Head out for a meal with your S/O and don't have a beer. Have something else instead. It's really not rocket science. No, it's not A-OK to be driving on prescription drugs that limit your ability to drive either.
AC is better in some instances, but for long distance power transmission DC is much better. AC suffers reactive losses that DC doesn't. In the past we didn't use HV DC for long distance because of the losses associated with the inverter at the transmitting end and rectifier at the other end, however, we have very efficient solid state inverters and rectifiers today which makes it more efficient. HV DC also allows you to tie two grids much more easily, for example between two countries since you no longer need to synchronise the AC grids of each country.
I suspect neither airliners nor trains will run off batteries in my lifetime.
The ease in handling liquid fuel and their energy density (and the fact that as you use up the fuel, the plane gets lighter) will be keeping airliners running off Jet-A for the foreseeable future. For trains, it'll probably always be far cheaper just to put electric wires above the tracks. The wires will last longer and be able to deliver a lot more power. Outside of North America, every high speed railway network is electrified and has been for decades already. Those which aren't (predominantly the UK, which is rather behind on high speed rail compared to most of Europe) are currently being electrified by means of overhead wires.
Trains with stored electricity have niche uses, for example the tram system in the city of Zaragoza lacks overhead wires in the old part of the city. The trains run off super capacitors and charge at each stop while they are away from the wires. However, high speed and freight is far better done with overhead electrification. Cheaper and more efficient in the long run.
Radar coverage I'm sure goes all the way down to the surface on the US-MX border. The US puts up balloons at about 15,000 feet on tethers with radars looking down (the balloon sites are all charted).
However, a small enough drone with only a small amount of metal might still be very hard to detect. The drone could also drop its payload and then continue flying so when the authorities go to collect the drone (hoping to catch the people recovering the goods) they just get an empty drone, while the goods may have been dropped off at any point in between.
Never ascribe to malice that which can adequately be explained by incompetence.
A lot of people are posting that Apple had some sort of malicious intent (lock people in) when really it's more likely they just didn't think it through properly. The whole thing can easily be solved just by making a simple, easy to find webpage to turn iMessage off. Even customers who aren't switching may find it useful (abroad with your iPhone with data turned off because it's ridiculously expensive, but left the iPad at home and forgot to turn it off so your iPad is happily getting your messages but your phone not, would be an example where it would be useful).
I've never seen the explanation for how a microwave works written as in your message until today. All the explanations I've seen are what's stated in the article; so I think it's your explanation that's wrong for how microwave ovens heat water.
We can transport electricity very well and losses are nowhere near 50%. The UK national grid for example only has losses of 7% and this is typical for a developed nation.
Why is it not practical? It's no more difficult to wire a multistory carpark than any other building. Car park users are not expecting rapid charging - low current charging will be fine since the car will be sat there for about 8 hours at a time, so it wouldn't even require out of the ordinary wiring.
What you can have is a mostly electric hybrid. Instead of the current hybrids with a petrol engine plus electric system, the whole car is an electric car with a fuel cell added. Normally, you'd operate purely electric. But those 2 or 3 occasions per year when you want to drive 500 miles you'll use the hydrocarbon fuel cell so you can also run regular fuel too and have the quick refilling times.
But it's all kind of pointless. All that power is not really useful in a car especially in a commuting setting. Even on the open road, the speed limits are too low for the power to be of much use, so all it gives you is far worse fuel economy.
The only vehicle where more power is really any use at all is a motorcycle, but even that won't get you anywhere much faster - my commute times on my F800ST are really no quicker than on the 125cc bike I used to own (and on the 125cc bike, I can beat a Ferrari into work without even working up a sweat, because I can do something the Ferrari can't - I can overtake and fit into small spaces, so I can get past slow moving traffic, and since filtering is perfectly legal (and expected) here, I can filter past cars to the head of the queue at traffic lights.
If I were in that situation, before even beginning to consider an electric car, I would be considering moving house to somewhere closer to work. Sure, there are reasons why this might not be possible (for example, you may be doing short term contracts, so you're not going to be at that job for long anyway, and other examples) but quite a few people are at regular, steady permanent full time positions but live stupid commuting distances away. Even if the property is more expensive where work is, if you're not spending $100 a week on fuel, that's $100 a week more you can spend on your property (which if you own, is putting money into something you can sell later, not disappearing out your tailpipe).
