Sujet : Re: fast tires
De : shouman (at) *nospam* comcast.net (Radey Shouman)
Groupes : rec.bicycles.techDate : 23. Jun 2025, 15:44:21
Autres entêtes
Organisation : None of the above
Message-ID : <871praecvu.fsf@mothra.hsd1.ma.comcast.net>
References : 1 2 3 4 5 6 7 8 9 10 11 12 13
User-Agent : Gnus/5.13 (Gnus v5.13)
AMuzi <
am@yellowjersey.org> writes:
On 6/19/2025 3:53 PM, Catrike Ryder wrote:
On Thu, 19 Jun 2025 16:27:01 -0400, Radey Shouman
<shouman@comcast.net> wrote:
Catrike Ryder <Soloman@old.bikers.org> writes:
>
On Thu, 19 Jun 2025 12:48:26 -0700, Jeff Liebermann <jeffl@cruzio.com>
wrote:
>
On Thu, 19 Jun 2025 14:46:09 -0400, Catrike Ryder
<Soloman@old.bikers.org> wrote:
>
On Thu, 19 Jun 2025 14:20:34 -0400, Radey Shouman
<shouman@comcast.net> wrote:
>
Catrike Ryder <Soloman@old.bikers.org> writes:
>
On Wed, 18 Jun 2025 12:58:56 -0400, Frank Krygowski
<frkrygow@sbcglobal.net> wrote:
(...)
IOW if you turn an object loose with only its weight acting
on its mass,
it accelerates downward at one "gee."
>
Count me unimpressed by Krygowski's cut and paste.
>
I'm reasonably sure that was written extemporaneously. Any engineering
professor should be able to do the same. Any practicing engineer will
have gone through the same reasoning many times.
>
I'm reasonably sure he copied out of a book.
>
To impress you, must one now memorize all the proofs and calculations?
That seems a bit excessive. Do you memorize everything? I don't,
mostly because my memory is not as good as when I was young.
Secondarily, because I don't like distributing potentially wrong
proofs and calculations. If you have memorized everything, I too
would be very impressed.
>
I don't learn things by rote, I learn by knowing how things work.
>
If only you knew how force, mass, and acceleration worked you could
also write out an explanation similar to that of Prof. Krygowski.
And I'd probably get it wrong. I'd say, "Who cares?" Krygowski would
have to very sure he got all the commas and brackets exactly right.
--
C'est bon
Soloman
>
That's true, which is why knowing that is important to him. Maybe not
important to you.
>
For simple machining, one needs to know basic geometry to calculate
cutting speed for turning or boring and you also need to know optimal
cutting speed constants for whatever material(s) you have. It's
possible to sorta try different speeds and see how it goes but that's
impractical if you are not in a position to chuck several pieces in
the scrap bin along the way.
For engineering calculations the units and dimensions absolutely have to
agree, otherwise the calculation is nonsense. This is not a matter of
elegance or style, it's a really basic check on correctness. Add
millimeters to acres and you get garbage.
People do have amazing memory capacities which occasionally astound
me. For example, a guy I thought was not one of the brightest. I was
nearby when he was discussing baseball with someone else and he could
recount plays from 30, 40 years ago, along with the player stats
before and after that game. And many iterations of those plays.
Depends on what's important to you.
--