kautaq wrote:
> Jeg så lige på Discovery Channel for lidt siden, at verdens
> første motoriserede flyvning (flyvemaskine) blev udført af
> en tyskfødt amerikaner i 1901. Navnet var Whitehead/Weiskoph?
> Motoren blev drevet af gas. Det er to år før brødrene Wright!
>
> Så skal flyvningens historie vel skrives om eller hvad?
>
Hej Kautaq
Her er mere om de første flyvninger - se i afsnittet historie:
http://da.wikipedia.org/wiki/Flyvemaskine
Richard Pearse
FIRST FLYER
http://www.nzedge.com/heroes/pearse.html
Citat: "...
Richard Pearse: "Mad Pearse", "Bamboo Dick", self-taught inventor,
prophetic designer, trail blazing aviator and eccentric visionary. On or
about 31st March 1903 a reclusive New Zealand farmer Richard Pearse
climbed into a self-built monoplane and flew for about 140 metres before
crashing into a gorse hedge on his Waitohi property
....
eight months before the Wright Brothers entered the record books at
Kitty Hawk North Carolina on 17th December 1903.
....
Unlike the Wright’s attempt in Kitty Hawk, no one in Waitohi wielded a
camera or measured the airspeed of the gorse-bound transit. No proof
exists to pinpoint the date or offer proof of the flight
....
a great deal of eyewitness testimony, able to be dated circumstantially,
suggests that 31 March 1903 was the likely date of this first flight
attempt." One or two eyewitnesses have mentioned the date of March 1902
as the first take-off date, but with all surviving witnesses now dead
and no extant documentary evidence, the claims are likely to remain unproven
...."
-
Men som andre i tråden skriver, har der været problemer med dokumentationen.
Folk (og myndigheder) var svære at overbevise:
Ridiculed science mavericks vindicated.
Weird science versus revolutionary science:
http://www.amasci.com/weird/vindac.html#j29
Citat: "...
While it's true that at least 99% of fringe science announcements are
just as bogus as they seem, we cannot dismiss every one of them without
any investigation.
....
Wright bros (flying machines)
After their Kitty Hawk success, The Wrights flew their machine in open
fields next to a busy rail line in Dayton Ohio for almost an entire
year. American authorities refused to come to the demos, and Scientific
American Magazine published stories about "The Lying Brothers." Even the
local Dayton newspapers never sent a reporter (but they did complain
about all the letters they were receiving from local "crazies" who
reported the many flights.) Finally the Wrights packed up and moved to
Europe, where they caused an overnight sensation and sold aircraft
contracts to France, Germany, Britain, etc.
...."
Wright Brothers:
http://www.airlineintl.com/krone/krone_wrightbrothers.htm
Citat: "...This time, their invention wasn't so amusing to outsiders;
some even turned up to watch the anticipated attempt to fly..."
http://www.eskimo.com/~billb/weird/skepquot.html
Citat: "...
"When a thing is new, people say: 'It is not true.' Later, when its
truth becomes obvious, they say: 'It is not important.' Finally, when
its importance cannot be denied, they say: 'Anyway, it is not new.'"
- William James, 1896
...."
-
http://da.wikipedia.org/wiki/Br%F8drene_Wright
-
Lidt om hvordan en flyvinge fungerer:
http://da.wikipedia.org/wiki/Diskussion:Vinge
Citat: "...
Bernouillieffekten forøger blot den kraftvirkning der opstår via Newtons
3. Lov.
Når man derfor vil forstå hvordan en flyvemaskine holder sig i luften
skal man nærme sig sagen på en anden måde.
....
Når der er opstået denne ombytning mellem årsag og virkning ved
Bernouillieffekten er der givet begrundet i følgende: Man har jo at gøre
med en flyvemaskine, hvor man vil forklare hvorfor den holder sig i
luften. Man søger derfor at fastslå de kræfter der kan holde den i
luften. Man konstaterer, at der er et undertryk over vingen, og man
konstaterer, at luftstrømmen accellereres over vingen. Altså en
Bernoullieffekt. Da man som sagt søger de kræfter der holder
flyvemaskinen i luften falder man for den psykologiske trang og lader
effekten gå den "rigtige" vej rundt og som altså er den forkerte nemlig,
at årsagssammenhængen ved Bernouillieffekten over vingen er, at den
hurtigere luftstøm skaber det lavere tryk. Men sammenhængen er omvendt
nemlig, at det lavere tryk ( opstået på anden vis) skaber den højere
hastighed over vingen. Bernouilliprincippet er jo et
energivevarelsesprincip, og kan derfor gå begge veje.
Henning Rolapp..."
-
I øvrigt har man svært ved at forklare hvordan insekter kan løfte så
meget som de kan. Før i tiden kunne man ikke engang forklare hvordan
humlebien kunne flyve:
(kopi uden billeder desværre)
Scientific American: Solving the Mystery of Insect Flight:
http://www.google.dk/search?q=cache:213.176.1.196:800/Default/www.sciam.com/2001/0601issue/0601dickinson.html+%22Solving+the+Mystery+of+Insect+Flight%22
http://213.176.1.196:800/Default/www.sciam.com/2001/0601issue/0601dickinson.html
Orignal adresse (virker ikke):
http://www.sciam.com/2001/0601issue/0601dickinson.html
Citat: "...First, the extra force produced by delayed stall is enough to
explain how an insect remains airborne but insufficient to explain how
many insects can lift almost twice their body weight
....
Per second, flying expends about 10 times more energy than locomotion on
the ground. On the other hand, per kilometer traveled, flying is four
times more energy-efficient than ground locomotion. Thus, flying is very
hard to achieve but has great value for organisms that can do it.
...."
-
Insekter er faktisk ret utrolige:
(registrering kræves for at se hele artiklen:)
Ing.dk, 03.07.2003: Insekter navigerer med polariseret lys:
http://www.ing.dk/apps/pbcs.dll/article?AID=/20030703/NATUR/107040031/0/BYGGERI
Citat: "...skarabæen, ''Scarabaeus Zambesianus'' der lever i Sydafrika,
eftergør biers og vikingers trick blot under langt vanskeligere forhold
- i månelys..."
-
16 October 2001, Physicsweb: Lasers illuminate the flight of the bumblebee:
http://physicsweb.org/article/news/5/10/9/1
Citat: "...The apocryphal story about bees not being able to fly arose
because the roughness and flexibility of their wings was neglected in a
quick calculation. The wings of a bumblebee bend to create vortices that
provide lift on both the upward and downward strokes..."
mvh/Glenn
-