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Out of the Warehouse: Climate Researchers Rescue Long-Lost Satellite Images

dak664 Re:Straight to the pointless debate (136 comments)

NASA did destroy a large amount of imagery in the 1980s, despite a public outcry I certainly contributed to. The official line was that no one knew how to read the warehouses full of 7 track tapes to for conversion to CD (the 2400 foot tape could store 5 to 140 MB depending on density). The obvious reason was no one wanted to spend the money to replace all the classified pixels with innocuous ones. And so mankind lost a large amount of wealth.

about 3 months ago
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Brookings Study Calls Solar, Wind Power the Most Expensive Fossil Alternatives

dak664 Units were chosen for the conclusion? (409 comments)

Can't be bothered to read TFA, and got a life-threatening yawn scanning the overly complicated rebuttal.

Dollars of carbon offsets vs. megawatts of installed capacity is mostly a measure of the average capacity factor during operation, possibly adjusted by the fossil fuels needed for maintenance but that is way beyond this level of analysis.

Capacity factor is something like 20% for solar (5 full sun hours most days), 40% for wind in a favorable location, 95% for nuclear until something bad happens In the end if they all have the same cost per installed MW then nuclear wins. If solar had 5x less installed cost then it wins, similarly for wind at 2.5 less.

about 4 months ago
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New Map Fingers Future Hot Spots For U.S. Earthquakes

dak664 I'm happy here in North Carolina (49 comments)

where the state legislature is not afraid to make suh environmental dangers illegal.

about 5 months ago
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TSA Prohibits Taking Discharged Electronic Devices Onto Planes

dak664 Re:Christmas is coming early this year (702 comments)

Such a bomb could well house a small battery for detonation, big enough to also power the device for a short time for the trigger swipe. Rejecting devices that don't work is absolute insanity.

about 5 months ago
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Elon Musk's Solar City Is Ramping Up Solar Panel Production

dak664 Re:Engineering win (262 comments)

But no net energy that way, just pointless multiplication of PV panels. If you want a energy return equal to the energy that went into making the first panel, the first 5 years is a loss - all it does is produce a panel. If you produce no more panels after that it takes another 5 years to recover the energy you could have used 10 years earlier to do something useful. Only after that is net energy. Some of the net energy can be used as a new source of useful energy, the rest to produce more panels and ultimately as the energy source to develop a Dyson sphere. When you stop building panels, it's all net energy.

about 5 months ago
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Elon Musk's Solar City Is Ramping Up Solar Panel Production

dak664 Re:Engineering win (262 comments)

Energy Return on Energy Invested (EROEI) of PV can be 3-4 in favorable cases but the rate of return is also important if you want to multiply the resource. If energy parity for the first panel takes 5 years then its output could produce a second panel in another 5 years. So for 10 years you get no net energy, after which you can tap some of the output for other uses while still continuing to add panels at an accelerating rate. Doesn't matter if you start with 10 or 10 billion, there is still no net energy for 10 years. Starting with a large number could cause energy shortages and social unrest which could end the sustainable growth entirely.

Yes, we should have started 20 years ago.

about 6 months ago
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South African Schools To Go Textbook Free

dak664 Re:This always ends well.... (76 comments)

As always, there is plenty of free and superior course material. The real graft is at whatever level can issue the mandate that the latest and priciest must be used. Nothing but the best for our children, etc.

about 6 months ago
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Google Foresees Ads On Your Refrigerator, Thermostat, and Glasses

dak664 Does anyone look at ads anyway? (355 comments)

I have script and ad blocks and bogus host file entries to speed up browsing but can honestly say I don't pay attention to ads when they get through, When looking for something to buy I do the search and find it hard to believe unsolicited ads bring in any customers.

Are there really people who click through and buy something because an ad says they need it?

about 7 months ago
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How To Build a Quantum Telescope

dak664 Re:The image formation process is still the same (60 comments)

That's the infinite plane wave approximation for lattices of infinite extent. Scattered spherical waves from finite objects will result in some energy passing through the aperture for every spatial frequency. Although it could be difficult to sort out which frequencies are contributing (aliasing). Analysis of the through focal series can do that, also changing the convergence of incident illumination.

But if the source is known to be two points, accurate measurement of the spacing between the resulting PSFs is limited only by signal to noise.

about 8 months ago
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How To Build a Quantum Telescope

dak664 Re:The image formation process is still the same (60 comments)

Yes, and what's more diffraction causes no fundamental limit to resolution, it just happens to be the distance between the first zeroes of an interference function. For two point sources of equal intensity that leads to an easily seen contrast difference of around 25% but trained observers can detect 5%. On electronic displays the contrast can be cranked up arbitrarily.

