And while that's true. Few people (if any?) have died from their sprinklers coming on. Many people have died in a fire...

So the cost of "fire" vs. "sprinkler" isn't symmetric.

Which is interesting from a European background. We've definitely noticed for a long time, and our cars don't squeal nearly as much in the movies as US ones do. It was something I grew up with, learning that american cars apparently squealed their tires on ever turn. I even remember news pieces talking about the difference in tire technology between the US the Europe and how american cars actually squealed more IRL than ours... Wasn't so, it turned out.

So, given that we've gotten rid of bullets going an annoying "pew pew" in was movies, is there any chance of US cars not squealing their way around every single corner?

As someone who developed GPRS for Ericsson back in the day, I don't even know where to start...

There were a number of different competing standards, in different parts of the world. That CDMA wasn't mandated in the US was not for lack of trying by the US manufacturers.

And, no, if we're talking about true packet data, i.e. not "phone modems", GSM/GPRS did emphatically not use a dedicated slot per user for data communication. Instead all the available "data" slots (and there can be many) were/are shared dynamically between all the users wanting to receive/transmit using dynamic reservation protocols (depending on, among other things, whether you have data to send/receive). Indeed EDGE is just GSM/GPRS with more data slots available, and with mobiles that can use more slots in sequence.

All this is moot anyway, as the explosion of demand for mobile IP, necessitated completely new systems anyway. And since they were new, they weren't hampered by what was already there. You say that UMTS is based on CDMA, which is true, but there are also FDMA and TDMA parts, and even versions of the UMTS protocols. So that UMTS is CDMA and that's superior to GSM which is TDMA does not follow.

I could write a book about the rest, but that'll have to do for now.

Well, for completeness sake, there are specialised situations in which it can yield highly valuable results, and criminals for example, know that. I'm thinking of situations like "Tell me the combination to your safe, or else..." and the like. Time locks on bank vaults were for example invented to stop the all too popular kidnapping the bank manager and holding his family hostage, "or else".

But of course you're right, that as a means of intelligence gathering these situations are so uncommon, as to render the method completely useless.

And here's what the actual historians have to say about that: http://www.reddit.com/r/badhis...

Well, he wasn't all that wrong. You do get substantial grain deformation in the lengthwise direction when you draw steel (as it's a cold forming process). And that increases strength in the direction of pull.

So the rope analogy kind of works, only the fibres are really really small... :-) And they're made from the steel in the first place.

That's not to say that there isn't more to say on the subject, since I haven't studied this in a couple of decades, I did some googling and came up with http://ro.ecu.edu.au/cgi/viewc... .

But of course you're not going to "print" steel wire. We're in violent agreement there.

Sure. You can't extrude a honeycomb. You need a "constant" cross section that's not too big, instead using the length of the extruded section to get the size you want. So you can extrude a beam easily enough. A honeycomb like the one you saw, not so much. (Doing it the "other way" would work though, and likewise wouldn't work on a CNC. You can't mill to those depths.).

Actually Volvo had a system like this in trials in the eighties. Our city busses in Trollhaettan, Sweden (where SAAB was built, and Volvo makes/made airplane engines) ran with a system like this. I remember riding and watching the energy storage meter that was installed for the amusement of the passengers. (Just four green lights marked 25%, 50% aso).

This was an air/hydraulic system and it worked very well, and had advantages over the flywheel solution that was also tried at the time; as it was lighter, more compact and cost less both to install and to operate. However, even riding you could tell the problem with it and similar systems that rely on braking. You have to use the brakes. Some bus drivers, especially early on, changed their way of driving and then the system worked very well, i.e. instead of coasting to a stop and relying on engine braking, they maintained speed and braked into the stop, allowing the system to store energy that could be reclaimed accelerating out of the stop (you could hear clearly when the hydraulic motor cut out and was replaced by the diesel).

Other drivers though, used their old ways, driving as smoothly as possible instead, relying more on engine braking. And that mean no stored energy and no recovery.

