Terminal velocity of skier
Eber Lambert
A skiiers terminal velocity is reached when he can no longer make the necessary turn to keep him from going into the woods.
These speeds are best attempted early in the day
Control is for the tamed.
- Kami
--
Carl J Lydick
>Someone has claimed that a skier in the Olympic speed skiing event can exceed
>the velocity of a person free falling from an airplane. This seems patently
>rediculous, but I would like to prove it using physics and mathematics to
>settle a bet. Can anyone provide a rigorous proof?
It may be ridiculous, but it's certainly not "patently" so. Bear in mind that
these skiers do their best to minimize drag. This means they assume a "tuck"
position. This shape may be aerodynamically unstable. If so, someone
free-falling would begin to tumble, which could increase drag dramatically.
However, the skier has an advantage here: the fact that his skis are in
contact with the ground allows him to stabilize himself, so he continues to
present the minimum-drag profile.
Please note: I'm not saying that the assumptions in my analysis are correct,
just that it would take quite a bit of work to disprove them if they're
incorrect.
--------------------------------------------------------------------------------
Carl J Lydick | INTERnet: CA...@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL
Disclaimer: Hey, I understand VAXes and VMS. That's what I get paid for. My
understanding of astronomy is purely at the amateur level (or below). So
unless what I'm saying is directly related to VAX/VMS, don't hold me or my
organization responsible for it. If it IS related to VAX/VMS, you can try to
hold me responsible for it, but my organization had nothing to do with it.
kis...@iowasp.physics.uiowa.edu
(Carl J Lydick) writes:
> In article <1992Feb14....@u.washington.edu>, l...@cac.washington.edu
> (Les Pennington) writes:
>>Someone has claimed that a skier in the Olympic speed skiing event can exceed
>>the velocity of a person free falling from an airplane. This seems patently
>>rediculous, but I would like to prove it using physics and mathematics to
>>settle a bet. Can anyone provide a rigorous proof?
>
> It may be ridiculous, but it's certainly not "patently" so. Bear in mind that
> these skiers do their best to minimize drag. This means they assume a "tuck"
> position. This shape may be aerodynamically unstable. If so, someone
> free-falling would begin to tumble, which could increase drag dramatically.
> However, the skier has an advantage here: the fact that his skis are in
> contact with the ground allows him to stabilize himself, so he continues to
Terminal velocity of a person falling spread-eagled is about 120 mph. If you
reach back and grab you ankles, you're in a stable position with a higher
terminal velocity. Skiers can tuck to reduce drag. They buy and wear really
expensive clothes, which may or may not make a difference. Their terminal
velocity may be higher than free fall, but they've also got drag between the
skis and the ground.
On a related, folklore-ish, topic, how about the old-wives tale that if you
shave all the hair off your body, you can swim faster? Maybe it's better
described as an old-coaches' tale. The premise, as I understand it, is that
by reducing your drag coefficient by a millionth of a percent, you can gain
that extra millisecond in the quarter-mile freestyle that will make all the
difference in the world. (Now there's a daunting body of folklore: all the
health crap athletes and non-athletes believe because someone with a marketing
degree says it's scientific.)
Allen Kistler
kis...@iowasp.physics.uiowa.edu
Tony Leneis
>On a related, folklore-ish, topic, how about the old-wives tale that if you
>shave all the hair off your body, you can swim faster? Maybe it's better
>described as an old-coaches' tale. The premise, as I understand it, is that
>by reducing your drag coefficient by a millionth of a percent, you can gain
>that extra millisecond in the quarter-mile freestyle that will make all the
>difference in the world. (Now there's a daunting body of folklore: all the
>health crap athletes and non-athletes believe because someone with a marketing
>degree says it's scientific.)
The reason why you shave all your hair off is because you *FEEL* like you're
going faster. Your body is much more sensitive to the water, and you really
feel fast. (Perhaps it's because of the dead skin which is removed?) In
any case, I would say that most of the effect of shaving is 99.99%
psychological. I'm a former swimmer, and have experienced this first-hand...
If a swimmer shaves, he can expect to knock off a significant amount of time.
We're talking tenths of a second to perhaps a full second or three in 200 yd
races; however, if you shave often you lose this effect. Of course we
always tell ourselves that we're going fast because we have no hair, are
wearing ridiculously small and tight suits, etc., but really it seems like
it's more of a ritual which allows the swimmer to focus on what he's doing.
Tony Leneis
ale...@jarthur.claremont.edu
J.D. Lewthwaite
Newsgroups: alt.folklore.science
References: <1992Feb14....@u.washington.edu>
How about a skier decending a vertical [or near vertical] slope ?
wouldn't he (or she) reach the same maximum velocity ?
--------------------------------------------------------------
Don't belive anything I tell you, 'cos it's all rubbish.
Dave is... cs...@seq1.kl.ac.uk, and proud of it.
I may be ugly, but you're drunk and... er... damn.
Curtis Jackson
In article <1992Feb14....@cis.ohio-state.edu> pito...@iroquois.cis.ohio-state.edu (Andrew Pitonyak) writes:
}Sky divers wear things that are very bulky (ussually) that produce lots
}of drag. Remember that your terminal velocity is related to things
}like this.
This is not nearly so true anymore. The standard body position of a
skydiver is spread-eagled facing the earth. In this position, top speed
is somewhere around 120 mph (lots of variables involved). But a
skydiver can also elect to go head-down with arms flat against the
sides. This will give a top speed of somewhat over 200 mph, and I
might add it is quite a thrill!
Somehow I don't expect skiers to equal this speed unless they, too,
are falling head-first off a very tall cliff while wearing Spandex...
--
Curtis Jackson @ Adobe Systems in Mountain View, CA (415-962-4905)
Internet: cjac...@adobe.com uucp: ...!{apple|decwrl|sun}!adobe!cjackson
"They that can give up an essential liberty to obtain a little temporary
safety deserve neither liberty nor safety". -- Benjamin Franklin (1759)
P MacFarlane
>shave all the hair off your body, you can swim faster? Maybe it's better
>described as an old-coaches' tale. The premise, as I understand it, is that
>by reducing your drag coefficient by a millionth of a percent, you can gain
>that extra millisecond in the quarter-mile freestyle that will make all the
>difference in the world. (Now there's a daunting body of folklore: all the
>health crap athletes and non-athletes believe because someone with a marketing
>degree says it's scientific.)
I don't know about this but a guy in my class at school used to shave
his legs because he was really into cycling and he claimed it improved
his aerodynamics enough to provide extra speed when cycling. This didn't
stop everyone laughing at him about shaving his legs though :-).
