Follow Slashdot blog updates by subscribing to our blog RSS feed

 



Forgot your password?
typodupeerror
Get HideMyAss! VPN, PC Mag's Top 10 VPNs of 2016 for 55% off for a Limited Time ×

Comment Re:Oh boy (Score 5, Insightful) 334

For what it's worth, the magazine The Economist deeply prefers Clinton over Trump. Trump seems to make vague, wishful-thinking promises. The few verifiable economic statements he's made, for instance not having to raise the tax rate yet balancing the budget due to an expected surge of growth, are wild products of wishful thinking.

On this point, I agree with The Economist. Trump makes a lot of noises about big changes because they sound good to the uneducated. On the other hand, Clinton has a much more complete and realistic picture of what she'd do with economic policy; with Clinton at the helm there would be many fewer changes than with Trump. Given that the last 8 years have seen the Dow recover from the Bush-induced lows in the 6000s to today's record highs in the 18000s and unemployment in America shrink below 5%, more of the same sounds much better than trusting that Trump's string of brainfarts will amount to an even bigger improvement.

Comment Re:Chirality probably didn't come from space (Score 1) 56

I've seen this work too, and I don't buy it. The effects are far too subtle to influence chemistry enough for life to care. Once one chirality started getting used by an early microbe, there's no compelling reason to start experimenting with the other, and the chances that the weak force's minuscule influence had any significant influence on which enantiomer was chosen are pretty much nil.

Comment Chirality probably didn't come from space (Score 3, Informative) 56

TFA suggests a beautiful idea: that life bears the imprint of handedness derived from cosmic dust. The idea may be beautiful, but it's wrong. It's much more likely that the chirality of biomolecules we see on Earth came from spontaneous symmetry breaking on Earth itself than by space seeding any preferred chirality.

Complex molecules in living beings are assembled from consistent smaller molecules, known as monomers. Some of these monomers have a handedness (they have two enantiomers), and in that case living things will almost always use just one of the enantiomers. The best explanation for why living things tend to use just one enantiomer is the same reason you would hate to have two slightly different kinds of Lego blocks with incompatible pitch: this diversity usually just gets in the way of assembling complex macromolecules without providing any compelling value.

Thus, we know even given no seeding of chirality from space, life would pick one chirality since having just one is usually useful. Add to that the facts that we haven't yet found a non-racemic mixture of anything in space, and that even if we did the fraction of space-derived non-racemic molecules on the Earth's surface would hardly noticeably change the balance of chiralities found in proto-life Earth, and it's pretty clear that the chirality of biomolecules in living things is totally independent of biased enantiomers from space.
 

Comment Should allow smartphone ordering too (Score 1) 921

So, they're building machines that replace the ordering and payment part of the process. While they're at it, why not build a smartphone app that lets you order before you even get to the restaurant? How is making a dedicated kiosk the exclusive way to place an order a good thing?

Comment DARPA specs (Score 4, Informative) 102

You can read about the specifics here: https://www.fbo.gov/index?s=op....

The call is for a human-deployable system after 4 years. It should read from a million neurons and be able to write to 100,000 neurons, 1000 neurons in full duplex read-write, with 60 dB channel isolation, all in a tiny package that doesn't significantly overheat the brain tissue its up against.

Who thinks that's possible?

Comment Re:Experimental evidence says that is unlikely (Score 1) 120

Hi Wdi,

Do you have a citation for the meteorite work?

Also, even if there's a slight chiral asymmetry in space rocks, space is a high radiation environment compared to the primordial soup. Tinkerton makes a very good point: when the chiral chemical effects of beta decay are this weak even under lab conditions engineered to maximize their strength, it's hard to imagine this asymmetry would play a significant role in the wild.

Submission + - Rambus' tiny diffractive camera adds eyes to any digital device (computerworld.com)

LeDopore writes: Patrick Thibodeau from Computerworld writes about a technology I'm developing:

There's a type of camera technology emerging with a view of the world similar to what a honey bee sees. The images appear blurry and hazy, but if you're a bee, good enough for finding flowers and people to sting.

We use a spiral diffraction grating plus computation instead of a lens, which lets us shrink our sensor much smaller than any sane conventional optical system. The grating is only 200 microns in diameter, and the whole sensor can be made using only standard CMOS techniques, meaning it will cost only a trivial amount to add low-resolution eyes to any digital device.

Comment Store money too, not just power (Score 1) 245

Regardless of how good battery tech gets, it will always be easier to store money than to store energy. How can the former substitute for the latter? There are some latency-insensitive electricity consumers, like heating, cooling, pumping water, etc. While there's a shortage of supply, give the consumers an incentive to store money (not pay for expensive electricity) until there's more supply, and they can make up for the backlog then.

Letting the electricity price float is a natural way to give consumers an incentive to shift their consumption. If a smart thermostat could pay for itself in less than a year by monitoring prices and price forecasts, we'd all buy them, and then we'd be able to store money rather than energy, which is technologically a much easier prospect.

Comment Employment nearly a human right (Score 1) 566

Employment should be thought of as almost a human right. If a spouse isn't allowed to pursue his calling simply because of where he lives, and he sticks by his working wife for over half a decade on a no-working-allowed H4 visa, that actually sucks pretty hard. It crosses the line from "tough choice" to "ok, now this policy is actually breaking a person's ability to develop". Economics aside, I have a moral objection to placing these kinds of restrictions on a human's development for so long.

Some who disagree with me will say it's the H4's fault for falling in love with a worker going to an H1B job. Others will say that if it's not worth the sacrifice, they should both go home. I say that both of these counterarguments are kind of disheartening: do you really want to force other people into making these tough choices? That doesn't feel like what America is all about.

