We often take the piss out of wimminz and niggerz, because of their complete disconnect from reality, they think things that are not merely improbable, but that have no actual basis in reality whatsoever.
The revival of the electric car thread reminds me of something far, far, far worse.
The complete and utter ignorance of the physical world, physical laws, physical constraints.
If I wave a magic wand at you and go la-la-la-la-your-cancer-is-now-cured I’ll get hauled in front of a judge.
If I say something equally physically impossible about electric cars or renewable energy or paying off the national debt… nobody questions the physically impossible aspects, the only things up for debate will be what colour the electric cars are, what type of renewable energy, and how many weeks will the payments be over.
Back in the day, one horsepower was defined as 550 foot pounds per second, and it was foot pounds, not pounds feet, or pounds feet of force, or any other such shit, foot pounds.
It basically says that raising 550 lbs 1 foot in 1 second is the same amount of WORK as raising 1 pound 550 feet in one second.
Taking a 56lb sack of potatoes and carrying it up a hill from 10 feet above sea level to 110 feet above sea level may take different amounts of energy per sack of potatoes, depending on the transport method used, a cableway will use a lot less than dragging it across the ground, no friction with the ground, but the POTENTIAL ENERGY in each 56 lb sack has been raised by EXACTLY the same amount for EVERY sack.
56 lb x 100 feet = 5,600 ft/lb
5,600 / 550 = 10.18, so assuming no friction one horsepower will take 10.18 seconds to raise that 56 lb sack of spuds 100 ft.
If we have 100 sacks it will take 1,018 seconds, or nearly 17 minutes.
Need to do it in 5 minutes, OK you need 17 / 5 = 3.4 horsepower
This is the beauty of physical laws, they are not THEORIES, like the theory of relativity, they are LAWS, like the law of gravity.
There is no way to take a 56 lb sack of spuds and raise it 100 feet, and do anything other than increase its potential energy by 5,600 ft/lbs, and by expending (losses to friction etc aside) 5,600 ft/lbs of work.
Horsepower is therefore a RATE of work, by definitions, 550 foot pounds per SECOND.
A daily commute along a given route this has a variable but broadly similar rate of work, the hills climbed and descended are pretty much the same, the overall distance travelled pretty much the same, the rolling resistance and kerb weight of the vehicle we are in is pretty much the same, and the time it takes to make the journey is pretty much the same.
If we say the journey takes 600 kWh of fuel to do, eg 60 litres, and 8 hours to drive, then we can work back, 60/8 = 7.5 litres an hour, or 75 kWh an hour, which is a rate of energy consumption of 75 kW, or 75,000 Watts, and since 746 watts = 550 foot pounds per second we can say 75,000 / 746 = 100 and a bit horsepower.
Actual numbers for a 460 mile journey I did a few days ago.
An actual quite new 4 door german car doing 85 mph is asking the engine to produce 100 hp
100 hp will take me, and that car, 1.4 miles every minute.
this is 71 and a bit hp per me-and-my-german-car-per-mile… at that speed
but, if I go at 60 mph, then 50 hp will take me one mile a minute.
In other words it takes nearly 50% more hp, or work, to drive the car a given mile at 85 mph instead of 60 mph, only a fool would doubt the lion’s share of this is wind resistance, but it is there nonetheless.
A man walking produces about 65 watts, that is less than a tenth of a horsepower, sure, it will take me a quarter of an hour to walk that same mile, at 4 mph, but.
Me, alone, walking, 4 mph, 1 mile in 15 minutes, rate of work 0.1 hp
Me, in car driving, 85 mph, 1 mile in 42 and a bit seconds, rate of work, 100 hp
15 mins / 42 seconds = 21.4
100 hp / 0.1 hp = 1,000
It takes 1,000 times the rate of work, or energy consumption, to drive that mile at 85 as it does to walk it at 4 mph, and for the 1,000 fold increase in energy consumption rate we get a paltry 21.4 reduction in time ratio.
Yeah yeah, I can’t walk or run at 85… not the fucking point, leave the car in tickover in 1st gear it will do 3 and a bit mph, and it will be consuming energy at the rate of 10/15 hp, 10 hp is a shit load less than 100 hp, but compared to my walking 0.1 hp…. it is still a HUNDRED times greater… and this is basically eliminating all the wind resistance from the car, all the acceleration and braking, a lot of the tyre deformation rolling resistance, etc, at this point we have basic road and transmission friction and losses, and dragging all that weight around, 1,400 or so kilos of it.
THIS, coming now, IS THE FUCKING POINT.
