On 26/04/14 20:38, Francois Labreque wrote:

> Yet-Another-Bogus-Assumption-Made-By-Andy.
> 

From now on, this is to be known as a YABAMBA

John
-- 
Protect the Earth
It was not given to you by your parents
You hold it in trust for your children

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> Officer: Ma'am, what color was the car that hit you?
> Woman: All of them.
> Officer: WAT?
> Woman: Well, you know how a CD changes color when you move them in your
> hand, the car was like that!

FWIW, apparently this already exists.

Well, not the entire rainbow, but apparently by suspending metal 
particles in the paint, you can get two contrasting colours.

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On Sat, 26 Apr 2014 21:16:07 +0100, Orchid Win7 v1 wrote:

> FWIW, apparently this already exists.

Yes.  It has for years. :)

Jim



-- 
"I learned long ago, never to wrestle with a pig. You get dirty, and 
besides, the pig likes it." - George Bernard Shaw

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On 26/04/2014 5:13 PM, Orchid Win7 v1 wrote:
>
> I'm sure things have changed. Just perhaps not as rapidly and
> dramatically as the original revolution.

I don't think that you realise how long the "industrial revelation". 
went on for. At least for sixty possibly eighty years. Not exactly 
rapid, from a historical perspective. It just seems like that looking at 
it from the 21st Century.

-- 
Regards
     Stephen

I solemnly promise to kick the next angle, I see.

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> Presumably what you do is make a translucent layer which has inclusions
> inside it that refract the light. So the outer surfaces are smooth, yet
> you still get colour. Hard to see how you could do that cheaply though.

Well you could just make it in two parts, so long as the two materials 
had different refractive indices. A bit like how a CD is made. Maybe you 
could use some photo-etch process on the first layer, borrowed from IC 
manufacturing?

> Has anybody invented a UV coating that actually works yet?

Yes, people rely on them not to get skin cancer or go blind! Also the 
one on your car paint works. I'm sure you can find spectral response 
curves if you are interested.

> I'm sure things have changed. Just perhaps not as rapidly and
> dramatically as the original revolution.

You could argue that in some ways things are changing even faster now. 
Continuing with your plastics example, at the start hardly anyone used 
plastic and development was slow. Today plastic is used in almost 
everything and there are millions of different types. I'm sure if you 
plotted a graph of the number of new plastics invented against time it 
would be going upwards.

> This is very interesting. From what I can gather, the primary problem is
> the absurd amount of computer power required.

Indeed, it looks like they had to spend most of the effort trying to 
reduce the computing power needed whilst maintaining a decent image 
quality. Maybe in 5 or 10 years someone will come back to this 
technology and it will be able to take off.

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> Also, car manufacturers (and patio furniture manufacturers, for some
> reason) do not like to call them plastics because people have a tendency
> to associate the word with cheap and flimsy polymers like polyethylene
> or polypropylene, so they'll use words like "polymer", "DuraFlex(TM)",
> or "synthetic resin".

Never mind that those cheap and flimsy polymers are exactly what you 
need for something like a car bumper (you want it to bend rather than 
crack or split when deformed). It's also odd how in the past shiny 
glossy plastics were seen as cheap, so everyone applied texture to the 
surfaces to make it look less "plasticy", but now it seems be back in 
fashion to have a high gloss finish (much to the dismay of the plastic 
moulders).

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On 28/04/2014 08:59 AM, scott wrote:
>> Presumably what you do is make a translucent layer which has inclusions
>> inside it that refract the light. So the outer surfaces are smooth, yet
>> you still get colour. Hard to see how you could do that cheaply though.
>
> Well you could just make it in two parts, so long as the two materials
> had different refractive indices. A bit like how a CD is made. Maybe you
> could use some photo-etch process on the first layer, borrowed from IC
> manufacturing?

That sounds quite plausible. Although probably not as cheap as just 
spraying some dye onto things, which is what we do now.

>> Has anybody invented a UV coating that actually works yet?
>
> Yes, people rely on them not to get skin cancer or go blind! Also the
> one on your car paint works. I'm sure you can find spectral response
> curves if you are interested.

Interesting. I was under the impression that UV-resistent coatings are 
just overly-optimistic marketing, and in reality none of these coatings 
actually work.

>> I'm sure things have changed. Just perhaps not as rapidly and
>> dramatically as the original revolution.
>
> You could argue that in some ways things are changing even faster now.
> Continuing with your plastics example, at the start hardly anyone used
> plastic and development was slow. Today plastic is used in almost
> everything and there are millions of different types. I'm sure if you
> plotted a graph of the number of new plastics invented against time it
> would be going upwards.

Really?

OK, really ancient plastics weren't very good. But the plastics I see 
today and the plastics I saw 30 years ago seem pretty much identical in 
every respect. What's changed?

>> This is very interesting. From what I can gather, the primary problem is
>> the absurd amount of computer power required.
>
> Indeed, it looks like they had to spend most of the effort trying to
> reduce the computing power needed whilst maintaining a decent image
> quality. Maybe in 5 or 10 years someone will come back to this
> technology and it will be able to take off.

Much like how we had CDs for decades before DVDs were invented. Clearly 
a lot of people *wanted* DVDs, but the necessary computer power was 
simply unavailable.

Then again, we're trying to simulate the interaction of billions of 
photons in a large 3-dimensional space. Maybe there are 
quantum-theoretical reasons why you can't do that any faster than the 
real world can? (At least, not without using a computer many times 
bigger than the real-world system it's trying to simulate!)

