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Comments

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DARPA Developing the Ultimate Auto-Pilot Software

joe_frisch Re:Pilots crash planes (66 comments)

The full report on the AF447 flight paints a somewhat different picture than the media described. The pilots were at fault, but not as blatantly as it seemed. A badly designed controls interface hid the airspeed indications (which were correct but so low that the computer flagged them as invalid).

The trim feedback system normally adjusts the elevator trim so that the joystick can be kept centered. In this case, since the aircraft pitch wasn't responding normally, the slightly back stick position caused the trim to continuously put in more up elevator.

The pilots set the correct pitch and full power - in normal conditions this would have worked. The problem here was that since the plane was in a deep stall, the angle of attack was much larger than the pitch angle.

The stall indicator cuts out when the angle of attack and airspeed are out of a reasonable range. At one point early on, the co-pilot started to put the nose down, but the stall alarm turned ON (because the angle of attack was no longer to large as to be invalid), and in response he pitched up again - probably having confused the stall indicator with some other warning. Note that the plane was in the coffin-corner where stall speed and mach overspeed are quite close together.

The pilots *should* have figured this all out, but it wasn't trivial to do so with the information they had available. Airliner accidents are almost always due to a long chain of unlikely problems.

5 hours ago
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Americans Uncomfortable With Possibility of Ubiquitous Drones, Designer Babies

joe_frisch Re:Designer babies (152 comments)

On of the problems is that some very positive features may be associated with some very negative ones. Is compulsive behavior linked to high productivity in some jobs? Great leaders and great revolutionaries may have similar traits. Is artistic ability linked to depression?

I fear creating a world full of "ordinary" people, because we don't want a Cesar.

yesterday
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Kepler-186f: Most 'Earth-Like' Alien World Discovered

joe_frisch Re:Should we say hello? (221 comments)

Some human organizations have survived ~1000 years, its taken ~500 years to finish some cathedrals, so the time scale isn't completely unreasonable. OTOH, I don't think advertising our presence is the best idea.

2 days ago
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Kepler-186f: Most 'Earth-Like' Alien World Discovered

joe_frisch Re:Great, now all we need to do... (221 comments)

They are really hard. Hard to imagine a magnet that has enough strength to weight to collect enough hydrogen, and much of the hydrogen isn't ionized anyway. Then you need to be pretty efficient or you generate so much drag collecting the hydrogen that you don't gain from fusing it. Then there is the problem that it is almost all H1, not deuterium, and H1 fuses incredibly slowly, so its hard to imagine the reactor.

No crazier than other ideas, but really really hard.

All this is a bit silly. The equivalent of the first human to paddle a log across a river arguing that crossing the ocean is impossible because your arms would get tired. (only the increase in technology is much worse for interstellar from where we are now).

2 days ago
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Kepler-186f: Most 'Earth-Like' Alien World Discovered

joe_frisch Re:Great, now all we need to do... (221 comments)

Dust could be an issue - at near C, it will look like very heavy high energy particles. The interstellar gas looks like a very high intensity proton radiation environment.

You are right that slowing down is a big issue. Guess you need to convince the guys on the receive end to build a deceleration laser. ("we are aiming straight at your planet at 0.7C, you can build a laser to slow us down, or not - your choice.....")

There is some drag on the sail from the interstellar medium, but not enough to slow down in a reasonable time.

2 days ago
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Kepler-186f: Most 'Earth-Like' Alien World Discovered

joe_frisch Re:Great, now all we need to do... (221 comments)

Light sales (x-ray). A 10KeV X-ray laser (about 0.1 nanometer wavelength) with a 10 kilometer final focus optic has a divergence of 1e-14, will be 10 kilometers wide at 1e18 Meters or about a light-year. the final lens could probably be a 10km zone plate out by the orbit of Neptune. The 10KeV X-rays will be stopped in a few microns of (tungsten) sail material.

The sail will weigh 10s of tons. Need a laser power around a few to tens of terawatts to get around 1G.

All depends on what you consider "plausible".

