
A Norwegian town built a giant mirror to deflect the sun (2017) - happy-go-lucky
http://www.bbc.com/future/story/20170314-the-town-that-built-a-mirror-to-catch-the-sun
======
outside1234
This is sort of off topic, but this valley is pretty famous actually for being
a strategic place in World War II (but not widely known) because it was a
crucial source of heavy water.

If you haven't seen it already, I'd highly recommend the Netflix series "The
Heavy Water War" (trailer:
[https://www.youtube.com/watch?v=_K3Ry2K4yNE](https://www.youtube.com/watch?v=_K3Ry2K4yNE))

~~~
NullPrefix
What's heavy water?

~~~
salty_biscuits
Water with the deuterium isotope of hydrogen, instead of the common isotope of
hydrogen.

------
johnyzee
I'm fascinated by heliostats. Living in an apartment, I have always wanted to
put up 'suncatchers' outside my windows and lead sunlight in through fibre
optics to all the corridors and darker rooms. Something like this [1][2].

[1] [https://www.parans.com/products/parans-luminaire-diffused-
na...](https://www.parans.com/products/parans-luminaire-diffused-natural-
light-with-a-quadrant-touch/)

[2]
[https://en.wikipedia.org/wiki/Light_tube#Optical_fiber](https://en.wikipedia.org/wiki/Light_tube#Optical_fiber)

~~~
bitcurious
Super cool. Have you looked into the price for the parans system? I can't seem
to find it anywhere.

~~~
sfjailbird
Well if you have to ask... it's probably incredibly expensive. The Wikipedia
link list customers as international airports, universities, etc., and calls
it 'quite expensive'. Probably out of reach for private homes.

------
duxup
I grew up on the Great Plains of the US. I remember my first visit to
Switzerland clearly. We get into this town in a valley with these massive
mountains all around. I had this really strong sense of being confined, along
with feeling like the mountains could come tumbling down on me at anytime.

It was strange, but also really odd when it felt like the sun would go down so
early as it crossed behind the mountains.

~~~
wavefunction
I experienced serious anxiety the first time I drove through North Texas (flat
as a pancake), having grown up in Colorado with the mountains ever present. It
was a weird time in my life and... I was coming from Colorado, but I felt like
I was going to slide right off the earth with such a flat horizon surrounding
me.

~~~
dylan604
I grew up in North Texas, and I still feel very weird by how flat it is.

------
jclarkcom
My startup has been working on a virtual skylight that produces a pretty good
proxy for feeling like you are outside in the sun even if you are underground.
The key invention is in collimating a large area light source so it travels in
a straight line and appears to be miles away. We will be showing it at a
conference in Philadelphia next week if anyone is interested.
Https://Innerscene.com/products

~~~
Darthy
Interesting. How do you differentiate yourself from CoeLux, which has been
doing a very similar thing for a few years now?

~~~
jclarkcom
Coelux has a nice product, compared to it ours takes up 14 times less space in
the ceiling for the same viewable area, the sun is at true infinity so you can
create arrays where the sun seamlessly follows you as you walk around, it has
dynamic spectrum and dimmable, price is half, weighs ~10X times less so
structural install shipping is easier/cheaper, more energy efficient,
programmable, just to name a few...

~~~
Darthy
I haven't seen either product in person, but from looking at youtube videos of
both, it seems like CoeLux has a clearly defined, properly round sun, while
with your product, the sun looks fuzzy and cross-shaped, like viewed through a
diffraction grating [1]. Am I correct in this characterization?

[0] [https://youtu.be/EM8psaLBsr8?t=112](https://youtu.be/EM8psaLBsr8?t=112)

[1] [https://youtu.be/_GYpxeum12U?t=138](https://youtu.be/_GYpxeum12U?t=138)

~~~
jclarkcom
Good observation. That is an older video from a prototype - take a look at
this:
[https://www.dropbox.com/s/7dwa7mj39rpely6/facia%20and%20mull...](https://www.dropbox.com/s/7dwa7mj39rpely6/facia%20and%20mullion.mp4?dl=0)

I'd say they are pretty similar, Coelux may be slightly less diffusive but
it's beam divergence angle is pretty high so it doesn't hold up for very much
distance compared to ours - you can see it spreads out into a non-rectangular
shape on the wall.

~~~
Darthy
Fascinating. Is it correct that with both implementations, you cannot move the
virtual sun around - it's always shining from the exact same angle?