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> Interesting. I was under the impression that UV-resistent coatings are
> just overly-optimistic marketing, and in reality none of these coatings
> actually work.

One of the first image results from google gave this:

http://www.alpineastro.com/filters/uv_ir_cut_specs.htm

That's a pretty sharp fall-off below 400 nm. Whether it works or not is 
unquestionable, what is usually up for debate is whether it's actually 
useful on a camera. On skin, eyes or paint of course it works and is 
useful.

> OK, really ancient plastics weren't very good. But the plastics I see
> today and the plastics I saw 30 years ago seem pretty much identical in
> every respect. What's changed?

What you see today is them used in many places where they simply 
couldn't be used 30 years ago because plastics with the required 
performance didn't exist or were too expensive to manufacture. Car 
bumpers were metal or fibre-glass that got dented or cracked, pipes in 
your house were copper, anything involving even slightly corrosive 
chemicals was stainless steel. Today plastics can be and are used in all 
those places, ultimately making things cheaper.

Then there are all the things the consumer doesn't even notice. Like 
plastics that are easier to mould (more complicated shapes are possible 
to be made faster with finer details), possible to process in thinner 
films, flame retardants that are environmentally friendly, stronger and 
stiffer plastics that enable things to be made with less plastic for the 
same performance etc.

The software we use here for simulating the moulding of a plastic part 
(to make sure it will fill correctly and not leave any sink marks, weld 
lines etc) has a built-in database of plastic materials to choose from. 
There are over 10000 of them, and there are plenty not in the list. They 
have all been developed for a specific reason, and most of them recently 
(not 30 years ago).

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> On 28/04/2014 08:59 AM, scott wrote:
>>
>> You could argue that in some ways things are changing even faster now.
>> Continuing with your plastics example, at the start hardly anyone used
>> plastic and development was slow. Today plastic is used in almost
>> everything and there are millions of different types. I'm sure if you
>> plotted a graph of the number of new plastics invented against time it
>> would be going upwards.
>
> Really?
>
> OK, really ancient plastics weren't very good. But the plastics I see
> today and the plastics I saw 30 years ago seem pretty much identical in
> every respect. What's changed?
>

First, You have a tendency to be totally oblivious to what's around you. 
  You wouldn't see the changes if they hit you in the face (in fact, one 
of those changes is actually sitting right there on your nose!)

Second, you worked in the chemical industry for over 10 years.  I'm sure 
you're familiar with the names 3M, Dupont and BASF, just to name those. 
  Don't think for a second that these companies don't have large R&D 
depts that work round the clock trying to come up with newer compounds 
that are easier to work with, thereby reducing production costs, more 
resitant, less dangerous, or biodegradable, just to name those 
characterisitcs, thereby increasing their marketing value.  They're not 
just sitting there waiting for Nylon(tm), Teflon(tm) or Kevlar(tm) 
royalties to pad their bank accounts.

Many of these plastics will have special medical or industrial 
applications, but here are a few examples of everyday uses that you may 
have seen:

Have you noticed how nowadays most eye glasses are made of plastic? 
Clear plastics with higher IOR (sorry for getting slightly on-topic for 
P.O-T) than glass were unheard of 30 years ago.  The progresses made in 
the domain of contact lenses is even more impressive than that of 
conventional glass lenses.

The same goes for the plastic covers on most car headlights.  The 
average human doesn't often stop to admire the complexity of a car's 
tail lights, - unless you're stopped behind a Lamborghini at a stop 
light - but there's been tremendous developments made in that area, too.

I know you don't have kids, but the plastics used in baby bottles and 
toys have also changed a lot in the last 10 years, due to various "Won't 
anyone think of the children?!?!!!?" reasons.

The "technical" garment industry has also greatly benefited from these 
new polymers.  You're a skier, so you've most certainly seen the 
74732327523 tags that are sewn or attached on a new ski jacket or 
gloves, touting the amazing breathability, yet still impermeable, 
feather light, yet warm as a mammoth pelt, machine washable, yet won't 
fade properties these clothes now offer.

> Then again, we're trying to simulate the interaction of billions of
> photons in a large 3-dimensional space. Maybe there are
> quantum-theoretical reasons why you can't do that any faster than the
> real world can? (At least, not without using a computer many times
> bigger than the real-world system it's trying to simulate!)

To perfectly emulate it, we'd need at least one processor per photon, 
able to do all the physics calculations and share Heisenberg-principle 
violating amounts of information with other processors, in real-time.  I 
think Slatibartfast was on the right track!

-- 
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/*        @        */{P(0,a)P(a,b)P(b,c)P(2*a,2*b)P(2*b,b+c)P(b+c,<2,3>)
/*   gmail.com     */}camera{orthographic location<6,1.25,-6>look_at a }

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> OK, really ancient plastics weren't very good. But the plastics I see
> today and the plastics I saw 30 years ago seem pretty much identical in
> every respect. What's changed?

Since Francois mentioned 3M, that reminded me they make lots of 
*plastic* optical films that are used in your mobile phone to improve 
brightness, viewing angle and sunlight readability. Another area that 
has been continuously improving over the last decade and will continue 
to, but which most consumers wouldn't know about.

Or surely you've heard about 3D printers recently? The materials they 
use (the professional ones, not the hobby ones) are state-of-the-art 
polymers to give the final piece properties as close as possible to 
traditional injection moulded plastics. It's not like those materials 
existed 30 years ago.

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