We all know how fixed wing aircraft work;
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Even with my limited knowledge of physics I know how helicopters, hot-airballoons, airships and ornithopters work (or don't work in the case of ornithopters)
However, in this picture of a magic carpet the front is half rolled up in the usual way [IMG] 
[/IMG] but I beleive this design for the leading edge would create a vortex as the air passing to the underside would follow the surface of the carpet around and end up trapped in the fold, the bottom set of arrows in my picture, making it extreemly unstable, or at least creating an enormous amount of drag.
Am I missing something or the design intended to be unstable in the same way that, for example, a Eurofighter is?
Also, on the one in the photograph there appear to be very few, if any, controls for the pilot. How does the autopilot system work on these? There's nothing on the Boeing, GE or BAE websites about this. We have a carpet fitter at work at present in the top floor office, I asked him, assuming that someone who worked in the industry would know but he was clueless on the matter.
its a brave new world
We all know how fixed wing aircraft work;
Except that's not actually how fixed wing aircraft work. If you understood it properly, the magic carpet would be obvious.
Er, physics is physics.
Magic carpets are magic.
They fly cos Paul Daniels tells em too.
Your schoolboy aeroplane wing diagram is a myth. How would planes fly upside down in that case?
Yeah, the top diagram uses Bernoulli's Principle to explain lift and while the principle itself (derived from Newtons Second Law) is pretty sound, the application of it to aircraft wings in generally not - what is written up there is often referred to as the Equal-Transit Time Fallacy.
Have a look at the Coanda Effect for a more detailed explanation of how lift is generated on an aircraft wing.
As to the Magic Carpet, it should be obvious that it's actually on a conveyor belt...
Superb thread, andrew.
I wondered if it was soemthing to do with the thickness of the magic carpet - in your picture it looks much, much thicker than your average Allied Carpets rug effort. Perhaps that is the secret? Also, where are the fuelling ports for re-fuelling with magic?
you're wrong
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Well you've first diagram's wrong, that's not how wing lift works.
There's some nice coloured pulsed air wind-tunnel footage showing that the air on the bottom arrives before that on the top.
In much the same way that if you peel off at a motorway junction then rejoin the traffic at the next one, there's no force meaning you've got to rejoin at the same point in the traffic flow.
The magic carpet looks fine to me, just give a decent angle of attack and enough power at it should be fine. The control system works on magic* just like an A380.
*The clues in the name of the craft.
its got nothing to do with physics. Aircraft stay aloft through the collective will of the passengers not to die.
Here's one in action.
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I'm pretty sure the magic carpet you have there is faulty. The front edge has been rolled. They normally lie flat (ish)
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Is that navigation light approved by the CAA?
In much the same way that if you peel off at a motorway junction then rejoin the traffic at the next one, there's no force meaning you've got to rejoin at the same point in the traffic flow.
Bad analogy. There's no force equalising the distribution of cars like there is air molecules (ie pressure).
[i]Bad analogy. There's no force equalising the distribution of cars like there is air molecules (ie pressure).[/i]
Nah, it works fine, but if you want it with fluids, take a straight section of river. If you then diverted half of it along a 10 mile meandering path and the rejoined it 100 metres down stream, do you think the water in the side arm would race along due to the pressure to join up with the rest ?
seem to remember Stephen Fry saying at the end of a QI that there's 3 different theories to explain how planes fly and they contradict each other - is that correct?
The lift from an aircraft wing comes predominantly from the angle of attack. There's no reason why this shouldn't also be true for your carpet.
It's the method of propulsion that is magic, and everyone knows this is limitless. It's what we should be researching as the ultimate sustainable energy source.
I wonder if magic cats are behind it all.
Nah, it works fine, but if you want it with fluids, take a straight section of river. If you then diverted half of it along a 10 mile meandering path and the rejoined it 100 metres down stream, do you think the water in the side arm would race along due to the pressure to join up with the rest ?
In support of molgrips here, despite his poor record on Physics, he is right, you are wrong, [b]MAGIC FACT[/b] even though using this fact to explain wing lift is wrong...