More importantly, if you're spending that much on fuel for commuting, you're also spending a huge chunk of *time* on commuting which you can never recover. Earlier in the thread someone remarked about their 40 mile each way with traffic jams commute, that's probably 3 hours of life he wastes a day sitting in a car, 3 hours where you can do nothing else but drive (and it's not even fun driving). Those 3 hours have to be worth something.
That would be generally impractical as the cells would need very very very high C ratings if you were to use one at a time to be able to provide sufficient current (and running lithium batteries near their maximum current rating is quite hard on them). Running the whole pack in parallel is much better since you can use batteries with lower C ratings and you're less hard on them.
MIPS may (or may not be) "open source", however it is not free to implement. Implement the latest MIPS ISA without a license agreement from MIPS and you'll be sued to smithereens. You won't be sued if you implement OpenRISC though.
Ignoring the OP's (idiotic) bias against perl, you probably tailor the test to the kind of job it is. If it's a job that might require a reasonable understanding of mathematics and the use of that in a constrained environment (imagine writing software for remote sensors which run on 8 bit microcontrollers out in the field), then that sort of question might be appropriate. Although you're never going to do that in your job it's a straightforward way to see how the candidate thinks and it's a task that can be completed in a short period of time in few lines of code (you can hardly ask someone in a candidate screening test to write a large non-trivial piece of code, so you've got to find something that's suitably trivial but at the same time can provide talking points for the actual interview)
You don't use the coding test alone. You have a coding test, and then in the interview you pick a few of the responses to the test and ask the candidate why they implemented in that particular way (as an example) to show the candidate actually understands what they wrote.
That doesn't make sense. If a maker of an unreliable car had long warranties, they would end up paying out a lot of money on warranty work. The rational thing for a car maker with an unreliable product to do is to have the shortest warranty possible.
I think the parent meant a truck that *weighs* 2 tonnes, not a truck with a payload of 1/2 ton. Your F150 almost certainly weighs at least 2 tonnes, and so does the Ford Explorer. 20mpg is not considered efficient anywhere except in North America.
Car built-in stuff generally isn't worth it. Modern cars can easily last 20 years (my last one did). The inbuilt radio in that car is now positively archaic - FM/AM/LW with a tape player. The same thing will happen to in-car satnav systems, in-car wifi hotspots - within the car's useful life they will fall so far behind they may not even be usable (updates for that satnav? a hotspot that is what 9600 baud WAP over GSM is today when compared to 4G?)
Today all I want built into the car is an amplifier with some input standard that's going to last (for example Bluetooth, or even just a 3.5mm jack plug in). I'll supply my own satnav/music system/WiFi hotspot. I can keep updating them for trivial cost rather than to try to keep built-in car systems up to date at enormous cost.
They don't own the airspace. Generally ATC in the US works on the principle of "first come first served". You can fly a small single engine Cessna 150 in the same airspace as the airliner. If you're on an IFR flight plan and call ATC before the airliner, guess what, you get to go before the airliner. But since where the incident happened is probably in class B airspace, you have certain minimum standards that you have to meet:
- you must be at least a certificated private pilot or student pilot with a signoff to use Class B airspace. - you must have a Mode C transponder - you must have a 2 way radio - you must have a clearance from ATC. - you still have an obligation to see and avoid if flying in VMC (visual meteorological conditions)
Until drones get all of the above, they need to remain clear of controlled airspace. Indeed they should be remaining below 400 feet. Drones aren't very good at "see and avoid". If a private pilot had done what that RC pilot had done, the FAA would have busted his ass and he would be looking at a suspension of his privileges plus a pretty big fine. However, unlike the drone, the AA airliner wouldn't have probably had that nasty surprise - with the hypothetical light aircraft carrying a transponder, both ATC and the airliner would have been able to see the light aircraft electronically and taken avoiding action long before it was in visual range.
Birds don't and can't know any better. (Also birds are quite good at dodging aircraft, that's why there are so few bird strikes). However people flying RC or drones should know better and can predict ahead of time that if their drone goes into a turbine engine, it could end up hurting a lot of people, and so should be able to reign in their wants to fly drones where manned aircraft tend to fly.
Also birds aren't full of metal and carbon fibre and lithium batteries. The stuff a bird is made of is less likely to cause a turbine engine to stop.
However, he was almost certainly within class B controlled airspace. If you're flying full scale, you need a clearance to enter class B. The same ought to be true of RC and drones (certainly if they are to operate above 400 ft).
