Become a fan of Slashdot on Facebook

 



Forgot your password?
typodupeerror

Slashdot videos: Now with more Slashdot!

  • View

  • Discuss

  • Share

We've improved Slashdot's video section; now you can view our video interviews, product close-ups and site visits with all the usual Slashdot options to comment, share, etc. No more walled garden! It's a work in progress -- we hope you'll check it out (Learn more about the recent updates).

×

Comment: Re:A dollar in design... (Score 1) 77

by Rei (#49499137) Attached to: Incorrectly Built SLS Welding Machine To Be Rebuilt

Indeed, the figures Musk cited a couple years ago was that over 80% of the part count of a Falcon 9 is sourced in-house; it's a critical part of their approach to keeping costs down. He wanted to do that with Tesla as well but it proved impossible, only about 20% of their parts (at the time) were produced in-house. Unsurprisingly the biggest problems in their early days came from external suppliers, like the gearbox issue on the Roadster.

Comment: Re:Give the money to Elon Musk (Score 1) 77

by Rei (#49499119) Attached to: Incorrectly Built SLS Welding Machine To Be Rebuilt

ESAB is a Swedish company. What use is it to NASA to dote largess on a Swedish welding firm?

I'm actually rather disappointed with ESAB here. I have one of their MIG welders from the 1960s and it still works; they're a respectable name.

I feel bad for NASA mind you, in that I don't think many of their problems are their own. They get all sorts of legacy systems forced upon them due to political reasons ("You can't do decision X that would be more efficient because 1000 people in my district would lose their jobs"), they never get the funding to engineer new things from scratch based on lessons learned, etc. I do wonder, mind you, whether their heavy reliance on external contractors is something they could reform.

Comment: Re:Sexes ARE different, thankfully (Score 1) 556

1. That's not "a" study, it's from a metastudy. The simple fact of the matter is, while the news makes a big deal of any study that shows a statistically significant difference between genders, most of these statistically significant differences are barely above the level of noise.

2. Where are you getting that quote from the paper? A search for those words doesn't reveal that.

There absolutely are some very demonstrable differences in certain psychological regards - mainly sexual. The most obvious of these, for example, is the fact that women are more likely to be attracted to men and men to women. But that's far from the majority of studied sexual differences that get so much play in the press. " With very few exceptions, variability within each sex and overlap between the sexes is so extensive that the authors conclude it would be inaccurate to use personality types, attitudes, and psychological indicators as a vehicle for sorting men and women. "

3. Girls are far less likely to get involved in chess to begin with in all countries (again, the fact that children mimic sex distribution of behaviors of the previous generation, no matter what they are in the particular society one is in), so one shouldn't be surprised that this is reflectected in the highest levels. Chess, as a competitive sport, has always been predominantly a "men's sport", internationally. But as XKCD notes, this is changing. The Polgár sisters are a great example. Their upbringing was an experiment by their father; to see what would happen if children were raised with extensive training in a specialist intellectual topic from an early age. One ended up an International Master while the other two ended up as Grand Masters, with Judit ending up one of the world's most powerful players of any gender. Their father's choice removed gender self -selection from the picture.

4. Oh please, you're not seriously going to pretend that there weren't tremendous pressures in Victorian society for women to not be involved in STEM-style careers, or that they weren't usually expressly banned from such. Even women who took them up as hobbies (usually well-to-do women) were often strongly advised against it, that it was harmful to a woman's delicate composition to be mentally straining one's self (a risk of the catch-all Victorian women's distorder "hysteria"; the cure for "hysteria" was to refrain from all serious physical and mental activity). This is the culture that ours came from, and it's been a slow incremental process of moving away from it ever since. The fact that you'd call "citation needed" on that is absurd, that's like "A normal human hand has five digits [citation needed]."

5."I'll see your 50% and raise it to 100%" - how does this even make sense? Women are 50% of the population (roughly). Nobody is talking about disinteresting men from pursuing STEM careers. There's already interest there. The goal is to try to also get more interest from women, to work against the carryover cultural connotations of STEM as "men's work".