I think it would be worth noting that there is a great deal of smoke eminating from the rear of the carpet; on further inspection we can reveal that the person at the rear of the carpet (for the purpose of illustation we'll call him 'Al') is in fact lifting his outfit, or 'skirt', with the smoke ballooning out around him. This would imply that 'Al' is in fact himself a human/android/hovercraft hybrid riding on a cushion of air, and his passenger is merely travelling on his exceptionally large and disproportionally flattened penis. If you look closely you can see the join.
I'm here to help.
Your magic is weak padwan.
The air on the top arrives at the back before the stuff on the bottom, there's nothing in physics that requires an equal transit time.
The force does not flow true in you.
You might be onto something, but that might not be smoke, it might just be a follow on (or though) from the earlier thread about how many farts are needed to keep a 747 flying.
I've had some pretty magical farts in the past, just not the right carpet.
Shirley the reason a plane stays in the air is because it imparts a net downward velocity onto the air flowing over its's lifting surfaces.
The air on the top arrives at the back before the stuff on the bottom, there's nothing in physics that requires an equal transit time.
That I think is true, but I don't think that's quite what you or molgrips discussed above, but if that is what you want to say then fine. You must realise that if the air does not arrive at the same time then the air over the top or the back will be restored into the gap by the low pressure created under the wing by the lack or air..
All of the above.
(a) Wings deflect air downwards. Diagrams like the one at the top rarely show this but it is a fundamental and necessary part of what they do as per Newtonian action/reaction (unless you're flying *very* close to the ground).
(b) They do this by inducing higher pressure underneath, lower pressure above.
(c) Angle of attack is the most fundamental way of achieving (b).
(d) Normal wing designs have assymetrical cross-sections to achieve (b) more efficiently while inducing less drag. But aircraft which are supposed to fly upside-down on a regular basis (aerobatic light aircraft) or go supersonic (fighter jets) tend to have more symmetrical wing sections and depend mostly on (c).
(e) In normal flight airflow *is* faster over the top and the streams *do not* arrive at the trailing edge at the same time.
... is that clear...?
[EDIT] Attempting inverted flight on a flying carpet is probably still not a good idea though 😉
ononeorange - Member
I wonder if magic cats are behind it all.
I had thought of that. One often sees them acting as co-pilot on broomsticks but rarely on a carpet, which is odd as carpets are much larger. Do they have to travel in the hold on carpets as they would in a conventional airliner?
Slight side storey, Gordon has been in training as co-pilot but has been unable to find a job on broomstick due to not being black enough. He will taking his case for racial discrimination to the appropriate authorities.
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Anything will fly given a big enough engine. The F104 Starfighter being a classic example; a fracking great engine with tiddly little wings stuck on each side. 'Course, as the Luftwaffe found, fail to maintain the engine properly and it'll drop out of the sky like a brick. "How do you obtain a Starfighter? Buy an acre of land in Germany and wait"
GeeBee racers in the States were another example of the minimum amount of wing surface attached to the biggest damned rotary engine available.
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for the fixed wing diagram, conservation of mass gives that flow over the top needs to be the same as that underneath, an given the the top stuff has further to go, it has to be faster. besides whiche you only need to measure the velocities around the wing to see what happens
For what it's worth, the explanation in your diagram at the top, is best described as 'bollocks'. It's one of those explanations people give because the real answer is ridiculous complicated. I would attempt to explain it, except I'm pissed, and I barely understand it when I'm sober...
PS. I'm sure someone has mentioned the above in the posts above, so apologies if i'm just repeating what everyone else has said...
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http://www.grc.nasa.gov/WWW/K-12/airplane/wrong1.html
If you're really bored, read this thread, lots of links to the actual theory and various over explanations that are 'wrong' to varying degrees...
http://forums.xkcd.com/viewtopic.php?f=7&t=64908&start=40
It's obvious how that magic carpet works.
They have photoshopped out the fairies underneath.
It's obvious how that magic carpet works.They have photoshopped out the fairies underneath.
