... It's not that I don't agree. You might come up with the right answer for some sub-calculation. I don't know, I don't care, and I'm not even going to bother to check, much less agree. The issue is that I have already solved the problem, and arrived at the correct answer (within reasonable limits). So I don't HAVE to agree or disagree with you. I've already done it, according to the correct textbook-approved physics. AND (unlike you) I checked my work and it checks out. And unlike your answer it doesn't violate conservation of energy. ... [Jane Q. Public, 2014-09-13]

I just showed that Jane/Lonny Eachus solved the "correct answer" to a different question. Instead of holding the electrical heating power constant like Dr. Spencer did, Jane/Lonny held the source temperature constant. In that case, the electrical heating power required to keep the source at 150F drops by a factor of two after the enclosing shell is added. This shows that holding the electrical heating power constant like Dr. Spencer did is different than holding the source temperature constant like Jane/Lonny did.

... SIMPLE CALCULATION, which I have already shown several times: power "sufficient" to heat the heat source under initial conditions to 150F: 41886.54 Watts. Power input at the source remains constant. ... [Jane Q. Public, 2014-09-13]

No, in your example the electrical heating power drops by a factor of two after the enclosing shell is added. And once again, your calculation of the power sufficient to heat the heat source would be exactly the same if the chamber walls were also at 150F. But the right answer there is zero, because an electric heater wouldn't be necessary. Is this really so hard to understand, or are you deliberately spreading misinformation?

... For a given gray body, its thermodynamic temperature is related ONLY to emissivity, radiant power output, and the S-B relation (emissivity)* (S-B constant) * T^4. PERIOD. That's physics. ... [Jane Q. Public, 2014-09-13]

And that's why what you're calculating isn't Dr. Spencer's electrical heating power, because it should be "zero" if the chamber walls are also at 150F.

... I repeat: given your OWN "draw a border around it" thermodynamic reasoning, the power input (whether it is electrical, chemical, or something else) must equal that output. That's physics. You're trying to bring in energy from elsewhere, but it isn't relevant to this calculation AT ALL; it is erroneous thinking. Power input is specified to be constant. Calculating the total power in initial conditions is, as I stated before, "dirt simple". Specified emissivity is known: 0.11. Temperature is known: 338.71K. Solving for the above we get 82.12 W/m^2. We already have ALL the information needed to calculate this, given the Stefan-Boltzmann relation (above), relating these numbers. Nothing else is required, and in fact trying to introduce other factors is ERROR. That is what the accepted science says. ... [Jane Q. Public, 2014-09-13]

If you draw a boundary around the heated source, you have to account for the 0F chamber walls because they're radiating power in through the boundary. Otherwise you're not actually calculating Dr. Spencer's electrical heating power, or you misunderstand conservation of energy.

So it seems like in your interpretation, Dr. Spencer's challenge is basically: "Assuming the source temperature is held fixed, does the source temperature change after a passive plate is added?"

If the power input to the heated sphere is fixed, then the power output in the form of radiant temperature is fixed: (epsilon)(sigma)T^4. It's physics! It doesn't matter how you try to squirm and twist this. You have been owned. End of story. [Jane Q. Public, 2014-09-13]

Jane, didn't it seem odd that you interpreted Dr. Spencer's challenge to mean "Assuming the source temperature is held fixed, does the source temperature change after a passive plate is added?"

How is that different than asking "Assume x = 150 forever. Will x change?"

Isn't that a silly question? Shouldn't you at least consider the possibility that you've misinterpreted "power input to the heat source"?

Records of human civilization go back over 3000 years. Industrial civilization goes back less than 200. A good starting point is the opening of the Liverpool and Manchester Railway in 1830, the first non-demo steam passenger railway. There were earlier locomotives, but this is the moment the industrial revolution got out of beta and started changing people's lives.

Only in the last 80 years or so has human exploitation of natural resources been able to significantly deplete them. Prior to WWII, human efforts just couldn't make a big dent in the planet. Things have picked up since then.

There are lots of arguments over when we start running out of key resource. But the arguments are over decades, not centuries or millenia. The USGS issues mineral commodity summaries. There are decades of resources left for most minerals, but a lot of things run out within 200 years. Mining lower and lower grade ores requires more and more effort and energy. For many minerals, that's already happened. People once found gold nuggets on the surface of the earth. The deepest gold mine is now 4 miles deep.

For many minerals, the easy to extract ores were used up long ago. Industrial civilization got going based on copper, lead, iron, and coal found in high concentrations on or near the surface. All those resources were mined first, and are gone. You only get one chance at industrial civilization per planet.

Civilization can go on, but it will have to be more bio-based than mining-based. Energy isn't the problem; there are renewable sources of energy. Metals can be recycled, but you lose some every round. It's not clear what this planet will look like in a thousand years. It's clear that a lot of things will be scarcer.

(And no, asteroid mining probably won't help much.)

Right. Especially since, when you're looking at your smartphone, it's looking back at you.

This would be valuable for vehicle driver speech input, which has to reject a lot of noise.

I stand by my statement that parents haven't been good for the industry. I wouldn't be surprised if Amazon has spent more on fighting patent-related lawsuits than they ever received in royalties from their own patents. Bezos himself has famously expressed his doubts about the current patent system both many years ago, and again more recently. Having entered the cutthroat world of mobile devices, I can imagine the patent minefield there is a pretty massive headache for them, as it seems to be for other major players.

