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People Who Claim To Worry About Climate Change Don't Cut Energy Use

dhj Re:No real surprise (710 comments)

Wish I had mod points to vote you up. Cheers for not blindly following dubious "science" and calling out those who do. Not only is it a shitty study with corresponding shitty methods and assumptions it vaguely admits as much (while keeping a sensational and contradicting talking point). The effect of people who are concerned more about global warming use more energy is "largely due to the effect of age, as older households were much more likely to agree with this statement, and also had lower energy consumption". When that effect was accounted for there was "only a weak trend" to show that people who care about the environment cut their energy usage... So when you account for the effect of "old people use less energy and don't give a shit about global warming" then you get the effect of ... people who care about global warming only do a little to reduce their energy usage.

This study is ridiculously pathetic and says more about its fake-spin-science-touting promoters than it does about anything.

about 4 months ago
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O3b Launches Four More Satellites To Bring Internet To 'Other 3 Billion'

dhj Re:Throughput? (80 comments)

Good question. According to their FAQ their satellites will be capable of delivering "gigabytes of capacity". Obviously that would be split among individual beams, and sliced up into smaller pieces for individual service providers and again for individual people. It is based on the Ka-Band which currently supports about 500 megabits per beam (with multiple beams).

about 5 months ago
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O3b Launches Four More Satellites To Bring Internet To 'Other 3 Billion'

dhj Re:Ping (80 comments)

The 150 ms / 300 ms round trip was the "simulated" ping time. They ran real ping tests over 24 hours to the most remote coverage location at the Cook Islands.

One was from Surrey, England to the Cook Islands and averaged 570-800ms round trip -- the other was from California, US to the Cook Islands and averaged 420-620ms round trip. These were performed once per second for 24 hours and can be found in Figure 5 of the research paper.

about 5 months ago
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Consciousness On-Off Switch Discovered Deep In Brain

dhj Interesting, but N=1 and... (284 comments)

From TFA:

Anil Seth, who studies consciousness at the University of Sussex, UK, warns that we have to be cautious when interpreting behaviour from a single case study. The woman was missing part of her hippocampus, which was removed to treat her epilepsy, so she doesn't represent a "normal" brain, he says.

Normally a scientist will not ethically be able to put deep brain electrodes in a person, but this was likely part of a larger experiment related to the hippocampus surgery. It will be interesting to see if similar cases present similar behaviors and more interesting if the same thing happens in someone with a full hippocampus.

about 5 months ago
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US Government Introduces Pollinator Action Plan To Save Honey Bees

dhj Re:Poor Bees (143 comments)

Good point.

about 5 months ago
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US Government Introduces Pollinator Action Plan To Save Honey Bees

dhj Re:Poor Bees (143 comments)

[citation needed]

about 5 months ago
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3D-Printed Material Can Carry 160,000 Times Its Own Weight

dhj Re:Space Elevator? (60 comments)

In additon to tensile strength it would also have to have very high shear strength. From TFA this (and most 3D printed strength improvements) is an improvement in compressive strength. The only strength component not relevant to a space elevator cable.

about 5 months ago
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Bitcoin Security Endangered By Powerful Mining Pool

dhj Re:Ghash.IO is not consistently over 51%, yet anyw (281 comments)

Is it 51% or 50%+1? There is a big difference. If it's 51% then DDOS as soon as someone gets 50%-1 would work to prevent an exploit. If it's 50%+ then now many false transactions could they make at 51% (or 50%+2) before the DDOS is activated? If it's 50%+ then maybe the DDOS needs to come at 49% or 48% by community agreement. It does set an unsettling precedent that there could be DDOS battles over percent hashing contributions.

On the other hand, maybe this is enforcement that a bitcoin fork needs -- explicit support for mining pools. Such that the ability to get to say 40% by any one actor (pool or individual) is explicitly guarded against. There could be some sort of enforced diminishing returns with viability consensus like transaction consensus. Surely if you are trusting transactions to hash consensus you could also trust "ability or degree to contribute" to the same mechanism. If no-one could get over 48% then no-one could get over 50%. Does anyone know if that's a possible solution?

