Inflatable helmet, really

On Sep 12, 7:32*pm, Tom Sherman °_°
wrote:
On 9/12/2010 7:16 PM, André Jute wrote:

snip blah, blah, blah *[1]

See
http://en.wikipedia.org/w/index.php?title=Bandon%2C_County_Cork&diff=....

Scroll down to "People".

[1] For André Jute and Michael Press, this is NOT a quote of previously
posted text.

Hey, little did I know that Bandon, Oregon (funky beach town) is named
after Bandon, Irland. Live and learn. http://www.ci.bandon.or.us/

lotta grim looking people in Or'gun

anyone ride a bicycle down the Siskyou's interstate grade ?

On Sep 12, 3:26*pm, !Jones wrote:
On Sun, 12 Sep 2010 11:36:02 -0700 (PDT), in rec.bicycles.tech Frank



Krygowski wrote:
There's some very twisted logic in that post!

For a much better parallel to typical helmet promotion: *Medical
science has found no anti-cancer benefit for huge doses of vitamin C,
Linus Pauling notwithstanding.
http://www.quackwatch.com/01Quackery...s/pauling.html
Are you saying that despite such data, we should still promote vitamin
C as the most important defense against cancer? *Are you saying that
even if we don't, that any particular individual is justified in
believing that vitamin C will prevent or cure their cancer?

The logic generally used in medical and health science is, if tests
show something to be ineffective, don't pretend it's effective. *Move
on.

I'll also add, logic also says if data shows a problem to be
minuscule, don't over overemphasize it. *Granted, that one is much
more frequently violated.

Here we have a case where people seem to be pretending cycling causes
lots of serious head injuries, more than other activities, despite
data to the contrary. *And they're pretending that helmets are usually
very effective in preventing those head injuries, despite data to the
contrary.

- Frank Krygowski

Paragraph 1:
H1: The treatment population receiving huge doses of vitamin C will
have fewer cancers than the control group.

H0: There is no difference between the treatment group and the control
group that cannot be explained by pure chance beyond a probability =
0.05.

They run their T tests and that probability that any difference may be
purely luck is running in the 0.3s. *What do the researchers do,
Frank?

A: They should accept the null hypothesis (H0).
B: They should conclude that they cannot reject the null hypothesis.

The correct response is 'B'.

It appears you're inventing numbers. Certainly, the situation you
describe has never occurred with Vitamin C and cancer. I don't
believe it's ever occurred with bike helmets and head injuries in
large population data, either; but if you have such data (and I don't
mean numbers you imagine out of thin air!) we can talk about it.

Paragraph 2: "The logic generally used in medical and health science
is, if tests show something to be ineffective, don't pretend it's
effective."

Absolutely not! *Didn't you have a freshman class in statistics,
Frank? *I thought these were required. *The logic generally used in
medical and health science is, if tests do not show something to be
effective, then make no statement at all.

:-) Speaking of logic, why do you think my statement saying "don't
pretend it's effective" somehow violates your statement saying "make
no statement at all"? You're agreeing with me, although you're either
too befuddled to realize it, or too trollish to acknowledge it!

Further trolling trimmed.

- Frank Krygowski

On Sep 12, 4:18*pm, "Bill Sornson" wrote:


And what you just did also has a name: *"pulling Frank's covers".

Bill "it's amazing he hasn't shivered to death by now" S.

Bill, don't pretend you understand the conversation. Everyone knows
you don't.

- Frank Krygowski

On Sep 12, 5:59*pm, Dan O wrote:
On Sep 12, 11:16 am, Frank Krygowski wrote:

On Sep 12, 1:31 am, Dan O wrote:
Go ahead, dumbass - define the problem. *I will solve it for you.

Given: that much of the data in the cited paper involved a total
impact velocity (helmet to ground) of only 6.5 mph; and given that
according to the CPSC helmet standard, an appropriate vertical
component of that impact velocity is 14 mph;
Find: the horizontal travel velocity which will limit the total impact
velocity to 6.5 mph. *Or hell, to 8.5 mph (the other velocity in that
test) if you prefer.

Sorry, I still don't understand the problem. *How can the impact
velocity be less than the vertical component? *(Maybe there is missing
information?) *I am interested if you want to show me how to solve it,
though.

The point, Dan, is that it's impossible. If the vertical component is
14 mph, the total cannot be less than 14 mph.

Thus the pro-helmet paper was ludicrous in pretending that helmets
can't cause rotational brain damage, because a 6.5 mph impact looked
safe. The CPSC helmet standard people would laugh at a helmet being
tested at only 6.5 mph, and many other people have scoffed at CPSC's
14 mph as being unrealistically gentle.

For further help with this:

a) Tom Sherman's remark about your needing to ride at a velocity of v
* i was using the math shorthand in which "i" is the square root of
negative one, i.e. imaginary numbers.

b) Skipping stones on water has nothing at all to do with friction
between solid objects during impact.