In any case, the One-Click patent is a perfect example of why the patent office can't be trusted to adhere to the "patently obvious" principle anymore - at least, not with software. Such a mechanism was pretty damn obvious to anyone who knew how cookies worked, and was a pretty obvious extension of that existing technology, certainly not worthy of a patent, and not for such a ridiculously long time. It was simply a legal license to extort money from competitors because Amazon happened to beat everyone to the punch in patenting a rather obvious web-based mechanism for making shopping more convenient.

I don't like your type.

No. Holding constant the electrical power heating the source is very different than holding constant the source temperature. Like Jane, let's assume the source temperature is constant (rather than the electrical heating power) and use Jane's equation and notation:

... we have 4 surfaces, which I will call 1, 2, 3, 4 moving outward, so 1 is the surface of the heat source, 2 the inside of the hollow sphere, 3 the outside of the hollow sphere, and 4 the chamber wall. T3 for example would be radiative Temperature of surface 3. ... [Jane Q. Public, 2014-09-10]

Draw a boundary between the source (T1=150F) and the chamber walls (T4=0F) before the hollow sphere is added. Power in = power out. Variable "electricity_initial" flows in at whatever rate is needed to keep T1=150F. Net heat transfer flows out from source to chamber walls. Power in = power out:

electricity_initial = p(14) = (e)(s) * ( T1^4 - T4^4 ) = (e)(s) * (8908858139.78) = 55.5913 W/m^2

Now add the hollow sphere and draw a boundary between the source (T1=150F) and the inside of the hollow sphere (T2). A different "electricity_final" flows in, and heat transfer p(12) flows out.

electricity_final = p(12) = (e)(s) * ( T1^4 - T2^4 )

Now draw a boundary between the outside of the hollow sphere (T3=T2) and the chamber walls (T4=0F): "electricity_final" flows in, and heat transfer p(34) flows out. Since power in = power out:

electricity_final = p(34) = (e)(s) * ( T2^4 - T4^4 )

Combine these two equations:

T1^4 - T2^4 = T2^4 - T4^4

Solve for:

T2 = T3 = 305.47K = 90.176 deg. F.

electricity_final = 27.8 W/m^2.

So if the source temperature is held constant at 150F, adding the hollow sphere reduces the necessary electrical heating power to keep the source at 150F by a factor of two, from 55.6 to 27.8 W/m^2.

Can we agree on that?

We don't have to break the treaty. We can withdraw from the treaty instead. From the treaty

Like disk storage today

>newfangled
correct

There, fixed that for you.

Why can't you just go up on your roof and mount a VHF/UHF antenna?

So call it a 'programming' course. Computer science marginally overlaps with programming, but a programming course is not computer science.

While we're at it, we could stop calling Computer Science a science and admit it's applied mathematics with silicon thrown in.

... input power at steady-state is fixed, and a value that we already know: 41886.54 W. ... [Jane Q. Public, 2014-09-12]

Again, we disagree about what's held fixed. That value you keep calculating isn't the constant electrical power heating the source.

In this experiment there is a "... constant flow of energy into the plate from the electric heater... flowing in at a constant rate... the electric heater pumps in energy at a constant rate. ..."

In my interpretation, Dr. Spencer's challenge is basically: "Assuming an electric heater pumps energy at a constant rate to the source, does the source temperature change after a passive plate is added?"

You've repeatedly noted that there are no other factors involved in calculating your 82 W/m^2 (41886.54 W) value. So if it's held fixed, the source temperature is also held fixed.

So it seems like in your interpretation, Dr. Spencer's challenge is basically: "Assuming the source temperature is held fixed, does the source temperature change after a passive plate is added?"

Is that right?

>Linux, cryptography, HTML and JavaScript.

That's computer science?

What about algorithm complexity analysis, type theory, normal forms and well, computer science.

As an independent software developer, I'd feel much more relieved if software patents were completely abolished. I *know* I'll never willingly infringe on someone's trademark or steal their source code. Those are things that are simple enough to check for. However, software patents are a ticking time bomb waiting to explode in your face. The sheer number of them and the impossibility of easily searching for them means any significant piece of software I write has a high likelihood of infringing on someone's patent.

At the moment, software patents are really nothing but legal nuclear missiles. Every company of significant size has to keep a significant arsenal in order to prevent getting nuked by others. So, now instead of mutually assured destruction, we have "cross-licensing". And you have the patent trolls (arms dealers) who simply leech profits from the legal system by amassing quantities of patents on the cheap, and them attempting to sue "infringing" companies, hoping that a settlement will be cheaper than a legal battle, and the damned thing is, it often works, perpetuating the whole sordid system.

Honestly, I'm not really even generally opposed to the concept of patents, or even of software patents in general. My stance is a more pragmatic one: I feel that we've seen demonstrable evidence that software patents have done a significant amount of harm to our industry, and I've seen no real evidence that the industry benefits in any real way, save for those few people that directly benefit from the "industry" around patents themselves. The government has proven itself absolutely inadequate to the task of judging the merits of these patents in a responsible way, and as such, I think we need to either revoke the ability to patent software altogether, drastically shorten the patent length, or put into law a much, much higher bar for new software patents.