higher (150%) cancer risk, then it's only 29% higher for a fixed radiation flux per square meter.

However, let's look further at this. Given the smaller size of members of a female crew, you can shrink the spacecraft occupant space by 8% on each axis, or a volumetric decrease of 26%. Mass changes are more difficult to reckon. Life support, food, water, etc is dependent on metabolism, which the article shows is dramatically lower for women in space. Fuel needs are proportional to all other mass issues. Only a few things (such as computers and scientific equipment) don't trace back to crew member size and mass. Regardless, for a given launch weight, it's clear that you can afford the mass of a significantly increased amount of radiation shielding for a female crew due to the weight savings elsewhere, probably easily more than offsetting the cancer risk.

Beyond this, the average US astronaut age is 34, an age well after when most women are done having children (assuming that they even want to have children). Given that the article states the risk is from breast, ovarian, and utirine cancer, I wouldn't be surprised if many would consider full hysterectomy for the ability to travel to Mars.

Comment: Re:Compelling, but a mix still better... (Score 3, Interesting) 252

by Rei (#48190177) Attached to: NASA's HI-SEAS Project Results Suggests a Women-Only Mars Crew

Despite how radical that statement sounds, it's actually perfectly reasonable for a zero-G environment. They're not only dead weight, they're also in the way and make you require larger accomodations.

Even in Mars's gravity field a legless person would deal quite well, at least inside the facility (picture how easily you could get around without your legs if you suddenly were given 2.5x the arm strength, didn't have your legs weighing you down, and on top of that add in how most double amputees already have good arm strength to begin with). They should be able to "hop" with their arms all the way to a 2 1/2 meter ceiling without trouble, and the full arc would take a good two seconds to come back down. On the moon it'd be even easier. Of course, if they're legless, why would they even need such tall ceilings to begin with?

Comment: Re:Fantasy based laws. (Score 1) 310

by Dixie_Flatline (#48188773) Attached to: Manga Images Depicting Children Lead to Conviction in UK

Even if the person is never weaned off the images, as long as they never offend against a real person, I'd consider that a win.

Every once in a while a story comes up about a doctor that says that these people should be protected if they come out to a medical professional so they can get treatment, and inevitably in the comments, people scream about locking them up and punishing them right away, even if they've never done anything wrong. As a consequence, these people DO go on to offend because they can't get help, and two lives are ruined in the process. I never understand why, if we're interested in harm prevention and reduction, that they'd allow even one innocent child to be hurt when that could be prevented with significantly more humane laws.

(Actually, from what I understand, that IS how it works in Canada--you can ask for treatment and get it--and I hear there are good results here. I don't know the comparative statistics, though.)

Comment: Re: Moral Imperialism (Score 4, Insightful) 310

by Dixie_Flatline (#48188711) Attached to: Manga Images Depicting Children Lead to Conviction in UK

Don't forget Australia's law where if the person looks young, it counts as CP. It effectively puts a ban on taking pictures of women with small breasts (if they're in their 20s or otherwise look young).

What this means is that it would be illegal to take pictures of a young-ish looking 24 year old with A-cups, but perfectly legal to have sex with her 16-year-old sister as long as you didn't take pictures of it.

Remember, laws always exactly reflect what is moral. If it's not illegal, it's not immoral!

Comment: Re:F the UK (Score 3, Insightful) 456

by Rei (#48185113) Attached to: In UK, Internet Trolls Could Face Two Years In Jail

I agree. If by "poisoning" they mean people making insolts or dispatching flying penises in Second Life or stuff like that, then it's a bill too far. But if by "poisoning" they mean launching flickering images on an epilepsy forum to try to cause seizures, "doxxing", making legitimate rape and murder threats, etc, then I think it's absolutely justified. All too often is there the assumption that what happens online doesn't warrant enforcement, even if it's something that crosses over into the real world.

Everyone has the right to free speech, but it ceases being free speech when it crosses certain bounds (shouting fire in a crowded theatre, incitement to violence, solicitation of criminal activity, etc). All of these cases are nuanced and require careful balance, but what they should not be is ignored.

Comment: Re:Overly broad? (Score 1) 388

by Rei (#48182001) Attached to: Soda Pop Damages Your Cells' Telomeres

Exactly what I'm thinking. I respect peer-reviewed research, and take results seriously - preferably consensus positions, but on lesser researched topics, individual studies. But isn't this pretty useless without more details? Is it sugar consumption? Then diet soda doesn't count. Is it phosphate consumption? Then are all kinds of other foods also a threat? Is it caffeine? If so, then coffee is a threat and caffeine-free soda is fine. Is it other lesser ingredients, such as certain flavorants or colorants? What element in their test soda is so harmful that it has such a dramatic effect? Surely it's not all ingredients, or the act of consuming them at once...

