ted@imsvax.UUCP (Ted Holden) (10/10/85)
At least one reader has misunderstood one of my statements regarding the posssibility of a living creature using gliding as a primary means of transportation. I have never stated that gliding against the wind was impossible, ASSUMING YOU HAVE ALTITUDE TO BEGIN WITH. In the case of Quetzelcoatlus Northropi, however, we are talking about something different. For this creature to have survived as a glider, assuming the whole notion wasn't preposterous in the first place, which it is, and also assuming it had some magical way of getting airborne from low ground, which it didn't, it still had one insurmountable problem remaining: getting home. It would have had to land on low areas for the carrion which by all accounts constituted its diet. Then, assuming it was a glider, and assuming also it had a magical way of getting airborne, it could not have glided home against the wind, STARTING FROM SEA-LEVEL. In reality, of course, nothing lives as a glider. There are two models for the life-style and flying characteristics of the Texas Pterosaur, a 300 lb. flying creature of the archaic world: a. In our world, in our gravity, after the first 1/2 second of flight, during which its long wing bones would snap from the stress, the correct model would be an ordinary red brick dropped over the edge of a high building. b. In the archaic world, with its lesser gravity, the correct model would be a vulture-like creature which mostly glided and sought free rides in thermal currents and winds, YET NONETHELESS HAD THE POWER TO TAKE OFF FROM LOW GROUND AND TO GET BACK HOME AGAINST THE WIND IF IT ABSOLUTELY HAD TO.
throopw@rtp47.UUCP (Wayne Throop) (10/11/85)
Imagine a pterosaur cocktail party, as an older, experienced 'saur gives some advice. Let's listen in..... "I got just one word for any young glider graduating from college. Just one word." "What's that, Mr. Robinson?" "Thermals!" "How's that Mr. Robinson?" "Thermals! You know... updrafts and all that. Not them fuzzy long underwear, mind you, I mean the atmospheric phenomenon. I understand they can be important to gliders! Yes my boy, you want to corner the market in thermals! Why I bet you could stay airborne for hours... even days maybe, and travel hundreds of miles against the wind. Hardly ever have to flap! The possibilities are tremendous!" -- Wayne Throop at Data General, RTP, NC <the-known-world>!mcnc!rti-sel!rtp47!throopw
clewis@mnetor.UUCP (Chris Lewis) (10/12/85)
In article <425@imsvax.UUCP> ted@imsvax.UUCP (Ted Holden) writes: > >At least one reader has misunderstood one of my statements regarding the >... >b. In the archaic world, with its lesser gravity, the correct model would be ??????????????????????? >a vulture-like creature which mostly glided and sought free rides in thermal >currents and winds, YET NONETHELESS HAD THE POWER TO TAKE OFF FROM LOW GROUND >AND TO GET BACK HOME AGAINST THE WIND IF IT ABSOLUTELY HAD TO. Are you *STILL* spouting this bullshit? SHEESH! -- Chris Lewis, UUCP: {allegra, linus, ihnp4}!utzoo!mnetor!clewis BELL: (416)-475-8980 ext. 321
pamp@bcsaic.UUCP (pam pincha) (10/14/85)
In article <425@imsvax.UUCP> ted@imsvax.UUCP (Ted Holden) writes: > >At least one reader has misunderstood one of my statements regarding the >posssibility of a living creature using gliding as a primary means of >transportation. I have never stated that gliding against the wind was >impossible, ASSUMING YOU HAVE ALTITUDE TO BEGIN WITH. I'm not sure which reader is being referred to, but I for one did not misunderstand -- and still disagree. I've seen lots of instances of gliding birds come off the ocean with little or no wind -- without flapping. Altitude is not as big a factor as one might think. > In the case of >Quetzelcoatlus Northropi, however, we are talking about something different. >For this creature to have survived as a glider, assuming the whole notion >wasn't preposterous in the first place, which it is, and also assuming it >had some magical way of getting airborne from low ground, which it didn't, it >still had one insurmountable problem remaining: getting home. It would have >had to land on low areas for the carrion which by all accounts constituted its >diet. Then, assuming it was a glider, and assuming also it had a magical way >of getting airborne, it could not have glided home against the wind, STARTING >FROM SEA-LEVEL. > >In reality, of course, nothing lives as a glider. There are two models for >the life-style and flying characteristics of the Texas Pterosaur, a 300 lb. >flying creature of the archaic world: > >a. In our world, in our gravity, after the first 1/2 second of flight, during >which its long wing bones would snap from the stress, the correct model would >be an ordinary red brick dropped over the edge of a high building. I don't understand the mistaken attitude that the bones can't take the stress? The bone for these types of reptiles (and birds for that matter) are specially adapted for the stresses. These bones are not like ours. They are rigid (reinforced with extra compact bone (perichondrium and especially periosteal material) with strut-like features within the marrow portion (which