Darby's Grandfather Meets a TT

M

MEM

Quantum Scribe
Darby\'s Grandfather Meets a TT

A time traveler from 1955 meets Darby’s grandfather in the 1911 and tries to explain how jets fly.

TT_1955: In the future we fly planes made of metal.

DARBY’S GRANDFATHER: Really? Planes made of metal? If your plane were made of metal it would fall from the sky like a brick. I just “proved” planes made of metal can’t fly, ergo you are not a time traveler.

TT_1955: By flying very fast one is able to generate enough lift so that a plane made of metal can fly.

DARBY’S GRANDFATHER: It is impossible for a propeller to spin fast enough to generate enough lift so that a plane made of metal will fly.

TT_1955: Planes in the future don’t have propellers.

DARBY’S GRANDFATHER: No propellers? Next you will be claiming that planes travel faster than sound.

TT_1955: Planes made of metal can fly faster than sound.

DARBY’S GRANDFATHER: Well TT_1955, if a plane travels faster than the speed of sound compressibility would tear the airplane to pieces.

TT_1955: It is possible to pass the sound barrier by designing the wings and body to move the shock wave down the plane as you surpass the speed of sound.

DARBY’S GRANDFATHER: You claims violate the fundamental principles of physics. More “proof” you are a hoax.
 
Re: Darby\'s Grandfather Meets a TT

Wow, I am not sure in 1911 we even knew there was a Sound barrier (Mach 1)

Let alone what you call Sound Compressability. They did use metal in the design but the structure of the aircraft was mostly wood.

and none of those claims violate the fundamental nature of physics. again, not sure we knew there was a sound barrier in 1911 but anyone who understands the basics of aerodynamics knows that even in 1911 they understood the principal of the Wing. That with enough thrust/pull anything could be put airborne as long as the wing maintained the lift. Lift is accomplished by a higher pressure/lower pressure moving along the wind creating this upwards force. I also believe in 1911 although I can't confirm, that someone was already working on the basics and design of a modern Jet engine. I know in the 30's Hughes built one, and when the US government didn't want it, the japanese bought it and turned it into the Zero. so I think someone in 1911 would say that this was possible, and not that it violated the fundamental nature of physics.

Does anyone know when we discovered the sound barrier? (this is diff depending on air pressure, density, as sound travels faster through more dense molecules).
 
Re: Darby\'s Grandfather Meets a TT

oh I get it MEM... You were trying to prove a point, I got your point. Loud and clear, I just think it was a bad way to go about it... Sure the fundamental nature of physics may change in the next 100 years that would make everything we Thought we knew, obsolete... I just think your point could have been made better without this little Darby's Grandfather story...
 
Re: Darby\'s Grandfather Meets a TT

"I don’t have any interest in directly challenging Emmett’s (Darby's) veracity. He and I are having fun with a battle of wits. Cat-and-mouse rhetoric as it were. I’m getting ready for the next round..."
 
Re: Darby\'s Grandfather Meets a TT

"Try to be a little more cat, a little less mouse." - Runaway Jury (not sure the exact person who says it though)
 
Re: Darby\'s Grandfather Meets a TT

MEM,

My grandfather was a mathematician and an engineer. I don't think that he would have answered quite like that (though at 10 years old, in 1911, he might have.)

But the entire premise of the theoretical Q&A doesn't pass muster. As I recall my history of physics, Isaac Newton first proposed that vehicles could be powered by reaction engines through the expulsion of hot gas at high velocity.

The theory of flight dynamics was pretty well understood by the late 1870's. Metalurgy and power plant technology was the real issue. Power plants with sufficient power to weight output ratios was the problem. As to jet powered flight, you don't really think that Whittle sat down one morning in 1928 and dreamed up jet engines over breakfast, do you? He proposed his first jet engine to the RAF in the early 1920's.

(Why do I have to respond to this particular Urban Legend several time a year when the history of flight is well documented?)

For some reason people assume that 1900 marks the end of the Science Dark Ages and that everything "modern" that we know about science was discovered after 1900. No one seems to place Maxwell, Lorentz, Newton, Roentgen, both Curies, Becquerel, Damiler, Maxim, Langley, etc. in the correct century. They made their discoveries about reaction engine propulsion, radiation, E&M theory, optics, gasoline engines and flight before 1900.

Oh, yeah...and Ernst Mach, of course. He explained the physics of acoustic mechanics, compressibility and supersonic dynamics in 1877.
 
Re: Darby\'s Grandfather Meets a TT

Oh, yeah...and Ernst Mach, of course. He explained the physics of acoustic mechanics, compressibility and supersonic dynamics in 1877.
Click to expand...
I was waiting for your reply to this, Darby. You can imagine I was eager to jump in, but figured I would give you the fun.

I dunno. MEM claims to have an engineering degree, but with such errors about the history of fluid mechanics I would question that.

And let's not forget Daniel Bernoulli who described dynamic pressure!

RMT
 
Re: Darby\'s Grandfather Meets a TT

MEM,

Your response illustrates my point better than anything I could write.
Click to expand...

Thanks. But I take no pride in it. I make my living based on my writing skills, so it's expected that I would have some advantage.
 
Re: Darby\'s Grandfather Meets a TT

Thanks. But I take no pride in it. I make my living based on my writing skills, so it's expected that I would have some advantage.
Click to expand...

Hello. McFly. Is anyone home? /ttiforum/images/graemlins/smile.gif
 
Re: Darby\'s Grandfather Meets a TT

We knew about the sound barrier, cracking a whip is breaking the sound barrier.

--- Razimus
 
Re: Darby\'s Grandfather Meets a TT

Raz you look terrific. Your hair is absolutely fabulous! /ttiforum/images/graemlins/smile.gif

Copy.The sound barrier was accidentally broken by a propeller plane of a specialy designed, during the late 1920 or early thirties.

This was a specially designed aircraft, in a dive and from what ground references had calculated, the plane broke the speed of sound.

Insert, from the text, [This must have been an accident, as they were testing for stability in a power dive configuration.The planes speed simply got away from the pilot and the calculated speed as observed by ground, was about seven hundred miles per hour.}*Note this was said a biplane.

source Airplanes Of The World, by Douglas Rolfe, Simon & Shuster
 
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