Comment: Re:Baby steps (Score 1) 348

by Rei (#48179831) Attached to: White House Wants Ideas For "Bootstrapping a Solar System Civilization"

Wrong. I said mass manufacture - you don't have to re-engineer curiosity from scratch and hand-build it every time. And if you can pay to build a super-heavy-lift vehicle, or tons of smaller (but still very large) launches to get your ~100 tonne manned Mars round trip spacecraft into orbit, then you can launch a 100x 889kg curiosity rovers.

You literally can launch about 100 mass-manufactured curiosity-sized rovers for the cost of one manned mission. The scientific bang for your buck is way, way, way higher with robots.

And FYI, if your goal is to be able to help people "live on another planet", then you absolutely should not be supporting wasting money on a trip to Mars on today's way overpriced launch systems. You should be supporting spending it on developing novel systems for orders-of-magnitude reduction of launch prices, be they scramjets, launch loops, coilguns, metastable fuels, nuclear thermal propulsion, or in general insert-your-favorite-potential-cost-reducer-here, so that it doesn't cost an impractical amount of money to send people there. (never mind that we're not even centuries away from being able to recreate a full self-sustainable tech tree on Mars.. see earlier in the thread)

I always find it funny to hear people the same alt-space fanboys complaining vitriolically about how maintaining ISS is a huge waste of money but then insisting that we set up a manned outpost that would cost orders of magnitude more to maintain ;)

Comment: Re:Baby steps (Score 1) 348

by Rei (#48175493) Attached to: White House Wants Ideas For "Bootstrapping a Solar System Civilization"

What "all purpose robot"? A robot or person's capabilities are limited by what scientific equipment they have on hand, not by whether they can digest corn or catch a cold. I'm talking about a robot like Curiosity. A person could mass-manufacture and dispatch a hundred Curiosity rovers to every corner of Mars for the cost of one manned mission and would collect dozens of times more data.

Comment: Re:Baby steps (Score 1) 348

by Rei (#48175481) Attached to: White House Wants Ideas For "Bootstrapping a Solar System Civilization"

Ref. It took 30 seconds. Please don't ask other people to use Google for you, you're (presumedly) an adult and should be able to manage these sort of things on your own.

But in order to avoid thermalizing your fission fragments the reaction is going to need to be in near-vacuum

The reaction is done in a near vacuum. But that doesn't mean that there's almost no fuel. Fission fragments and neutrons behave totally differently, fission fragments are positively charged and respect Lorenz force, neutrons are neutral and do not, so it's easy to separate the two (as well as from the fuel, which becomes negatively charged and is not moving at relativistic velocities).

These things have been fully simulated, there's nothing unreasonable about them.

but our best neutron mirrors can only get total reflectance at angles of incidence of less than a single degree

I have no clue where this is coming from. Neutron reflectors (more properly thought of as scatterers) can scatter back, and in fact moderators produce a relatively anisotropic thermal neutron flux. The current proposal for a dusty fission fragment reactor involves U235 fuel and a moderator in the shell of the reactor.

Comment: Re:Baby steps (Score 1) 348

by Rei (#48172161) Attached to: White House Wants Ideas For "Bootstrapping a Solar System Civilization"

Oh please, be serious. It's humans running the robots who make the decisions. The only benefit a human on Mars has is latency. But that's a really silly benefit, given that there's no urgency to get the data and just travel there takes months and the limiting factor on how much data you'll collect overall is how long your scientific equipment lasts. And no, an astronaut on Mars isn't going to be repairing a broken mass spectrometer or the like, it's a silly concept. And it'd, as noted, be orders of magnitude cheaper just to send a second robot.

Comment: Re:First taste of Mac OS X (Score 1) 300

by Dixie_Flatline (#48170297) Attached to: OS X 10.10 Yosemite Review

I prefer the OS X method of window/application switching. But more to the point, I think expose is a better method than the alt-tab method, straight up. You can do it for all windows or just the application you're in. I've always found it faster. It's something I miss when I'm on other systems. (I've tried the Windows versions, but I've yet to find one that's nearly as good.)

If it's worth doing, it's worth doing for money.