6. " Are there laws or even customs, that prevent girls from entering a STEM field and excelling in it" - it's like you didn't even read my post.

7. "But what if it is bilogicial — as seems perfectly probable?" - not according to the actual research. And if one person wastes their time trying to become a physicist when they'd have made a better fry cook? Well whoop-di-freaking-doo. The world is still a better place.

Comment: Re:I like it... (Score 4, Interesting) 100

by Rei (#49497293) Attached to: Exploit For Crashing Minecraft Servers Made Public

I once coded for a game, Eternal Lands, where I discovered a major security bug. The game had a feature where if a person said a URL, it would turn into a clickable link. This was opened via a popen call. No input sanitization. Aka, vulnerable to injection. A person who simply speaks a malicious URL and makes it look like something interesting to click (hiding the insertion command in the path) could run it on anyone's computer who clicks to open the link.

Big problem. Simple fix. But try as I might, I couldn't get them to let me fix it. They were fine with me writing a whole new special effects graphics system for them, but one simple input sanitization, noooo, the popen works, let's not mess with it and possibly "introduce a bug"! Eventually it took me writing a sample command on the forum that would make a file in the user's home directory (which anyone who knows anything about unix commands could make far more malicious) by clicking on the URL. Suddenly they let me patch the system immediately (and deleted the forum thread... I don't blame them).

I didn't want to have to resort to that. But I didn't want a potentially dangerous exploit sitting in the system.

I never got approval to fix all of the other potential exploits in their system. Their networking protocol was terrible. I only ever saw the client code, but there was literally zero authentication that the server was who they said they were and that packets weren't malformed. Their entire security model was "let's initiate a TCP connection to a hard-coded IP and unconditionally trust everything that we receive". I can't imagine what their server code is like. But they wouldn't even let me add in trivial bounds checking to make sure that the packets weren't oversized - the most minimal of sanity checking.

The fear of changes breaking stuff often leads developers to neglect security. Changes to improve gameplay or graphics? Of course, our users will love it! Changes to the protocol? Nonono, the protocol is working, why risk breaking it?

The short of it? Don't have too much faith that that MMORPG you're playing isn't hackable in a way that could be nasty to your system.

Comment: Ummmm.... no (Score 1) 117

by Sycraft-fu (#49495033) Attached to: AMD Withdraws From High-Density Server Business

Sorry but you are having some selective memory. AMD actually was only a performance leader for a very brief period of time, that being the P4 days. That was also not because of anything great they did, but rather because the P4 ended up being a bad design because it did not scale as Intel thought it would. Outside of that they were competitive during the P3 days, but behind other than that.

They also had serious problems outside of any business practices from Intel. The three big ones that really screwed them today:

1) Their disastrous chipset situation. When the Athlons came out, their chipsets were garbage. The AMD made chipsets lacked any advanced features. The VIA chipsets were full featured, but poorly implemented. I bought an Athlon, excited at the performance upgrade I'd get from my P2 and drawn in by the price. I spent two weeks fighting and fighting to make it work, before finally finding out that GeForce graphics card were just incompatible with the boards because of VIA's out-of-spec AGP implementation. I sent it all back, got a P3 on an Intel chipset, and it all worked from the word go. Experiences like that really put many people and vendors off of AMD (combined with things like lacking a thermal halt on the chip so if a heatsink fell off the chip would bur out).

2) Their utter lack of innovation/resting on laurels. AMD took FOREVER to get out any kind of real new architecture, that being the Bulldozer, and it was poor when it happened. For too long they kept rehashing their same CPU architecture, while Intel kept moving theirs forward. This became particularly acute when the Sandy Bridge came out, which was a really good architecture improvement. Having nothing new and just trying to glom more cores on the server products was not a winning strategy long term.

3) Ignoring the software side of things. One of the things that makes Intel chips perform so well is their excellent compiler. It generates faster code than any other compiler, in every single test I've ever seen. That matters in the real world since people aren't going to waste time hand-optimizing assembly. Only recently did AMD get a compiler out (I haven't seen benchmarks on how good it is), for most of their life they just relied on other compilers and whined that the Intel compiler was mean to their chips. That has been a problem, particularly in research settings where people need high performance but are not primarily programmers and need something good at automatic code optimization.

