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Comment: Re:Car Dealers should ask why they're being bypass (Score 1) 94

by TechyImmigrant (#47915529) Attached to: Court: Car Dealers Can't Stop Tesla From Selling In Massachusetts

My algorithm for buying a new car is:
1) Spend about a year deciding what I want and/or need.
2) Simultaneously, start saving the cash.

It's not like you can't tell when a car is nearing the end of time, relative to whatever your own level of love for car maintenance is.

When the time comes, you know what you want and you've got the cash, which makes the bargaining rather trivial.

Comment: Of course you use force control to run fast. (Score 5, Insightful) 35

by Animats (#47915427) Attached to: MIT's Cheetah Robot Runs Untethered

That article is written as if that crowd invented running using force control. Of course you use force control. Everybody in the field knows that by now. I patented that 20 years ago. The Scout II robot at McGill, developed by Prof. Martin Buehler, used that approach. Buehler went on to become the designer of BigDog, but never got much public credit for it and quit to work for iRobot.

The key to legged running in non-trivial situations is careful management of ground traction. Traction is first priority, then balance, then foot placement. Historically, everybody worried about foot placement first, but that turns out to be backwards. As soon as you get off flat surfaces with good traction, traction control dominates.

The next unsolved problem in that area is not going fast. It's starting, stopping, and turning fast. Most of the legged robots accelerate very slowly, and don't make abrupt high-speed turns. Big Dog starts by trotting in place, then extending the gait out. Starting fast, stopping fast, and turning fast are all facets of the same problem. You have to take one stride using completely different control algorithms than you use for normal locomotion. That's all I'm going to say about this for now.

Comment: Jane/Lonny Eachus goes Sky Dragon Slayer (Score 1) 154

by khayman80 (#47914831) Attached to: 3 Short Walking Breaks Can Reverse Harm From 3 Hours of Sitting

... Since emissivity doesn't change the input required to heat source to achieve 150F is constant, regardless of where it comes from. But as long as the walls of the chamber are cooler than the source, NONE of the power comes from the chamber walls... [Jane Q. Public, 2014-09-15]

But if the chamber walls are also at 150F, they're not cooler than the source and the input required to heat the source to 150F is zero.

Comment: Jane/Lonny Eachus goes Sky Dragon Slayer (Score 1) 154

by khayman80 (#47914733) Attached to: 3 Short Walking Breaks Can Reverse Harm From 3 Hours of Sitting

... do you still maintain that after the enclosing passive sphere is inserted, the central heat source raises in temperature to approximately 241 degrees F? You haven't said anything about that in a while, so I'm just checking. [Jane Q. Public, 2014-09-15]

Once again, if the electrical heating power is held constant, the heat source has to warm. Once agin, Jane's heat source keeps the source temperature constant by halving its electrical heating power. Jane/Lonny Eachus might ask himself why his required electrical heating power goes down by a factor of two after the enclosing shell is added.

Comment: Jane/Lonny Eachus goes Sky Dragon Slayer (Score 1) 154

by khayman80 (#47914709) Attached to: 3 Short Walking Breaks Can Reverse Harm From 3 Hours of Sitting

... Of course it wouldn't need a separate heat source if its environment were maintained at 150 degrees. ... [Jane Q. Public, 2014-09-15]

In other words, the electrical heating power is determined by drawing a boundary around the heat source:
power in = electrical heating power + radiative power in from the chamber walls
power out = radiative power out from the heat source

Since power in = power out:

electrical heating power + radiative power in from the chamber walls = radiative power out from the heat source

Right?

Comment: Re:If there was only one viable choice ... (Score 1) 101

by Dutch Gun (#47914393) Attached to: Court Rules the "Google" Trademark Isn't Generic

It wasn't just about interface. People tend to forget how search engines did an absolutely horrible job of intelligently ranking the sites you wanted to see. They relied primarily upon keywords and other sort of fairly obvious metrics on the site itself, which of course can be significantly gamed. I've seen "tag clouds" on some sites and blogs, which I'm presuming is due in part to one of the historical metrics being how large a visible word is on a site - the obvious presumption being that keywords in titles should be weighted more heavily.

