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Comment Re:Shocking! (Score 4, Insightful) 171 171

Utility of a 2.8 second 0-60 time for most ICE car owners = 0.
Utility of being able to drive 500 miles and then 'recharge' in five minutes = lots.

Utility of having decent range and never having to stop at a gas station = priceless!

Seriously. Buy a second car (owners of this Tesla can certainly afford one). Or borrow a friends (they'll be happy to drive you Telsa for a day). Or rent a car for your trip. The convenience of having a fully charged car every morning more than makes up for any range anxiety I might have had, and my electric has less than half the range of a Tesla.

Comment Re:... break most modern cryptographic codes? (Score 1) 62 62

Agreed - except that Diffie-Hellman relies on the difficulty of solving the discrete log problem, not integer factorization - so that only RSA is vulnerable here, and only if bit-wise close primes were chosen for the key.

Comment Re:Obvious machine not subtle furniture problem (Score 1) 720 720

There's always the Mac Pro: Small; built to be hammered with ridiculous workloads; extremely quiet; and comes with that lovely trash-can-sleek styling. We play Windows games on mine using a Parallel's Virtual machine, but you'll want to boot directly to your game's OS for best results.

The price isn't pretty, but nobody said marriage is cheap.

Comment Re:There is no "almost impossible" (Score 2) 236 236

"Almost Impossible" can be made very precise. Indeed, modern cryptography is based on the understanding that certain algorithms are "almost impossible" to reverse. Cryptographers prove theorems with wording like "indistinguishable from random by any polynomial time algorithm" when they mean almost impossible. So, Apple may be quite correct in their statement.

My take on this is that Apple likely has received legal orders it can not disclose, and implementing real, strong security to protect user's data.

Comment Re:So wait... (Score 2) 462 462

"Good afternoon, Officer. My time is valuable. Your time is valuable. Please don't waste time by asking questions I am not required to answer."

"Sir, Have you been drinking?"

"Am I required to answer that question?"


"Please stop wasting time. As I said, my time is valuable. Am I free to go now?"


Comment Re:Lacking data (Score 4, Informative) 491 491

Here's what the US National Academies have to say: "One might think that airplanes, trains, and buses would consume most of the energy used in this sector but, in fact, their percentages are relatively small--about 9% for aircraft and about 3% for trains and buses. Personal vehicles, on the other hand, consume more than 60% of the energy used for transportation."

Completely eliminating emissions from buses would make only a small difference in the big energy picture.

That said, electric buses might not be such a bad thing. I'm driving an electric car these days and it is awesome (even if it isn't a Tesla).

Comment Re:Not all that surprising... (Score 1) 131 131

Modern type safe languages have a lot going for them, but they don't solve the hard problems of concurrency. (n.b. purely functional languages allow easy parallelization of some mathematical functions, but do not solve the hard problem, either). Highly efficient threading, especially at the system level, is not made easier by type safety.

This instruction set extension offers transactional memory access, so a thread can begin speculative execution that modifies a block of memory, and roll back on a conflict, rather than stalling on a semaphore lock.

Comment Re:Keratoconus (Score 1) 550 550

If you look around, you can find eye surgeons performing corneal collagen cross-linking in the US. My doc works in Colorado. The basic idea is that the combination of riboflavin (vitamin B2) and UV light causes the corneal layers to bond more tightly to teach other. The stiffer cornea is likely to maintain a better shape, but the main advertised benefit is stabilization, preventing worsening of the keratoconus.

In my case, laser ablation was used to remove the corneal epithelium (outer layer of cells) so the riboflavin eye drops would more readily diffuse into the cornea. I was a good candidate for the procedure, with a relatively thick cornea, and the outcome was good. The experience was a also a lot more painful than I expected, but worth the suffering. My eyesight is now OK (neither terrible nor great), and I can now consider Lasik if I want.

Of course, Intacs (small rings inserted into the eye that circle -- and help shape -- the cornea) are FDA approved for keratoconus, but the approval is under a Humanitarian Device Exemption, meaning they have not been proven effective.

Comment Re:hype (Score 1) 243 243

OK. Now you are just plain wrong. Please read about car suspensions. You can start with the wikipedia article on camber angle: "The inside edge of the contact patch would begin to lift off of the ground if the tire had zero camber, reducing the area of the contact patch. This effect is compensated for by applying negative camber, maximizing the contact patch area." [Wikipedia]

Comment Re:hype (Score 1) 243 243

[Please read comments carefully before posting.]

I stated the fact that many suspensions attain desirable negative camber while turning as a consequence of body roll. That cars are set up for neutral camber when driving straight is not at issue. The interesing part is that this Mercedes rolls the opposite way, and I wonder what changes were made to suspension geometry to account for this.

Comment Re:hype (Score 1) 243 243

On the contrary, body roll is, in my admittedly subjective experience, quite noticeable. I drive two cars, a typical family car and a sporty two seater. The difference is night and day. One can easily feel the family car "sway" into and out of turns.

Cars can gain traction in turns if body roll results in negative tire camber (especially on the outside wheel). I wonder if Mercedes has engineered a sort of reversed suspension to take advantage of this property. Or is that what they mean when they say the design is "not ... for increasing cornering speeds"?

Comment Re:Move along nothing to see here. (Score 1) 56 56

200 steps per rotation is normal for motors. However, the drivers everyone is using do 16x microstepping, good for 3200 steps per revolution. Accurate steps per revolution. That's better then 4096 +- 2 steps.

No, those motors are not good for 3200 accurate steps/rev: Motor accuracy here is likely to be +/-5% (10% range), so ideal accuracy will be closer to 2000 steps/rev, but real world accuracy drops with increased microstepping resolution due to varying load and detent torques, stiction, etc.

The good news is that this level of motor accuracy is irrelevant here. All you really need to do is beat the required positioning resolution (likely on the order of a few mils). A 20tpi lead screw and 200 step/rev motor easily beat this without microstepping. You probably still want a microstepping driver, though, since it can prevent mid-band resonance in addition to other features.

Comment Re:This act is highly illegal (Score 1) 322 322

What's illegal about it?

"Whoever ... knowingly and with intent to defraud, accesses a protected computer ... exceeds authorized access, and by means of such conduct furthers the intended fraud and obtains anything of value ... shall be punished ..." - CFAA (18 USC 1030).

That's what. (Disclaimer: IANAL and therefore don't know what I am talking about).

Steve Jobs said two years ago that X is brain-damaged and it will be gone in two years. He was half right. -- Dennis Ritchie