Submission + - Tiny Lensless Camera Demo at Mobile World Congress 2014

LeDopore writes: I introduced a new kind of camera at Mobile World Congress 2014 that can be made tiny because we replace the lens with a smaller and simpler-to-build binary diffraction grating plus a beefy reconstruction algorithm. With optics only 200 microns wide, the Lensless Smart Sensor was picked up by Tom's Guide, where it won 3rd place of all of MWC 2014. Tech Radar Pro also picked up the story. Our prototype takes pictures of only limited resolution — about 128 x 128 pixels, and I don't expect this technology to be able to scale to multiple megapixels. Still, all the optics needed can be made with wafer-scale manufacturing techniques, meaning that adding a camera to any digital device would cost only pennies and add less than a millimeter of thickness. The majority of eyes in all animals on planet Earth (such as insect and starfish eyes) have resolutions less than this level; now, for a tiny incremental cost, we can give all our chips a little bit of vision.

Comment Memorization, or attention to detail? (Score 5, Informative) 123

I have a PhD in sensory neuroscience from UC Berkeley. It could be the effect mentioned in TFA is sensory, not memorization.

Caffeine is known to increase acetylcholine release. Acetylcholine makes your brain pay more attention to here-and-now details than to its internal model of what's going on.

I'm also dubious about the idea that any one, simple chemical can ever make you smarter in any general way without adverse consequences. Evolution has a lot of time to scope out all simple neurochemical effects, so beware studies that suggest they've found a "smart pill". Sure, it's possible to take a drug to make you better at one specific task to the detriment of some others, but the idea that there is any simple cognitive enhancing substance would imply either "evolution couldn't mimic the effect of this substance on the brain" or "cognitive enhancement isn't an evolutionary good move". Neither seems very likely.

Comment Re:Which part is most disturbing? (Score 2) 221

What post-quantum assymetric crypto is there?

Wikipedia to the rescue: https://en.wikipedia.org/wiki/Post-quantum_cryptography. My personal favorite is the McEliece cryptosystem, based on error-correcting codes: https://en.wikipedia.org/wiki/McEliece_cryptosystem. They key size is huge (well, under 1 MB still) but computation isn't too bad. I'd still recommend adding RSA plus several post-quantum schemes in an XOR chain as I described.

About increasing key size without a clear need, a lot of crypto algorithms take compute time that grows faster than linearly with key size. Executing several independent algorithms in parallel is better for two reasons: first, the key sizes of each one aren't large so don't suffer the nonlinear slowing, and second, they can be executed on separate cores in parallel.

I'd welcome advice from an expert, but my impression is that the mainstream crypto researchers think that it's more conservative to adopt a single, trusted crypto algorithm and bet the farm on it. My instincts are that this is a bad approach. Composed algorithms like the one I described where all of (say) 5 schemes must be cracked before the attacker gets anywhere are more conservative in my view since they are at least as strong as each of their constituents. However, I'm not a crypto researcher, and there might be a good reason not to shield RSA (which we know is secure to classical but not quantum attacks) with a variety of layers that each provide a good chance of being robust against a quantum attack.

When will we have quantum computers? One reasonable scenario is that by 2020 we'll have a Sputnik moment where somebody will build a quantum computer much better than the sleepy mainstream expects, yet not powerful enough to run Shore's algorithm against 1024-bit RSA. This will shock the world into a bit of a panic that a bigger quantum computer will come soon, and RSA and elliptic curves will be seen as untrustworthy by 2025. We'd be better off adding a layer of protection now, especially since we're sending data now that we wouldn't want to be public for a lot longer than 2025.

Comment Re:Which part is most disturbing? (Score 1) 221

Then all that happens is we adopt those other schemes faster, spot the holes faster[....]

I agree, and I'd argue we don't go far enough yet. We should adopt a few of these post-quantum schemes now alongside a trusted but quantum-vulnerable protocol such as RSA.

You ensure that communications are safe unless all schemes can be broken. Here's how. Most public key cryptography is used to send a roughly 128 to 256 bit long one-time use key for a symmetric cipher like AES. It would be possible to select, say, 5 different public key protocols: 4 new (and therefore perhaps flawed) post-quantum schemes plus one quantum-vulnerable but trusted protocol like RSA. Generate your AES key, then generate 4 random bitstrings of the same length. Then, using the 5 protocols, use the first protocol (RSA) to securely send the key XORed with the 4 random strings, and use each of the other 4 protocols to securely send one of the random keys. An attacker who can crack any 4 of the 5 protocols cannot obtain any information about the key.

The upside to this is that if you take a diverse set of promising strategies for post-quantum public key crypto from several agencies that don't trust each other, chances are there will be at least one that's OK. Even if none of them work well, you're still no worse off from a secrecy standpoint than with plain RSA.

The downside is that keys will become longer (many post-quantum algorithms need many kilobytes) and computation will be more substantial. Practically, that means you won't want to ever have to read your public key to someone over the phone (but you could read them a hash of it - almost as good), and tiny, frequent crypto-protected payloads would see an increase in CPU utilization, but there would not be as much of a change for long payloads where the cost of the public key handshake to transfer the AES key is amortized over much more data.

With computation becoming faster, and with the Internet increasingly carrying data that may be sensitive even a few decades in the future, we should start using quantum-prudent methods defensively ASAP, especially since the downside is negligible already, and it's shrinking with Moore's law.

Slashdot Top Deals

You know you've landed gear-up when it takes full power to taxi.

Working...