Now I know
From the bootnote:
Joules are very small people
People-powered Olympic shopping mall: A sign of utter tech illiteracy
It's just about certain, now: Almost everybody in the world has no idea of the most basic facts regarding energy use. Most people don't even know that the words "energy" and "power" have different meanings1, and just about everyone is so massively ignorant on the subject that they actually consider that the use of special floor …
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Sunday 27th May 2012 12:56 GMT Destroy All Monsters
In the "western world" it's called "campaign contributions"
Pfff... bribery is a totally normal business practice down south or in sandy lands and is attacked only if people of the progressive persuasion are feeling the strong Sunday-morning urge to fix reality by inventing scandals and the laws that go with them, preferably applied world-wide.
As for Siemens, I thought they sold everything off except the fridge-making business?
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Sunday 27th May 2012 10:13 GMT Circadian
Re: Poor Siemens...
Maybe Siemens believe the adage that big things are made up of very small things, and so even small contributions are meaningful.
At least, they definitely believe that in their pricing models, where they charge extra for even the tiniest effing thing that you would expect to be included in the original quote (the weaselly bastards - "oh you wanted faceplates on your network ports rather than bare wires? That's extra then.").
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Sunday 27th May 2012 08:47 GMT Sandtreader
Energy calculations.
(warning, from memory and in head, so could be very wrong!)
Ok, so 4e7 visitors generate (say) 4e5 Wh, that's 1e-2 Wh per visit = 36J
Assuming average visitor mass 50kg (in Stratford?), dropping from a height of 0.1m, PE = mgh = 50J. Assume no losses to air friction (no wing suits, only shell suits), KE on impact = 50J. Assume no way to capture take-off energy, 50J per footstep.
Tiles are 60cm wide, assume walkway about 6m wide, you could have a double row and capture 2 footsteps per entrance and exit, 4 footsteps in all = 200J.
So conversion efficiency required = 36/200 = 18%. I guess that's not outlandish, even it was a simple alternator driven from a rack-and-pinion gear. No idea of the efficiency of piezo electric...
Which is not to detract from the fact that 4e5 Wh is a pathetic amount of energy in the first place...
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Sunday 27th May 2012 09:34 GMT Sandtreader
Re: Energy calculations.
Looked at another way, 4e5 Wh (*) over 1e4 hrs/yr is about 40 W average power. Allowing a duty cycle of 25% (say 6 hours use in darkness per day), and some storage (one 100 Ah leisure battery would do it), that gives you 160W of lighting. Say 20 small CF or LED fittings. Actually to light that particular piece of walkway, I guess that's doable.
The other issue is where this energy comes from. The pedestrians were relying on the hardness of the floor to reflect energy for the next step. Take that away and like walking on sand it requires more energy. Given the nature of the place let's assume it comes from increased consumption of sugary drinks. That comes from sugar beet in the UK, in a process that involves input of lots of embedded energy in fertilisers, plus direct input to dissolve and recrystallise in the factory, not to mention transport and packaging. So even leaving aside the capital energy cost of building the tiles, it could even be negative on a revenue basis...
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Sunday 27th May 2012 10:43 GMT Sandtreader
Re: Energy calculations.
Oh, on the 7W thing... A rival firm Powerleap claims 5Ws (5J) per step. So I'm guessing the journo or subbie changed 7Ws to 7 Watts.
It also adds up with the claim that 5% of energy is enough to light the luminaire in the tile itself. Assuming it lights for 1 sec test gives you 0.5W of LEDs - about the same as a medium-sized torch, so fair enough.
Enough now. Mines the one with the wind-up torch in the pocket.
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Tuesday 29th May 2012 04:40 GMT Allan George Dyer
Re: Energy calculations.
Actually, Sandtreader, on a revenue basis it sounds very good - for the Mall: Visitor walks in, feels tired, buys sugary drink. Visitors, however, should pinch the free granulated sugar packets from the coffee shops, as recompense for being unpaid treadmill-slaves.
Reduced carbon footprint at this Mall can only mean they are providing visitors with small charcoal sandals.
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Sunday 27th May 2012 08:51 GMT LaeMing
As much as I am a big fan of alternate energy,
I am really wondering if the energy gentrated by these tiles can even cover the emissions gentrated by their manufacture, shipping-to-site and installation. I suspect if someone gets the data and does the maths, they would turn out to be a net contributor to emissions.