Google showed up and not only provided a vastly superior interface (look, all you want is to search, right? Here you go!), it also was the very first search engine that actually had a really good chance at returning the most relevant search as the very first result due to it's PageRank algorithm - hence, the "I'm feeling lucky!" button. Such a button would have been labelled "I'd love to win the lottery!" for other search engines, since the results you were looking for might well be on page 13 of a hundred pages of results returned.

One could argue that although Google did not invent web searching, they may have been the first ones to invent truly effective web searching algorithms. It was only the pressure of Google's overwhelming effectiveness that forced other companies to significantly improve their own search engines. Even today, other companies have a hard time even reaching parity with Google search, let alone exceeding it, although such metrics are obviously somewhat subjective.

Comment: Jane/Lonny Eachus goes Sky Dragon Slayer (Score 1) 154

by khayman80 (#47914127) Attached to: 3 Short Walking Breaks Can Reverse Harm From 3 Hours of Sitting

You asked me if I believed the power usage of the heat source would be the same if the walls were also at 150F. The answer is YES, and here is why: You are proposing to bring the whole system up to a level of higher thermodynamic energy, rather than just the heat source. And you are somehow proposing that it doesn't take more energy to do that. But of course it does. The power required to bring the heat source up to 150F remains the same, because the Stefan-Boltzmann law says it has to be. But NOW, you are ALSO bringing the walls up to that higher temperature, and THAT would require even more power (because of the slightly larger surface area). [Jane Q. Public, 2014-09-15]

Again, that's completely ridiculous. I've explained why the power used to set the chamber wall temperature is irrelevant. Any power used is simply being moved from some point outside the boundary to another point which is also outside the boundary. Because that power never crosses the boundary, it's irrelevant.

For example, you could simply place the vacuum chamber somewhere with an ambient temperature of 150F. That would require zero power, but once again it doesn't matter even if the vacuum chamber were on Pluto. Because that power never crosses the boundary.

Either way, as long as the chamber walls are held at 150F, the heat source would need absolutely no electrical heating power to remain at 150F. Zero. Period.

You asked me if I believed the power usage of the heat source would be the same if the walls were also at 150F. The answer is YES... [Jane Q. Public, 2014-09-15]

Here's our disagreement. Conservation of energy demands that a heat source at 150F requires no electrical heating power inside 150F vacuum chamber walls.

Comment: Jane/Lonny Eachus goes Sky Dragon Slayer (Score 1) 154

by khayman80 (#47913475) Attached to: 3 Short Walking Breaks Can Reverse Harm From 3 Hours of Sitting

You're either disputing conservation of energy, or you're not calculating the actual electrical heating power. If you're calculating the actual electrical heating power, your calculation has to account for radiation from the chamber walls because it passes in through that boundary. That's why the electrical heating power would be zero if the chamber walls were also at 150F!

Nonsense. This is textbook heat transfer physics. We have a fixed emissivity. Therefore, according to the Stefan-Botlzmann radiation law, the ONLY remaining variable which determines radiative power out is temperature. NOTHING else. That's what the law says: (emissivity) * (S-B constant) * T^4. That's all. Nothing more. This makes it stupidly easy to calculate the radiative power out, and therefore the necessary power in. [Jane Q. Public, 2014-09-15]

It's "stupidly easy" to calculate radiative power out and power in through what boundary? The boundary you're describing has to include the source's radiative power passing out through it, without including radiative power from the chamber walls passing in. I think that's impossible, but feel free to explain exactly where such a boundary would be drawn.

One question only: do you agree with the Stefan-Boltzmann relation: power out P = (emissivity) * (S-B constant) * T^4 ?? No more bullshit. "Yes" if you agree that equation is valid, or "No" if you deny that it is valid. Just that and no more. I'm not asking your permission. I'm just trying to find out whether you're actually crazy or just bullshitting. [Jane Q. Public, 2014-09-15]

Once again, I agree that "power out" through a boundary drawn around the heat source is given by the Stefan-Boltzmann law. But I've obviously failed to communicate that the power from the chamber walls has to pass in through that boundary, so you're only using half the equation to calculate the electrical heating power.

