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Comment: Re:Harder: self-stabilizing parachute, or balance (Score 1) 469

by steveha (#49741407) Attached to: The Brainteaser Elon Musk Asks New SpaceX Engineers

I'd argue you are going to need a heck of a lot more rocket fuel for deceleration than the mass a parachute system would require.

I'm not so sure of that. But I'm not an expert. Most of what I (think I) know about space I learned by reading through long discussions on the Internet.

In this case I am thinking back to discussions of SSTO craft and whether or not wings make sense; the experts all agreed that it would be better to land as a rocket than add extra mass to the system. And the key is that the thing lands almost empty... when it's taking off it's boosting itself full of fuel plus whatever upper stage(s) are in use; when it's landing it's just decelerating its own empty weight.

Comment: Re:Harder: self-stabilizing parachute, or balance (Score 2) 469

by steveha (#49740453) Attached to: The Brainteaser Elon Musk Asks New SpaceX Engineers

Which of these strategies do you choose:
a) Attach a parachute to the nose and let basic physics work.
b) Try to balance it atop rocket engines firing from the bottom.

I realize you were going for humor (and got it; congratulations on being moderated +5 Funny). But here's a serious answer.

It depends on what you are trying to accomplish:

If your top priority is to save the rocket stage, then you pursue an engineering strategy that has the best chance of saving the rocket booster. Maybe that means a parachute system; I don't know.

But a parachute system adds mass and complexity. It becomes another critical system ("if the parachute fails, we lose the rocket stage"). The rocket stage needs functioning rocket engines, so landing on the rocket engines is another use for those engines rather than a new system with a single purpose. All else being equal, the simpler design with fewer systems is more likely to succeed in its tasks.

If you add a few hundred kilograms of parachute system mass, that's going to mean the booster can push less mass to orbit. I'd guess that the loss factor is higher than 1... that each additional kilogram of non-fuel mass on the booster reduces the to-orbit capacity by more than one kilogram. But ask a physics expert for the actual numbers.

Note that new software to make the booster land on its engines does not add mass to the booster.

So I'd say that if your top priority is to efficiently deliver stuff to orbit, the parachute system is right out and the clear engineering decision is (b).

Comment: Re:My god you people need to think about economics (Score 1) 1065

by steveha (#49733571) Attached to: Los Angeles Raises Minimum Wage To $15 an Hour

pays their full-time workers so little that they can't afford food or a place to live without welfare and foodstamps?

Could you please provide a source for this claim? In 2014, the Wal-Mart blog fisked a hit piece that was claiming things similar to what you just claimed, and pointed out that the average hourly wage at Wal-Mart was $12.91 per hour (and that is specifically not including highly-paid management).

How does it help me that my tax dollars have to subsidize Walmart employees

Wal-Mart makes about 3% profit. In comparison, Apple Computer makes about 24% profit. Additionally, Wal-Mart has a more ethnically diverse set of employees than Apple Computer has. You seem to hate Wal-Mart; do you hate Apple Computer even more?

Also, low-income people like to shop at Wal-Mart because the low prices are a benefit. Some economists have written papers attempting to estimate the impact.

So, to summarize: Wal-Mart pays a lot of taxes, employs a lot of people at an average hourly rate 78% over the US federal minimum wage, and benefits the poor by helping them spend less on the things they need.

I just don't understand all the Wal-Mart hate.

Comment: Re:Daily carry (Score 1) 277

by steveha (#49704007) Attached to: Ask Slashdot: What's On Your Keychain?

What I have in mind for the "companion tool" is the sawblade, the metal file/metal saw, magnifying glass, and possibly pliers. Plus whatever else they can fit without making it any wider.

The problem is that they sell a knife that has everything my knife has on it, plus some or all of the above list. (Example: the Craftsman) I don't want the weight or bulk of a single tool with all of that stuff.

Comment: Re:Daily carry (Score 1) 277

by steveha (#49703877) Attached to: Ask Slashdot: What's On Your Keychain?

Brother, you better hope you never fall off a pier, or you're gonna sink like a stone.

According to my kitchen scale, everything I listed (other than the cargo pants and the extra money in the wallet) together weighs 360 grams. That's 12.7 ounces or a little over three-quarters of a pound, and it's spread across two pockets.

When I wear dress pants, like for a suit, I don't carry all that stuff but it's more because the pockets would visibly bulge and not because it's a lot of weight.

Comment: Daily carry (Score 3, Interesting) 277

by steveha (#49701709) Attached to: Ask Slashdot: What's On Your Keychain?

Almost all the time, I wear cargo pants because I want pockets.

On my keychain, I have a simple tool for poking reset buttons that are inside small access holes; I made it from a paperclip. I also have a SwissTech folding pliers tool, which I mostly use for its screwdrivers.