Philip.
Sebastian Theriault
>
>things such as wind resistence........
I remember reading an article in Quebec-Science (or maybe it was the
NRC's magazine) describing aerodynamic tests done at the NRC
windtunnel in Ottawa. They had the skiers in the windtunnel, wearing
different kinds of suits. It turned out that the for women, the lowest
drag was achieved when they were wearing nothing.
--
Jean-Sebastien Theriault "This is my signature quote."
j...@dcs.ed.ac.uk -me
Peter Benson
>On a related, folklore-ish, topic, how about the old-wives tale that if you
>shave all the hair off your body, you can swim faster? Maybe it's better
>...
I don't know about this but a guy in my class at school used to shave
his legs because he was really into cycling and he claimed it improved
his aerodynamics enough to provide extra speed when cycling. This didn't
stop everyone laughing at him about shaving his legs though :-).
The reason bicycle racers shave their legs is not to reduce aerodynamic
drag, but to reduce the potention for infection after getting a bad road
burn in a crash. It is required by the UCI (the international cycle racing
sanctioning organization). The wind resistance line is good when people
are laughing at you as you shave your legs though.
David C Daye
>shave all the hair off your body, you can swim faster? Maybe it's better
>described as an old-coaches' tale. The premise, as I understand it, is that
>by reducing your drag coefficient by a millionth of a percent, you can gain
>that extra millisecond in the quarter-mile freestyle that will make all the
>difference in the world. (Now there's a daunting body of folklore: all the
>health crap athletes and non-athletes believe because someone with a marketing
>degree says it's scientific.)
>
Doc Counsilman (sp) at Indiana U. or some such place; sorry, I'm not a
swimmer.
I was interested in this c. 1972 upon noticing the wave patterns generated
by swimmers were identical, grossly, to those made by my racing sailboat.
Naval architects have long known that the generation of surface waves puts
a practical cap on top speeds of surface vessels; even submarines encounter
this effect underwater if motoring near the boundary between waters of very
different salinities and/or temperatures. At the surface, wave drag can go
up by the *6th* power of speed increase, once the speed in knots exceeds the
square root of twice the waterline length in feet, for some vessels.
Anyways I conjectured that the top speeds of sprinting swimmers would therefore
be about what you'd get out of 6' sailboats. Actually they were some %
faster, but only in the short sprints. At longer races the swimmers operate
well below the wave-generation "barrier," as do most powered ships.
Anyways the swimmers and coaches hadn't a clue about this effect, even tho'
they're taught to avoid the surface after dives because they go faster when
far beneath it. One thing led to another and I found the problem unexplored
by "Doc," then the reigning coach and experimenter in the field, but far, far
beyond my capabilities when I started looking up the math of water flow around
bodies.
Everything conceivable to the swimmers had been looked at: length of hair,
swim caps, angles at which bodies are positioned in the water, finger po-
sition during stroking. Subsequently I think they've tinkered around with
viscosity of water in the pools (won't help a competitor but could make an
event more prestigious if records are broken), etc., etc.
As an ex sail racer I'm used to gaining inches-per-mile, and in my ex
sport there's *lots* of opportunity for creative cheating. FOr example,
when the US won back the America's Cup I think a fellow took a year's leave
of absence from *star wars* research just to super-computer-design the boat's
keel. Well, that's not cheating but it illustrates the complexity of the
problem.
Back to swimming;
One tank discovery I recall is that nakedness was generally faster than any
type of suit, plus or minus doing something about the naughty bits that stick
out into the water flow. Around that time I recall the E. German team being
*hypnotized* to believe they were naked at the Olympics, and their coaches
believing it made a difference. I wonder if the coaches thought they could
peak into the hynpo-sessions without being affected? :)
But "Doc's" book and doubtless many more recent works can be found in your
library; maybe ask your local coach. 10 bucks says they still haven't figured
out wave-making resistance.
Marsha Cook Woodbury
>In article <1992Feb14....@cis.ohio-state.edu> pito...@iroquois.cis.ohio-state.edu (Andrew Pitonyak) writes:
>>
>>These skier types are quite frequently using gear designed to reduce
>>things such as wind resistence........
>
>I remember reading an article in Quebec-Science (or maybe it was the
>NRC's magazine) describing aerodynamic tests done at the NRC
>windtunnel in Ottawa. They had the skiers in the windtunnel, wearing
>different kinds of suits. It turned out that the for women, the lowest
>drag was achieved when they were wearing nothing.
>
At least that is what the wind-tunnel workers told the women.....>
--
Marsha Woodbury mars...@uiuc.edu
"A simile is like a metaphor"
Home of the University of Illinois--yes, Urbana-Champaign
Philippe Grant
In article <1992Feb14....@cco.caltech.edu>, ca...@SOL1.GPS.CALTECH.EDU
(Carl J Lydick) writes:
> In article <1992Feb14....@u.washington.edu>, l...@cac.washington.edu
> (Les Pennington) writes:
>>Someone has claimed that a skier in the Olympic speed skiing event can exceed
>>the velocity of a person free falling from an airplane. This seems patently
>>rediculous, but I would like to prove it using physics and mathematics to
>>settle a bet. Can anyone provide a rigorous proof?
>
> It may be ridiculous, but it's certainly not "patently" so. Bear in mind that
> these skiers do their best to minimize drag. This means they assume a "tuck"
> position. This shape may be aerodynamically unstable. If so, someone
> free-falling would begin to tumble, which could increase drag dramatically.
> However, the skier has an advantage here: the fact that his skis are in
> contact with the ground allows him to stabilize himself, so he continues to
> present the minimum-drag profile....
Terminal velocity of a person falling spread-eagled is about 120 mph. If you
reach back and grab you ankles, you're in a stable position with a higher
terminal velocity. Skiers can tuck to reduce drag. They buy and wear really
expensive clothes, which may or may not make a difference. Their terminal
velocity may be higher than free fall, but they've also got drag between the
skis and the ground.
----------------
Why is it then, that commentators always praise skiers who don't
"take off", keeping the most contact between their skis and the
snow?
--
Philippe Grant | ba...@info.polymtl.ca
Etudiant, Genie Informatique | If it ain't broke,
Ecole Polytechnique de Montreal | DON'T FIX IT!!!