~~~
tropo
Likely, but it isn't too hard to imagine how that could be fixed for an even
greater cost. I wonder how the two products work.

I'd probably shine an array of narrow-beam LEDs through a sheet of aerogel.
(the aerogel disperses the blue light) If the LEDs are on long horizontal rods
that can rotate, that lets the angle change. You'd need the beams focused down
to about half a degree, with at least a dozen viewed in a circle of that size
from the perspective of a tall person under the light.

Another way is just an RGB array, with different lenses on the different
colors. The blue gets a fish-eye lens, while the green and red get focused
down to about half a degree. Again there can be rods that rotate, and at least
a dozen LEDs need to be in a circle of half a degree when viewed by a tall
person under the light.

------
el_benhameen
In a sort of related/inverse vein, I thought the engineering at play here was
pretty interesting. 96 million shade balls on a public water supply reservoir:

[https://www.youtube.com/watch?v=uxPdPpi5W4o](https://www.youtube.com/watch?v=uxPdPpi5W4o)

~~~
tenpies
I just find it hilarious that they do this on the tail of wanting to ban
plastic everywhere.

Why yes, please take these black plastic balls, coat them in a known
carcinogen, place them over drinking water, and let them bake over the sun[1].

\---

[1]
[https://en.wikipedia.org/wiki/Shade_balls](https://en.wikipedia.org/wiki/Shade_balls)

~~~
seltzered_
“The shade balls used in the Los Angeles project are made of high-density
polyethylene (HDPE) with carbon black additive to protect the plastic from
ultraviolet radiation. Adding carbon black also prevents the formation of
bromate, a suspected human carcinogen.

[...]

The black coating on the balls, called carbon black, is a petroleum derivative
which is classified as a carcinogen if inhaled as dust. ”

So you have balls made with a known carcinogen (if inhaled as dust) to prevent
formation of another carcinogen formed in water. I’m guessing they researched
the risks already and it’s a net positive.

~~~
chupasaurus
You forgot the part that the color is added in form of a masterbatch.

------
badideaprojects
Rjukan (the town from the article) is also a great destination for ice
climbing. Lots of frozen waterfalls only a stones throw from the road.

Only a couple of hours drive from Oslo.

In case you need an excuse to visit.

~~~
marvin
Also some of Norway's most reasonable real estate prices, with detached homes
starting at less than $100,000.

~~~
okusa
I used Google Translate's camera feature to translate a few estate agent
window ads while I was there and genuinely assumed I must have been looking at
the deposit prices given the price of everything else in Norway.

~~~
marvin
If you were anywhere else, you'd probably see the deposit price and figure it
was the full price of the property :P

Actually, things are not as bad as in Seattle/SF/LA/New York, but modest
things are still very expensive in our cities.

------
joshe
There are home versions of these heliostats too, I always thought it would be
a nice home improvement. You could make a new sunny room, sunnier garden, or a
warmer patio.

Just googling, $2,000 gets you 1300 watts of heat. Or 115,000 lumens. (100
watt incandescent is 1600 lumens). The mirror part is about 4 feet x 4 feet.

[https://lm.solar/order/](https://lm.solar/order/)

~~~
slumos
Really neat. I can see mounting their $300 mirror on my apartment balcony to
extend my “direct” sunlight a couple of hours.

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tobib
It's a neat idea but I wouldn't say "three mirrors, each measuring 17 sq m" is
particularly "giant".

~~~
ducktypegoose
Depends on how you think about it, relative to the mirrors that were there
before they are collosal. I do take humbrence with the author's use of the
word, "deflecting". Sounds like they're trying to divert the Sun's wonderous
glory away from their town. Reflecting is the word, praise the Sun.

~~~
monktastic1
I don't mean to be a grammar Nazi, but by "humbrence with" do you mean
"umbrage at?"

In a neat coincidence "umbrage" and "umbrella" apparently share a common
origin in Latin "umbra" (shade).

