The Monty Python Tribute thread

[SkaPaladin]

Question 1. What is the air speed velocity of an unladen swallow?

Okay, now, for the real questions...

First off, a little loose skin in the mid section. How should I go about getting rid of that? Sit ups? One of those "stomach sweat" thingies?

Second question. Those icky stretch marks. I heard that you can't really get rid of those. I should never let them get there in the first place, of course. But, I hear that really muscular people get them too... Well, what is a good way to get rid of them, or hide them, without having to hide my "killer body"? I mean, can I scrub away the skin there, and have my new skin cells kinda, replenish in the area? So it's more even? Or a vitamin E lotion?

Oh, and finally, blonde streaks? Or burgundy streaks? I wanted blonde, but my aunt (a stylist) says burgundy.

[Richt]

Re: Got a quick question. Or two. Do you have an answer?

Question 1. What is the air speed velocity of an unladen swallow?

.

African or European?

[SkaPaladin]

Re: Got a quick question. Or two. Do you have an answer?

YES! I knew someone would get it!

"I don't know... AAAHHHHhhhh!!!!"


"How do you know so much about swallows?"

"You have to know these things as a king..."

[Richt]

Re: Got a quick question. Or two. Do you have an answer?

Question 1.

First off, a little loose skin in the mid section. How should I go about getting rid of that? Sit ups? One of those "stomach sweat" thingies?

It almost impossible to "spot train". By that I mean, its hard to concentrate on one specific area. But stomach crunches or any "core" excercises will help the most.

Second question. Those icky stretch marks. I heard that you can't really get rid of those. I should never let them get there in the first place, of course. But, I hear that really muscular people get them too... Well, what is a good way to get rid of them, or hide them, without having to hide my "killer body"? I mean, can I scrub away the skin there, and have my new skin cells kinda, replenish in the area? So it's more even? Or a vitamin E lotion?

I am not sure on this one I am afraid

Oh, and finally, blonde streaks? Or burgundy streaks? I wanted blonde, but my aunt (a stylist) says burgundy.

I think you should go 100% blonde. But thats just my preference

Rich

[Richt]

Re: Got a quick question. Or two. Do you have an answer?

YES! I knew someone would get it!

"I don't know... AAAHHHHhhhh!!!!"


"How do you know so much about swallows?"

"You have to know these things as a king..."

Ooooh, Dennis, there's a lot of dirt over here (or something like that)

But my favourite bit of that film, is the Black KNight closely followed by Castle Anthrax.

[Carbaholic]

Re: Got a quick question. Or two. Do you have an answer?

'What's your favourite colour?'
'Burgundy......no! Blonde!! Ahhhhhhhhhh...'

ALL of the English on this forum will know the ol' 'African/European Swallow' gag!!! It's practically part of the curriculum at school...

[Richt]

Re: Got a quick question. Or two. Do you have an answer?

'What's your favourite colour?'
'Burgundy......no! Blonde!! Ahhhhhhhhhh...'

ALL of the English on this forum will know the ol' 'African/European Swallow' gag!!! It's practically part of the curriculum at school...

Yes indeed, and the person that started this thread is in Texas!!!! Maybe it has international fame.

[SkaPaladin]

Re: Got a quick question. Or two. Do you have an answer?

The fame they share is international, most definitely. When I discovered that movie, I tried to get my dad to watch it with me, thinking he had no clue what it was. He had seen it when he was a bit younger as well.

"Yes! A Spanking"

[SkaPaladin]

Re: Got a quick question. Or two. Do you have an answer?

'Ello, Miss?

What do you mean "miss"?

<pause> I'm sorry, I have a cold.

[Richt]

Re: Got a quick question. Or two. Do you have an answer?

The fame they share is international, most definitely. When I discovered that movie, I tried to get my dad to watch it with me, thinking he had no clue what it was. He had seen it when he was a bit younger as well.

"Yes! A Spanking"

I was thinking about the other thing that went on in the castle other than the spanking, but can't really post it here

[SkaPaladin]

Re: Got a quick question. Or two. Do you have an answer?

"Nobody expects the Spanish Inquisition!"

Great, now you got me quoting things...

I think I know what you're talking about. I wouldn't mind facing that peril, even if it is far too perilous...

[Richt]

Re: Got a quick question. Or two. Do you have an answer?

"Nobody expects the Spanish Inquisition!"

Great, now you got me quoting things...

I think I know what you're talking about. I wouldn't mind facing that peril, even if it is far too perilous...

I'm going to move this thread to chit chat.

Can you post your original question here again please?

[dotsamantha]

Re: The Monty Python Tribute thread

Estimating the Airspeed Velocity of an Unladen Swallow

Hashing out the classic question with Strouhal numbers and simplified flight waveforms.
by Jonathan Corum

After spending some time last month trying to develop alternate graphic presentations for kinematic ratios in winged flight, I decided to try to answer one of the timeless questions of science: just what is the airspeed velocity of an unladen swallow?

What do you mean, an African or European Swallow?

To begin with, I needed basic kinematic data on African and European swallow species.

South African Swallow (Hirundo spilodera) European Swallow (Hirundo rustica)

Although 47 of the 74 worldwide swallow species are found in Africa,1 only two species are named after the continent: the West African Swallow (Hirundo domicella) and the South African Swallow (Hirundo spilodera), also known as the South African Cave Swallow.

Since the range of the South African Swallow extends only as far north as Zaire,2 I felt fairly confident that this was the non-migratory African species referred to in previous discussions of the comparative and cooperative weight-bearing capabilities of African and European swallows.3

Kinematic data for both African species was difficult to find, but the Barn or European Swallow (Hirundo rustica) has been studied intensively, and kinematic data for that species was readily available.