Klaus Ole Kristiansen
>On a related, folklore-ish, topic, how about the old-wives tale that if you
>shave all the hair off your body, you can swim faster? Maybe it's better
>described as an old-coaches' tale. The premise, as I understand it, is that
>by reducing your drag coefficient by a millionth of a percent, you can gain
>that extra millisecond in the quarter-mile freestyle that will make all the
>difference in the world. (Now there's a daunting body of folklore: all the
>health crap athletes and non-athletes believe because someone with a marketing
>degree says it's scientific.)
I once heard of this theory that part of our evolution had taken place
in water. The two main arguments for this were:
1) We are covered with hair only on the top of the head, which is the
the only place that would need protection from the sun if we were
living in water.
2) All the hairs on our bodies are oriented so as to offer the least
possible resistance to swimming.
Klaus O K
(References? In a FOLKLORE group?)
Michael Edelman
ba...@siegfried.vlsi.polymtl.ca (Philippe Grant) writes:
(lots deleted for brevity's sake)
>
>Why is it then, that commentators always praise skiers who don't
>"take off", keeping the most contact between their skis and the
>snow?
>
>--
>Philippe Grant | ba...@info.polymtl.ca
>Etudiant, Genie Informatique | If it ain't broke,
>Ecole Polytechnique de Montreal | DON'T FIX IT!!!
>
When a skier jumps he or she has to come out of the tuck position
into an erect position, arms out for balance. That's a very high
drag attitude. It far outweighs the drag of the skis.
--mike edelman med...@cms.cc.wayne.edu
Robin Fairbairns
> j...@dcs.ed.ac.uk (Sebastian Theriault) writes:
>
>>In article <1992Feb14....@cis.ohio-state.edu> pito...@iroquois.cis.ohio-state.edu (Andrew Pitonyak) writes:
>>>
>>>These skier types are quite frequently using gear designed to reduce
>>>things such as wind resistence........
>>
>>I remember reading an article in Quebec-Science (or maybe it was the
>>NRC's magazine) describing aerodynamic tests done at the NRC
>>windtunnel in Ottawa. They had the skiers in the windtunnel, wearing
>>different kinds of suits. It turned out that the for women, the lowest
>>drag was achieved when they were wearing nothing.
>
> At least that is what the wind-tunnel workers told the women.....>
My reaction precisely.
I also wondered why on earth the effect should apply to women and not
men. Was this explained in the article?
--
Robin Fairbairns, Senior Consultant, postmaster and general dogsbody
Laser-Scan Ltd., Science Park, Milton Rd., Cambridge CB4 4FY, UK
Email: ro...@lsl.co.uk --or-- r...@cl.cam.ac.uk
Brian Scearce
> They had the skiers in the windtunnel, wearing different kinds of
> suits. It turned out that the for women, the lowest drag was achieved
> when they were wearing nothing.
This is a well-known effect of women's clothing, and the source of
the expression "in drag".
Brian "Note the lack of male transvestites in professional skiing" Scearce
--
Brian Scearce (b...@robin.svl.cdc.com -or- robin!b...@shamash.cdc.com)
"Yes, Mr. Saint Peter is quite an amusing fellow, isn't he?"
Any opinions expressed herein do not necessarily reflect CDC corporate policy.
Mike Dedek
|> >Someone has claimed that a skier in the Olympic speed skiing event can exceed
|> >the velocity of a person free falling from an airplane. This seems patently
|> >rediculous, but I would like to prove it using physics and mathematics to
|> >settle a bet. Can anyone provide a rigorous proof?
|>
|> It may be ridiculous, but it's certainly not "patently" so. Bear in mind that
|> these skiers do their best to minimize drag. This means they assume a "tuck"
|> position. This shape may be aerodynamically unstable. If so, someone
|> free-falling would begin to tumble, which could increase drag dramatically.
|> However, the skier has an advantage here: the fact that his skis are in
|> contact with the ground allows him to stabilize himself, so he continues to
|> present the minimum-drag profile.
|>
|> Please note: I'm not saying that the assumptions in my analysis are correct,
|> just that it would take quite a bit of work to disprove them if they're
|> incorrect.
|> Carl J Lydick | INTERnet: CA...@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL
In addition, I think that the friction between the ski and snow is less than
the friction between the skier and air. That may allow for faster speed.
-Mike Dedek
Sean D. O'Neil
>l...@cac.washington.edu (Les Pennington) writes:
>
>>Someone has claimed that a skier in the Olympic speed skiing event can
>>exceed the velocity of a person free falling from an airplane. This seems
>>patently rediculous, but I would like to prove it using physics and
>>mathematics to settle a bet. Can anyone provide a rigorous proof?
In what sense rigorous? Surely not in the sense understood by mathematicians,
because in that case you had better define your proposition very tightly.
This is similar to the problem faced by software verification---you can't
prove anything rigorously without stating what it is you want to prove in
very precise and unambiguous terms.
>Good grief, a one-line paragraph...
>Skiers can use skipoles to increase their speed, as well as using the skis
>to force downward speed. I would guess that you could use this to increase
>the speed past that of freefall, which is after all just gravity and
>wind resistance. Consider that a man wearing a rocket booster can also
>increase his downward speed past that of freefall.
My God, this paragraph leaves me speechless! Just what are they teaching
at U of Indiana these days?
Obviously, Ben, you have never skiied, or were semi-conscious at best if
you ever did. Even when I am X-C skiing, I am unable to use my poles
to increase my speed after I have reached top speed on a moderate to
expert-slope hill. Why? Because I just can't swing my arms fast enough
to even keep up with the current speed, let alone increase it. When you
consider the fact that I am probably going no faster than 30 mph on such
hills, and that terminal velocity is somewhere above 100 mph, it's obvious
that poles aren't going to help one increase speed above that. Ever notice
when watching skiiers in the Downhill event, that the poles are used at
the very start to push off, and then are never used again? Same reason.
And you can bet that they would use those poles if they would help
increase their speed in the slightest.
Sean
Grant Edwards
:
: I don't know about this but a guy in my class at school used to shave
: his legs because he was really into cycling and he claimed it improved
: his aerodynamics enough to provide extra speed when cycling. This didn't
: stop everyone laughing at him about shaving his legs though :-).
:
: Philip.
Shaving your legs should increase the air flow across the skin, thus
increase the cooling effect, leading to better performance on a hot
day. I've also heard that shaved legs don't get road rash as badly
when you crash.
It's probably mostly psycological, but I thought I would throw out a
few ideas.