AMD has done a lot to screw themselves over long periods and it has built up to a situation now where they are struggling in a big way. If you think Intel is all to blame you've your head in the sand.

Comment: ...and? (Score 1) 117

by Sycraft-fu (#49494845) Attached to: AMD Withdraws From High-Density Server Business

What is your proposal, people should purchase AMD chips as a charity?

Nobody other than Intel zealots wants to see AMD go away. However if AMD's products are not competitive for what they want, why should they buy them? Trying to argue charity buying is a non-starter and a very bad strategy.

AMD has been really screwing up on their processors as of late. Their performance is not that good in most things and their performance per watt is even worse. So for a great many tasks, they are not a great choice. Their "APU" concept is an interesting one, but one who's time seems to be up as Intel's integrated graphics have been very good lately and getting better with each generation so "a CPU with good graphics" is likely to just be what we think of as a CPU.

If AMD wants more sales they have to make a product that is compelling in some way. As it stands, it isn't compelling in that many markets.

Comment: Sure (Score 2) 117

by Sycraft-fu (#49494789) Attached to: AMD Withdraws From High-Density Server Business

Look up "Shadowplay" by nVidia. That is their software that uses the "nvenc" feature of their new GPUs. It has near zero CPU and GPU load, just load on the disk. All encoding is done by a special dedicated encoder on the chip. It's a fast encoder too, it can do 2560x1600@60fps.

The downside is it is not as good looking per bit as some of the software encoders (particularly X264) so if the target is something low bitrate you may wish to capture high bitrate and then reencode to a lower bitrate with other software later.

Bandicam also claims to support the hardware encoders of all the platform (Intel calls their QuickSync, AMD calls there's AMD APP).

Comment: Re:Sexes ARE different, thankfully (Score 1) 556

Or, maybe, women and men simply aren't the same?

The anatomy and physiology are demonstrably different.

Obviously what's at hand here is mental differences. Are there demonstrable mental differences? Yes! But there's only one issue with that...

In almost any sentence where people say "Women (verb)..." or "Men (verb)..." and it's about something psychological (as opposed to, say, something involving reproductive organs or a statistical difference in strength / height or the like), 99% of the time it's equally accurate to simply say "People (verb)..." The popular perception of the degree of differences between genders (including the effects of both brain structure and hormones) is often vastly different from the statistical reality. Screw Mars and Venus; men and women are from Earth. Psychologically, we're statistically virtually identical in most measures. And in many cases where there are differences that even manage to meet statistical significance, what differences there are may well be artifacts of culture.

Human children learn through imitating. They adopt role models (such as their parents at an early age) and mimic their behaviors, to the degree that it can even hinder them (one of the sort of psychological tests where chimps perform better than human children is to lay out a puzzle and have an adult solve it in front of the subjects, but insert a bunch of needless time-wasting steps; the human children almost invariably perform all of the time-wasting steps while the chimps catch on quickly that they're pointless and skip them). As a general rule, children most mimic members of their gender, something that socially they're rewarded for. By the very nature of this system, it inherently perpetuates the carryover of any totally non-gender-related but nonetheless gender-segregated activities from the previous generation. If you had a society where eating apples was something almost exclusively done by men, even if you didn't specifically teach the next generation that apples are a "men's fruit", the vast majority of girls wouldn't take up eating apples.

Given this, whether there would be any factual basis or not for women to be better or worse at STEM, the very fact that historically there were fewer women in STEM (a legacy from the old Victorian moral system), this will automatically lead to there being fewer women in STEM in the next generation. Now, one can do nothing and just hope that, after enough generations, the problem will remedy itself. Or, one can decide that having 50% of the human population having a solid interest in the sort of careers most valuable to the improvement of the human condition is a good thing, and maybe we should give a shot at remedying this, even if just on the "offchance" that it's not biological.