The wind is indeed always blowing somewhere. I'm willing to bet my life on it. And if the wind stops blowing everywhere it's because the sun went out and the whole thing becomes kind of moot.
As always electricity generation should always be a mix of stuff. It would be a bad idea to power the whole grid off just wind due to the amount of excess capacity that would be needed. At the same time it would be silly to power the entire grid off just nuclear or just natural gas because then you've got all your eggs in one basket. So you have some wind power, some solar, some gas, some nuclear, some tidal etc.
Incidentally from the point of view of the UK National Grid, wind is not seen as intermittent. You can be pretty damn certain what the wind generators will be doing in 20 minutes time. However, Sizewell B (one of the largest single generators) could go offline 30 seconds from now completely unexpectedly. So you need a lot of 'spinning reserve' and load shedding techniques because of Sizewell B and Drax and other large power stations that can suddenly go offline and deprive you of a great deal of capacity. Wind on the other hand is made up of many very small generators and if one goes faulty, you don't really notice it, and the windspeed doesn't change much over a period of a couple of hours.
Also a lot of the stop signs need to go. I've noticed in the US that most places they would put a yield sign here, they put a stop sign. And many roads which would have a broken line in the centre (meaning you can overtake) have double yellows in the US. For a country which is generally not so nanny state, the road design is incredibly nannyish. I reckon about 95% of stop signs in all the places in the US that I've driven could quite safely be yield signs. Car drivers at least seem to treat them as such, it seems like less than 5% of cars actually stop at a stop sign.
OK, so let's make a fair road tax for the cyclist. What could be fairer than basing it on how much damage a vehicle does to the road? So let's charge cyclist just $5 (or equivalent thereof per year), and have everyone pay proportionately to road damage.
Since road wear goes up approximately at the fourth power of axle weight, a bike has usually around no more than 50kg per axle. A small car is about 600kg per axle, so causes roughly 20,000 times as much road wear and so to be fair should pay 20,000 times more. Now how about that $100K a year road tax? Too much? Well to tax the cyclist fairly, the amount would have to be so tiny it's not worth collecting.
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Head out for a meal with your S/O and don't have a beer. Have something else instead. It's really not rocket science. No, it's not A-OK to be driving on prescription drugs that limit your ability to drive either.
AC is better in some instances, but for long distance power transmission DC is much better. AC suffers reactive losses that DC doesn't. In the past we didn't use HV DC for long distance because of the losses associated with the inverter at the transmitting end and rectifier at the other end, however, we have very efficient solid state inverters and rectifiers today which makes it more efficient. HV DC also allows you to tie two grids much more easily, for example between two countries since you no longer need to synchronise the AC grids of each country.
I suspect neither airliners nor trains will run off batteries in my lifetime.
The ease in handling liquid fuel and their energy density (and the fact that as you use up the fuel, the plane gets lighter) will be keeping airliners running off Jet-A for the foreseeable future.
For trains, it'll probably always be far cheaper just to put electric wires above the tracks. The wires will last longer and be able to deliver a lot more power. Outside of North America, every high speed railway network is electrified and has been for decades already. Those which aren't (predominantly the UK, which is rather behind on high speed rail compared to most of Europe) are currently being electrified by means of overhead wires.
Trains with stored electricity have niche uses, for example the tram system in the city of Zaragoza lacks overhead wires in the old part of the city. The trains run off super capacitors and charge at each stop while they are away from the wires. However, high speed and freight is far better done with overhead electrification. Cheaper and more efficient in the long run.
Radar coverage I'm sure goes all the way down to the surface on the US-MX border. The US puts up balloons at about 15,000 feet on tethers with radars looking down (the balloon sites are all charted).
However, a small enough drone with only a small amount of metal might still be very hard to detect. The drone could also drop its payload and then continue flying so when the authorities go to collect the drone (hoping to catch the people recovering the goods) they just get an empty drone, while the goods may have been dropped off at any point in between.
Never ascribe to malice that which can adequately be explained by incompetence.
A lot of people are posting that Apple had some sort of malicious intent (lock people in) when really it's more likely they just didn't think it through properly. The whole thing can easily be solved just by making a simple, easy to find webpage to turn iMessage off. Even customers who aren't switching may find it useful (abroad with your iPhone with data turned off because it's ridiculously expensive, but left the iPad at home and forgot to turn it off so your iPad is happily getting your messages but your phone not, would be an example where it would be useful).