--
Grant Edwards |Yow! I'm IMAGINING a
Rosemount Inc. |sensuous GIRAFFE, CAVORTING
|in the BACK ROOM of a KOSHER
gra...@aquarius.rosemount.com |DELI --
Michael T Pins
>phi...@castle.ed.ac.uk (P MacFarlane) writes:
-:
-: I don't know about this but a guy in my class at school used to shave
-: his legs because he was really into cycling and he claimed it improved
-: his aerodynamics enough to provide extra speed when cycling. This didn't
-: stop everyone laughing at him about shaving his legs though :-).
-:
-: Philip.
>Shaving your legs should increase the air flow across the skin, thus
>increase the cooling effect, leading to better performance on a hot
>day. I've also heard that shaved legs don't get road rash as badly
>when you crash.
>It's probably mostly psycological, but I thought I would throw out a
>few ideas.
Not only does it reduce the chance of infection after a crash, most
masseurs won't touch someone with hairy legs, as the hair is a major
pain to deal with.
Firestar
--
*****************************************************************************
* Michael Pins (Firestar) | Internet: ami...@isca.uiowa.edu *
* ISCA's Amiga Librarian | #include <std.disclaimer> *
*****************************************************************************
Pete Moore
>shave all the hair off your body, you can swim faster? Maybe it's better
>described as an old-coaches' tale. The premise, as I understand it, is that
>by reducing your drag coefficient by a millionth of a percent, you can gain
>that extra millisecond in the quarter-mile freestyle that will make all the
>difference in the world. (Now there's a daunting body of folklore: all the
>health crap athletes and non-athletes believe because someone with a marketing
>degree says it's scientific.)
As an occasionally competetive :-) swimmer, I can attest that this is
definitely not just an old [wives|coaches] tale. By shaving off body hair,
you gain much more than a millisecond in 400m. The hair on your head
obviously makes the biggest difference; shaving it, or wearing a swimming
cap (the preferred alternative for most people!) will gain you up to half a
second per 50m length compared to simply cutting your hair short, and
shaving body hair about another 0.2-0.3 seconds.
--
+------------------- pe...@bignode.equinox.gen.nz -------------------+
| The effort to understand the universe is one of the very few things |
| that lifts human life above the level of farce, and gives it some |
| of the grace of tragedy - Steven Weinberg |
+---------------------------------------------------------------------+
Scott Merrilees
>Someone has claimed that a skier in the Olympic speed skiing event can
>exceed the velocity of a person free falling from an airplane.
>This seems patently rediculous, but I would like to prove it using physics
>and mathematics to settle a bet. Can anyone provide a rigorous proof?
ful...@copper.ucs.indiana.edu (Ben Fulton) writes:
>Skiers can use skipoles to increase their speed, as well as using the skis
>to force downward speed. I would guess that you could use this to increase
>the speed past that of freefall, which is after all just gravity and
>wind resistance. Consider that a man wearing a rocket booster can also
>increase his downward speed past that of freefall.
Imagine you are in a car, doing 100mph, and you have skipoles.
Neglecting things such as inertia, do you thing you can generate much
horizontal force pushing against the ground ? You would have to push
that pole to the ground, and push very very quickly, otherwise you
would get the pole dragged out of your hand.
I would think that any small increment of speed you got would mostly
be eaten up trying to fight the extra air resistance.
I would think that extra speed would come from gravity.
A rocket booster would give a lot more power than is generatable from
skipoles. Skipoles are good for getting started, but give me a nice
steep smooth mountain any day.
kis...@iowasp.physics.uiowa.edu writes:
>Terminal velocity of a person falling spread-eagled is about 120 mph. If you
>reach back and grab you ankles, you're in a stable position with a higher
>terminal velocity. Skiers can tuck to reduce drag. They buy and wear really
>expensive clothes, which may or may not make a difference. Their terminal
>velocity may be higher than free fall, but they've also got drag between the
>skis and the ground.
Skydivers wear slick suits to go fast, probably comparable to downhillers.
The 120mph is very easy to exceed in freefall, just roll on to your
back, & tuck into a ball, or go into a dive.
Sm, Skydiver & Skier.
--
Scott Merrilees, BHP Information Technology, Newcastle, Australia
Internet: S...@bhpese.oz.au Phone: +61 49 40 2132 Fax: ... 2165
Jeff Mortensen
told by Paul Lynd on the Hollywood
squares tv show. He was asked if
Kiwee birds of Austrialia really buried
their heads in the sand. His reply was
"sure especially when dropped out of air
planes".......
Now thats a terminal joke.
.
Jack Campin
> As an occasionally competitive :-) swimmer, I can attest that this is
> definitely not just an old [wives|coaches] tale. By shaving off body hair,
> you gain much more than a millisecond in 400m. The hair on your head
> obviously makes the biggest difference; shaving it, or wearing a swimming
> cap (the preferred alternative for most people!) will gain you up to half a
> second per 50m length compared to simply cutting your hair short, and
> shaving body hair about another 0.2-0.3 seconds.
I've heard that there is one other way to reduce friction: the fastest
recorded time for the women's 100 metres is not accepted as an official
record because the East German who did it didn't have a swimsuit on at
the time.
Put the "gymn-" back into gymnastics, I say.
Is there a Nude Olympics? If so, a few dramatic unofficial records might
irritate some of the complacency out of the athletics establishment...
--
-- Jack Campin room G092, Computing Science Department, Glasgow University,
17 Lilybank Gardens, Glasgow G12 8RZ, Scotland TEL: 041 339 8855 x6854 (work)
INTERNET: ja...@dcs.glasgow.ac.uk or via nsfnet-relay.ac.uk FAX: 041 330 4913
BANG!net: via mcsun and ukc BITNET: via UKACRL UUCP: ja...@glasgow.uucp
Tamara Stephas
>gra...@aquarius.rosemount.com (Grant Edwards) writes:
>
>>phi...@castle.ed.ac.uk (P MacFarlane) writes:
>-:
>-: I don't know about this but a guy in my class at school used to shave
>-: his legs because he was really into cycling and he claimed it improved
>-: his aerodynamics enough to provide extra speed when cycling. This didn't
>-: stop everyone laughing at him about shaving his legs though :-).
>-:
>-: Philip.
>
>>Shaving your legs should increase the air flow across the skin, thus
>>increase the cooling effect, leading to better performance on a hot
>>day. I've also heard that shaved legs don't get road rash as badly
>>when you crash.
>
It has been found that (as mentioned) hairy vs. hairless legs do not
appreciably affect cyclists' times (although they matter in the event
a crash).
However, as with swimmers, effects *are* noticed from the drag caused
by long hair flapping out from under a helmet, or by moderate length hair
(i.e. anything much more than a crewcut) either without a helmet or with
the "leather hairnet" which used to be commonly worn for races.