I also try to never be without a paper towel or at least napkin in a pocket. If someone spills coffee or something I have the fastest response time, and sometimes I want to dry my hands in a bathroom that is out of towels.

I carry a Swiss Army knife, one that isn't as thick as my forearm so it doesn't have pliers or a saw. It does have both scissors and a corkscrew. I used to carry one with a Phillips screwdriver, but the SwissTech on my keychain covers that now, and once when someone really needed a corkscrew I didn't have one. Never again! Not on my watch!

(By the way, I have always wished that the Swiss Army knife companies would make a "companion" tool, that doesn't have the basic knife blades and screwdrivers but has the saw, the file, and the other more exotic tools. I'd sooner carry two slim tools than one thing as thick as my forearm.)

I carry a Fenix E11 pocket flashlight. It runs for many hours on a single AA cell, with plenty of light, and it has a high-power mode. It claims 8 hours for the 35 Lumens mode, and less than 2 hours for the 100 Lumens mode. I haven't verified those numbers. I love this thing: it uses a Cree LED to produce a really bright white light. It's 21st Century technology; nobody could make such a thing in the 20th Century.

I carry a Spyderco "Delica" folding knife. It's just the thing for opening packages from Amazon or whatever. It locks open for safety, and I love the thumb hole for one-handed opening. (I'm amazed that they were able to patent that. Once that patent expires I reckon most lock-back knives will have a thumb hole for opening.)

I also carry a Spyderco "Rescue Jr." folding knife. It's specifically designed for tasks like cutting a seat belt when rescuing someone from a crashed car. I've never needed it for this purpose, so its other purpose is that I keep it clean, and if someone needs a clean and sharp knife for food, I offer that one. The Delica usually has little slivers of packing tape or other crud on it from opening delivery boxes.

I carry an "unbreakable" pocket comb. Not only do I use it to comb my hair, but I usually use it to prop a door open when I want to make sure the door doesn't lock closed behind me.

I carry a Fisher "space pen" in black ink, and a cheap disposable pen in blue ink. I can easily tell which is which, and if someone wants to borrow a pen I usually loan them the cheap one and don't get upset if I don't get it back. (If I loan the Fisher, I keep the cap; this reminds people that they need to give it back.)

I carry enough cash for cab fare or a meal, buried in my wallet. I try never to use this as I want it to be there if I ever need it.

I also have a backpack that has a whole bunch of stuff in it (USB charger and USB cables kit, mini first aid kit, etc.) but the above is what I carry all the time.

Comment: Enough with the Keurig hate (Score 1) 270

by steveha (#49700097) Attached to: Here Comes the Keurig of Everything

I'll state up front that I agree: Keurig coffee isn't great. The beans were ground months ago, the amount of coffee isn't a lot, and it's pretty easy to do better.

Yet these machines fill a niche. There is a reason why they are popular, and that reason isn't "everyone but you is an idiot".

Several places the Keurig works:

A small office, where a conventional coffee maker would result in throwing away half-full pots of unused coffee. The Keurig contains the mess, so the office won't have coffee grounds everywhere. (If you work at an office where nobody ever makes a mess and leaves it for others to clean up, great! Get a real coffee grinder and something better than a Keurig!)

A small restaurant like a burger shack, where sometimes people order coffee but it's not that common. The Keurig is fast and the coffee will be better than most ways a burger shack could make coffee.

At home, for someone who values convenience more highly than saving money or having tasty coffee. Or, as a way someone who doesn't drink coffee can offer coffee to guests. (The K-cup capsules have a longer shelf life than fresh coffee beans.) Also a way for someone who normally doesn't drink decaf to keep a little bit of decaf around.

I don't own a Keurig and I don't want one. But I don't sneer too much at those who choose to own one.

P.S. If you run a burger shack and you want to serve coffee, look into the AeroPress. Not as convenient as a Keurig but convenient enough, and makes better coffee.

Comment: Re:Snowball effect (Score 1) 469

by steveha (#49635289) Attached to: Why Was Linux the Kernel That Succeeded?

I think perhaps my original post doesn't give enough credit to Linus himself. I'll correct that here: not only was he diligent in rolling up contributed code, he was skillful at managing the project. Like Steve Jobs, he gave "unity of command" and made many more correct decisions than incorrect decisions.

Not only that, but he was able to adapt as the project evolved. I imagine that what he does these days is very different from what he was doing in the earliest days, but he has grown and learned and he's still doing a fantastic job.

So add that to the list: another reason why Linux became the kernel that succeeded: because it had Linus Torvalds managing it, and Linus managed brilliantly.