The fundamental limit to resolution is signal-to-nose.

about 8 months ago
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Ask Slashdot: What Essays and Short Stories Should Be In a Course On Futurism?

dak664 Technocracy Study Guide (293 comments)

http://www.technocracy.org/stu...

Written mostly during the 1930s by M. King Hubbert of peak oil infamy. Describes a sustainable society directed by science instead of wishful thinking.

about 10 months ago
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Mt. Gox Shuts Down: Collapse Should Come As No Surprise

dak664 Re:Can someone explain this theft? (232 comments)

Isn't the history of a bitcoin included in the block chain? And the stolen bitcoins identifiable?

If so whoever tries to use one risks being traced, moreover the recipient could be considered as knowingly accepting stolen goods..

Sort of like the haul from a bank robbery having an indelible "This money stolen from Bank X" printed on every bill.

about 10 months ago
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Fixing Broken Links With the Internet Archive

dak664 Re:Please no? (79 comments)

Presumably the wayback redirect would tell you the page does not exist, but the he last time it could be loaded, this was the content. What's wrong with that?

about a year ago
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Ask Slashdot: What's the Most Often-Run Piece of Code -- Ever?

dak664 Re:idle time (533 comments)

The idle loop is alive and well in embedded systems. In some cases energy use is minimized by using a slow clock chosen for some small fraction of idle time, in others by sleeping between bursts of fast processing.

x86 idle power reduction under unix started sometime in the late 1990s
https://blogs.oracle.com/bholler/entry/the_most_executed_code_in

Other OS starting using it around 2000
http://en.wikipedia.org/wiki/System_Idle_Process

Thus seti@home launched in 1999 could legitimately claim it made use of otherwise wasted CPU cycles on the Mac and Windows 95 clients.

about 10 months ago
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Ask Slashdot: What's the Most Often-Run Piece of Code -- Ever?

dak664 Re:idle time (533 comments)

On modern operating systems the idle loop is never coded in a high level language. It is painstakingly optimized in assembly language, for maximum speed.

about a year ago
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Windows 9 Already? Apparently, Yes.

dak664 Re:9.1 (1009 comments)

And a wireless mouse under the covers.

about a year ago
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Why We Think There's a Multiverse, Not Just Our Universe

dak664 Re:Greeks had that (458 comments)

Another advantage not mentioned in the wiki article was that someone could hold an office only once. That meant when some crises occurred there were probably several people immediately at hand who had previous experience directing public policy.

about a year ago
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How Asimov's Three Laws Ran Out of Steam

dak664 Re:ethics of killing and warfare (153 comments)

Moral killing may not be that hard to define. Convert the three laws of robotics into three laws of human morals by taking them in reverse order:

1) Self-preservation
2) Obey orders if no conflict with 1
3) Don't harm others if no conflict with 1 or 2

To be useful in war an AI would have to have to follow those laws, except that self-preservation would apply to whichever human overlords constructed them.

about a year ago
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The Quietest Place On Earth Will Cause You To Hallucinate In 45 Minutes

dak664 Re:Vacuum (332 comments)

I confess to being stupid but endeavor to learn. Your blind spot seems to be the assumption that in equilibrium the radiation from an object must re-emit the same energy per Hz as acquired from the absorption spectrum. Classical thermodynamics, while powerful, leads to an incomplete picture. Statistical thermodynamics says the incoming energy is rapidly randomized among probable states (fortunately for life some of those may start the electron transport chain). The excess energy populates an increasing number of available states until enough of them dissipate (or in vacuum radiate) the excess energy away. Which has very little connection with some hypothetical temperature of the incoming radiation.

1 year,16 days

Submissions

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Duke professor, billionaire debate higher education's value on '60 Minutes'

dak664 dak664 writes  |  more than 2 years ago

dak664 (1992350) writes "Vivek Wadhwa, a former high-tech entrepreneur in the Triangle who now teaches at Duke and Stanford universities, is matched against billionaire Peter Thiel Sunday night in a CBS "60 Minutes" segment exploring the value of a college degree.

Thiel is paying 20 young people $100,000 a year to drop out or not go to college in order to pursue new business ideas.

Wadhwa says Thiel is sending the wrong message."

Link to Original Source

Journals

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Nothing happened today

dak664 dak664 writes  |  more than 3 years ago

So this is just random gibberish. Move along, nothing to see here.
gkEDdlgmEmDGEkLjVmwjov

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