Does a mining pool really provide the ability to perform a 50%+ attack? They aren't running custom clients are they? Would it require ALL members of the mining pool to collude in the exploit?

about 5 months ago
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The $443 Million Smallpox Vaccine That Nobody Needs

dhj Re:Americans are bad at math (290 comments)

Lets examine how much time $443 million will buy us for budget examination... The 2011 budget expenditures are an estimated $3.82 trillion. So $443 million out of $3.82 trillion is 0.000116 of our budget. or 0.0116 % of the budget. If we spread that spending evenly throughout the year then 0.0116% of the 8760 hours in the year accounts for 0.99 hours. That's right -- less than one hour. That $443 million dollars will buy us less than one hour of time for budget examination. The cost of the wars in Iran and Iraq, however, was over $1 trillion. That would have bought us over 9 days per year every year over the last 10 years.

about 3 years ago
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MIT Unveils Sun-Free Photovoltaics

dhj Re:Battery Comparison (103 comments)

Good point... The summary left off an important bit of information from TFA:

"Based on that technology, MIT researchers have made a button-sized power generator fueled by butane that can run three times longer than a lithium-ion battery of the same weight; the device can then be recharged instantly, just by snapping in a tiny cartridge of fresh fuel"

So... using this to convert butane to electrical energy it lasts three times longer than a lithium-ion battery of the same weight.

But if you look at energy density of the two fuel sources: http://en.wikipedia.org/wiki/Energy_density

You find that butane/propane/gas/diesel is about 45 megajoules / kg and Li-ion batteries store about 0.75 megajoule / kg. Converted energy 2.25 megajoules (3x Li-Ion) out of stored energy 45 megajoules = 5% efficiency rate converting butane heat to electrical energy using this device.

--David

more than 3 years ago
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Blockbuster Trying To Woo Disgruntled Netflix Customers

dhj Re:Linux support (214 comments)

News flash: There is nothing preventing companies from developing DRM or closed binaries on linux. nVidia already has closed binaries, hulu (with drm obviously) runs on a linux OS. The reason companies don't support linux desktop is solely because the linux desktop market is so small that companies do not see a profit benefit in supporting it. So email your favorite(?) company and let them know you are a linux user and you would like for them to support linux.

more than 3 years ago
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Mozilla Labs: the URL Bar Has To Go

dhj Rapid Keyword Searches (591 comments)

Replace the URL bar with a tool to support more than just one command? Isn't that what keyword searches are for? I find the firefox URL bar to be extremely useful when combined with keyword searches. Here's how:

Go to any search field for instance the google search box, right click and choose "Add a Keyword for this Search...".

Give the search a single character "keyword" (eg g for google).

Now when you want to do a search you can do the following sequence:

Ctl-L # access the URL bar
Keyword [SEARCH TERMS] # eg "g slashdot" will perform a google search for slashdot

These are some of the keyword searches I use most often:

p for pubmed
g for google
gs for google scholar
gm for google maps
w for wikipedia
d for duckduckgo
ed for english dictionary
sd for spanish dictionary

The URL bar is by far the most useful feature of Firefox!

more than 3 years ago
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Ask Slashdot: What To Do When the Rapture Comes?

dhj Re:How can it be tied to local time zone? (673 comments)

You and the GP are missing the point here. God, obviously, will borrow Santa Clause's sleigh. Santa doesn't deliver all the presents at once, right? It takes time for him to ride his sleigh across the sky. So *logically* God will be driving Santa's magic sleigh across the sky approximately 6 hours behind the sun. Or maybe he's hitching a ride with FSM.

more than 3 years ago
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Verifying Passwords By the Way They're Typed

dhj Behind some crappy paywall? (140 comments)

Seriously? ... Let me be the first to welcome you to the world of academic journals.

more than 3 years ago
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What's Your Favorite Renewable Energy

dhj Re:Hydrogen (436 comments)

Ummm.. You guys do realize that "hydropower" means hydroelectric power? As in dammed rivers. Not "hydrogen power" as in hydrogen batteries? The parent is right, "hydrogen power" is just a form of portable energy. The GP whooshed. All of the alternative energies listed consist of converting a significant natural energy resource (like shining sun, blowing wind ... falling water) into electricity, with hamster power obviously being our most precious natural resource.

