Follow Slashdot blog updates by subscribing to our blog RSS feed

 



Forgot your password?
typodupeerror
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 internet speed test! ×

Comment Re:Only viable if all planes land themselves (Score 1) 305

He's talking about a circle over two miles in diameter, so over 6.3 miles long.

Meanwhile, the average commercial runway is between 1.5 and 2.5 miles long (and my understanding is that typically only the largest planes need to use more than a fraction of the runway)

So, for the "average runway length" you're talking about 85-145 degrees of curvature, and most planes won't use nearly that much, especially since they'll be able to land and take off with a headwind. Plus, most of that length will be used for accelerating or slowing down when firmly attached to the ground, which I believe is considerably less challenging than the brief window around takeoff and landing, which is where most accidents occur.

I don't imagine it will be without it's challenges, but it seems as though it's making the most dangerous part of the process considerably safer, at the expense of making the safer portion more challenging, which seems like a very reasonable trade off.

The biggest problem I see is pilot training - all existing pilots are trained on straight runways, and would likely need extensive practice to be able to land safely on a circular runway. Practice that would likely be largely wasted unless there were already a large number of airports being operated with circular runways.

Comment Re:Can batteries make the earth green? (Score 1) 138

Why would you include batteries at all? If you have brackish water at night, then you almost certainly have it available during the day as well, and can perform desalination then, when you have maximum power availability. Why waste money and power (batteries aren't free or 100% efficient) trying to spread the work over the full day cycle?

As a matter of fact I seem to recall a number of different solar desalination technologies out there, most of which use solar thermal rather than photovoltaics, thus more than quadrupling the available power while also cutting costs. (26% efficiency is absolute high-dollar cutting edge for photovoltaics)

Comment Re:Anti-matter (Score 1) 138

That's not a battery, that's a guaranteed to explode in the factory bomb. You'll need a bunch more mass to generate the magnetic containment field to keep the antimatter from annihilating normal matter until you're ready. Plus a reactor in which to perform the annihilation that can convert the gamma radiation that carries off most fo the energy into something useful. And serious radiation shielding to protect anyone nearby from being exposed to the radiation which doesn't get converted.

Comment Re:What's in the future for batteries? (Score 1) 138

Typically I believe nuclear batteries have much lower power density than most chemical batteries - they store far more total energy, but can't release it nearly as fast. And in fact they release it at a constant rate*, whether or not you're using it - radioactive decay doesn't come with an off switch. Plus, as current technology mostly depends on heat conversion, you've got to figure that for every watt of electric power it can delivers, it will also be delivering 2-3 watts of heat.

There's also the size issue - a nuclear battery needs both an energy conversion mechanism and radiation shielding - shrink that down to the size of a AA, and your maximum available power becomes pretty tiny, unless you're using something highly radioactive as the fuel source - in which case it will decay rapidly and need to be replaced much more frequently - and now your mostly-discharged battery is not only toxic but also radioactive.

*technically an exponential decay, but nothing you do with affect it appreciably

Comment Re: MapReduce is great (Score 1) 148

Worked for DISA. Can confirm, we had massive tape silos and entire teams that loaded/unloaded bulk lots of tapes in the LTO3/LTO4 days. Usually everything worked fine with the load time to snag the proper tape, load it to a free drive and start reading. Lot of that was done by mainframes using COBOL. Fun stuff.

The new Samsung 16TB SSDs will be substantial game changers in... oh, five years. They're shipping now, but if the price drops to a grand or two per SSD, it'll be really interesting for bulk storage. Petabyte level SSD storage in 5U, for a hundred grand, will be very nifty.

Comment Re:Sounds nice! (Score 1) 127

I'm far less certain of that - look how many people take life-extending drugs now, so that their failing heart/liver/kidneys/whatever won't kill them "before their time"

What makes you think a drug that benefits basically every aspect of your health, plus makes you look and feel younger, would be any less appealing? Granted, after a few decades of failing health perhaps the allure of several more would wear thin. Then again, our culture is rather obsessed with putting off dying as long as possible, at almost any price, so a relatively cheap and powerful aid to that goal would probably find a huge market, even if it did also accelerate the return to a more sane relationship with death.

Even then though, I would not be surprised if death from "old age" remained extremely uncommon, with people instead continuing to take the anti-agapics as long as possible, and then choosing a more pleasant way to go when they decide their time is up. I mean it's basically a choice between decaying as slow as possible and then taking a leap of faith when it's no longer worth it, versus willfully letting the misery of decay accelerate until it kills you.