2 days ago
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Apache OpenOffice Reaches 100 Million Downloads. Now What?

joe_frisch Re:always come back to MS Word (275 comments)

Same here. I want to move away from MS but (in my case) LibreOffice doesn't quite make it. It does 90% of what I need, but I also need the remaining 10%. Also too many other people use MS products and the 95% compatibility just isn't enough.

The one exception is LibreOffice draw which I use as my primary quick sketch / drawing package.

2 days ago
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'Thermoelectrics' Could One Day Power Cars

joe_frisch Re:E = (T2-T1) / T1 (173 comments)

In mobile systems (cars, planes, etc), the extra hardware to extract energy from the waste heat adds weight and can reduce the overall efficiency of the vehicle. In fixed power-plant type applications they already extract energy down to pretty low discharge temperatures.

This idea has been around for a LONG time - I remember in the early 70s reading an article in popular science on a system to extract waste heat from car engines. It "worked" but the added weight and expense made it not worth the effort.

An interesting tidbit is that modern aircraft jet engines are LESS efficient than piston aircraft engines in terms of mechanical energy delivered for the fuel used. Almost all modern transport aircraft use jets because the power to weight is so much higher than for piston engines that the overall efficiency of the aircraft is better than with piston engines.

3 days ago
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52 Million Photos In FBI's Face Recognition Database By Next Year

joe_frisch Re:Need laws on effects, not technologies (108 comments)

The law should limit what they can collect as well as what they can do with data they have. I don't see any alternative to laws to prevent the government from having access to data. They have the resources to get pretty much any data they want, certainly a non-expert will not be able to secure their data against the NSA.

3 days ago
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52 Million Photos In FBI's Face Recognition Database By Next Year

joe_frisch Need laws on effects, not technologies (108 comments)

We need clear laws on what law enforcement and government agencies are allow to know about us, not how they gain that data. Do we want the government to be able to track everyone's motions. If not, then it shouldn't matter if they use cell phone data, face recognition, satellite photos, tracking implants, or invisible flying monkeys that follow people around, it shouldn't be legal.

If we do want to allow the government to track out motions, then we should let them us the least expensive, most efficient technology available. Simply making it difficult but not impossible is crazy , WE (the tax payers of the country in question) are the ones paying for the service, we are just making it more expensive for ourselves.

People clearly disagree on how much tracking is OK, but that it true for a wide variety of societal decisions, we should go through the normal legislative process.

3 days ago
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52 Million Photos In FBI's Face Recognition Database By Next Year

joe_frisch Re:Don't take the job (108 comments)

You may have the luxury of choosing between multiple job offers, but many people don't.

3 days ago
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Will This Flying Car Get Crowdfunded?

joe_frisch A pony with sparkles (157 comments)

5 year old girls want a pony with sparkles - or maybe a unicorn, but they can't have one. Commuters want a flying car but they can't have one either.

Aircraft fly by moving a lot of air downward in order to counteract gravity. If they move less air quickly the total power the need goes up (force goes as mass/second * velocity, power goes as mass/second * velocity SQUARED). So, in order to be efficient they need to have very big wings, or very big helicopter rotors, or very big low density volumes.

Look at all conventional aircraft, they have BIG wings. Those wings will not fit on roads. So if you want a flying car you are left with a clunky folding wing contraption that is a terrible car AND a terrible airplane. No matter how pretty the CGI or fiberglass mock-up design it just isn't going to work.

5 days ago
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Obama Says He May Or May Not Let the NSA Exploit the Next Heartbleed

joe_frisch Re:The President doesn't micro-manage this stuff (134 comments)

If a military organization discovers a weakness in an enemy country's defenses, it is perfectly reasonable for them to keep this weakness secret and use it in future conflicts. Cyber security is different. Since we are all using roughly the same technology, by discovering a weakness in the defenses of another country, they have discovered a weakness in OUR defenses.