~~~
klibertp
Please don't downvote this guy. As a non-native speaker, I learned one nice
word and a bit of trivia about it. It certainly adds to the discussion, as
without the explanation I wouldn't know what the GP wanted to say.

~~~
monktastic1
Thanks for your comment. I was disheartened to see the downvotes. I'm glad it
was of some use to somebody!

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mpweiher
The Italian town of Viganella installed mirrors in 2006 (Rjukan was in 2013).

[https://en.wikipedia.org/wiki/Viganella](https://en.wikipedia.org/wiki/Viganella)

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nxpnsv
I’ve been there. It makes a few m2 in the town square slightly lighter. Neat
but certainly not mind blowing.

------
Udik
On a side note, having lived in a northern city famous for its bad weather
(Dublin) I always wondered why instead of building with dark red bricks they
don't coat the buildings with reflective material. And the sad part is that I
bet it's not done because it's for the benefit of the neighbors on the
opposite side of the street (though of course, it could be reciprocal).

------
cgh
I spent part of my childhood in a similar place in far northern BC. The north-
south orientation of the valley we were in prevented much winter sun from
hitting the town. On top of that, there was an asbestos mine nearby and
sometimes when they were blasting up at the mine site, dust would settle on
the town. Once the mine closed, the town was basically erased and everyone
left.

------
dang
Pretty sure this has had significant discussions on HN in the past, but I
can't find them. Anyone?

(The purpose is just curiosity. Reposts of a story are ok after about a year,
as the FAQ explains:
[https://news.ycombinator.com/newsfaq.html.](https://news.ycombinator.com/newsfaq.html.))

------
edoo
I think China was looking at putting up satellite solar reflectors to avoid
the electrical cost of night time illumination in cities. If that tech gets
cheap enough you could in theory target a town/agriculture like this to give
it an effective latitude shift towards the equator.

~~~
planteen
That doesn't really pass the sniff test... distance to GEO is 36,000 km, the
sun is approx. 0.5 degrees in angular size, that would mean a mirror with a
diameter of 314 km in GEO. We do not have the technology for that.

2 36000 tan(0.25 deg) = 314 km

~~~
edoo
[https://en.businesstimes.cn/articles/104124/20181018/chinese...](https://en.businesstimes.cn/articles/104124/20181018/chinese-
city-chengdu-orbit-massive-solar-mirror-bring-light-night.htm)

------
dhritzkiv
The people congregating in the sun spot in the middle of the town square
remind me of this Portlandia sketch:
[https://www.youtube.com/watch?v=G-ppr9LDaQE](https://www.youtube.com/watch?v=G-ppr9LDaQE)

------
turtlebits
I've always wanted my own heliostat(s) as I think they'd be more useful than
solar panels (at least for me) - sending concentrated sunlight and heat in
through your windows.

But can't find any good design/plans for DIY or anyone selling one.

~~~
jamiek88
[https://lm.solar/order/](https://lm.solar/order/)

I have the vacuum mirror focusing upgrade pack.

Works really well and I roughly calculate that you get 80% of the growing
power from the sun as direct light.

I use it for a part of the garden that never got light due to building and
trees and was always soggy and damp. Nothing grew there very long, now I
maintain native wildflowers and a butterfly garden there.

It’s really cool. The heliostat follows the sun mechanically and also can tune
in the focus with a vacuum system.

~~~
turtlebits
IMO, $2500 seems extremely expensive for focusing 1.45m2 of light, especially
when you can get at least 2.5kW of solar panels for the same price.

~~~
natch
It’s a completely different technology that’s solving a different problem. And
sun tracking is more complex when you are reflecting onto a fixed point as
opposed to simply pointing the surface (in the case of solar cells) toward the
sun.

------
natch
Here’s a cheap home version under development, funded through indiegogo. I was
a backer and am hoping to receive one soon but it’s been a long wait so far:

[https://solenica.com/](https://solenica.com/)

------
isostatic
I hope they don't try to steal candy from any babies!