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Monday 28th May 2012 12:09 GMT Imsimil Berati-Lahn
Re: As much as I am a big fan of alternate energy,
Not to mention the fact that the ultimate source of energy (the food which us mooing mall proles eat) is most likely produced, harvested, processed, refrigerated, stored, packaged, shipped and dispensed in a manner which uses in total, five hundred to a thousand times more energy than is contained in the food item itself [[citation needed: See Rob Newman for details]]. There are a number of rather glaring inefficiencies which need to be addressed in the energy production method suggested.
But then if said proles were going to be walking there anyway, why not parasitise their footfall?
I retract all the preceding, if you like.
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Tuesday 29th May 2012 15:07 GMT Oninoshiko
Re: As much as I am a big fan of alternate energy,
In fairness, the people likely would have eaten anyway, which bring along with it all that refridgeration and transporation cost.
Also, making each step harder means that each person burns more KCals. Everyone is treating that as a bad thing, but I'm not so sure. Clearly the Greenie "reasons" are utter tosh, they should be marketing this for the health benefits.
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Monday 28th May 2012 10:08 GMT Nigel 11
Energy / Power isn't complicated
It's just taught badly.
Everyone has an intrinsic feel for water, so do it this way. Energy is the total amount of water that goes down a pipe. Power is the rate at which it does so.
A toilet is high power, but flushes don't last long. A dripping tap is low power, but over a day will expend more water than flushing a toilet.
Electrical power relates to the flow of electricity rather than water.
If the height that the water descends is fixed, then there is an exact analogy (stored water has potential energy). Electrical voltage is analagous to pressure (which is determined by height).
Water also has the advantage that kids can muck around with it in a "lab" with no risk of anything other than getting wet.
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Monday 28th May 2012 15:23 GMT Daniel 1
Re: Energy / Power isn't complicated
To be sung to the tune of 'Ilkley Moor':
Power is the rate of doing work(doing work)
And energy, the ability to do work
Work is the distance, times the load
Work is the distance, times the load
And power is measured in watts
And Energy's measured in joules
And watts are joules per second
Once learned, never forgotten.
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Sunday 27th May 2012 09:35 GMT Anonymous Coward
On journalists
Michael Crichton summed up our schizophrenic attitude towards journalists:
"Briefly stated, the Gell-Mann Amnesia effect is as follows. You open the newspaper to an article on some subject you know well. In Murray's case, physics. In mine, show business. You read the article and see the journalist has absolutely no understanding of either the facts or the issues. Often, the article is so wrong it actually presents the story backward—reversing cause and effect. I call these the "wet streets cause rain" stories. Paper's full of them. In any case, you read with exasperation or amusement the multiple errors in a story, and then turn the page to national or international affairs, and read as if the rest of the newspaper was somehow more accurate about Palestine than the baloney you just read. You turn the page, and forget what you know."
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Sunday 27th May 2012 16:29 GMT Mark #255
Re: On journalists
First, the strawman - I too don't believe homeopathy works.
Now to the substance. Crichton wrote science fiction, often in a way suggesting it was reportage or documentary. Decent sci-fi generally allows a universe (or multiverse) wherein a maximum of one thing is changed from the current laws of physics (see the fiction of Ian Stewart, Charles Stross or Peter Watts, for examples) - FTL travel, a time machine, or the uploading of consciousness.
So, if you write about apes with language, you'd better not also invent a handy computer program which can magically decode that language (with 1980s technology)
Or if you write about time-travel back to the mediaeval period, you should get your history right (and again, not invent in-ear translation devices based 20th Century technology).
Anyway, it's still a sunny Sunday afternoon, so I'll end with a reference to Tom Clancy's comment that fiction is much harder to write than real life, because readers demand internal consistency from fiction.
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Monday 28th May 2012 10:19 GMT Nigel 11
Sci-Fi
FTL Travel and Time travel are effectively the same thing (if General Relativity is right). Both are impossible, at least for anything larger than a subatomic particle, if current physics is correct.
Uploading consciousness is not believed to be impossible. We simply don't know. Perhaps there is a fundamental problem (consciousness *may* be a quantum phenomenon). Perhaps not. It may be a mere technological problem, that will be solved within decades or centuries.