On the other hand, the *significance* of the effect (or lack thereof)
of all this aerodynamic worrying can be seen in snapshots of top women
racers --- snapshots which may show a racer with long hair leading racers
whose helmets cover their hair! If I were setting up an equation, I'd
probably just drop this term . . . :-)
The comment on cooling is a good point, but again, even more for the
head than for the legs. When I was cycling seriously, I wore a crewcut
--- which had nothing to do with reducing drag, and everything to do with
getting air moving under that helmet on fiery hot summer afternoons!
(okay, I contradict myself: that *is* reducing drag ... just not where
it's ordinarily meant!)
- Tamara Stephas Disclaimer: I don't post to this group;
ste...@dgp.toronto.edu it must have been my evil twin.
Tamara Stephas
pe...@bignode.equinox.gen.nz (Pete Moore) writes:
[... time gain for a swimmer from ]
>shaving body hair about another 0.2-0.3 seconds.
In a previous post, I shrugged off all effect of leg hair vs. no leg
hair for cyclists. Note that this is not necessarily a contradiction,
as the effect of drag from water is far greater than that from air.
Something which makes a difference of 0.2-0.3 seconds through _water_,
some of which may have be gained through greater tactile sensitivity to
the medium (as pointed out by an earlier writer), may have its effect
reduced below the threshhold of reliable measurability in _air_, a less
dense medium.
- Tamara Stephas
ste...@dgp.toronto.edu
Sebastian Theriault
... stuff about windtunnel deleted...
>
>I also wondered why on earth the effect should apply to women and not
>men. Was this explained in the article?
Something to do with body hair (I think).
A Rae
>Not only does it reduce the chance of infection after a crash, most
>masseurs won't touch someone with hairy legs, as the hair is a major
>pain to deal with.
(May have chopped a bit too much there...)
Anyway, I don't have any problems with hairy legs. The major pain is
shaved legs which are just growing back. While the oil softens longer
hairs, short cutoff hairs stay very sharp and tend to be a bit painful.
The main problem with hair is the tactle sensation. A lot of people
don't like it, but if you use a larger amount of oil that usual and
learn to ignore it it's no real problem.
The main problem full stop is people who tense up a leg or an arm, and
when you ask them if they can relax it claim that it _is_ relaved. Then
you feel the muscle relax... is it some kind of instinctive lie or what?
--
Angus G Rae ("Cathy" VoiceMail) | JANET: a...@uk.ac.ed.castle
c/o Archie Howitt, Room 1508, | ARPA: a...@castle.ed.ac.uk
JCMB, King's Buildings, |"Tigers don't worry about much, do they?"
Edinburgh |`No. It's one of the perks of being feral.'
Ken Johnson
In article <1992Feb19....@dcs.glasgow.ac.uk>
ja...@dcs.glasgow.ac.uk (Jack Campin) writes:
>I've heard that there is one other way to reduce friction: the fastest
>recorded time for the women's 100 metres is not accepted as an official
>record because the East German who did it didn't have a swimsuit on at
>the time.
Then again, you could swim in a pool that sloped.
--
//// Ken Johnson, A I Applications Institute
We won't be meeting again //// 80 South Bridge, EDINBURGH EH1 1HN
On the slow train, //// E-mail k...@aiai.ed.ac.uk
On the slow train. //// phone 031-650 2756 fax 031-650 6513
Brian Scearce
> Then again, you could swim in a pool that sloped.
Such pools are usually too full of water skiers to swim in.
Skibum
I heard today on the Idiot Box(tm) that the speed skiers
hit speeds up to 140mph..
I've also heard that the record for a non-motorized surface
human was set by speed skiing.
I've also head that when they fall at top speed the spandex
suit melts because of the friction..
-Jay "big ears" Jansen
"""\ Jay Jansen
@ ~0 Computervision, UUCP: {decvax|linus|sun}!cvbnet!jjansen
) keeping Prime alive Internet: jja...@cvbnet.prime.com
---------------------------------------------------------------------------
John Brownie
>This question brings to mind a joke
>told by Paul Lynd on the Hollywood
>squares tv show. He was asked if
>Kiwee birds of Austrialia really buried
>their heads in the sand. His reply was
>"sure especially when dropped out of air
>planes".......
I can't let this go uncorrected...
It's Kiwi, not Kiwee.
They come from New Zealand, not Australia (which is not Austrialia :-).
Ostriches are the birds which bury their heads in the sand, and they
are not native to either Australia or New Zealand. Australia does have
the emu, which is a little like an ostrich...
--
John Brownie
School of Mathematics and Statistics
University of Sydney
Internet: j...@maths.su.oz.au
Marsha Cook Woodbury
>This question brings to mind a joke
>told by Paul Lynd on the Hollywood
>squares tv show. He was asked if
>Kiwee birds of Austrialia really buried
>their heads in the sand. His reply was
>"sure especially when dropped out of air
>planes".......
>
GUESS WHAT! THE KIWI LIVES IN NEW ZEALAND.
IT'S THE AUSTRALIANS WHO BURY THEIR HEADS IN THE SAND.>
Henling, Lawrence M.
(Peter Benson) writes...
>
>The reason bicycle racers shave their legs is not to reduce aerodynamic
>drag, but to reduce the potention for infection after getting a bad road
>burn in a crash. It is required by the UCI (the international cycle racing
>sanctioning organization). The wind resistance line is good when people
>are laughing at you as you shave your legs though.
1) The UCI does not require shaved legs (1992 USCF rule book) and never has
(public opinion on rec.bicycles).
2) Leg shaving is a recurrent topic on rec.bicycles, involving aerodynamics
(positive and negative), massage, road rash and infections (again positive
and negative), etc. The consensus seems to be that any effect is negligible
except for conformity.
larry henling l...@shakes.caltech.edu
David Meiklejohn
>This question brings to mind a joke
>told by Paul Lynd on the Hollywood
>squares tv show. He was asked if
>Kiwee birds of Austrialia really buried
>their heads in the sand. His reply was
>"sure especially when dropped out of air
>planes".......
You'll find kiwis in New Zealand, not Australia (and note the spelling here).
Also, the birds that are known for (supposedly) burying their heads in the sand
are Ostriches, which you'll find in Africa. Australia has emus.
>Now thats a terminal joke.