[https://www.youtube.com/watch?v=a9Ve2pzTp3Q](https://www.youtube.com/watch?v=a9Ve2pzTp3Q)

------
McDev
It's like a giant SAD lamp, only you share it with other people

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anotheryou
They should move it from house to house and make it an occasion to invite the
next neighbors to dinner :)

------
mooneater
Perhaps large, light weight deflecting mirrors in orbit could help with
climate change.

------
kwhitefoot
Reflect not deflect :-)

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correlator
Simpsons did it

------
gpsx
I live in sunny California but I still have problems with not enough sun. I
used to be a cyclist and triathlete, being outside for many hours a week, and
now I am doing maninly dancing. I am inside way more than I used to be. I can
feel when I need more sun. Incedentally, I also had a recent physical where
they measured that I had a vitamin D deficiency.

They said a lot of interesting things in this article related to the sun, so I
leared some new things. At the same time I am surprised about some things they
did not say.

I'm not an authority on the bodies need for sun, but I will give my non-
scientifci observations. If some one finds this interesting they should do
some additional research on the topic before they do anything I did, rather
than just trust what I write here.

One thing that really interested me was an article I saw here on Hacker News a
several months ago. It said it is well known people with higher vitamin D
levels had some health bvenefits. However, one particular study found that
giving vitiamin D supplements did not seem to give the same health benefits.
The authors concluded from their results that people who have high vitamin D
often get this from the sun, and the sun gives them a different result from
just taking vitamin D supplements.

I tried going to a sun tanning salon and found that did make me feel a subtle
"high", as if I had been out on a sunny day. (Your experience may very.) From
what I understand it is UVB that is responsible for this, the "bad" UV. It is
considered bad because your body does not shield against it and it does not
cause you to tan.

General tanning salons want to give you UVA. The expensive machines limit your
UVB exposure, and the cheaper ones give you more UVB (salons often have
different options for beds). You want to go to the cheaper option. I used beds
at tswo salons with 5% and 6% UVB, for reference. They should know the UVA/B
statistics for the machines.

As far as length of time, you don't need to go that long. The point is not to
get a tan necessarily. I found that i would get more tired if I stayed in too
long, so there is sort of an optimal time, for me at least. (I am very pale,
by the way.)

I also noticed that the sun tanning bed was not enough. It is almost as if
there are two effects. I feel good from the tanning salon, but at the same
time it feels like there is something missing. I also need to go outside, I
assume to get visible light.

To repeat above, these are not scientific results. I find this seems to work
for me, and that is good enough. I would not suggest someone trust what I say
here as authoritative, but hopefully it can be an inspiration to look into
this if you have similar problems.

FYI, one thing I want to look into as a result of this article is timing of
getting visible light. I do know that if I wake up in pitch black I have
trouble getting out of bed. I would link to get more bright light in the
morning right when I wake up and see how that effects me.

------
kawfey
*reflect

Deflect means to shield an area from sun; this project is to bring sunlight
into a perpetually shaded area.

~~~
Johnny555
_Deflect (verb) cause (something) to change direction by interposing
something; turn aside from a straight course. "the bullet was deflected
harmlessly into the ceiling"_

~~~
intertextuality
Although you are correct and GP was mistaken in their definition, `reflect`
fits better here.

Definition of reflect

transitive verb 1 : to prevent passage of and cause to change direction

// a mirror reflects light

\---

Definition of deflect

transitive verb : to turn (something) aside especially from a straight course
or fixed direction

// armor that deflects bullets, deflecting a question

\---

With deflect, something is simply being diverted, whereas with reflect, it's
more intentionally being aimed somewhere. This is the nuance I feel innately,
although at this point we're splitting hairs I think.

~~~
Johnny555
_Although you are correct and GP was mistaken in their definition, `reflect`
fits better here._

I don't see why deflect isn't acceptable. Previously the sun was shining on
the hillside below, now it's been deflected to the town square.

~~~
sergioj97
What I understood is just that reflect seems to fit better here, given the
most common use cases for the word.