At the moment the US has a strong advantage in conventional warfare, but not so much in cyber warfare. In looking at overall national defense, patching holes in everyone's cyber defenses reduces the effectiveness of cyber war (where we are not clearly dominant), and moves the focus to conventional war where we are dominant.

about a week ago
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IRS Misses XP Deadline, Pays Microsoft Millions For Patches

joe_frisch Re:Stupid to use Windows in the first place (322 comments)

Even if in a particular application the total cost of using the proprietary software is lower because it makes workers more productive? Remember that the cost of the person using a computer is far higher than the cost of the computer and software installed on it. A full time person costs ~$100K. A 10% efficiency change dwarfs most software costs.

about a week ago
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Can You Buy a License To Speed In California?

joe_frisch Re:We have those in South Carolina too (325 comments)

I believe you are honest, I believe a lot of police are, but it seems like these plates create the potential for favoritism. No bribery, but the natural tendency for people to want to support people who support them. In a similar fashion an anti-police bumper sticker might well encourage a police officer to treat someone more harshly.

Police have a lot of leeway in traffic stops - which is fine, but it also makes it very easy for them to be influenced by a variety of subtle biases.

about a week ago
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Nat Geo Writer: Science Is Running Out of "Great" Things To Discover

joe_frisch Out of easy experiments? (292 comments)

We are not out of physics - still lots of big mysteries: Dark matter, dark energy, unification, quantum gravity etc. It is possible though that we are running out of small scale experiments and future ones will on average become more expensive and take longer. Bigger accelerators. Bigger telescopes etc.

I hope this isn't true and that people can become more clever, but it might be.

about a week ago
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Ask Slashdot: How To Start With Linux In the Workplace?

joe_frisch What is the use case? (451 comments)

What are they doing with the computers? Digital design? Publishing a newspaper? Handling invoices? Controlling a nuclear power plant? Software development? Defense work? Managing a taxi service?

The answer will depend entirely on the type of use.

about two weeks ago
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Meet the Diehards Who Refuse To Move On From Windows XP

joe_frisch Re:Viva La XP! (641 comments)

I have a XP based oscilloscope - 20Gs/s, 3.5GHz, deep memory. The vendor won't upgrade it. A replacement is probably >$20K. One of its features is that it can run on the network, but that requires security. Our lab has other expensive XP based hardware as well.

I don't think Microsoft should be *required* to keep supporting XP, but there are a lot of people who are using it because it is the most practical choice for their application.

For normal desktop computing I upgrade hardware and software on a reasonable schedule. Laboratory equipment tends to have a much longer useful life than desktops and is much more expensive. Most of the computers I use are modern, but most of the $$ value of computers are expensive specialized lab equipment.

about two weeks ago
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Elite Violinists Can't Distinguish Between a Stradivarius and a Modern Violin

joe_frisch Re:The value of a Stradivarius (469 comments)

Quality of sound is inherently subjective. The sounds were not identical, just the double blind preference did not favor the Strad. If someone believes that a Strad (or tube amp, of vinyl, or whatever) sounds better, then does it make any sense to argue? This is 100% about entertainment, so the Strad may be better IF you are allowed to tell the audience that is what you are playing.

Personally I wouldn't buy a $1M violin (if I still played and could afford it), .and I also don't have a tube amp and got rid of my vinyl records many years ago. However if someone receives more enjoyment from those things than without them, its their $$$ to spend as they like.

about two weeks ago

Submissions

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Ask Slashdot: Computers for the elderly

joe_frisch joe_frisch writes  |  more than 2 years ago

joe_frisch (1366229) writes "There is a growing group of elderly computer users who have learned to be productive with a particular interface, say windows XP and office 2003, and who do not have the interest or energy to learn something new like Windows 7 or the office "ribbon". They continue to use aging and unreliable computers because they do not know how to order new computers with the older interface. Many of these users are relatively wealthy so this is potentially a valuable market.

While it it possible to cobble something together, with time it becomes increasingly difficult, especially for the often minimally computer-literate people in this market. In addition, as older software is no longer supported it will be increasingly susceptible to viruses. What would be ideal is a old style interface to updated programs and operating systems.

What are the options — and remember the target market is NOT people who read slashdot, suggesting that they use Debian is not going to work."

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