forgotketchup's comments

That's right. We like to do science.

I don't know of anyone who publishes in Word (and universities don't publish papers, except for dissertations), but everyone composes papers in Word.

>What subfield of physics have you worked in?

Experimental condensed matter physics (free molecular beams). Never met anyone in my research group, or any other research group that anyone in my group collaborated with, who recently (in the past five years) composed a paper in LaTeX. I'm sure my thesis advisor did so when he was in grad school back in the dark ages, but even he uses Word.

> (e.g., on arXiv/quant-ph)

Yes, well, that is where the crackpots tend to like to hang out, isn't it?

> I've been checking the (Word-generated) "papers" from this guy's group at NASA, they're extremely shoddy.

Not defending this particular paper, but I'm curious why you highlighted the fact that it's written in Word. Just about everybody in physics these days uses Word to compose papers (Word + Mendeley is a dream, by the way). Maybe you think he's not a 'real man' because he doesn't sling raw LaTeX?

Worse from the customer perspective.

All their old apps now run probably 2 to 10 times slower, until new native binaries arrived. Compare that with the PPC->Intel transition, when old binary apps stayed about the same or maybe got a little faster.

Also, emulating Intel binary apps with the CPU pegged for twice as long nullifies any energy savings, so the battery life in practice gets worse. Even if it is 20% for native binary apps, consumers are going to see "new computer, worse battery life, Og smash!" during the transition.

You're not going to see a 20% gain in battery life for native binaries, though. The only way you'd see that is if the ARM CPU used no energy at all. Extraordinary claims, evidence, and all that.

Is there really any reason to think that an Intel and ARM chip of comparable performance will have significantly different package sizes? Intel has always been the leader in process technology, so it would surprise me if the ARM die were any smaller.

Why should they?

Intel chips blew the doors off PPC by the time Apple got around to the PPC -> Intel transition. That (and good emulation software) allowed a relatively pain-free transition for most consumers: PPC apps didn't feel any slower when run on a new Intel-based Mac. That made it fairly easy to accumulate a critical mass of users with Intel systems, yet it still took ages for native apps to become available from the likes of Adobe and others.

Fast forward to today.

ARM chips are, at best, a little slower than the Intel chips they would replace. On top of that, the x86 ISA has a reputation for being hard to emulate well. So put yourself in the shoes of the consumer: are you going to upgrade to the new ARMBook Air, if it runs all your old apps at 1/2 or 1/4 the speed (and I'm being super optimistic here) they ran on your old MacBook Air? No! You're not! You're going to stick it out until the second generation of ARMBook comes out.

That means no critical mass of people who own ARM-based Macs and are willing and able to pay for native ARM software. That means vendors will. not. follow. This doesn't even take into account that Apple have burned their bridge with Adobe (a major vendor of 3rd party software for Mac).

Last point: I think you're wrong about games. There are tons of games for Mac on Steam. Would vendors go to the trouble of making a Mac port if there was no money in it?

To expand on what avoid3d said:

You can make a plot of entropy vs. energy of a system. Further, you can calculate the derivative (slope) of that plot and give it a name. You could also calculate the quantity 1/slope and give that a name, too--and the name we give it is "temperature." So, the temperature of the system is negative any time the slope of entropy vs. energy is negative.

How do we get a negative slope? We need to find a place where entropy decreases when energy is added to the system. Entropy is proportional to the natural log of something called the "partition function (see below)." That means we need to find a place where partition function has a negative slope.

The partition function tells us essentially "how many distinct ways can we arrange (store) a given amount of energy in this system?" For almost all macroscopic systems, there are a greater number of ways to rearrange the system each time a unit of energy is added. However, it is possible to construct a system where adding a unit of energy actually restricts the number of ways you can arrange the system. And that is the basis for negative temperature.

The (historically) low price of bunker fuel led to the development of turbine locomotives for railroads[1]. The idea was that the low price made up for the inefficiency (in operational practice) of turbine engines. When the plastics industry figured out how to use bunker fuel, turbine locomotives became uneconomic to operate. I'd guess that nuclear cargo ships would simply lead to slightly cheaper plastic.

[1] http://en.wikipedia.org/wiki/Union_Pacific_GTELs

Lack of qualified operators is real operational problem.

Majoring in physics pretty much guaranteed you a NROTC scholarship, if you wanted one, back when I was in undergrad. Around a third of my cohort (and the ones graduating immediately before and after mine) were in NROTC, and every last one of them was earmarked for the nuclear program when they finished school.

I'd speculate that the Navy simply doesn't have enough personnel to put a nuclear drive-train on every cruiser, much less the entire fleet.

Edit: grammar

Edit2: Also, keep in mind that aircraft don't run on uranium. A carrier group needs tanker replenishment anyway, so switching to nuclear ship propulsion doesn't save you from needing to worry about the logistics of transporting large volumes of flammable liquid to the group.

You're correct that the text of FARs does not explicitly require a prior personal relationship. However, as they are applied and interpreted in practice, you're almost guaranteed to get in hot water if you fly-share as a private pilot on a regular basis with people you don't know. And that's really not news to anyone with a private pilot certificate or anyone who has spent time looking into getting one.

It's worth mentioning that the definition of common purpose in this letter is considerably looser that what the FAA has used in the past. I'm having trouble finding the link at the moment, but I seem to remember private pilots getting in trouble when they carried passengers (on the pilot's schedule, not the passengers', as in this case) who had a different purpose for the flight--in other words, both pilot and passengers had a purpose for the flight, but it wasn't a "common purpose."

The FAA letter also calls into question the legality of the entire purpose of Flytenow: The letter explicitly states that publically posting the particulars of the flight (destination, date, and time) is probably illegal.