*All* engineers *get* this point, to others, it needs to be pointed out, to everyone else, it doesn’t exist, wishful thinking and magic pink unicorns rule the day.
If you have less than 10 hp, then you are not in the car, not even at 4 mph with a top speed of 5 mph, it won’t go up any hills, not even in 1st, yeah you can add another gearbox and make it a sixteen speed two shift job, and all the weight of that kit, and at that point it will be overtaken uphill by tortoises and frogs.
It’s like stall speed in an aircraft, drop even 0.0001 mph below it and you are no longer flying, you are falling, then you crash and die…. you can’t make a jumbo fly at 90 mph.
All things in engineering have an equivalent, not a stall speed per se, but the same concept, like a step, you are either on this high step, or that low step, there is no slope anywhere in between, one or the other, those are the only options possible.
Modern motor car AS WE KNOW IT, run it on unicorn ejaculate if you like, but, when you convert back to good old 550 foot pounds per second horsepower, it better have at least 75 equivalent cheval ponies, available on tap, for a continuous duration of at least 6 hours… until the magic unicorn testes finally run dry.
Applies to everything else too, solar energy, wind energy, hydro, yadda yadda yadda, if it doesn’t produce “high step” energy, on demand, for as long as you want, then it is low step energy, and it is bollocks (its actually a lot worse than bollocks, but there we go, story for another day maybe), because “low step” energy simply does not do the SAME job.
low step energy is walking.
wind turbines and solar are low step.
electric cars, as they are made today, from the gwiz to the tesla, are all low step
the internet in the UK, and I’m not talking about your pc or my pc or Amazons cloud or google data-centres, I am talking *just* the fucking network itself, uses about 2 gigawatt’s, the phone system can use up to about 4 gigawatt’s if everyone picks up the phone, eg 9/11, eg the fucking phone system can absorb 10% of daily electricity consumption (diurnal cycles, 25 GW at night, 45/55 daytimes)
you wanna plug that into yer fucking windmills and solar PV?
Your laptop is running off it’s battery, Amazon’s data centre is running off the diesel backups, so provided there is enough wind between the two of you, and it is daytime and reasonably sunny, you can log on to Amazon and buy a book on saving the fucking planet…
About another 10% goes on moving potable water and sewerage around the country…. yeah, you can flush the toilet Tuesdays and Thursdays and alternate Saturdays.
Oh, and all these things will break down a LOT more frequently when you start running them in rolling brownout and blackout schedules, shit that had 36 months of 24/7 service life left in it pops a fucking bollock 72 hours into your brownout cycle.
The modern auto-mobile, the modern truck, the modern bus / train, as we know them, are all “high step”, the thing that makes them “high step” isn’t what they run on or how many polar bears are suffocated per mile driven or how much the seas rise, what makes them “high step” is the rate at which they can expend energy, and the fact they can do so for at least 6 hours without refuelling.
Fossil fuel is 46 megajoules per kilogramme, and 36 megajoules per litre.
li-on batteries are 0.4 megajoules per kilogramme, and 1.2 megajoules per litre
Fossil fuel has 100 times the energy per kilo, and 30 times the energy per litre.
Talking about “science” one day closing this fucking gap is like talking about “science” one day making a jumbo jet fly at 5 mph… it is fucking retarded and impossible… physically fucking impossible.
In fact, if we exclude everything that is basically “burning” something with hydrogen or hydrogen and carbon it it, the ONLY things that beat fossil fuels are, wait for it, fucking NUCLEAR.
Hello, this is basic 3rd form chemistry and physics for fucks sake, shit that used to be hammered into boys of 13, along with french and latin and chaucer.
Fucking COAL offers 30 times the energy per weight of li-on batteries, and 30 times the energy per volume.
If, in some fucking mystical narnia world of fucking unicorns and magicians and malleable physical laws, li-on batteries doubled in charge density every five fucking years, then by AD 20 mother-fucking 40 li-on batteries will be on a par with fucking COAL for fucks sake… oh hang on, the new coal powered Boeing unicorndreamliner just flew overhead…. escorted by a flock of Canada pigs flying south for the fucking summer…
So in 2040 AD, 1910 AD can call and ask for their fucking cars back
I’ve quoted Sagan too often on here..
The point of this post is high step / low step, it applies everywhere to everything, physically and in engineering and technology, if you’re teetering on the edge of the high step, and suffer a 1% loss, it’s a loooong fucking way down to the low step, and suddenly literally nothing is the same as it was on the high step.
That last bit in red is the point.