[citation needed]
I've never seen the explanation for how a microwave works written as in your message until today. All the explanations I've seen are what's stated in the article; so I think it's your explanation that's wrong for how microwave ovens heat water.
We can transport electricity very well and losses are nowhere near 50%. The UK national grid for example only has losses of 7% and this is typical for a developed nation.
Why is it not practical? It's no more difficult to wire a multistory carpark than any other building. Car park users are not expecting rapid charging - low current charging will be fine since the car will be sat there for about 8 hours at a time, so it wouldn't even require out of the ordinary wiring.
What you can have is a mostly electric hybrid. Instead of the current hybrids with a petrol engine plus electric system, the whole car is an electric car with a fuel cell added. Normally, you'd operate purely electric. But those 2 or 3 occasions per year when you want to drive 500 miles you'll use the hydrocarbon fuel cell so you can also run regular fuel too and have the quick refilling times.
But it's all kind of pointless. All that power is not really useful in a car especially in a commuting setting. Even on the open road, the speed limits are too low for the power to be of much use, so all it gives you is far worse fuel economy.
The only vehicle where more power is really any use at all is a motorcycle, but even that won't get you anywhere much faster - my commute times on my F800ST are really no quicker than on the 125cc bike I used to own (and on the 125cc bike, I can beat a Ferrari into work without even working up a sweat, because I can do something the Ferrari can't - I can overtake and fit into small spaces, so I can get past slow moving traffic, and since filtering is perfectly legal (and expected) here, I can filter past cars to the head of the queue at traffic lights.
If I were in that situation, before even beginning to consider an electric car, I would be considering moving house to somewhere closer to work. Sure, there are reasons why this might not be possible (for example, you may be doing short term contracts, so you're not going to be at that job for long anyway, and other examples) but quite a few people are at regular, steady permanent full time positions but live stupid commuting distances away. Even if the property is more expensive where work is, if you're not spending $100 a week on fuel, that's $100 a week more you can spend on your property (which if you own, is putting money into something you can sell later, not disappearing out your tailpipe).
More importantly, if you're spending that much on fuel for commuting, you're also spending a huge chunk of *time* on commuting which you can never recover. Earlier in the thread someone remarked about their 40 mile each way with traffic jams commute, that's probably 3 hours of life he wastes a day sitting in a car, 3 hours where you can do nothing else but drive (and it's not even fun driving). Those 3 hours have to be worth something.
That would be generally impractical as the cells would need very very very high C ratings if you were to use one at a time to be able to provide sufficient current (and running lithium batteries near their maximum current rating is quite hard on them). Running the whole pack in parallel is much better since you can use batteries with lower C ratings and you're less hard on them.
MIPS may (or may not be) "open source", however it is not free to implement. Implement the latest MIPS ISA without a license agreement from MIPS and you'll be sued to smithereens. You won't be sued if you implement OpenRISC though.
Ignoring the OP's (idiotic) bias against perl, you probably tailor the test to the kind of job it is. If it's a job that might require a reasonable understanding of mathematics and the use of that in a constrained environment (imagine writing software for remote sensors which run on 8 bit microcontrollers out in the field), then that sort of question might be appropriate. Although you're never going to do that in your job it's a straightforward way to see how the candidate thinks and it's a task that can be completed in a short period of time in few lines of code (you can hardly ask someone in a candidate screening test to write a large non-trivial piece of code, so you've got to find something that's suitably trivial but at the same time can provide talking points for the actual interview)
You don't use the coding test alone. You have a coding test, and then in the interview you pick a few of the responses to the test and ask the candidate why they implemented in that particular way (as an example) to show the candidate actually understands what they wrote.
That doesn't make sense. If a maker of an unreliable car had long warranties, they would end up paying out a lot of money on warranty work. The rational thing for a car maker with an unreliable product to do is to have the shortest warranty possible.
I think the parent meant a truck that *weighs* 2 tonnes, not a truck with a payload of 1/2 ton. Your F150 almost certainly weighs at least 2 tonnes, and so does the Ford Explorer. 20mpg is not considered efficient anywhere except in North America.
