Re: The insane progress nobody is talking about

On Mon, 1 Jul 2024 16:11:11 +0100, Robert Carnegie
<rja.carnegie@gmail.com> wrote:

On 22/06/2024 17:26, Paul S Person wrote:

On Fri, 21 Jun 2024 16:51:19 GMT, scott@slp53.sl.home (Scott Lurndal)
wrote:
 

Paul S Person <psperson@old.netcom.invalid> writes:

On Thu, 20 Jun 2024 17:21:54 GMT, scott@slp53.sl.home (Scott Lurndal)
wrote:
>

Paul S Person <psperson@old.netcom.invalid> writes:

On Wed, 19 Jun 2024 16:10:34 -0000 (UTC), Christian Weisgerber
<naddy@mips.inka.de> wrote:
>

People are bitching about a lack of flying cars or fusion power,
but hardly notice the actual, incredible, crazy progress that is
happening.
>
I'm talking of course about artificial illumination.  (Yes, again.)
Not sexy?  Too bad.
>
Recently a conventional light bulb that had escaped my purge revealed
itself by dying.  I replaced it with the latest generation of Philips
LED bulb that requires about 1/14 (!) as much energy for the same
light output and is specified with a lifetime of 50.000 hours, which
amounts to some 50 years of average use.

>
Rated, yes. And based on some sort of tests, no doubt.

>
Based on calculations.  For example, the resistors in
the product have certain characteristics such as resistance,
tolerance, working temperature,  power rating, etc.   Included in that >>>> is
a lifetime rating provided by the part manufacturer when the part
is used within specifications.
>
One can calculate the overall expected lifetime of a
product statistically based on that per-component data
accounting for effects that degrade the data such
as operating outside specification, etc.

>
The map is not the terrain.

>
The goal is to create a statistical certainly.  Obviously
any one bulb might be defective, but the majority
of bulbs will survive for the specified period.
>
>
>

But thanks for confirming the basic bogosity of these claims.

>
I did no such thing.

 
Actually, you did.
 
You confirmed that the length-of-life claims have no basis in how long
they actually last but merely in projections based on assumptions and
(have now added above ) are only true in the statistical sense -- as
opposed to the real-world sense.
 
The truth is that, unless everyone keeps strict records, we do not
have and never will have a true picture of how long they last under
various conditions.

>
It's science.  Science is pretty good stuff.
>
It's probably also conservative - in the sense
of under-claiming what is delivered.  In the
political sense, not wasting energy is the
opposite of conservative.

Claiming, on the same box, that LEDs last 11-22 years (IIRC) and that
CFLs last 7-9 years in one place and then that the LEDs actually
purchased can be expected to last 7 years (all at 3hrs/day useage) is
neither science nor conservativism.

It is marketing.

And it cannot be trusted or taken as in any way related to reality.

Look at the boxes for any LED bulbs you have purchased. Do they show
the same thing?

BTW, the two main bulbs (one now an LED, the other a CFL that has been
going for about 3.5 years per my records) are on during the day and
during the night (respectively). So between them, one or the other is
always on. So that is an average of 12 hours/day. Since 12 = 3 x 4,
7yrs/(12 hrs/3hrs/day) = 7/4 hrs = 1.75 years in realistic use. The
CFL, at least, is doing much better. And the LED is meeting
expectations.

If they want their claims to be valid, this is what they need to do:

-- create a standard specifying the various parts by /their/
electrical/electonic characterists
-- continue by specifying how they are to be put together
-- conclude by specifying how the tests are to be run and what they
must show for each number of hours allowed to be claimed
-- cite that standard on the packaging and display an emblem showing
that they actually complied with it

Saying "11-22 years" here and "7 years" there is /not/ the same as
saying "meets ISO ......... for <whatever> hours expected lifetime".

/Then/ they can claim to be putting out something other than marketing
bumpf.

I put "expected" in there because, being statistical, that is probably
what we are dealing with: the point at which half the bulbs will be
dead.

I still say it makes more sense to use them because they don't have to
be changed so often. Not to save money, not because of clearly BS
marketing claims.
--
"Here lies the Tuscan poet Aretino,
Who evil spoke of everyone but God,
Giving as his excuse, 'I never knew him.'"