is much lighter than normal). There are also special skeletal features such as reinforced ribs and a modified sternum that shows increased muscle attachment in its raised ridge(keel) to power the wing span it had. All very similar to the gliding birds of today. I still have not heard any physiological (bone or muscle-wise) reason why they couldn't have flown-- or that they flew much differently than our current gliders. Generalizations yes;specifics,no. > >b. In the archaic world, with its lesser gravity, the correct model would be >a vulture-like creature which mostly glided and sought free rides in thermal >currents and winds, YET NONETHELESS HAD THE POWER TO TAKE OFF FROM LOW GROUND >AND TO GET BACK HOME AGAINST THE WIND IF IT ABSOLUTELY HAD TO. Look if a seagull can make it back home in 70 mile an hour winds why can't a pterasaur. It can be done (maybe not in a straight line - but if one has the time....) At this point, I'd like to state that I personally would like to read a bit more on the specifics of some of these overly generalized rehashed arguments that keep cropping up. The anti-arguments seem to be getting overly complicated--more than seem reasonable. P.M.Pincha-Wagener
friesen@psivax.UUCP (Stanley Friesen) (10/15/85)
In article <425@imsvax.UUCP> ted@imsvax.UUCP (Ted Holden) writes: > >At least one reader has misunderstood one of my statements regarding the >posssibility of a living creature using gliding as a primary means of >transportation. Well, nobody has ever claimed that any animal was a *pure* glider. That is nobody has ever said that the large pterosaurs *never* flap thier wings, only that, like the modern Albatross and Vulture, they *rarely* flap thier wings - there is considerable difference. I gues it is a matter of what you mean by "primary means" of transportation. By my definition the Albatross uses gliding as its primary means of transportation, not powered flight. It uses powered flight(flapping) as a *supplement* to gliding. > In the case of >Quetzelcoatlus Northropi, however, we are talking about something different. >For this creature to have survived as a glider, assuming the whole notion >wasn't preposterous in the first place, which it is, and also assuming it >had some magical way of getting airborne from low ground, which it didn't, it >still had one insurmountable problem remaining: getting home. It would have >had to land on low areas for the carrion which by all accounts constituted its >diet. Then, assuming it was a glider, and assuming also it had a magical way >of getting airborne, it could not have glided home against the wind, STARTING >FROM SEA-LEVEL. > Only true if it wre a *pure* glider, given that it could flap its wings gently for a bit of extra push it could attain any altitude it liked. And as for taking off I have already shown that its low stall speed allowed it to take off from a standing start simply by facing into the breeze! >In reality, of course, nothing lives as a glider. That is except for the Albatross and the Condor! -- Sarima (Stanley Friesen) UUCP: {ttidca|ihnp4|sdcrdcf|quad1|nrcvax|bellcore|logico}!psivax!friesen ARPA: ttidca!psivax!friesen@rand-unix.arpa
scott@hou2g.UUCP (Colonel'K) (10/15/85)
Ted seems to be making the assumption that gliders
cannot climb. I don't know a hell of a lot about
(for instance) hang-gliding, but I'd say climbing is
not only possible, it is common. If so, what's wrong
with a "glider" going down wind to gain speed (and
height?) AND THEN TURNING UPWIND?
Of course, the above assumes Ted is correct in his
hypotheses, which is itself a faulty premise.
"What are you doing?"
"Examining the world's major religions. I'm
looking for something that's light on morals,
has lots of holidays, and with a short
initiation period."
Scott J. Berry
ihnp4!hou2g!scottdave@circadia.UUCP (David Messer) (10/18/85)
> If so, what's wrong > with a "glider" going down wind to gain speed (and > height?) AND THEN TURNING UPWIND? > > Scott J. Berry > ihnp4!hou2g!scott The wind is irrelevant to the operation of a bird or an airplane. It can gain altitude just as well upwind as downwind. -- David Messer UUCP: ...ihnp4!circadia!dave FIDO: 14/415 (SYSOP)
friesen@psivax.UUCP (Stanley Friesen) (10/26/85)
In article <675@hou2g.UUCP> scott@hou2g.UUCP (Colonel'K) writes: > >Ted seems to be making the assumption that gliders >cannot climb. I don't know a hell of a lot about >(for instance) hang-gliding, but I'd say climbing is >not only possible, it is common. If so, what's wrong >with a "glider" going down wind to gain speed (and >height?) AND THEN TURNING UPWIND? > To add some real evidence, I saw some vultures circling last weekend. I watched them for a few minutes and they were flying in *circles* without *ever* flapping their wings and without losing any altitude. Now, whatever else is true they *must* have been going upwind at least *part* of the time, tet they maintained altitude for a full circle without needing to so much as flutter their wings. Whatever the mechanism, it *works*, I saw it happen. -- Sarima (Stanley Friesen) UUCP: {ttidca|ihnp4|sdcrdcf|quad1|nrcvax|bellcore|logico}!psivax!friesen ARPA: ttidca!psivax!friesen@rand-unix.arpa