Comment: Re:Cuz Minix Dude Was A Old Guy (Score 5, Informative) 469

by steveha (#49632797) Attached to: Why Was Linux the Kernel That Succeeded?

Linux is not a copy of Minix, the code is quite different.

Yes. Linux and MINIX are both *NIX-style kernels. But MINIX uses a microkernel design while Linux is a monokernel.

Professor Tanenbaum famously told Linus "Be thankful you are not my student. You would not get a high grade for such a design :-)"!topic/comp.os.minix/wlhw16QWltI%5B1-25%5D

So anyone who claims that Linux is a "copy" of MINIX really doesn't know what they are talking about.

Comment: Re:Snowball effect (Score 4, Informative) 469

by steveha (#49632407) Attached to: Why Was Linux the Kernel That Succeeded?

A few more comments to expand on the above.

A project like Linux would not have been possible without the GNU project, most particularly the GCC C compiler. Commercial UNIX releases charged something like $2000 for a C compiler, but thanks to Richard Stallman there was a free C compiler for Linus to use, and Bash and everything else.

Before Linux was released, MINIX was a popular choice for a free *NIX. But licensing issues tangled up MINIX: to build MINIX you needed to buy Tanenbaum's book, get the source code that came with it, and then apply all the community patches (which had to be kept separate purely for licensing reasons). If Professor Tanenbaum could have released the source to MINIX under GPLv2, and he or someone else had worked as hard as Linus did to collect and apply patches to improve it, maybe MINIX could have gotten the snowball effect going. (Note that MINIX was what Linus was running when he wrote Linux!)

As others have noted, there was at least one BSD available around the time Linux got going, but there was the dark shadow of a lawsuit and the future of BSD looked uncertain. Linux had the advantage of being all-new code with no legal uncertainty. Absent the lawsuit, maybe BSD could have gotten the snowball going.

Comment: Snowball effect (Score 5, Insightful) 469

by steveha (#49631957) Attached to: Why Was Linux the Kernel That Succeeded?

It's not a big mystery. Linus released a primitive kernel that worked, at the right time, with the right license, and then diligently kept rolling up contributions and releasing the result.

Expanding a bit:

While the first release of Linux was primitive, it worked. People hungry for a free *NIX were able to grab it and run it. At the same time, HURD was a big research project; if you just wanted to run *NIX on your own computer, HURD was not at all ready.

Linus released it at the right time. It was just becoming possible for large numbers of people to get the kernel from him, and to send contributions back to him. Something like Linux might not have worked at all before the Internet and/or BBSs; it would have been too difficult to send releases out and collect contributions of code.

Linus used the right license. He has said that the choice of releasing under GPLv2 was the best decision he ever made. Arguably a BSD license could have worked as well, but many people have a fear that if they contribute to BSD projects, that evil companies might benefit from their work; with GPL they are comfortable contributing. Also, IBM contributed some code that uses IBM patents; because of the GPL, IBM knew that commercial entities wanting to use the patents would still need to license the patents from IBM. So Linux got the largest possible pool of contributors.

And then there is the fact that Linus worked hard managing Linux. He collected patches sent by people and rolled them in. These days he writes very little code himself; almost all he does is manage patches. I'm not sure how much code he wrote in the early days, but I think his diligent application of patches sent to him helped Linux to become stable and useful.

Given all of the above, Linux was a success, and success bred more success (the "Snowball effect"). People who just wanted something that worked could grab Linux as it worked better and better all the time; people who wanted to join an active project joined it as it was the most active project.

If Linus hadn't released when he did, another project might have gotten the snowball momentum thing going and become the big popular project. But he did, and he worked hard to keep it going, and the result is the kernel that changed the world.

Comment: Re:Apple may not keep that port forever (Score 1) 113

Dude, are you seriously this worked-up about a throwaway joke?

In any event, as the other AC noted, I was suggesting that this shipped port would never be official as it is not patented, and that a future watch would have a different and patented port.

My little bit of snark is somewhat founded on fact: Apple really does like to patent their connectors. MagSafe power connector: patented. Lightning: patented. So it is possible that Apple is going to keep this connector unofficial and undocumented, and later release a documented and patented connector. But really I was just having a bit of fun there.

Comment: Apple may not keep that port forever (Score 4, Insightful) 113

I remember the first model of iMac had an undocumented card slot. People speculated that Apple used the card slot for factory diagnostics on the iMacs; third-party companies took advantage of the slot to add 3D accelerators; and then Apple revised the iMac design and left that port out.

If Apple hasn't announced the port, the port may be gone from the next iWatch release.

Likely the problem is that there aren't enough patents on the port. Perhaps Apple will add a documented expansion port once they find some patents to encumber it.

Comment: My experience in 1989 (Score 1) 350

I lived in Aptos, CA when the Loma Prieta earthquake happened. My home was about 10 miles from the epicenter.