It’s a simple question of weight ratios

A 54-year survey of 26,285 European Swallows captured and released by the Avian Demography Unit of the University of Capetown finds that the average adult European swallow has a wing length of 12.2 cm and a body mass of 20.3 grams.4

Because wing beat frequency and wing amplitude both scale with body mass,5 and flight kinematic data is available for at least 22 other bird species,6 it should be possible to estimate the frequency (f ) and amplitude (A) of the European Swallow by a comparison with similar species. With those two numbers, it will be possible to estimate airspeed (U).

In order to maintain airspeed velocity, a swallow needs to beat its wings forty-three times every second, right?

Actually, wrong. By comparing the European Swallow with bird species of similar body mass, we can estimate that the swallow beats its wings 18 times a second with an amplitude of 18 cm:

SpeciesBody massFrequencyAmplitudeZebra Finch13 g27 Hz11 cmEuropean Swallow20 g≈ 18 Hz?≈ 18 cm?Downy Woodpecker27 g14 Hz29 cmBudgerigar34 g14 Hz15 cmNote that even the tiny Zebra Finch flaps its wings no more than 27 times a second while cruising.

If we ignore body mass and look only at bird species with a similar wingspan, we can estimate an average frequency of 14 beats per second and an amplitude of 23 cm:

SpeciesWingspanFrequencyAmplitudeBudgerigar27 cm14 Hz15 cmEuropean Swallow≈ 28–30 cm≈ 14 Hz?≈ 23 cm?Downy Woodpecker31 cm14 Hz29 cmEuropean Starling35 cm14 Hz26 cmBy averaging all 6 values, we can estimate that an average European Swallow flies at cruising speed with a frequency of roughly 15 beats per second, and an amplitude of roughly 22 cm.

Skip a bit, Brother

Last month’s article on The Strouhal Number in Cruising Flight showed how simplified flight waveforms that graph amplitude versus wavelength can be useful for visualizing the Strouhal ratio (fA/U), a dimensionless parameter that tends to fall in the range of 0.2–0.4 during efficient cruising flight.

For a European Swallow flying with our estimated wingbeat amplitude of 24 cm, the predicted pattern of cruising flight ranges from a Strouhal number (St) of 0.2:

... to a less efficient 0.4:

If the first diagram (St = 0.2) is accurate, then the cruising speed of the European Swallow would be roughly 16 meters per second (15 beats per second * 1.1 meters per beat). If the second diagram (St = 0.4) is accurate, then the cruising speed of the European Swallow would be closer to 8 meters per second (15 beats per second * 0.55 meters per beat).

If we settle on an intermediate Strouhal value of 0.3:

We can estimate the airspeed of the European Swallow to be roughly 11 meters per second (15 beats per second * 0.73 meters per beat).

Three shall be the number thou shalt count

Airspeed can also be predicted using a published formula. By inverting this midpoint Strouhal ratio of 0.3 (fA/U ≈ 0.3), Graham K. Taylor et al. show that as a rule of thumb, the speed of a flying animal is roughly 3 times frequency times amplitude (U ≈ 3fA).5

We now need only plug in the numbers:

U ≈ 3fA


f ≈ 15 (beats per second)
A ≈ 0.22 (meters per beat)
U ≈ 3*15*0.22 ≈ 9.9

... to estimate that the airspeed velocity of an unladen European Swallow is 10 meters per second.


Oh, yeah, I agree with that

With some further study, it became clear that these estimates are accurate, though perhaps coincidental.

An actual study of two European Swallows flying in a low-turbulence wind tunnel in Lund, Sweden, shows that swallows flap their wings much slower than my estimate, at only 7–9 beats per second:

“Compared with other species of similar size, the swallow has quite low wingbeat frequency and relatively long wings.” 7

The maximum speed the birds could maintain was 13–14 meters per second, and although the Lund study does not discuss cruising flight in particular, the most efficient flapping (7 beats per second) occurred at an airspeed in the range of 8–11 meters per second, with an amplitude of 90–100° (17–19 cm).


And there was much rejoicing

Averaging the above numbers and plugging them in to the Strouhal equation for cruising flight (fA/U = 7 beats per second * 0.18 meters per beat / 9.5 meters per second) yields a Strouhal number of roughly 0.13:

... indicating a surprisingly efficient flight pattern falling well below the expected range of 0.2–0.4.

Although a definitive answer would of course require further measurements, published species-wide averages of wing length and body mass, initial Strouhal estimates based on those averages and cross-species comparisons, the Lund wind tunnel study of birds flying at a range of speeds, and revised Strouhal numbers based on that study all lead me to estimate that the average cruising airspeed velocity of an unladen European Swallow is roughly 11 meters per second, or 24 miles an hour.

What is the capital of Assyria?

For those looking for additional answers, the four capitals of Assyria were Ashur (or Qalat Sherqat), Calah (or Nimrud), the short-lived Dur Sharrukin (or Khorsabad), and Nineveh.8 The ruins of all four ancient cities fall within the modern state of Iraq.
November 17, 2003

Jonathan Corum is principal of 13pt, a design and development studio. His favorite color is blue.

©2003–2004 style.org, a service of 13pt. CSS information.

[dotsamantha]

Re: The Monty Python Tribute thread

Wink wink, nudge nudge

[Richt]

Re: The Monty Python Tribute thread

Wink wink, nudge nudge

Say no more!

A nudge is good as a wink to a blind bat!