Donuts, rope - here we go again, or something new?

[LowObservable]

Some interesting images here:

http://bbs.keyhole.com/ubb/ubbthreads.php?ubb=showflat&Number=1216913&page=1

Skeptics, believers are free to chime in.

 

[Orionblamblam]

Some very nice satellite photos of a perfectly normal jetliner contrail.

 

[LowObservable]

Orion - What about the astro shots of a string of lights?

 

[Matej]

It sometimes happens under a special conditions. I also saw the dots-like contrail a few months ago over my house from the ordinary airliner. It doesnt mean that it is the only explanation of the every unusual contrail, but it happens sometimes.

 

[Stargazer]

Most interesting post of the topic in question is this:
http://bbs.keyhole.com/ubb/ubbthreads.php?ubb=showflat&Number=1217085#Post1217085
which asks some very valid questions and provides open minded people with food for thought.

 

[Ian33]

Edited because in wrong forum. Sorry.

As for the Pulse detonation? the fuel still being produced could be for ground research as well?

 

[Orionblamblam]

Orion - What about the astro shots of a string of lights?

I have a lot of photos like that myself (except using a much smaller lens than the telescope shown). A normal aircraft flying through the field of view of a long exposure will leave a trail of dots like this. Typically the trail of dots is red or green, but white dots would simply indicate a white (or perhaps yellow) flashing light.

Were this in fact a pulse detonation engine, those flashes would be a *lot* brighter. As it is, they look a bit dim. Most likely a high altitude aircraft with a flashing light. Note that there's not a lot of color visible in the photo, so I can't say whether the light is white, yellow, or really washed-out red or green.

 

[mz]

There are also spinning satellites that cause periodic flashes.

 

[Sea Skimmer]

I’ve seen contrails that looked a lot like this over my house before, and I’m certainly not in a location anyone would choose to fly a top secret aircraft over in broad daylight. Plus a pulse detonation engine on a high speed aircraft would be pulsing many thousands of times a minute, which means large spaces between puffs doesn’t really make any sense.

Anyway my experience with the PDE conspiracy theories is that the people spouting them usually have no clue what the actual advantages of PDE are. Mainly, people seem to always equate PDE with high speed and super secret awesomeness, when in reality its main advantage is high thermal efficiency. That means PDE technology is more likely to appear in a power plant or a commercial airliner using hybrid engine then some elite military spy plane program. If the military wanted to go fast in secret they’d just make a modern D-21 with a ramjet and call it a day.

 

[Orionblamblam]

I’ve seen contrails that looked a lot like this over my house before, and I’m certainly not in a location anyone would choose to fly a top secret aircraft over in broad daylight.

I've *watched* jetliners make that contrail. The problem generally is that the contrail initially appears normal, and only develops the "donuts" a dozen or three seconds later. By which time the jetliner has moved on, and may no longer be visible.

 

[Michel Van]

I've *watched* jetliners make that contrail. The problem generally is that the contrail initially appears normal, and only develops the "donuts" a dozen or three seconds later. By which time the jetliner has moved on, and may no longer be visible.

me too
i live under a "crossroad" for jetliner
even while i writing this post, a jetliner make contrail
and the wind makes a that "rope" out of it...