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Comment: Even so: Par2 (Score 1) 79

by cerberusss (#49770077) Attached to: No, Your SSD Won't Quickly Lose Data While Powered Down

Even though this sounds reassuring, I started creating par2 checksums for my family pictures (and then back up the whole bunch, of course).

If you run OS X on the desktop, it installs nicely via Homebrew:

  $ brew install par2

Then use as follows:

  $ cd familypics
  $ par2create par2file *

And to verify:

  $ cd familypics
  $ par2verify par2file.par2

It takes about 5% of extra storage. If you run Linux, you can get that back by using btrfs and mounting it compressed.

Comment: Re:I'll believe it when I see it... (Score 1) 116

by Rei (#49767671) Attached to: India Ends Russian Space Partnership and Will Land On the Moon Alone

Its not that simple. You can't just recover it from nuclear reactor waste because it's mixed in with other isotopes of plutonium, and isn't in that great of quantities to begin with. So first off you have to reprocess nuclear waste to extract the neptunium - which again, itself isn't in very great quantities, it takes a lot of waste, and most places don't want to do waste reprocessing to begin with due to cost and liability issues. You then have to make neptunium targets and expose them to a neutron flux - that is, using neutronicity that could otherwise be used for power generation or other valuable purposes (it takes a lot of neutrons to make a tiny bit of Pu238). Pu238 should be more thought of as a manufactured product than as a byproduct of particular types of nuclear reactors.

There are a few other candidates for use as space power sources that actually are waste products, but they're all significantly worse performers. There are two other alternatives. One is to make a Sterling RTG, which was in development, but funding has been cut off (it's also kind of tricky because you have to ensure that something with moving parts will operate for decades in the harsh environment of space). The other is to make an actual nuclear reactor. This means almost limitless power, but it comes at the expense of not only massive development costs and public opposition, but a large minimum size and massive radiator requirements, as well as the same reliability challenges of sterling generators.

There's no easy solutions. Except, of course, to stop bloody wasting plutonium once we have it.

Comment: Re:I'll believe it when I see it... (Score 4, Interesting) 116

by Rei (#49764673) Attached to: India Ends Russian Space Partnership and Will Land On the Moon Alone

"Love" is the nice way to put it. "Largess at the expense of all other solar system exploration" would be more accurate. Here's a graph. And it's always the same stupid justifications - how many times can we pretend to be excited about "revelations" that Mars was once in its past a wet place? Or that we're going to stumble into life any time soon in its perchlorate-rich, destroys-organics-on-contact regolith?

And it's not just huge amounts of money that they're wasting - they're also throwing away most of the remainder of our plutonium supply. At least there's money to start making it again, but it'll take time. Plutonium is precious, and it's needed for outer planet missions.

Comment: Re:Twenty five years of science destruction... (Score 2, Insightful) 116

by Rei (#49764639) Attached to: India Ends Russian Space Partnership and Will Land On the Moon Alone

I hate to be the one to tell you but academia generally pays poorly outside of the US. More so in a country like Russia that is still clawing its way back up from the economic collapse that occurred during the transition from communism to capitalism.

Perhaps if most of the country's wealth wasn't concentrated in the hands of a handful of corrupt oligarchs who live like a modern version of Roman emperors they'd be able to pay researchers a living wage.

Comment: Re:Ducted fans? (Score 1) 74

by Rei (#49763377) Attached to: The Hoverboard Flies Closer To Reality

You don't need "antigravity" (which in all likelihood is impossible). Diamagnetic hoverboards would be possible... if we could make ridiculously powerful, compact halbach arrays in the board. Also you'd need a clever mechanism to detect and deal with flying over ferromagnetic material, or otherwise it's going to smack into your board really hard.

Comment: Re: Meh... (Score 4, Insightful) 244

by Rei (#49757847) Attached to: California Votes To Ban Microbeads

The problem is, sewage treatment systems have a lot of trouble (at present, let's just simply say "can't") filtering them out. They go into the sewage, they will go into the sea.

Setting up filters for particles as small as 1 micron for all sewage going out into the ocean is obviously going to be a massive expensive. Who wants to pay for that so that people can keep sticking bits of plastic in cosmetics?

Seriously, whose bright idea was it to make bits of plastic, bite-size for plankton, looking like fish eggs, whose very design intent is to wash out into the ocean? And no, while they're not harmful to us, they absolutely will be to plankton - if not immediately (how healthy do you think you'd be if you wolfed down an entire meal-sized chunk of plastic?), then with time. Plastics act as chelators for heavy metals and a number of organic poisons, to such a degree that they might even be economical to mine. There's simply no way that this isn't going to have an impact.

And it's so stupid when one can just use soluble crystals (salts, sugars, etc) instead of plastic.

Comment: Re:Do people really take this risk seriously? (Score 5, Insightful) 230

by Rei (#49752865) Attached to: Asteroid Risk Greatly Overestimated By Almost Everyone

The article is also based on some terrible reasoning, like:

That means there will be no asteroids left in the Solar System, because they all will have struck Earth, in another few hundred million years. Think someone’s overestimated something there? Yeah, me too. Let’s take a look with the flaws in our fear-based reasoning.