Car built-in stuff generally isn't worth it. Modern cars can easily last 20 years (my last one did). The inbuilt radio in that car is now positively archaic - FM/AM/LW with a tape player. The same thing will happen to in-car satnav systems, in-car wifi hotspots - within the car's useful life they will fall so far behind they may not even be usable (updates for that satnav? a hotspot that is what 9600 baud WAP over GSM is today when compared to 4G?)
Today all I want built into the car is an amplifier with some input standard that's going to last (for example Bluetooth, or even just a 3.5mm jack plug in). I'll supply my own satnav/music system/WiFi hotspot. I can keep updating them for trivial cost rather than to try to keep built-in car systems up to date at enormous cost.
They don't own the airspace. Generally ATC in the US works on the principle of "first come first served". You can fly a small single engine Cessna 150 in the same airspace as the airliner. If you're on an IFR flight plan and call ATC before the airliner, guess what, you get to go before the airliner. But since where the incident happened is probably in class B airspace, you have certain minimum standards that you have to meet:
- you must be at least a certificated private pilot or student pilot with a signoff to use Class B airspace.
- you must have a Mode C transponder
- you must have a 2 way radio
- you must have a clearance from ATC.
- you still have an obligation to see and avoid if flying in VMC (visual meteorological conditions)
Until drones get all of the above, they need to remain clear of controlled airspace. Indeed they should be remaining below 400 feet. Drones aren't very good at "see and avoid". If a private pilot had done what that RC pilot had done, the FAA would have busted his ass and he would be looking at a suspension of his privileges plus a pretty big fine. However, unlike the drone, the AA airliner wouldn't have probably had that nasty surprise - with the hypothetical light aircraft carrying a transponder, both ATC and the airliner would have been able to see the light aircraft electronically and taken avoiding action long before it was in visual range.
Birds don't and can't know any better. (Also birds are quite good at dodging aircraft, that's why there are so few bird strikes). However people flying RC or drones should know better and can predict ahead of time that if their drone goes into a turbine engine, it could end up hurting a lot of people, and so should be able to reign in their wants to fly drones where manned aircraft tend to fly.
Also birds aren't full of metal and carbon fibre and lithium batteries. The stuff a bird is made of is less likely to cause a turbine engine to stop.
And no more than 400 feet up.
However, he was almost certainly within class B controlled airspace. If you're flying full scale, you need a clearance to enter class B. The same ought to be true of RC and drones (certainly if they are to operate above 400 ft).
The wind is indeed always blowing somewhere. I'm willing to bet my life on it. And if the wind stops blowing everywhere it's because the sun went out and the whole thing becomes kind of moot.
As always electricity generation should always be a mix of stuff. It would be a bad idea to power the whole grid off just wind due to the amount of excess capacity that would be needed. At the same time it would be silly to power the entire grid off just nuclear or just natural gas because then you've got all your eggs in one basket. So you have some wind power, some solar, some gas, some nuclear, some tidal etc.
Incidentally from the point of view of the UK National Grid, wind is not seen as intermittent. You can be pretty damn certain what the wind generators will be doing in 20 minutes time. However, Sizewell B (one of the largest single generators) could go offline 30 seconds from now completely unexpectedly. So you need a lot of 'spinning reserve' and load shedding techniques because of Sizewell B and Drax and other large power stations that can suddenly go offline and deprive you of a great deal of capacity. Wind on the other hand is made up of many very small generators and if one goes faulty, you don't really notice it, and the windspeed doesn't change much over a period of a couple of hours.
Also a lot of the stop signs need to go. I've noticed in the US that most places they would put a yield sign here, they put a stop sign. And many roads which would have a broken line in the centre (meaning you can overtake) have double yellows in the US. For a country which is generally not so nanny state, the road design is incredibly nannyish. I reckon about 95% of stop signs in all the places in the US that I've driven could quite safely be yield signs. Car drivers at least seem to treat them as such, it seems like less than 5% of cars actually stop at a stop sign.
OK, so let's make a fair road tax for the cyclist. What could be fairer than basing it on how much damage a vehicle does to the road? So let's charge cyclist just $5 (or equivalent thereof per year), and have everyone pay proportionately to road damage.
Since road wear goes up approximately at the fourth power of axle weight, a bike has usually around no more than 50kg per axle. A small car is about 600kg per axle, so causes roughly 20,000 times as much road wear and so to be fair should pay 20,000 times more. Now how about that $100K a year road tax? Too much? Well to tax the cyclist fairly, the amount would have to be so tiny it's not worth collecting.