Spinner strobing as a "Bird Strike Countermeasure"

"Yes - I have a name" wrote in message
news:H1d5j.7404$gs.1663@trndny08...
"Paul Tomblin" wrote in message
...
"Mxsmanic" wrote in message
.. .
This is completely incorrect. Human vision produces no such
artifact.
Anything moving beyond a certain speed is simply a blur; it never
appears
to
move backwards.
Except in this case he's absolutely right.


I'm sure I've seen wheels on cars that appear to be moving backwards. Are
my
eyes defective?



http://findarticles.com/p/articles/m...17/ai_18471030

I guess I'm not the only one.

Mxsmanic wrote:
writes:

And it takes two interlaced fields to make a frame, therefore US
broadcast TV standard (NTSC) is actually only 30 frames per second.

30 images, 60 frames

Wrong, exactly backwards wrong. Rutger was correct.

cavelamb himself wrote:
STANDARD FLAME POST version 3.432 (c) 1996-1997. Check all that apply.


I hadn't seen that in a long time. You need to update though to the
4.0(rec.aviation) version.

It replaces all of that with.

Shut the **** up, MX.

In a previous article, "Yes - I have a name" said:
I'm sure I've seen wheels on cars that appear to be moving backwards. Are
my
eyes defective?

That's due to something else strobing the light, such as the reflection
off other wheels or off the lugnuts. It's also reported that a steady
vibration of your eyes can cause the effect, such as when humming (or
probably while sitting in a noisy airplane).

http://findarticles.com/p/articles/m...17/ai_18471030

The discrete vision theory has been discredited.

Kline K, Holcombe A, Eagleman D (2004). "Illusory motion reversal is
caused by rivalry, not by perceptual snapshots of the visual field.".
Vision Res 44 (23): 2653-8. PMID 15358060.

Kline K, Holcombe A, Eagleman D (2006). "Illusory motion reversal does not
imply discrete processing: Reply to Rojas et al.". Vision Res 46 (6-7):
1158-9. PMID 16199075

--
Paul Tomblin http://blog.xcski.com/
C is *supposed* to be dangerous, damnit!
-- Anonymous, on "Safer C"

"Paul Tomblin" wrote in message
...

That's due to something else strobing the light, such as the reflection
off other wheels or off the lugnuts.

So Anthony's statement IS wrong :

"it never appears to move backwards."

Refer to MX rule #1

Gig 601XL Builder wrote:
cavelamb himself wrote:

STANDARD FLAME POST version 3.432 (c) 1996-1997. Check all that apply.



I hadn't seen that in a long time. You need to update though to the
4.0(rec.aviation) version.

It replaces all of that with.

Shut the **** up, MX.



Dude!
That's sweet.

Direct, to the point, and saves considerable bandwidth.

Wish this idiot could do the same.
But Noooooo.... Not this one.

Ah well.


Richard

In rec.aviation.piloting Mxsmanic wrote:
writes:

Any light that flickers at an appropriate rate will cause the prop to
appear to turn in reverse.

The likelyhood of being somewhere with lights that flicker is irrelevant.

It's highly relevant in aviation, where exposure to flickering lights is
essentially unknown.

A new appearance of Non Sequitur Kid.

The original statement was that it -ONLY- happens in movies and video, and
that absolute statement is false as are most of MX's absolute statements.

The original assertion was that it was an artifact of human vision, which is
never true.

The Revisionist appears to pull MX's butt from the fire and fails.

You do know this stuff is archived and it is trivial to show you are
lying?

--
Jim Pennino

Remove .spam.sux to reply.

In rec.aviation.piloting Mxsmanic wrote:
writes:

When observed directly under artifical light that "flickers", the most
obvious being a strobe light, but there are other types of artificial
lights that have flicker.

That is an artifact of the lighting, not of human vision.

Non Sequitur Kid suddenly appears...

Additionally, natural light (e.g., sunlight) does not flicker.

Captain Obvious puts in yet another appearance.

--
Jim Pennino

Remove .spam.sux to reply.

In rec.aviation.piloting Mxsmanic wrote:
Yes - I have a name writes:

My phonograph turns at either 33-1/3 or 45 RPM, which is just as relevant to
this conversation as your mention of turbofans.

At any given moment there are thousands of aircraft powered by turbofans in
flight.

The Non Sequitur Kid puts in a surprise appearance.

Yet he fails to state that at any given moment there are thousands of
phonographs in use.

--
Jim Pennino

Remove .spam.sux to reply.

On Dec 3, 7:21 pm, Harry K wrote:
On Dec 3, 2:45 pm, Just go look it up! wrote:





On Mon, 03 Dec 2007 21:52:04 -0800, Airbus wrote:
In article , says...

When observed directly under artifical light that "flickers", the most
obvious being a strobe light, but there are other types of artificial
lights that have flicker.

--

Fine - but which ones cause you to see the propellers turning in
apparent reverse? Do you frequently operate your airplane indoors?
Propellers are usually observed in natural light, which does not flicker. At
night, on the rare occasions where you actually see the props clearly, it is
from the aircraft's own lighting, which is DC. I have nbever seen the props
turning backwards on a real plane - see it frequently in movies though. . .

Night, near one of those big off-amber ramp lights, run the RPM up and
down, there's a range where it will look like it's going backwards. I
thought it was kind of interesting.

It's something similar to the poor-man's "is my RPM somewhat right"
test, it'll appear stopped at (I forget what RPM now) RPM and if your
tach is somewhat near, viola.- Hide quoted text -

- Show quoted text -

Been a long, long time but my rusty math skills says it would be about
3600 unless I am wrong (per wife that is my normal state). That is
the 1/2 harmonic of the rpm/flicker rate. 60 X 120 = 7200. The
phenomenon should appear at 1/2, 1/4, double rate etc intervals.

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.

Harry K