Are you colour blind? the fairies ( ->) are shown in black in the first diagram, dutifully holding up the wing while their pals playfully slide down the slopey bit. In real life fairies are red, but the first illustration is in black and white. If you can't see the fairies in the second illustration its because you can't see red. Which is your loss, as red fairies (or Red Arrows as they like to be known) are quite good at flying and put on rather an entertaining display
charlie is right by mentioning mass flow, but wrong when he talks about 'distance'.
the air flow speeds up cos it's flowing through/over a restriction - like a venturi or orifice plate.
mass flow rate ahead of the wing and over the wing and behind the wing are all equal, only the air above the wing is being restricted - so it travels faster, and in accordance with bernouli, the pressure falls.
it doesn't speed up cos it's further to go, it speeds up cos it's flowing past a restriction.
It's all done with wires, obviously. Which is why planes can still take off even if they're on a conveyor belt.
true awhile, but both models, 'distance' and ' flow contraction' are oversimplifications, one being the effect of the other. but yes, the distance model fails when the 'flow on the surface is considered. I'm not sure if it is helpful in trying to understand flight as a single effect. Any system which generates an overall downforce on the air results in flight (sort of). Different modes of flight capitalise on effects of different con current flow regimes. Probably
It's the method of propulsion that is magic
Well, I can't see a prop anywhere in that first picture, so that rules out a piston engine or a turbo-prop.
Which means the only remaining option is, by a process of elimination...
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a Turban Fan! 🙁
Please yerselves..........
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Livin' in the Jag, tablets for me nerves etc etc.............
Ah, Bobby Chariot!
or a turbo jet...
would the carpet fly if it was on a conveyor belt?
GeeBee racers in the States were another example of the minimum amount of wing surface attached to the biggest damned [b]rotary[/b] engine available.
Radial. Rotary engines (where the crankshaft is bolted to the airframe & the propeller to the crankcase - the whole engine block spins) went out of use shortly after WW1, and were deeply inefficient.
/pedantry
Andy
God you lot are stupid.
Look at how that bloke is looking at the woman on the carpet. He wants her like nothing else on earth. The science of lust is keeping that thing afloat.
The F104 Starfighter being a classic example; a fracking great engine with tiddly little wings stuck on each side. 'Course, as the Luftwaffe found, fail to maintain the engine properly and it'll drop out of the sky like a brick
The aerodynamics don't tell the full story, the Spanish and Italian air forces lost very few of their F-104s. Superior training and tactics played a big part here.
Besides, the English Electric Lightning offered comparable performance with far better stability and manoeuvrability.
If you can get hold of it, [url= http://en.wikipedia.org/wiki/Captain_Lockheed_and_the_Starfighters ]Captain Lockheed & The Starfighters [/url]is a great take on the whole Starfighter story.
Various bits on youtube:
Have it on vinyl LP (ask your dad) if anyone wants a shonky copy.
Flying carpets can fly because they achieve lift by flying forwards very fast. They manage this by having a huge potential magic difference between the surface of the carpet and the lining underneath which is made from a different material with a massively higher magical conductivity.
This is also why Speedy Gonzalez can run so fast after shouting "underlay, underlay!"
If you can get hold of it, Captain Lockheed & The Starfighters is a great take on the whole Starfighter story.
One of my favorite concept albums!
ononeorange - Member
I wondered if it was soemthing to do with the thickness of the magic carpet - in your picture it looks much, much thicker than your average Allied Carpets rug effort. Perhaps that is the secret?
Cougar - MemberThey manage this by having a huge potential magic difference between the surface of the carpet and the lining underneath which is made from a different material with a massively higher magical conductivity.
So it's all in the lining and I've been looking in the wrong place all along? Does a thicker lining always help or do we hit a point of diminishing returns where the extra weight more than cancells out the extra lift?
Just worked it out. Static electricity. The bloke and the bird have been at it like the battery bunny, creating a huge static charge through friction on the carpet that's caused the carpet to react negatively to the earth's natural electromagnetic fields, thus creating lift. Like a maglev monorail. Simple.