The REASON there would not be as great a power DIFFERENCE if the chamber walls were also at 150F, is that the walls would themselves be radiating more power out, so there would be less heat transfer (in that case 0). It is NOT, as you assert, because the heat source would be using less power. That's false, by the S-B equation. Its power output remains the same because (Spencer's stipulation) the power input remains the same. The reason my solution does not violate conservation of energy, is that the power consumption of the chamber wall is allowed to vary. THAT is where the change takes place, not at the heat source. Again, this is a stipulation of Spencer's challenge. Once again: power out of heat source remains constant, because P = (emissivity) * (S-B constant) * T^4. There is nothing in these conditions that changes this at all. Therefore, BECAUSE the power out and power in at the heat source remain constant, so does the temperature. It's all in that one little equation. [Jane Q. Public, 2014-09-15]

Once again, no. Draw a boundary around the heat source:
power in = electrical heating power + radiative power in from the chamber walls
power out = radiative power out from the heat source

Since power in = power out:

electrical heating power + radiative power in from the chamber walls = radiative power out from the heat source

"Power in" has to include the radiative power passing in through the boundary. Otherwise energy isn't conserved, because power in = power out through any boundary where nothing inside that boundary is changing with time.

... EVEN IF we accepted your idea that the "electrical" power required to be input to the heat source is dependent on the temperature difference between the heat source and chamber wall (a violation of the S-B law), you still contradict yourself because your answer of a hotter heat source would still then require MORE power, because the difference is greater. But that is not allowed by the stated conditions of the experiment, and you keep glossing over that simple check of your own work which proves it wrong. So no matter how you cut it, your answer is wrong, by your own rules. ... [Jane Q. Public, 2014-09-15]

Once again, no. I've already shown that the electrical power in my solution remains constant.

Once again, that's because I'm correctly applying the principle of conservation of energy to determine the electrical heating power.

It seems like we can't agree that "power in" includes the radiative power passing in through a boundary around the heat source. Is that because you disagree that power in = power out through any boundary where nothing inside that boundary is changing with time? Or is it because you disagree that the radiative power from the chamber walls passes in through a boundary around the heat source?

The REASON there would not be as great a power DIFFERENCE if the chamber walls were also at 150F, is that the walls would themselves be radiating more power out, so there would be less heat transfer (in that case 0). It is NOT, as you assert, because the heat source would be using less power. ... [Jane Q. Public, 2014-09-15]

That's absurd. A 150F plate surrounded by 150F chamber walls wouldn't need an electrical heater at all. Period. The electrical heating power would be exactly zero. Maybe you're mistaking "electrical heating power" with "radiative power out"? Or maybe you're missing half the equation necessary to calculate the required electrical heating power, and it's leading you to bizarre conclusions?

Comment: Clueless (Score 1) 52

by Animats (#47911665) Attached to: New Data Center Protects Against Solar Storm and Nuclear EMPs

This keeps coming up. The effects of an electromagnetic pulse and a solar storm are completely different. EMP is a big RF pulse with a risetime in the nanoseconds. This is a risk to input transistors connected to external wiring. Twisted pair, coax, and small mobile devices are relatively immune. Fiber optics are totally immune.

Solar storms induce DC voltages across long distances of conductive landscape. This is a risk only to transformers with grounded center taps connected to long transmission lines.

Here are the PJM power grid emergency procedures for geomagnetic events. They had to be implemented for a day two years ago. Almost nobody outside of power grid operators noticed.

Comment: Re:And that is why the Spock/Logic way is incomple (Score 1) 855

by TopherC (#47911663) Attached to: Why Atheists Need Captain Kirk

I like that quote, even though it was a bit difficult to digest. The English language has evolved in the past century in a way that demands much less of the reader and conveys much less complexity and accuracy.

