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Comment: Re:Overseas comment (Score 1) 385

by DeathToBill (#46766215) Attached to: Slashdot Asks: How Do You Pay Your Taxes?

Well, as I said, you can do that calculation, and if they haven't got it right you can file a tax return. If you held two jobs in a year then you might well want to do that.

We have another good taxation innovation in the UK: donations to charities are tax exempt, but the money (usually) goes to the charity, not to the taxpayer. So if you've given £1000 to charity, the exchequer will give the charity another £250, so long as you sign a simple statement to go with the donation saying you're a taxpayer and have/will pay at least that much tax in the current year.

Comment: Overseas comment (Score 4, Interesting) 385

by DeathToBill (#46756705) Attached to: Slashdot Asks: How Do You Pay Your Taxes?

I like the UK system - if you're an employee and you're happy with the tax your employer has withheld on your behalf, you don't have to do anything. You get a statement at the end of the year telling you how much you've been paid and how much tax has been withheld - if you think they've got it wrong, or you want to claim deductions, you file a tax return saying so.

Comment: Hmmm (Score 1) 307

If you really want to use this method to calculate pi, here's how to actually go about it. What you need is a hundred yards or so of string, four stakes, a stick and something that's a reasonable approximation to a right-angle (perhaps a piece of a cardboard box salvaged from the apocalypse). If you're really stuck for a right angle you can construct one with three stakes and a piece of string by putting two stakes in the ground and using the string to mark a straight line between them, then tying one end of the string to one of the stakes and tying the third stake to the string, so that length of string between them is a bit over half the distance between the stakes in the ground. Mark out a circle using this. Then mark out a second circle with the other stake in the ground as the centre. These two circles will intersect at two places - use the string to mark a straight line between them. The two straight lines you have marked will be at right angles.

Now put two stakes in the ground, about 20 yards apart. Stretch string between them. Put your right-angled thing with one side against the string and the right-angle corner at one of the stakes. Measure another piece of string to be the same length as the piece stretched between the two stakes. Tie it to a third stake and stretch it out so that it runs along the other side of the right-angled thing. You've now marked out two sides of a square with string. Repeat to form the other two sides.

Take your stick and break it down to about a foot long. Use it to mark out on the ground equally-spaced marks along each side of the square. Get two people to hold each end of a fifth piece of string across the square so that you can mark straight lines on the ground, dividing the square into a grid.

Cut your fifth piece of string to be the same length as one side of the square. Tie one end to one of the stakes. Now use the other end to mark out an arc from one corner of the square to the opposite corner.

Count the number of squares that are inside the arc and the total number of squares. Take the ratio of these two numbers and multiply it by 4. Here is your approximation to pi.

This method has many advantages over the one proposed: With the dimensions given above, it gives a considerably better answer, correct to four significant figures (3.141). It is easy to scale for better accuracy - make the square 100 yards and the stick four inches and you get six correct digits (3.141590123). You don't need to correct for uneven shot pattern. And, crucially I'd say in an apocalypse, you don't need a shotgun or ammunition and, if you do happen to have them, you can use them for useful things like fending off the zombies or hunting.

Comment: Re:Might look like less of a (Score 2) 477

by DeathToBill (#46713887) Attached to: New French Law Prohibits After-Hours Work Emails

Well colour me puzzled. Surely the expression "whatever the French call la dolce vita" demonstrates that, whatever the French do call it, they don't call it la dolce vita? So he knows it's not a French expression, he just doesn't know what the equivalent expression in French is.

Well done for supplying the French equivalent.

Comment: Sort of (Score 2) 227

by DeathToBill (#46684681) Attached to: Nanodot-Based Smartphone Battery Recharges In 30 Seconds

Once electric cars become prevalent, the charging time doesn't really matter for the supply and HV distribution side of the grid - each car sucks either 10.2MW for 30s or 10.2kW for a bit over eight hours (30,000s). Once there are enough that the spikes in charging smooth out, the demand increase is the same whichever charging rate you use. The only problem really comes at the edge of the grid, with the connection to individual houses currently being sized about three orders of magnitude wrong for this use. At this point, it's probably not too unreasonable to ask homeowners to pay to have their grid connection upgraded to give them the privilege of a 30-second charge for their car.

Comment: Charge in 30 seconds? (Score 1) 227

by DeathToBill (#46684611) Attached to: Nanodot-Based Smartphone Battery Recharges In 30 Seconds

Let's see, a 4,700mAh 5V battery has a capacity of 23.5 VAh or 84.6kJ. To charge that in 30s, you'll need a 2.82kW charger output. So whether it's feasible or not probably depends on what jurisdiction you're in - a British 240V 13A socket will give you 3.12kW, so as long as your losses are below 10% you'll just get it. An Australian 240V 10A socket will give you 2.4kW, so allowing for 90% efficiency of the charger you'll get about 40s to charge. A US 110V 15A socket will give you 1.65kW, requiring about 57s at 90% efficiency to deliver a full charge.

Comment: Re:Fuck Bennett (Score -1, Offtopic) 162

by DeathToBill (#46683953) Attached to: Judge (Tech) Advice By Results

Of course, I'm sure now I'll be buried in crap telling me either a) how crap Wordpress is and how much better blogging-platform-XYZ is or b) how useless the advice is because Bennett will never follow it and how my metrics for assessing the advice I give out is all wrong.

Seriously, Bennett? You don't think maybe researchers who devote their lives to figuring out good advice on health, diet and exercise know just a teeny bit more about experimental design than you? Sorry, I forgot, teenagers know everything.

% APL is a natural extension of assembler language programming; ...and is best for educational purposes. -- A. Perlis