Comment: Re: Video from the barge (Score 1) 109

by Rei (#49492993) Attached to: An Engineering Analysis of the Falcon 9 First Stage Landing Failure

Not necessarily. A stronger RCS system would probably have for example saved this last rocket - even though that wasn't the fundamental problem. Again, that's the purpose of backup systems. They're not the primary - they're there for if the primary fails, which it will sooner or later even if you've ironed out the major bugs.

I'd wager that they chose nitrogen not because of the best thrust / mass combination for their needs, but to try to make regulatory approval for landing on land easier.

Comment: Re:Private details about employees (Score 5, Insightful) 137

by Rei (#49492449) Attached to: Wikileaks Publishes Hacked Sony Emails, Documents

It's not like anyone else with Wikileaks (which today amounts to only a handful of people) has any ability to change the head. As Assange put it, "I am the heart and soul of this organisation, its founder, philosopher, spokesperson, original coder, organiser, financier and all the rest. If you have a problem with me, p**s off." There were lots of people that tried to get him to step down in late 2010. They are all no longer with Wikileaks, either by choice or by being explicitly kicked out.

Wikileaks could have been something great, long lasting, a major global value to society. In its early days it really looked like it was heading in that direction. Sadly ego can ruin any project. When you feel the need to start blackmailing Amnesty International for nearly a million dollars by threatening to not redact the names of their sources if they don't pay up, you've lost the moral high ground.

Comment: Re:Redacting things is hard, I guess. (Score 1) 137

by Rei (#49492409) Attached to: Wikileaks Publishes Hacked Sony Emails, Documents

I have to say, I have to agree with you. There's still some missing pieces of the Snowden picture and contradictions that need to be resolved to really understand all of his actions and motivations, but overall I think of all of the major leak issues that came up, he handled his the most responsibly.

Still would have rather he avoided Greenwald, who's always been a sensationalist self-aggrandizer, but at least he made sure there'd be some sort of filter to at least try to protect the innocent (I think the filter should have been even tighter, but no question that there needs to be a debate about the fundamental points of the leaks, and it took a leaker to make that happen).

Comment: Re:WikiLeaks are fuckers (Score 3, Insightful) 137

by Rei (#49492381) Attached to: Wikileaks Publishes Hacked Sony Emails, Documents

Huh? Could someone explain to me that it's a bad thing that Sony was investigating subcontractors and a foreign subsidiary for signs of corruption? Not being forced to, not being charged with it, but on their own? Isn't this what we want companies to do when they find evidence that there may be illegal or immoral activity among some of their employees? Or is this some sort of horrible shocking news that a company with 140,000 employees just within the main unit itself might have to police itself?

And let's not pretend that we're idiots here and that this sort of stuff makes up even the tinest fraction of a fraction of a percent of the leaked, non-redacted material full of personal information about regular employees doing nothing wrong.

Comment: Re:Alighting on land (Score 1) 109

by Rei (#49491857) Attached to: An Engineering Analysis of the Falcon 9 First Stage Landing Failure

An empty stage with no payload gets about 1 1/2 orders of magnitude more delta-V for its last kilogram of fuel than it got for its first kilogram of fuel when the countdown hit zero at the pad. And on top of that it's already got altitude, and can use the atmosphere to shed unwanted lateral momentum or aerodynamically redirect it to change direction, with little consumption of fuel. Its these things that make flyback a lot easier than it sounds at first glance.

Still not "easy", but a lot easier.

Comment: Re:Video from the barge (Score 1) 109

by Rei (#49491839) Attached to: An Engineering Analysis of the Falcon 9 First Stage Landing Failure

Is "The Vehicle" a euphemism for something? ;) What exactly are you talking about loosing?

(And I hardly think that suggesting a more powerful RCS as a backup (backups being critically fundamental rocket design) is "redesigning the whole thing"). I don't know why they went with cold gas thrusters, but hydrazine RCS thrusters are mature tech, one that even SpaceX themselves uses - they're reliable and have a good power to weight ratio for their size. I presume there's a reason they went with nitrogen instead, but I don't know that reason.

Behind every great computer sits a skinny little geek.

Working...