Spinner strobing as a "Bird Strike Countermeasure"

"cavelamb himself" wrote in message
...

So, which way is the naked lady spinning?

http://www.sonnyradio.com/spinninglady.html

Interesting. I kept seeing her CW, and tried it several times, and was truly
beginning to wonder. But then suddenly she switched. At first it seemed to
be a function of time with me, but then I tried an experiment base on the
angry face example. I put my thumb up half way between the screen and my
eye, and had much better luck switching her back and forth. Seems depth of
field or focal point seems to have a big effect with me. See if it works for
you.

"Gig 601XL Builder" wrote:
Mxsmanic wrote:

I'm not looking for friends. I'm only here to discuss aviation.

Bull****. You are hear to argue about aviation discussions and I
understand completly why you do it. It is because you have some
psycological need to argue and if you did it the way you do here you
would get your ass beat.

So whats that make you?














Besides being a bad speller...

On Dec 4, 8:25 pm, wrote:
In rec.aviation.piloting Harry K wrote:



snip

Harry K- Hide quoted text -

- Show quoted text -
After thinking that over...
It gets worse. There will be multiple rpm that will show the effect
under strobe conditions. With a 2 blade prop it can be sychronizing
every 1/2 rev. 3-blade prop every 1/3 or 2/3 rev, etc. in addition to
synching on the harmonics.

It isn't that bad.

Synchronization only occurs on integral fractions and engine RPM is
usually 1000 and about 2700 RPM so the possibilities are limited.

For a 2 bladed prop:

7200/2= 3600 - 1800 RPM

7200/3= 2400 - 2400 RPM and 1200 RPM

7200/4= 1800 - 1800 RPM and 900 RPM

etc.

I leave it to someone else to show how many blades you see at each RPM.

--
Jim Pennino
Since the prop appears stationary, you would see all the blades.

Yes, but how many virtual blades will you see?

Simple example: You are illuminating a 2 bladed prop running at 1000 RPM
with a strobe light pulsing at 4000 pulses per minute.

In the time between pulses, the prop makes 1/4 of a turn.

The prop is therefor lite up every 1/4 turn and it appears as though
the prop has 4 blades.

--
Jim Pennino

Remove .spam.sux to reply.- Hide quoted text -

- Show quoted text -

Nope. The prop appears stationary and you see only the two.

What you see is the complete image (frame), not a composite of 4
'frames'.

Harry K

Mxsmanic wrote:

I'm only here to discuss aviation.

You are not, you lying vermin. You have posted dozens of messages in
aviation-related newsgroups that have nothing to do with discussing
aviation. You're a tedious, useless, off-topic troll.

Now shut the hell up, loser-boi.
--
dgs

cavelamb himself wrote:
Gig 601XL Builder wrote:
cavelamb himself wrote:



So, which way is the naked lady spinning?

http://www.sonnyradio.com/spinninglady.html



I called it up and saw her rotating CCW for about a minute even after
bleinking and looking around the room and then back at the pic she
was still CCW.

Then I looked up and book marked the page and and then sent a link
to my wife and when I looked back she was CW. And just now I popped
back over and she is still CW.




HaHa!

I can make her do the "Twist", but it makes my eyes hurt...

So can my wife and while I love her dearly she does not have a 160 IQ and
she would be the first to admit it. Hell, she married me that pretty much
will keep her out of Mensa alone.

Darrel Toepfer wrote:
"Gig 601XL Builder" wrote:
Mxsmanic wrote:

I'm not looking for friends. I'm only here to discuss aviation.

Bull****. You are hear to argue about aviation discussions and I
understand completly why you do it. It is because you have some
psycological need to argue and if you did it the way you do here you
would get your ass beat.

So whats that make you?


Someone that is getting tired of his constant crap ruining a perfectly good
forum.














Besides being a bad speller...

No, bad typist who counts on spell check to catch stuff and I tend to forget
that unless I hit the spell check button it doesn't work on this program.

Harry K writes:

Nope. The prop appears stationary and you see only the two.

What you see is the complete image (frame), not a composite of 4
'frames'.

You are both incorrect.

Airbus writes:

Forget it dude - I'm not like you - will not make categorical statements
about subjects I know nothing about.

Then why are you making categorical statements about me?

I'm so impressed.

Why? Anyone can look up the specs, even though many people are too lazy to do
so.

Mxsmanic wrote in
:

Harry K writes:

Nope. The prop appears stationary and you see only the two.

What you see is the complete image (frame), not a composite of 4
'frames'.

You are both incorrect.





Nope.


Bertie

writes:

There's a well-known phenomenon that can incapacitate pilots. A
propeller spinning so that it cuts through the sun's glare and causes
a stroboscopic effect on the pilot's eyes can result in confusion. A
frequency of less than between 25 and 55 Hz, depending on the
individual, can cause dizziness or nausea. It's called "flicker
vertigo" and the fact that it happens tells me that the human eyeball
(or at least the visual cortex) does have a frequency function of some
sort. 25 Hz on a two-blade prop would be 750 RPM and 55 would be 1650.
Some tests have found that frequencies as low as four to 20 Hz will
induce it rapidly.

It is probably more a consequence of intermittent photic stimulation, the same
phenomenon that can trigger seizures in susceptible individuals. As I recall,
the bulk of the response is outside the visual cortex.