Comment Re:Rotten Tomatoes is getting self-important (Score 1) 395

>Plus, I use Linux so my time is already worth nothing.

I know it can be hard to adjust, but just because you would have been flushing all that time down the toilet dealing with Windows problems doesn't mean it's worthless. It just means that Windows was a terribly abusive partner. Go, take your newfound free time and learn to live again!

Comment Re: Or... (Score 1) 395

But how many people use Rotten Tomatoes to decide what they might be interested in watching in the first place? It seems much more likely that it's the previews that catch people's interest and then RT lets them know if the movie managed to appeal to the same people as the previews.

I mean there's plenty of abysmal movies with lots of great explosions and fight scenes (looking at you Michael Bay), whose previews don't really promise anything else. And they generally get good popular reviews for the simple reason that they deliver what's promised. Their critic reviews are often terrible, but that's to be expected - they're terrible movies seen through the eyes of someone who watched them in order to write a review, rather than because he preview led them to believe they'd like it.

Comment Re:Can't see the forest for all the trees (Score 1) 395

I'd say the usefulness of aggregators lies in the extremes - if the aggregate score is 80-90%, that's a remarkably wide range of people saying it was good, so clearly it has a broad based appeal and you'll likely enjoy it too. Similarly, if something is ranked at 10-20%, that's a remarkable consensus that it's bad.

The more midrange scores though - that's where things get murky, likely lots of conflicting opinions, so you have to venture further afield to figure out where our own tastes are likely to lie.

There's another way of looking at it though - if you assume most people are initially interested in a movie because of the previews, then even the horribly crude rankings of an aggregator could tell you one important detail: how well does the movie deliver on the promises of the preview? If the preview accurately captures the essence of the movie, then most people who were attracted by the preview are liable to like it. If not... well then the popular review is likely going to be bad unless the movie really managed to do something else *really* well.

Comment Re:Sounds nice! (Score 1) 127

You are assuming that anti-agapics will only prolong the productive years. What if they prolong the long, decaying years as well? I mean it's already obvious that, at least within the US, people are in no hurry to let themselves die just because they're old and worn down, and an anti-agapic might well work to extend those non-productive years just as log as the productive ones.

There's a whole lot of knock-on effects to consider.

Comment Re:This will be denied by all the idiots (Score 1) 373

Real science has been questioning - and NOBODY has come up with ANY alternate explanation for the data. CO2 is a clear and obvious climate forcing factor.

>Data shows no direct correlation to CO2 levels and global temperatures.
Of course not. Data will also show no direct correlation between the height of the flame under a pot of water and the temperature of the water. The relationship is with the rate of warming, not with the temperature. And with a "water pot" the size of Earth, it takes centuries for temperatures to adjust to changes in "flame height".

>Data shows CO2 levels have been insanely higher in the past than they are now.
Yes, if you go back far enough. Like, many times longer than the existence of the human species. But when CO2 is high, Earth has always been a "hothouse", experiencing a radically different set of climate options than anything seen in the last 2.6 million years of ice age (we're only in an interglacial period now - we've still got polar ice caps). And the transition between ice age and hothouse causes a massive planet-wide extinction event lasting for thousands of years.

And no, Global Warming hasn't been debunked - it was even been confirmed by the researchers working directly for Exxon, etc., who decided to keep quiet and fund a massive disinformation campaign to preserve their business model instead. The shift to calling it "Climate Change" was because some people were incapable of understanding that just because the planet as a whole is warming, doesn't mean that every individual location will get warmer - changing weather patterns, like the polar vortex extending all the way down into the US, can easily cause localized cooling.

Comment Re:This will be denied by all the idiots (Score 1) 373

That's the question isn't it? Have we already crossed the tipping point into a "hothouse Earth"? If so we've got some hard adjustments in front of us and it will likely be millions of years before our planet sees another ice age. If not, and we can get our fossil fuel addiction under control, then we may be able to maintain the current interglacial period indefinitely, though sooner or later we're liable to stop managing it and the natural oscillations will resume (if nothing else the collapse of civilization is a recurring theme in history, and today our civilizations are all hopelessly interlinked and likely to fall together)

We've found the keys to an incredibly powerful driver of global climate change - they hold great potential, if we wield them responsibly.

Slashdot Top Deals

"I never let my schooling get in the way of my education." -- Mark Twain

Working...