My home came through it okay. Our cats were pretty freaked out but I don't think we even had any broken windows. (I've heard that the waves increase in amplitude as they get further away from the epicenter, so perhaps we were lucky to be so close.)

We were without power. I think phones were down but I'm not sure.

We didn't have much else to do, so we spent a lot of time listening to the radio. We learned some useful stuff:

* stay at home; the roads should be clear for emergency services.

* Cook and eat the contents of your freezer and fridge before things go bad.

* don't drink the water without boiling it, but it's okay to flush toilets.

* (Later) Okay, the water lines tested out, so go ahead and drink the water.

Also, we heard updates about the freeway bridge that collapsed, the destroyed buildings in San Francisco, etc.

But for the most part, the people talking on the radio didn't have anything too important to say. They filled a lot of airtime with repetitions of the above points, comments like "oh this is terrible", etc. So we stopped listening after a while and read books.

Still, in any future emergency, I will want a radio. The Internet could be down but the radio will still work. Lower-tech old-fashioned solutions are great in an emergency.

Just get a low-tech radio, rather than relying on a radio feature in something complex like a smartphone. Bonus points if you have solar cells and/or a crank to power the radio.

Comment: VP9's place in the landscape (Score 4, Informative) 109

by steveha (#49420363) Attached to: Google Rolls Out VP9 Encoding For YouTube

I'm not a codec expert. I'm just a dilettante, reading blog posts from time to time. I trust that if I screw anything up, someone will correct me.

VP9 is superior to H.264. It's based on VP8, which is not as good as H.264, but it's roughly in the ballpark (meaning it's much better than H.262 used in MPEG-2). My guess is that VP9 probably isn't quite as good as H.265, but it is definitely in the ballpark.

Google got VP8 by buying a company called On2. On2 claimed that their video coder was the best thing ever, better even than H.264, but now that people have seen the source code it's clear that was just puffery. (I guess VP8 is better than the "baseline profile" of H.264, but hardly anyone uses that; they use the more advanced features of H.264 which are better than the best VP8 can do.)

Google paid over 100 million dollars for On2. I believe they did this mostly to get insurance for their YouTube business. YouTube really needs a good video coder: if the videos are terribly high in bandwidth, Google spends too much on the bandwidth and the customers have a bad experience (videos take forever to buffer on phones and/or look bad). But if H.264 is the only game in town, Google would be totally at the mercy of the patent owners. It was worth 100 million dollars to Google to hedge their bets and have a Plan B if the MPEG licensing guys ever tried to take advantage of Google's critical need for a really good video coder.

After buying On2, Google was silent for almost a year. I believe that during that time, Google lawyers were poring over the VP6 code and making sure that nobody would win a patent infringement suit when Google released the code. Then they released the source code to VP8, and forever gave up any patent rights. VP8 is completely open source and unencumbered by patents.

The general strategy of On2 seems to have been to read all the patents from coders like H.264, and then implement something similar, but different enough not to infringe. When VP8 was released, several people here on Slashdot opined that VP8 simply had to infringe on some patents, being as similar as it is to H.264. Well, it's years later now and the lawyers haven't gotten rich by suing Google yet. I think Google is in the clear.

In fact, the MPEG Licensing Authority tried to put together a patent pool, with all the patents VP8 infringes. Over a year later, there were still no patents in the pool. Google made a one-time payment to MPEG-LA, and MPEG-LA gave Google a lifetime promise to not sue. Some here on Slashdot opined that this meant Google was admitting they had infringed on H.264 patents, but no; this was unconditional defeat for MPEG-LA, who got a little money but are not able to charge royalties or in any way control what anyone does with VP8.

Now, here's the thing: VP8 was too late to win the war with H.264. All modern phones contain hardware acceleration for H.264, but likely not for VP8. But VP9 is not too late for the war with H.265; and I'm personally cheering for the BSD-licensed technology to win over the patent-encrusted technology.

I'll still count it as a win if every phone ships with H.265 and VP9. I don't need H.265 to lose to be happy.

The one thing that worries me a little bit was the recent story that someone is putting together a new patent pool, outside of MPEG-LA. The only sane reason I can imagine for this: MPEG-LA has agreed never to sue Google; maybe someone wants to sue Google and this is the first step.

My guess is that Google lawyers didn't screw anything up, and Google would eventually win the court battle; but perhaps the FUD caused by a lawsuit would make the hardware manufacturers pass on VP9. By the time the court battle was over, H.265 would be the hardware standard the same way H.264 is now.

I hope I'm just wrong about this last part. It could simply be that a few companies want to get more money from H.265.

Don't hit the keys so hard, it hurts.