So the system/experiment was deemed a failure and it never came into production.

The moral of the story is that you have to combine these systems with engine management as well. That is; no coasting. Like the Tesla, when you take your foot of the gas, the vehicle starts reclaiming kinetic energy, and you decelerate. If you want to maintain speed you have to use the accelerator. People don't use the brakes as they would have to in order for systems such as these to live up to potential.

Yes, indeed. We're in violent agreement. That probably had something to do with him being just as poor a student as the rest of us. He had to make it work with the hardware he could afford. :-)

What? That's news to me. I was on comp.os.minix when Linus announced it, and downloaded version 0.11 (but I don't think I ran it until 0.12).

The only other UNIX-like OS at the time IMHO was Minix, but due to Tannenbaums resistance to "complicating" Minix into something that used the full capabilities of the 386 (i.e. the MMU etc.) Linux took off like a rocket. (There was even a patch set adding i386 capabilities to Minux, but it had to be distributed as a patch set, Tannenbaum wouldn't let it be integrated into Minix proper.

So, sure, 0.10, 0.11 and 0.12 weren't even complete but it only took on the order of weeks before Minix was left in the dust feature wise, and the rest as they say, is history. Remember that while 0.10 etc. may have lacked an init, it ran almost everything else, in particular they could self host gcc, i.e. they could compile gcc, which was no mean feat. (And something that Minix couldn't, though my memory is vague on that point).

So what were these other systems that were so much more sophisticated? You aren't thinking about the various i386 BSD-variants that sought to bring BSD to the masses? They weren't really "hobby projects", the legal ramifications weren't at all clear, so their development was severely hampered, and the people had this stick up their collective asses about what hardware was good enough to be worthy of support. Which lead to the consequence that you couldn't actually run your BSD-of-the-month on hardware you had. Linux was above all a much more pragmatic affair. If the hardware was in widespread use, it usually got support quite quickly, no matter how much of an ugly cluge it was deemed to be. But of course some of them were fairly feature complete, since they were original UNIX, source code and all. (And also slower on i386, but that's another story.)

Since the difference per volume is quite a bit larger. With steel being stronger both per weight and obviously volume, we should be making fighter aircraft out of steel, then?

Hint, there are other qualities that are more important than a couple of percent in difference in tensile strength.

If you take your chill pills and climb down off the walls, you might learn something you know...

No, he's actually correct. They're roughly the same in terms of strength per weight, which is what he said.

However, they're not nearly as similar when it comes to density, with titanium being about half of steel, and aluminium being about half of titanium.

That's not to say that there aren't any differences at all, even when considering strength/weight, esp. when we take the many different alloys into account, which in certain application (fighter jets) can make a difference.

You mean it doesn't?

Isn't that what people said to John Nash as well?

There are many areas where we can do a lot better than we're doing today, and there are many areas that aren't nearly as difficult as people think. Not that this form of sports is necessarily one of them.

Having worked at SKFs research lab writing software (developing a measurement system) in the nineties I can only concur. Turns out there's a ton of interesting and exciting stuff, at the cutting edge of mechanical engineering and science, to be done in the field of rolling bearings. It was one of the best jobs I've had.

But it's perceived as so boooring(!) that it's difficult to recruit new talent to the field. The mechanical engineering master's students at one of the biggest universities here in Sweden even used to have a contest to see who could throw the SKF main catalogue the farthest. And SKF, true to form, even supplied the catalogues, to try and have at least some positive influence on the proceedings. They were not in a position to act all butt-hurt, but instead tried to put as positive a spin on it as possible (at least we're not grumpy, and look at all the drink and swag we provide).

That's not to say that the pay was anything to write home about, but, and that's something I've noticed before in many technical fields, the young'uns, students in particular, seem to lose interest and jump ship much faster than society actually ramps down. I've seen it in analogue electronics, I've seen it in electrical power distribution, though not in tribology (but that's probably because rolling bearings had their hay day more than a hundred years ago). The need for people with those skills outstripped availability in short order.