Groan! :-)
--
David Meiklejohn | Internet : dav...@qdpii.comp.qpdi.oz.au
Computer Systems Officer, QDPI | Fax : +61 70 92 3593
Mareeba, Australia | Voice : +61 70 92 1555
Dave Johnson
>>l...@cac.washington.edu (Les Pennington) writes:
>>Someone has claimed that a skier in the Olympic speed skiing event can
>>exceed the velocity of a person free falling from an airplane.
>>This seems patently rediculous, but I would like to prove it using physics
>>and mathematics to settle a bet. Can anyone provide a rigorous proof?
>ful...@copper.ucs.indiana.edu (Ben Fulton) writes:
>>Skiers can use skipoles to increase their speed, as well as using the skis
>>to force downward speed. I would guess that you could use this to increase
>>the speed past that of freefall, which is after all just gravity and
>>wind resistance. Consider that a man wearing a rocket booster can also
>>increase his downward speed past that of freefall.
The record for speed skiing at the moment is 139mph (Learnt this yesterday), it
is not an Olympic event, it just involes standing at the top of a steep hill
assuming a tuck posistion and going in a straight line done the slope. An
english design for a new type of speed ski has come up with as ski whos base
looks like this: Not this is to scale. The theory is however that a layer of
air is trapped beneith the skis and will
------------------------------ reduce the drag on the skis. The hope
\ ---------------- / is to get the record up to 150mph.
\ / \ /
\ / \ /
\/ \/
Dave J.
Klaus Ole Kristiansen
>In article <BABY.92Fe...@watson.siegfried.vlsi.polymtl.ca>
>ba...@siegfried.vlsi.polymtl.ca (Philippe Grant) writes:
> (lots deleted for brevity's sake)
>>
>>Why is it then, that commentators always praise skiers who don't
>>"take off", keeping the most contact between their skis and the
>>snow?
>>
>>
>When a skier jumps he or she has to come out of the tuck position
>into an erect position, arms out for balance. That's a very high
>drag attitude. It far outweighs the drag of the skis.
Also, when you run down slope, gravity is pulling you forward,
increasing or maintaining your forward speed. When jumping/falling
through the air, no force is pulling you forward.
Klaus O K
cs87ejh
:
: In article <1992Feb19....@dcs.glasgow.ac.uk>
: ja...@dcs.glasgow.ac.uk (Jack Campin) writes:
:
: >I've heard that there is one other way to reduce friction: the fastest
: >recorded time for the women's 100 metres is not accepted as an official
: >record because the East German who did it didn't have a swimsuit on at
: >the time.
:
:
: Then again, you could swim in a pool that sloped.
Go the whole hog and get thrown out of a plane wearing skis at the same
time as a swimming pool full of water. Don't forget to use your ski poles
to fall faster
Roger
--
+=============================================================================+
| cs8...@brunel.ac.uk Roger Binns Brunel University - UK |
|:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::|
| Humans were created by water to move it uphill |
+=============================================================================+
Pete Ashdown
>In article <1992Feb14....@cis.ohio-state.edu> pito...@iroquois.cis.ohio-state.edu (Andrew Pitonyak) writes:
>>
>>These skier types are quite frequently using gear designed to reduce
>>things such as wind resistence........
>I remember reading an article in Quebec-Science (or maybe it was the
>NRC's magazine) describing aerodynamic tests done at the NRC
>windtunnel in Ottawa. They had the skiers in the windtunnel, wearing
>different kinds of suits. It turned out that the for women, the lowest
>drag was achieved when they were wearing nothing.
Looks like the women's speed-skiing event at the Olympics is going to be more
interesting than I previously imagined.
--
"I am an infinite number of monkeys with USENET access." - David Vacca
DISCLAIMER: My writings have NOTHING to do with my employer. Keep it that way.
Pete Ashdown pash...@javelin.sim.es.com ...uunet!javelin.sim.es.com!pashdown
David Meiklejohn
>
> I heard today on the Idiot Box(tm) that the speed skiers
> hit speeds up to 140mph..
Wrong! The winter olympics are happening in a metric country - you heard the
figure of 140 alright, but it's km/h, not mph.
140 km/h = 87.5 mph
Henling, Lawrence M.
>In article <27...@cvbnetPrime.COM> jja...@skibum.Prime.COM writes:
>>
>> I heard today on the Idiot Box(tm) that the speed skiers
>> hit speeds up to 140mph..
>
>Wrong! The winter olympics are happening in a metric country - you heard the
>figure of 140 alright, but it's km/h, not mph.
>
> 140 km/h = 87.5 mph
>
Rec.sport.olympic (sic?) certainly has been disagreeing with the metric
interpretation in many posts, part of one included below.
------
LES ARCS, France (UPI) -- Organizers are predicting that preparation
of the Aiguille Rouge speed skiing piste will be good enough for the
finals Saturday to enable skiers to reach speeds of up to 150 mph.
Michael Prufer holds the current world record of 139 mph set in 1988
on the old course at Les Arcs.
Speed skiers wear aerodynamic helmets which reduces air drag by
between 6-10 percent and spoilers on the back of their legs.
------
larry henling l...@shakes.caltech.edu
John Chambers
|> I once heard of this theory that part of our evolution had taken place
|> in water. The two main arguments for this were:
|>
|> 1) We are covered with hair only on the top of the head, which is the
|> the only place that would need protection from the sun if we were
|> living in water.
|>
|> 2) All the hairs on our bodies are oriented so as to offer the least
|> possible resistance to swimming.
This has been a popular debate in various (pseudo-? semi-?) scientific
circle for years. There are a lot more bits of "evidence" than just
these. Actually, these two have alterntive explanations. Thus the
direction of the back hair in humans (mostly downward) is also
consistent with an upright posture, as well as in swimming. Other
primates tend to have back hair that goes "sideways", but that's also
downward for them, so it's not convincing.
Another oft-mentioned curiosity is the swimming reflexes of newborn
humans. Like other aquatic mammals, very young humans tend to react to
being dropped in water by ceasing to breath, making vaguely swimming
motions, slowing the heart rate, and so on. Other young primates tend
to just start drowning. Anyway, there are people who give swimming
lessons to infants, and they claim that all the right reflexes are
there; all that is needed is experience. There have been TV shows that
show infants swimming well, though they couldn't yet walk upright.
There's also a bit of demography: If you draw a 100-km border along
all the world's ocean shores and the largest lakes, this supposedly
catches more than 90% of the human species. Most of the rest live
along the major navigable rivers. Furthermore, all human societies
(with the exception of a few small desert groups) have known how to
make boats, catch fish, and so on. Modern humans (and all our direct
ancestors, according to the archaeological record) are by far the most
aquatic of all primates. In Europe, China and Africa, houses on
pilings go back many millenia.
