Would a Flying Saucer leave a contrail?

[Akhenaten]

Or you just keep pulling back on the stick until your socks roll down.

F22 Raptor​

 

[Paul C. Anagnostopoulos]

I think you saw the chemtrail's shadow.

The chemtrailies assure me that is a black chemtrail. Pay no attention to the white chemtrail alongside it.

~~ Paul

 

[Akhenaten]

Sometimes you can be just hangin' around.

Cobra​

 

[I Ratant]

On the other hand, if you go fast enough . . .

[qimg]http://www.yvonneclaireadams.com/HostedStuff/SonicBoom.jpg[/qimg]
Boom!​

.
No.
Not supersonic
Those condensation clouds are due to the shape of the plane condensing the humid atmosphere.
Note the small cloud at the peak of the canopy, where the canopy begins to slope backward.
There's no sonic boom from these airshow type demos.
It's the same thing seen in the SF bay flybys.
In the the next image of the F-22, the condensation results from the plane pulling g, which can be done at very low speeds.
The only way an A-10 could go supersonic would be to transport it someplace inside a supersonic transport...
And the mighty Herc gets nifty prop clouds.

 

[I Ratant]

The chemtrailies assure me that is a black chemtrail. Pay no attention to the white chemtrail alongside it.

~~ Paul

.
The first time I'd heard of the "black chemtrail"/ UFO thingy I wondered why the fantasist hadn't observed the source, but instead was terrified by the apparition.
You do have to be at the right place at the right time, as the generating contrail and the sun are both moving and the effect goes past very quickly.
And the atmosphere has to be dirty so the particles aren't reflecting sunlight as usual.

 

[Paul C. Anagnostopoulos]

The first time I'd heard of the "black chemtrail"/ UFO thingy I wondered why the fantasist hadn't observed the source, but instead was terrified by the apparition.

Because there shall be chemtrails.

~~ Paul

 

[I Ratant]

Because there shall be chemtrails.

~~ Paul

.
Disirrefutable logic, that is, I must say!

 

[Soapy Sam]

I've spent a load of hours looking out of aircraft windows.
Contrails are pressure phenomena. Engine exhaust is not the primary cause.

And gliders most certainly do make contrails. Consider the space shuttle, which , on reentry , is a glider.

Most gliders are not built for the sort of high speeds and high -g turns needed to squeeze water out of the air. Hell, meteorites leave contrails- and they don't have engines, except the disguised saucers.

 

[I Ratant]

I've spent a load of hours looking out of aircraft windows.
Contrails are pressure phenomena. Engine exhaust is not the primary cause.

And gliders mst certainly do make contrails. Consider the space shuttle, which , on reentry , is a glider.

Most gliders are not built for the sort of high speeds and high -g turns needed to squeeze water out of the air. Hell, meteorites leave contrails- and they don't have engines, except the disguised saucers.

.
Watched/heard one come back to Edwards.
Nice BIG bang, and a contrail.

 

[steve s]

Contrails are pressure phenomena. Engine exhaust is not the primary cause.

So why do they form behind engines instead of over the full width of the wing?



Steve S

 

[Bell]

So why do they form behind engines instead of over the full width of the wing?

[qimg]http://www.internationalskeptics.com/forums/imagehosting/thum_81544bddd4f805da5.jpg[/qimg]

Steve S

My uneducated guess would be that the air is being pressurized inside the engines.

 

[Soapy Sam]

They form where the pressure gradient is high enough. Other things equal, I imagine engine cowlings are one of those places, As relative humidity is obviously a factor too, the fact of a high temperature , hydrocarbon aerosol enriched airstream will be part of the picture too. I surely don't deny that engines are one source- just not the sole, or necessary cause.

 

[Verde]

unicorns prancing out of my butt.

That sounds extremely painful.

Please keep in mind I'm not really taking this seriously.

Oh, All right then.

V.

 

[steve s]

We just need the Mythbusters to rent a passenger jet, take it up to 40,000 feet on a day when the weather conditions are right, and shut off the engines.

Steve S

 

[Akhenaten]

.
No.
Not supersonic
Those condensation clouds are due to the shape of the plane condensing the humid atmosphere.
Note the small cloud at the peak of the canopy, where the canopy begins to slope backward.
There's no sonic boom from these airshow type demos.
It's the same thing seen in the SF bay flybys.
In the the next image of the F-22, the condensation results from the plane pulling g, which can be done at very low speeds.
The only way an A-10 could go supersonic would be to transport it someplace inside a supersonic transport...
And the mighty Herc gets nifty prop clouds.

Hmm . . .

​

 

[I Ratant]

They form where the pressure gradient is high enough. Other things equal, I imagine engine cowlings are one of those places, As relative humidity is obviously a factor too, the fact of a high temperature , hydrocarbon aerosol enriched airstream will be part of the picture too. I surely don't deny that engines are one source- just not the sole, or necessary cause.

.
On frosty mornings, cars just beginning to warm up will be exhausting water drops and vapors.
For the usual airplane contrail, it's that exhaust that we see.
There's a large temperature difference between the exhaust and the ambient air at altitude.
It's not usual to see the condensation from the other parts of the plane, but it does occur.

 

[I Ratant]

None of the videos appended thereunto show supersonic flight.
All the condensation scenes are just local effects of the pressure gradient in humid air.
The boom doesn't happen in those passes.
In this one, the boom is obvious... and note the plane has passed before the boom is heard.
http://www.youtube.com/watch?v=uQ2pkmISOLM
.
A moderate busting of the sound "barrier" is quite uncomfortable when within say 1000 feet of the buster.

 

[Akhenaten]

​

 

[I Ratant]

The video that "explains" sonic booms left out the noise.
Annotated their graphic a bit..
And, here's the actual data from one of the Mach 1.28 runs Darryl Greenamyer made at Mudd Lake in 1977.
Note how quickly the noise/pressure levels diminish in only 600 feet.
.
Googling "sonic boom" gets many many videos of planes doing strange and destructive (at times) things... such as an F-14 that disintegrates at the pull-up from a sonic pass... and those crazy Frenchmen flying at sand-scraping level in Africa.

 

[Akhenaten]

Okie dokes, no further argument here about supersonic flight. I actually know more about sonic booms and stuff than I've been letting on, but it was a good excuse to post some cool clips, and I'm not going to be silly enough to try and use YouTube as reference.

Back to the OP though, I'll argue come hell or high water that you can get contrails from a rock if you throw it hard enough.

They are a product of the Venturi effect that produces lift, be it generated by wings, turbine blades, propellors, helicopter rotors or really fast rocks.