The "hardest" SF doesn't wilfully break the generally believed laws that govern our universe. It runs with them.
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Monday 28th May 2012 12:35 GMT Anonymous Coward
Re: On journalists
It's easy to dismiss Crichton because "he was a just a fiction writer". In fact he was a good bit more ... he got an MD from Harvard Medical School, and taught courses in anthropology at Cambridge University. If you get the chance take a look a look at a talk he delivered at Caltech in 2003 "Aliens Cause Global Warming" which bemoans the lack of scientific understanding in our public debate.
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Sunday 27th May 2012 09:30 GMT frank ly
Down with this sort of thing! (When will it end?)
This sort of thing has been going on for years, at regular intervals. I am fed up with architects, 'designers' and various know-buggerall idiots proposing this sort of thing. If they did it alone, among their friends, then it wouldn't matter. As it is, they can influence politicians and real town planners (with budgets to spend) and cause money to be spent (wasted) on 'feasilbilty studies' and 'technology demonstrator projects'.
Nobody, not anybody, should be allowed to spend public (taxpayer) money on any project with any technology content unless they have at least an 'O' level (the old style one) in physics.
There, that's my first draconian law as World Dictator. I have many more but I won't bother you with them on a Sunday morning.
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Sunday 27th May 2012 09:38 GMT Ottman001
Just what I needed...
...a good moan to start off the day.
I do take issue when people fail to fully quantify a unit measurement and as such leave it literally meaningless. Any attempt to extract meaning are liable to make an incorrect assumption. And as my dad always told me, "assumption is the mother of all cock ups."
I most commonly experience such bursts of pedantry when dealing with the measure of torque output from servos as used in radio control models. Usually this specification is measured in kilogram/centimetres. Surely kilogram/meters would be a more common measure of torque in engineering? Therefore, when people refer to "5Kg torque" I feel utterly compelled to correct their lazy, incompetent, fuzzy-minded thinking.
</rant>
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Sunday 27th May 2012 10:15 GMT John Hughes
Re: Just what I needed...
Uh, torque is force x distance, i.e. newtons x metres.
I guess you meant to write kilograms x centimetres rather than kilograms / centimetres, but that's still wrong, the kilogram is a unit of mass, not force.
Sounds like someone has been doing stupid translation from non SI units, pound feet, forgetting that the pound is a unit of force and not mass.
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Sunday 27th May 2012 21:21 GMT Chris Miller
@John
I forgive you, since you may well not be ancient enough to have been taught Imperial units - but the pound is a mass unit, although (just as with kg) it is often used loosely to describe a force. There's even an imperial unit of force, the poundal: that force sufficient to accelerate a mass of one pound at a rate of one foot per second per second (it's roughly half an ounce weight at standard g).
Here endeth the history lesson.
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Sunday 27th May 2012 22:58 GMT Nuke
@Ottman001 - Re: Just what I needed...
Wrote :-
"Usually [torque] is measured in kilogram/centimetres. Surely kilogram/meters would be a more common measure of torque in engineering?"
Indeed. Centimeters are a dressmakers' unit. In my engineering industry we use microns, millimeters, meters, and kilometers. I understand that the SI recommend factors of 1000 between preferred units in this way.
However, in volume, the centimeter does appear because we go : cubic mm, cc (cubic centimeter), litre (cubic decimeter) and cubic meter, because these volumes are also factors of 1000 apart.
OTOH there is not enough attention being given in this discussion to the BVS (British Vernacular System) which for length goes : thickness of a human hair, the lengths of a matchbox, a London bus, and a football pitch, the circumference of the Earth, and from here to the Moon and back. These lengths deliberately have no rational relationship to each other and are not to be confused with the units of >height< which involve Nelson's Column etc.
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Monday 28th May 2012 14:26 GMT Anonymous Coward
Re: @Ottman001 - Just what I needed...
I've noticed cl centilitres in use on drinks cans and bottles, so it's not just cm :)
Good old cm are on a far more human scale than using hundreds and thousands of mm IMHO - don't knock the dressmakers who have probably got more common sense than many engineers, LOL
And although the Bel isn't metric as such, you'll find that deci comes into play with the dB being the usual way to express units of sound levels.
Sticking to factors of 1000 is a bit dull really :)
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