I've even seen an amusing criticism of the Siberia-Alaska land bridge
theory of the colonization of the Americas. The criticism goes: Who
needs a land bridge? Humans even 50,000 years ago were building boats
and exploring large bodies of water. The 80-km gap of the Bering Sea
wouldn't have been a gap at all to humans 10,000 or 30,000 years ago.
You can see Alaska from the tops of the hills in eastern Siberia. They
would have crossed over in their fishing boats.
|> (References? In a FOLKLORE group?)
We don't need no steenking references around here...
ISCA Amiga librarian
>There's also a bit of demography: If you draw a 100-km border along
>all the world's ocean shores and the largest lakes, this supposedly
>catches more than 90% of the human species. Most of the rest live
>along the major navigable rivers. Furthermore, all human societies
>(with the exception of a few small desert groups) have known how to
>make boats, catch fish, and so on. Modern humans (and all our direct
>ancestors, according to the archaeological record) are by far the most
>aquatic of all primates. In Europe, China and Africa, houses on
>pilings go back many millenia.
Most of the population lives near water because it has always (well, at least
since humans learned to build boats) been much easier to transport goods over
water than to do so over land.
>We don't need no steenking references around here...
Isn't folklore neat that way. :-)
Tapani Lindgren
really are. The Olympic speed-skiing event will start at 11.15 GMT
(12.15 Central Europe, 13.15 EET, 06.15 Eastern US, 03.15 Pacific US).
The slope is good and they expect to break the old records.
The current records were made in 1988 in Les Arcs, and they are
for men, 223.741 km/h (139.056 mph) by Michael Pru:fer, Monaco/France,
and for women, 214.413 km/h (133.259 mph) by Tarja Mulari, Finland.
They surely beat the skydivers.
Tapani Lindgren
Tapani Lindgren
Michael Pru"fer from Monaco/France won the mens' race with
a velocity of 229.299 km/h (142.510 mph) and Tarja Mulari from
Finland won the womens' race with a velocity of 219.245 km/h (136.263 mph).
An unfortunate accident happened earlier in the morning, as
Nicholas (sp?) Bochatay from Switzerland reached his Terminal Velocity.
Tapani Lindgren
Tim Aubrey
>In article <27...@cvbnetPrime.COM> jja...@skibum.Prime.COM writes:
>>
>> I heard today on the Idiot Box(tm) that the speed skiers
>> hit speeds up to 140mph..
>Wrong! The winter olympics are happening in a metric country - you heard the
>figure of 140 alright, but it's km/h, not mph.
> 140 km/h = 87.5 mph
Sorry wrong! The speed skiers reach speeds of 220 km/h (approx 140mph)h
In fact they expect to go even faster at the Olympic demonstration.
Bob Vernon
>>Someone has claimed that a skier in the Olympic speed skiing event can exceed the velocity of a person free falling from an airplane. This seems patently rediculous, but I would like to prove it using physics and mathematics to settle a bet. Can anyone provide a rigorous proof?
>
>things such as wind resistence........
>
>of drag. Remember that your terminal velocity is related to things
>like this.
Hate to disappoint you but skydivers also "wear things" to minimize
drag. In the old days of skydiving, big floppy jump suits were the
fashion but nowadays we use skin tight, slick suits to try and get as
much speed and clean air as possible.
That said, there is not much difference in absolute speed. By wearing
a slick suit we increase speed in our standard freefall position from
about 180km/h to 190km/h (for the unmetric minded say 110mph to
120mph). Not much in absolute speed, but a big difference in relative
speeds between freefallers.
The original question was asking if speed skiers can reach the same
speed as freefallers. According to winter olympics tv commentaters
(can I believe them?) downhill skiers reach speeds of up to 120km/h
which means they have a way to go to catch us freefallers. Besides,
if I stand on my head and go into a no-lift dive I can increase speed
to something like 250 to 280 km/h. Those girlie downhillers are just
not in the race.
There isn't much science or folklore in my statements above. But if
ask nicely in rec.skydiving (where I've directed followups) you'll find
a few posters who would love to give you many facts and figures.
There'll probably be a bit of disagreement with my numbers as well as I
don't think anyone has ever accurately measured freefall velocity.
Bob V!
Philippe Grant
> Tapani Lindgren
What happened that day is such a joke. (A tragic one, yes)
I just turns me off to see these people go out and do things
"higher", "faster". The same thing happened with that french
(women's) figure-skater, who attempted a quad-axle, and failed
miserably.
The french always seem to want to do things better than the
competition, but upside-down - on their hands.
(my 0.02 cts worth)
--
Philippe Grant | ba...@info.polymtl.ca
Etudiant, Genie Informatique | If it ain't broke,
Ecole Polytechnique de Montreal | DON'T FIX IT!!!
Grant Edwards
: Well, in just a couple of hours we will find out what the top velocities
Terminal velocity for a skydiver spread eagle in a baggy jump suit is
about 200 km/h. Tucked into a cannonball or delta position, wearing
less baggy cloathing a skydiver can easily exceed 250 km/h, probably
close to 300 km/h.
It's pretty pointless to talk about beating somebody who is trying to
go as slow as he can. There is no way that a skier can beat a
skydiver who is trying to go fast.
--
Grant Edwards |Yow! I am deeply CONCERNED
Rosemount Inc. |and I want something GOOD for
|BREAKFAST!
gra...@aquarius.rosemount.com |
Ron Dippold
>That said, there is not much difference in absolute speed. By wearing
>a slick suit we increase speed in our standard freefall position from
>about 180km/h to 190km/h (for the unmetric minded say 110mph to
>120mph). Not much in absolute speed, but a big difference in relative
>speeds between freefallers.
Okay, there we go. I was watching the olympic coverage today, and
they noted that the speed skiers (point downhill and go) hit 130 mph
(miles, not kilometers).
>which means they have a way to go to catch us freefallers. Besides,
>if I stand on my head and go into a no-lift dive I can increase speed
>to something like 250 to 280 km/h. Those girlie downhillers are just
>not in the race.
However, they can't beat that.
--
Cynic: A person searching for an honest man, with a stolen lantern. -- Shoaff
Carl J Lydick
>a slick suit we increase speed in our standard freefall position from
>about 180km/h to 190km/h (for the unmetric minded say 110mph to
>120mph). Not much in absolute speed, but a big difference in relative
>speeds between freefallers.