Yeah, in a universe where our solar system is some sort of perfect steady state. Which, of course, it is not. Asteroids collide or - more commonly, come close to other bodies and gravitationally interact - and throw each other into different orbits. When that happens, non-Earth-crossing asteroids can become Earth-crossing ones. For example, one of the candidates for the K-Pg extinction event is a Batisma-family asteroid. This family came from an asteroid breakup 80 million years ago.

A person well versed in the field would be aware of the fact that asteroids are not in some sort of unchanging steady state. Which is why they're the ones paid to do the research on the subject.

And more to the point, we really don't have a good handle on what's out there. We have trouble making out dwarf planets in the outer solar system. We really have no bloody clue what could be on its way into the inner solar system, apart from studying how often major events happen.

And on that note, another flaw in his logic, given that until recently, the vast majority of Tunguska-style events would never even have been detected, having occurred over the oceans, remote deserts, the poles, etc. So by all means it's perfectly fair to say that the fact that an asteroid hitting earth is more likely to hit a remote uninhabited area is perfectly fair. But saying that while mentioning the rarity of inhabited areas having been hit in the past is double-counting. The historical record is evidence of how often they hit populated areas, not how often they hit Earth.

Lastly, his claim that only one person has ever been "hit by an asteroid" is ridiculous. 1500 people were injured by the Chelyabinsk one in 2013 badly enough to seek medical attention. Yes, they weren't "hit by rocks", but that's not what large asteroid impacts do; they mostly or completely vaporize by exploding in the atmosphere and/or on impact. And there's lots of reports throughout history of people getting struck by asteroids; just because they weren't documented by modern medical science doesn't mean it never happened. Seriously, what's the bloody odds that the only person to ever in historical times be hit by an asteroid would be in the 1950s in the middle of a first-world nation? Now what's the odds that someone being hit in the 1950s in the middle of a first-world nation would be well documented, publicized, and believed?

Just a lot of really bad arguments.

Comment: Re:Seems obvious now (Score 4, Interesting) 214

by Rei (#49742243) Attached to: Secret Files Reveal UK Police Feared That Trekkies Could Turn On Society

Can you imagine the dystopian dictatorship where trekkies come to power? All of the halls of power full of people walking around in spandex and fake ears and brow ridges, the fed directed to work toward the absolution of currency, the military directed to accelerate development of phasers and for all recruits to undergo "Kobayashi Maru" training.... NASA would finally get their proposed $18,5 billion dollar annual budget passed - except that the bill would have the word "annual" crossed out and the word "monthly" written in its place. National anti-bullying legislation would be passed, probably with a name like Spock's Law. And of course they'd insist on referring to the UN as the United Federation of Planets.

Comment: Re:Satellites (Score 1) 403

by Rei (#49681273) Attached to: Ask Slashdot: After We're Gone, the Last Electrical Device Still Working?

LEDs have lifespans of what, 50-100k hours? So maybe a couple decades. And some will significantly outlive their design life, as is always the case with failure curves. The solar cells should be good for decades, until the contacts corrode.

One *could* design devices to last for thousands of years. But that's not usually a design constraint ;)

Comment: Re:Compares well (Score 2) 408

No-fault is about taking money away from lawyers, who used to litigate each and every auto accident as a lawsuit in court before the insurers would pay. Eventually the insurers decided that they spent more on lawyers than accident payments, and they had no reason to do so.

If you want to go back to the way things were, you are welcome to spend lots of time and money in court for trivial things, and see how you like it. I will provide you with expert witness testimony for $7.50/minute plus expenses. The lawyers charge more.

In general your insurer can figure out for themselves if you were at fault or not, and AAA insurance usually tells me when they think I was, or wasn't, when they set rates.

Comment: Re:More than $100 (Score 1) 515

If we don't have more than two children per couple, the human race would've died out a long time ago.

I think the proper way to state that is "If we didn't in the past", not "If we don't". If we were to have 2 children per couple (approximately, the real value is enough children to replace each individual but not more) from this day on, it would not be necessary to adjust the number upward to avoid a population bottleneck for tens of thousands of years.

Comment: Re:$30 (Score 1) 515

The Northern California Amtrak is actually pretty good for commuting from Sacramento to the Bay Area and back because the right of way is 4 tracks wide in critical places and it has priority over other trains for much of the time.

Acela in the Boston/NY/DC corridor is also good, because the right of way is 4 tracks or more for most of the way, and it has a track to itself along a lot of the route. Other railroads run on parallel tracks.

For the most part, though, Amtrak suffers from not having exclusive track. It runs on freight lines that host cars so heavy that the rail bends an inch when the wheels are on top of it (I've seen this first hand).

An Ada exception is when a routine gets in trouble and says 'Beam me up, Scotty'.

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