more than 3 years ago
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Windows 7 vs. Ubuntu 10.04

dhj Re:No Drivers for Windows (702 comments)

If only that were true. Video: intel i915.modeset=1, ATI nomodeset (until questionable drivers are installed). Downloading and compiling drivers for wifi (the new one I bought cause there was no chance of it working with an old card I dug up). Even after the headache of getting everything up and running X has crashed a few times. With Windows it just works. As much as it pains me to say that, its true. I am thinking I should go back to Fedora (first jump from Fedora to Ubuntu -- was with RedHat since well before Fedora split off and 10.04 has been a nightmare). You guys who say Ubuntu is best for hardware compatibility must be purchasing only hardware pre-screened to work. If you have a legacy system or didn't spec out every purchase for linux compatibility then it's a real pain in the ass. I would rather have out of the box hardware support over look and feel, bundled packages or anything else.

more than 4 years ago
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Preventing Networked Gizmo Use During Exams?

dhj Good call... (870 comments)

Good call not allowing an ipod in a physics class...

http://itunes.apple.com/us/app/matlab-mobile/id370976661?mt=8

Get the 4 function calculators. You can test physics knowledge with a 4 function calculator. I would say a 3x4 index card (or a formula sheet) would also be acceptable. That way you could better test their ability to apply formulas rather than memorize them. If a student needs a translation dictionary then there are very reasonably priced self contained models available. Well worth the investment for any class that allows it.

more than 4 years ago
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Wal-Mart To Launch Unlimited Wireless Family Plan

dhj Re:TOO MUCH! Tracfone is CHEAPER! (278 comments)

And Tracfone/Net10 uses the ATT network which, in the US, is 10x better than T-Mobile. You couldn't pay me to use T-Mobile's network. You mean I get to have calls dropped, calls missed and a plain inability to call out most of the places I go for only $45 / month?! OH BOY! Where do I sign up!

more than 4 years ago
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Hubble Finds Unidentified Object In Space

dhj Uh Oh... (716 comments)

That's what happened the last time a civilization constructed a 14 TeV large hadron collider! I need some protection. Where's my tinfoil hat!

more than 6 years ago
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McCain Answers Science Policy Questionnaire

dhj Re:The best answer to the science questionnaire (829 comments)

Hey. Just a little heads up. I know you've probably been slurping down the palin talking points when she says things like "Fannie Mae and Freddie Mac" just cost the people too much to remain viable. Unfortunately both of you are completely wrong. Fannie Mae and Freddie Mac are Government Sponsorded Enterprises (GSE). This means that they were incorporated by an act of congress, but are PRIVATELY OWNED. That's right privately owned. THEY WERE NOT RUN BY THE GOVERNMENT. The deregulation (by republicans) of these two organizations allowed them to be run into the ground. Now the taxpayers are HAVING to pay for a bailout to slow the plummeting republican shitstorm that is our current economy.

I don't know where you get this whole federal money competes with and beats out private funding idea. Do you really think that federally funded research somehow precludes private research investment at universities? You obviously don't work in an academic setting. Both federal and private projects coincide together with no problem.

Great 25 charities fund $1.2 billion in private research. I think science (and subsequently business who can make money off freely published results) would appreciate and benefit from an additional $1.2 billion or so from the government. That $1.2bil can come from a slice of the money we are wasting in the optional war in Iraq that's distracting us from the real front on terror (Afghanistan) and real domestic issues.

--David

more than 6 years ago

Submissions

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Self Assembling Photovoltaic Cells

dhj dhj writes  |  more than 4 years ago

dhj (110274) writes "MIT scientists have developed a self-assembling photovoltaic cell in a petri dish. Phospholipids (think cell membranes) form disks which act as the structural support for light responsive molecules. Carbon nanotubes help to align the disks and conduct electricity generated by the system with 40% efficiency. The assembly process is reversible using surfactants to break up the phospholipids. When filters are used to remove the surfactants the system reassembles with no loss of efficiency even over multiple assembly/disassembly cycles. The results were published September 5th in Nature Chemistry."
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