I wanted to add, somewhere, my $.02 about "faith." I'm told that early (1st century) Christians used what-we-translate-as-faith to be a kind of radical trust. More verb than noun. A trust in an idea, not fully understood or rationalized, that allowed them to lead lives that were unselfish, bold/foolhardy, non-violent extremists, anti-establishment, share-the-wealth sorts of people. The idea is that for them, faith was incompatible with certainty. Conviction deletes the possibility of faith. They did not have proof of deity, a consistent doctrine, etc. Reason was encouraged and appealed to, but knowledge was known to be incomplete.

What most people think about religion is that it is a doctrine (teaching or authority-based knowledge) that requires unwavering belief without question or reason. (My perspective here is Christianity rather than all religion, but I suspect that most major world religions are similar in this way.) Yet this is probably not a genuine or original form of any given religion but instead what human nature and politics have deformed religions into over time. People want to be told what to believe, and people who desire power cannot help but use fear and shame to great effect. I think modern-day Christianity is more about manipulating people and in most respects is the exact opposite of its earliest incarnations.

Science today has some of the same struggles. Science itself is an art, since the more precisely one tries to define it, the more inaccurate that definition becomes. Scientific knowledge is a little bit of an oxymoron since science can be described as a tool for disproving what is not true more than it is a means of proving what is true. This is true on all scales of complexity, but it's most evident at the reductionist frontier of particle physics and cosmology. The standard model is not logically consistent with general relativity, yet both theories are spectacularly successful. And there are problems of naturalness, etc. It is not tenable, not reasonable or scientific, to think that our most successful scientific theories are set to last. Modifications need to be made, and probably in big, fundamental, philosophically-challenging ways. The history of the development of physics is full of cases like this and physics is by no means "done." But people are eager to philosophize based on "what scientists know", and they are eager for answers from authority.

Authentic science, like authentic religion, is not authority-based. I'm not saying anything negative about consensus, just that there is always room for new theories and new experiments regardless of credentials. Data does not respect authority. And I don't believe there needs to be any contradiction between the two approaches of religion and science, as long as we are referring to religion as a searching process not a placating drug. Both science and religion address the basic problem of doing the best we can today with what little we know. Good scientists know that good questions are better than "right" answers, and good ... what, "religious" folk ??? (atheists included) ... know that it's better to be loving than right.

I suppose most of these ideas come from two books that might seem diametrically-opposed: The Underground Church, and Dreams of a Final Theory.

Comment: Re:it's means it is (Score 4, Insightful) 130

by Dutch Gun (#47904885) Attached to: 3D-Printed Car Takes Its First Test Drive

I think people are just getting a little tired of the 3D printing hype. Yes, it's a cool emerging technology, but the sensationalism of these headlines and articles are a little grating at this point.

Calling it a "3D printed car" is not exactly lying, but it borders on disengenuous, seeing that the guts of the car are, of course, still manufactured the traditional way. It's apparently the body and frame that were printed, from what I can tell. Seriously, would that have been so damn hard to mention in the summary or the article? Oh, but that sounds a lot less impressive, doesn't it...

It was stated in the article that the car had 40 parts. I'm pretty sure they meant there were 40 printed parts, because there's no way in fuck you can build a car in 40 parts, unless you're conveniently counting the engine and frame as a single "part". Or maybe they're just counting each pre-packaged assembly as a "part".

I don't think people would complain quite as much if there was any real semblance of critical reporting here - less hype and more tech.

Comment: Only Apple can't make sapphire work. (Score 0) 199

by Animats (#47903731) Attached to: Sapphire Glass Didn't Pass iPhone Drop Test According to Reports

Everybody who gets an iPhone immediately puts it into a rugged, generally rubberized, case.

That's pathetic. All that effort to make a super-thin device, and you have to put it another case to protect it. Nokia would laugh.

Get a non-toy phone.

It's amusing that Apple can't get sapphire-coated glass to work. Sapphire glass for checkout scanners is a standard product. Every Home Depot checkout scanner has sapphire-coated glass. People slide metal tools across those for years without damage.

An age is called Dark not because the light fails to shine, but because people refuse to see it. -- James Michener, "Space"

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