- Frank Krygowski

On Sep 12, 6:59*pm, James wrote:
On Sep 11, 12:41*pm, Frank Krygowski wrote:

On Sep 10, 4:59*pm, James wrote:
Maybe your Unliddedness has let your eyesight degrade. *I posted a
link. *MikeWhy found it. *Strangely you overlooked it. *Maybe, like so
much else you didn't like the message it brought and chose to sweep it
under the carpet and respond with more rubbish.

What utter bull****! *Did you even bother to read that paper?

Nope. *CBF. *Was waiting for you.

And meantime, you were trolling. Come back when you have real
information.

- Frank Krygowski

On Sep 13, 1:37*pm, Frank Krygowski wrote:
On Sep 12, 6:59*pm, James wrote:

On Sep 11, 12:41*pm, Frank Krygowski wrote:

On Sep 10, 4:59*pm, James wrote:
Maybe your Unliddedness has let your eyesight degrade. *I posted a
link. *MikeWhy found it. *Strangely you overlooked it. *Maybe, like so
much else you didn't like the message it brought and chose to sweep it
under the carpet and respond with more rubbish.

What utter bull****! *Did you even bother to read that paper?

Nope. *CBF. *Was waiting for you.

And meantime, you were trolling. *Come back when you have real
information.

Back at you, Frank.

JS.

On Sep 12, 8:35 pm, Frank Krygowski wrote:
On Sep 12, 5:59 pm, Dan O wrote:



On Sep 12, 11:16 am, Frank Krygowski wrote:

On Sep 12, 1:31 am, Dan O wrote:
Go ahead, dumbass - define the problem. I will solve it for you.

Given: that much of the data in the cited paper involved a total
impact velocity (helmet to ground) of only 6.5 mph; and given that
according to the CPSC helmet standard, an appropriate vertical
component of that impact velocity is 14 mph;
Find: the horizontal travel velocity which will limit the total impact
velocity to 6.5 mph. Or hell, to 8.5 mph (the other velocity in that
test) if you prefer.

Sorry, I still don't understand the problem. How can the impact
velocity be less than the vertical component? (Maybe there is missing
information?) I am interested if you want to show me how to solve it,
though.

The point, Dan, is that it's impossible. If the vertical component is
14 mph, the total cannot be less than 14 mph.

Thus the pro-helmet paper was ludicrous in pretending that helmets
can't cause rotational brain damage, because a 6.5 mph impact looked
safe. The CPSC helmet standard people would laugh at a helmet being
tested at only 6.5 mph, and many other people have scoffed at CPSC's
14 mph as being unrealistically gentle.

Sure, and FWIW, I regarded that paper at least as biased as those
others that I bemoan as such. (I kind of got a kick out of that part
about their instruments being too delicate to test with higher
speeds :-)


For further help with this:

a) Tom Sherman's remark about your needing to ride at a velocity of v
* i was using the math shorthand in which "i" is the square root of
negative one, i.e. imaginary numbers.

Imaginary, eh. Alrighty then.


b) Skipping stones on water has nothing at all to do with friction
between solid objects during impact.


Okay, but remember what you said about experience, and real crash
experience is not something easily gained ;-)

On Sun, 12 Sep 2010 20:26:11 -0700 (PDT), in rec.bicycles.tech Frank
Krygowski wrote:

It appears you're inventing numbers. Certainly, the situation you
describe has never occurred with Vitamin C and cancer. I don't
believe it's ever occurred with bike helmets and head injuries in
large population data, either; but if you have such data (and I don't
mean numbers you imagine out of thin air!) we can talk about it.

Frank, what can I say? I feel like I'm torturing a whale on a beach
chained to a tree. Based on some suspected trend, one formulates a
hypothesis. Then, after refining the hypothesis, studying the current
literature, and documenting a need for the study, one proposes the
study to his or her ethical oversight committee(s). (Here is where
any tests of helmets on humans would drop out because there might be
an effect.) Once approved, data collection begins.

In an experimental study, one has a treatment group and a control
group (again, as you pointed out, no such helmet study has ever been
or will be done.) One had better steer well clear of the word
"prove"... you hypothesize, instead. If you find a difference in the
two groups, the hypothesis is that the difference is attributable to
the treatment, whatever that was, within a certain arbitrary range of
probability... the null hypothesis is that any observed difference is
purely chance... merely the result of a random walk.

*** Now... watch carefully, Frank; this is called a point! ***

*** Are you watching? Here it comes... nothing up my sleeve! ***

Scientific studies don't prove that a treatment had no effect; the
studies you're throwing around like garlands simply failed to reject
the null hypothesis... that does happen. It does *not* mean that the
treatment is ineffective; it means the study failed to find that it
*has* an effect.

*** That was a point, Frank. Did you see it? ***

Of course, helmet studies are all post facto studies. This means that
they're based on existing data. Since the researcher cannot control
group selection (aka, the independent variable), you have no control
group. Post facto studies generally cannot attribute cause and
effect; however, such studies of smoking are, at long last, considered
conclusive.

Jones