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Comment Re:except they don't. Voltage of 120 batteries (Score 1) 115

The charging comment is only true up to a point. As you get larger solid packs, the surface area doesn't increase as fast as the volume and the insides can get very hot. Thermal management is super critical for many battery types so this is a major limitation.

With a small cylindrical battery, the empty packing space between the cells provides a perfect channel for cooling.

Comment Re:How does space elevator save energy? (Score 4, Insightful) 139

The person you heard that from was wrong.

In a rocket,:
- Rockets are quite inefficient, about 16% energy efficient to reach orbit.
- You have to lift your propellant, only to throw it all away
- The rocket not only has to do work against gravitational potential, it also has to provide lateral kinetic energy to reach orbit. The kinetic energy component is huge.

For a space elevator:
- The lifting motors are highly efficient, you just have to keep the power beaming losses reasonable.
- You only have to work against gravitational potential. The tether/earth provides the lateral kinetic energy.

Comment Re: non-story (Score 1) 199

There are degrees of off/standby. It's good engineering practice and environmentally that when you "soft" power down, you turn off as many internal circuits as you are able and only retain basic functionality required to turn back on again.

LED off
Camera sensor off completely
WiFi chip in low power / periodic transmit mode
CPU at lower clock speed or sleep mode with periodic wake up timer.

Not doing this means that the camera designers were either:
1) Lazy and unprofessional
2) Planning to retain the camera functionality for nefarious uses.

Comment Re:NYC taxi system could DESTROY uber (Score 2) 210

The main difference in the business models is that Taxi companies have to pay hundreds of thousands of dollars for a taxi license/plate/medallion, the supply of which has been artificially restricted by government regulation. This forces costs up for them and prices up for customers.

There is no such regulation on Uber and so they are competing on unequal terms.

I'm not a big fan of taxi companies but they have a point. In order to be fair, the Government may need to start handing out some refunds on taxi licenses / medallions.

Comment Re:What's so hard about R-Pi mounting? (Score 1) 197

I use several ODROID C1's as micro servers in my closet, and hands down the RPi2's are much more stable. Not sure about the C1+ though.

Sure, the C1 is more powerful and that's the reason I bought it, but they are finicky on SD card compatibility and often fail to reboot properly. They are also electrically more sensitive - touching some of the exposed pins makes them reboot, grounding is a mess, and one unit I have seems to not like booting unless I have a serial console plugged in.

By comparison the RPi just works.

Comment Enough of the voting machines. (Score 2) 172

Many countries around the world have proven that paper and pencil voting is reliable, traceable, and scalable. Even in countries with mandatory voting where the turnout density is higher than the US.

In Australia, most public schools & town halls become voting centers for the day, so most people don't have to travel far and the numbers are manageable. A small army of trained electoral commission recruits control the process, and do the counts at the end of the day. The results are in that evening, which is plenty fast enough.

Paper voting has several distinct advantages:
1) It has a visible and tangible chain of trust, and can be directly inspected by the lay-person.
2) It directly involves people in the democratic process, not machines
3) A lot of the money required to run the election goes to individuals, not corporations.

"Everybody is talking about the weather but nobody does anything about it." -- Mark Twain