'I don't believe planes can fly' blog discussion

Former_MSE_Helen · 31 October 2011 at 6:37PM

This is the discussion to link on the back of Martin's blog. Please read the blog first, as this discussion follows it.

Read Martin's "I don't believe planes can fly" Blog.

Please click 'post reply' to discuss below.

Mandelbrot · 31 October 2011 at 8:08PM

Hmmm ... that bolt through the neck seems to have done some damage to Martin's central nervous system.
Either that, or sanding his forehead flat before applying the green paint.

Reaper · 31 October 2011 at 8:31PM

Lol. Most people think the plane stays in the air because of the airflow hitting the underside of the wing. If this were all it had it would indeed fail to fly and you would be right to be worried.

In reality that accounts for only about 20% of the lift. The remaining 80% comes from low pressure ABOVE the wing sucking it upwards.

It's a bit hard to explain why but I will try. The curved surface above the wing means the airflow has to travel faster over the top than it does underneath. That leads to a drop in air pressure which sucks it up.

You can try this for youself. Get 2 sheets of paper and hold them close together then blow in between them. You might think they would seperate more but they don't - they get closer together. The fast moving air between them is at a lower pressure than the still air outside so it pulls them together.

That is how a wing holds a heavy plane up, as long as it keeps moving and keeps that airflow passing over the wing.

DdraigGoch · 31 October 2011 at 9:04PM

I have my doubts about planes too! Every now and then I expect to see a huge chubby hand emerge from a cloud, holding a string to the front of the plane LOLs

Yes, I know how it works but it just doesn't FEEL right!

MSE_Martin · 31 October 2011 at 9:07PM

Reaper wrote: »

Lol. Most people think the plane stays in the air because of the airflow hitting the underside of the wing. If this were all it had it would indeed fail to fly and you would be right to be worried.

In reality that accounts for only about 20% of the lift. The remaining 80% comes from low pressure ABOVE the wing sucking it upwards.

It's a bit hard to explain why but I will try. The curved surface above the wing means the airflow has to travel faster over the top than it does underneath. That leads to a drop in air pressure which sucks it up.

You can try this for youself. Get 2 sheets of paper and hold them close together then blow in between them. You might think they would seperate more but they don't - they get closer together. The fast moving air between them is at a lower pressure than the still air outside so it pulls them together.

That is how a wing holds a heavy plane up, as long as it keeps moving and keeps that airflow passing over the wing.

Yeah right! Pah you're just part of the conspiracy

Reaper · 31 October 2011 at 9:33PM

MSE_Martin wrote: »

Yeah right! Pah you're just part of the conspiracy

I am but I can be very convincing :cool:. For an encore I plan to convince you black is white, the moon is made of cheese, and the EU rescue package has solved the problem.

Actually I may struggle a bit with that last one.

2sides2everystory · 1 November 2011 at 2:10AM

Reaper wrote: »

Lol. Most people think the plane stays in the air because of the airflow hitting the underside of the wing. If this were all it had it would indeed fail to fly and you would be right to be worried.

In reality that accounts for only about 20% of the lift. The remaining 80% comes from low pressure ABOVE the wing sucking it upwards.

It's a bit hard to explain why but I will try. The curved surface above the wing means the airflow has to travel faster over the top than it does underneath. That leads to a drop in air pressure which sucks it up.

You can try this for youself. Get 2 sheets of paper and hold them close together then blow in between them. You might think they would seperate more but they don't - they get closer together. The fast moving air between them is at a lower pressure than the still air outside so it pulls them together.

That is how a wing holds a heavy plane up, as long as it keeps moving and keeps that airflow passing over the wing.

Reaper, were you taught the "equal transit time" idea (of air over and under the wing) to explain why the air over the top 'has to travel faster'? I was. Then I bumped into an Aeronautics lecturer on a university open day recently. He posed the question so what about wings that are pretty much as flat on top as they are underneath ? And he also showed us how a cylindrical wing could fly if it was rotating, and sacre bleue he even poo-poo-ed the idea that a body of air split by the passing of the wing met up again at the trailing edge ...

There is something called "circulation" which makes the explanation of lift a tad more difficult to take onboard than it has been for most pilots for most of the past 100 years - I have no doubt that wrestling with these lesser known circulatory aspects of lift generation around an airplane wing really would have been good enough to distract Martin from the pain of the Great South Run

Percy1983 · 1 November 2011 at 2:13PM

Don't forget those remote control planes you see flying about sometimes, you think they are massive and very high, its all just an illusion!

Reaper · 1 November 2011 at 3:12PM

2sides2everystory wrote: »

Reaper, were you taught the "equal transit time" idea (of air over and under the wing) to explain why the air over the top 'has to travel faster'? I was. Then I bumped into an Aeronautics lecturer on a university open day recently. He posed the question so what about wings that are pretty much as flat on top as they are underneath ? And he also showed us how a cylindrical wing could fly if it was rotating, and sacre bleue he even poo-poo-ed the idea that a body of air split by the passing of the wing met up again at the trailing edge ...

There is something called "circulation" which makes the explanation of lift a tad more difficult to take onboard than it has been for most pilots for most of the past 100 years - I have no doubt that wrestling with these lesser known circulatory aspects of lift generation around an airplane wing really would have been good enough to distract Martin from the pain of the Great South Run

I was indeed taught "equal transit time" and how it was responsible for the drop in pressure. I can see I will have to go back to the drawing board and swot up on circulation before my next flight before I too stop believing a plane can fly.

taxedtodeathbylabour · 2 November 2011 at 2:42PM

Well lets see, we could start by employing member of parliment support officers. They could do the job for a third of the price. They would not have any real powers to make decisions, just to be there in HI VIS suits so that are visible.
Then we could reduce the number of MP's by 20%, roughly by 130 or so. MP's would have to have a licence to work an MP. This would be issued by a governing body and would have to be paid each year by the MP's themselves, say £1000 per year to practice.
When MP's stand down especially after lost election we should remove there thank you and goodbye payment. Expenses will only be paid with a receipt and must be proportionate and justifiable, e.g. first class plane ticket is not proportionate when using tax payers money.
As an MP you must work until you 95; and pay 46% of your wage towards your statue in the house of commons if your the PM. :rotfl:

ukmonkey · 2 November 2011 at 3:11PM

Totally agree about the Aeroplane thing.

I think about things like this each and every day...

Flicking a switch and the light comes on - amazing!
Telephones - amazing!
The Internet - amazing!

I could go on, and suffice to say that I understand the technology behind all of the above, but still find it utterly amazing.

EDIT: Human reproduction (or any reproduction for that matter). How can one tiny tiny egg and one teeny tiny sperm make a baby - it just doesn't seem possible...but it is!

'I don't believe planes can fly' blog discussion

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