>
>The original question was asking if speed skiers can reach the same
>speed as freefallers. According to winter olympics tv commentaters
>(can I believe them?) downhill skiers reach speeds of up to 120km/h
That WAS 120 MILES/h. The record is now 142 and change miles per hour.
>which means they have a way to go to catch us freefallers. Besides,
>if I stand on my head and go into a no-lift dive I can increase speed
>to something like 250 to 280 km/h. Those girlie downhillers are just
>not in the race.
Pretty damned close, though, once you get your units right.
--------------------------------------------------------------------------------
Carl J Lydick | INTERnet: CA...@SOL1.GPS.CALTECH.EDU | NSI/HEPnet: SOL1::CARL
Disclaimer: Hey, I understand VAXes and VMS. That's what I get paid for. My
understanding of astronomy is purely at the amateur level (or below). So
unless what I'm saying is directly related to VAX/VMS, don't hold me or my
organization responsible for it. If it IS related to VAX/VMS, you can try to
hold me responsible for it, but my organization had nothing to do with it.
Geoff McCaughan
> I remember reading an article in Quebec-Science (or maybe it was the
> NRC's magazine) describing aerodynamic tests done at the NRC
> windtunnel in Ottawa. They had the skiers in the windtunnel, wearing
> different kinds of suits. It turned out that the for women, the lowest
> drag was achieved when they were wearing nothing.
And I suppose for the men the drag was lowest when they wore nothing and
it was *really* cold?
[from a connoisseur of aerodynamic efficiency]
Geoff - Sysop Equinox (equinox.gen.nz) +64 (3) 3854406 (4 Lines)
Email: ge...@satori.equinox.gen.nz - or - MCCAU...@kosmos.wcc.govt.nz
"If I post something lucid, is that satorial eloquence?"
Geoff McCaughan
> This question brings to mind a joke
> told by Paul Lynd on the Hollywood
> squares tv show. He was asked if
> Kiwee birds of Austrialia really buried
> their heads in the sand. His reply was
> "sure especially when dropped out of air
> planes".......
>
> Now thats a terminal joke.
It sure is. I think this guy needs a new gag writer. Let's see;
It's Kiwi not Kiwee.
They're from New Zealand, not Australia.
I think the folklore about burying heads in sand refers to the ostrich.
It's not funny anyway.
The Hepburn
the American educational system has been teaching people
what to think rather than how to think, this warning must
be placed on all submissions for the benefit of the clueless.
In article <jhb.698541475@galois>, j...@maths.su.oz.au (John Brownie) writes:
|>
|> Ostriches are the birds which bury their heads in the sand, and they
|> are not native to either Australia or New Zealand.
That's right; everyone knows that ostriches come from Austria...
--
Alan Hepburn "They that can give up essential liberty to obtain
National Semiconductor a little temporary safety deserve neither
Santa Clara, Ca liberty nor safety."
al...@berlioz.nsc.com Benjamin Franklin
Klaus Ole Kristiansen
>I think the folklore about burying heads in sand refers to the ostrich.
It is. Ostriches will actually press their head against the ground, not
bury it.
Klaus O K
Mark Bobak
>This is not nearly so true anymore. The standard body position of a
>skydiver is spread-eagled facing the earth. In this position, top speed
>is somewhere around 120 mph (lots of variables involved). But a
>skydiver can also elect to go head-down with arms flat against the
>sides. This will give a top speed of somewhat over 200 mph, and I
>might add it is quite a thrill!
>Somehow I don't expect skiers to equal this speed unless they, too,
>are falling head-first off a very tall cliff while wearing Spandex...
>--
>Curtis Jackson @ Adobe Systems in Mountain View, CA (415-962-4905)
>Internet: cjac...@adobe.com uucp: ...!{apple|decwrl|sun}!adobe!cjackson
> "They that can give up an essential liberty to obtain a little temporary
> safety deserve neither liberty nor safety". -- Benjamin Franklin (1759)
If memory serves me correctly, the speed record for a skier is right around
130 - 135 mph, and that's for a guy with the spandex suit and aerodynamic
helmet. You won't see anything near that speed in the Olympics, even in
the downhill.
Russ Kepler
#WARNING: The following submission may contain bits of humour. Since
# the American educational system has been teaching people
# what to think rather than how to think, this warning must
# be placed on all submissions for the benefit of the clueless.
#
#In article <jhb.698541475@galois>, j...@maths.su.oz.au (John Brownie) writes:
#|>
#|> Ostriches are the birds which bury their heads in the sand, and they
#|> are not native to either Australia or New Zealand.
#
#
#That's right; everyone knows that ostriches come from Austria...
Naaah - that's kangaroos. *Everyone* knows that!
--
.signature: not found. Create?
John Chambers
|> >There's also a bit of demography: If you draw a 100-km border along
|> >all the world's ocean shores and the largest lakes, this supposedly
|> >catches more than 90% of the human species. Most of the rest live
|> >along the major navigable rivers. Furthermore, all human societies
|> >(with the exception of a few small desert groups) have known how to
|> >make boats, catch fish, and so on. Modern humans (and all our direct
|> >ancestors, according to the archaeological record) are by far the most
|> >aquatic of all primates. In Europe, China and Africa, houses on
|> >pilings go back many millenia.
|>
|> Most of the population lives near water because it has always (well, at least
|> since humans learned to build boats) been much easier to transport goods over
|> water than to do so over land.
Um, you have a serious chicken-and-egg problem here. Do humans build
boats as an aspect of their aquatic nature (which may be a primitive
characteristic and may not be); or did they become semi-aquatic as a
result of the gains in efficiency from boat-building? The
aquatic-nature argument is basically that our ancestors became
swimmers and fisheaters and other semi-aquatic things, and
boat-building came along later. There's probably not much direct
evidence in the fossil record to support either claim.
Still, we are notably more aquatic than most other primates. In
particular, the other great apes are primarily arboreal, and even when
there are rivers at hand, they don't do much swimming or fishing. I
seem to recall that orangs have been seen eating fish, but humans do
this a lot. Even other non-forest primates like baboons don't use
water for much more than drinking. Of course, there is always the
fishing monkey as an exception, and the Japanese snow monkey is known
to play and swim in water.
In the long list of ways in which humans differ from other primates,
our strong involvement with water is one of the more striking entries.
|> >We don't need no steenking references around here...
|>
|> Isn't folklore neat that way. :-)
Yup. Actually, professional folklorists would insists on references,
but we probably won't attract very many of them here. (Except for the
ones that are quietly watching and taking notes. ;-)
