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Comment: Re:combining micropayments with hefty sticker pric (Score 1) 473

by mrvan (#48409537) Attached to: Elite: Dangerous Dumps Offline Single-Player

Do you know whether it is pay-to-win (i.e. in-app purchases have a significant effect on gameplay) or mainly cosmetic (buying a paint job on your ship)?

If I pay real money for a game (>20 EUR) I expect it to be playable without subscription fees, microtransactions etc. For free or almost free games, I can understand either subscription OR microtransactions, but certainly not both...

Comment: Re:Ok but that's electricity, not energy (Score 4, Insightful) 488

by mrvan (#48367025) Attached to: Denmark Faces a Tricky Transition To 100 Percent Renewable Energy

Heating and cooling is not symmetrical.

For one, it gets coldest during the night, when most people are in bed and blankets are a good tool to stay warm. It gets hottest in the middle of the day when most people are up and about (in countries without a siesta culture).

Also, isolating a house to keep in heat is much easier than isolating it to keep heat out, especially if you want to keep windows etc.

Third, warm clothing allows you to operate comfortably even if it is cold, a warm sweater means a room of around 18 celcius / 65 fahrenheit is comfortable. Stripping down is more difficult, but especially less acceptable in a business environment. Current business fashion originates in Northeastern Europe during the 'little ice age' of the 18th century, wearing a three piece suit with shirt, undershirt and tie is much more suited for 18/65 than for 25/77 degrees.

I live in Amsterdam and have the thermostat set to 19/66 degrees when I am at home, it cools down to something like 16 degrees during the night. I don't have A/C but in the summer the temperature easily goes up to 25/77 degrees in house, which is fine with light clothing. On hot summer days it can go up to 30/86 degrees, which is too hot to be comfortable for me, but that is quite rare.

Finally, Denmark might 'see' 15-30 degrees below zero once every century, but average low (night) temperature in January is more like -2. So, a delta of also around 15-20 degrees from room temperature.

Comment: Re:Home storage (Score 2) 488

by mrvan (#48366625) Attached to: Denmark Faces a Tricky Transition To 100 Percent Renewable Energy

Avg US household use is in 2012 was 10,837 kWh per year, or about 29.7 hWh per day, so 50kWh is less than 2 days..

This is a story about Denmark, not the US. America has one of the highest per capita electricity uses in the world*. According to the wiki, Americans use almost three times more electicity than Danes, probably due to air conditioning and low energy prices (US is listed as .08-.17 $/kWh, Denmark 40.38)

Anecdotal evidence: I just checked my electricity consumption, which is around 4,000kWh for the past year, including a large TV and more computers than any sane 2 person household would need. According to an energy cost comparison site, the average 2+2 person household consumes 4,500 kWh per year.

So, assuming that an average Danish household consumes around 5,000 kWh per year = 13.7 kWh per day, that battery will last them 3 days.

*) Interestingly, Norway and Iceland are listed even higher - presumably because they have lots of hydropower and electric heating.

Comment: Re:Just moves a choke point (Score 1) 395

by mrvan (#48147597) Attached to: Battery Breakthrough: Researchers Claim 70% Charge In 2 Minutes, 20-Year Life

Aire de Berchem is Luxembourg is (according to Dutch wikipedia) the busiest gas station in the world (mainly because Luxembourg has the cheapest gas in the region and it is on a number of busy roads). It pumps 850.000 liters per day, enough to fill up 17000 cars*. If every car needs 70% of 85KWh, this requirs 85k * .7 * 17k = 1GWh per day. If they can spread perfectly over the day, it means they need a 50MW power plant, which I guess is not too far out there. This will probably require some impressive capacitator / battery setup to get enough peak power though, no clue if something like that is feasible.

(the total amount of energy in 850k liters of gasoline is 42.4 MJ/kg * 0.77 kg/L * 850kL = 27 TJ = 7.5GWh. So it seems that the total efficiency of electric cars is about 8 times higher, assuming equal range, which is probably false. But a factor 5 might be around right...?)

*) the wiki mentions it's 80% diesel, and while diesel cars are pretty common here, I would assume that means that the majority of liters goes to trucks. Now suppose your Tesla truck with 500KWh needs to charge in 5 minutes....

Comment: Re:Wow (Score 1) 134

by mrvan (#48080717) Attached to: Google's Security Guards Are Now Officially Google Employees

Our cleaning is outsourced and the cleaners generally have little command of the local language. I know most of them by now, however, and have a little chat when I can. I leave my wallet and phone on my table if I go grab a coffee to allow them to clean my office (I work late a lot of times). Nothing untoward ever happened and I've not heard any of my colleagues complain.

Comment: Re:Proper Science is hard. (Score 4, Informative) 795

by mrvan (#47966195) Attached to: How Our Botched Understanding of "Science" Ruins Everything

Scientist here - by geekoid's definition at least.

Scientists use jargon for the same reason sailors do - to efficiently communicate a very specific concept. In a sailing vessel at sea in a storm, you really don't want to take a minute to explain that you mean the green-white striped rope that connects the beam to the hull - you say mainsheet*.

Now, there is a lot of nonsense going on in science, with ridiculous performance metrics, a discouragement of actually innovative high-risk research, a sometimes religious worship of established names and theory; and a lot of stuff gets published not because it is particularly innovative, enlightening or even robust, but because it uses the right buzz words and cites the right people. However, that does not make science as an endeavour less wortyh - it's a bit like** how democracy is a good idea even if a lot of politicians (the ones in high places, at least) are dodgy.

* if my English sailing jargon is correct - not a native speaker
** my next analogy will be about cars, I promise

Comment: Re:A Little Perspective (Score 3, Interesting) 14

by mrvan (#47823829) Attached to: Ireland To Host Robotic Sailing Championships

This doesn't matter that much. Larger yachts sail more or less the same as smaller yachts; the main effect is that all forces are multiplied. For humans this makes a lot of difference: needing winches instead of pulling ropes by hand, being hit by the boom during a jibe changes from unpleasant to lethal, the ability to push off against the wall is greatly diminished, etc. For automatic sailing, however, the main effect will probably be cost rather than difficulty, as none of those factors are really important until material strenght becomes a problem. Smaller boats can even be more difficult to handle since the intertia is smaller compared to the wind forces (mass is cube of size, wind area square), making a smaller boat less stable.

Comment: Re:is it better than random? (Score 5, Informative) 177

by mrvan (#47621371) Attached to: Algorithm Predicts US Supreme Court Decisions 70% of Time

That is correct, but not what the GP meant. If you can model the distribution (e.g. you 'know' that B is 90%) then you can weigh your random guessing such that it is correct in >50% of the cases, even without looking at the case itself (it is still 'random' in that sense)

Extreme case: I can predict whether someone has Ebola without even looking at them with >99.99% accuracy by just guessing "no" every time, since the prevalence of Ebola is >.001%.

Suppose the supreme court has 70% chance of overturning (e.g. because they choose to hear cases that have 'merit'), then an algorithm that guesses 'overturn' 100% will have a 70% accuracy. A random guess that follows the marginal of the target distribution (e.g. guess 70% overturn) also scores >50% (58% to be precise).

In every non-trivial program there is at least one bug.

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