To anyone thinking that 18m² isn't that big for how large the space is, please recall how bright reflective things shine during the day when you hit the right angle.

18x18 is 324m^2

To give an easy visualization for most people (average Americans, really, because most other people in the world already know what a meter looks like), imagine that the average doorknob is about 1m above the floor, so imagine basically the bottom part of a typical interior door is about 1m sq. Now, make a square out of 18 of those pieces wide by 18 pieces high.

Americans will measure with anything but the metric system.

And if they do, they will call it things like "square doorknob".

Except for those few of us who grew up interested in science, because science pretty much world-wide (even in the USA) uses metric for pretty near everything. I've used metric for my entire life, and been ridiculed for it that entire time by all the same morons that think any interest in science makes you a "nerd" even if you also happen to play and enjoy sports (despite almost the entire rest of the world standardizing on metric long ago), and despite the fact that most folks in the USA are already using metric themselves every single day. Yet somehow metric is "too hard to learn, waaah!" (It's based on tens, just like our money. Too complicated? Gimme a break!) Hell, our sugary fizzy drinks even all come in 1 and 2 liter bottles, FFS!

I feel "about a 8 floor building" would be a good ROM :)

At that level of specificity, you could just say that a meter is "about a yard".

So very roughly a 300kW spotlight pointed at a relatively small area (wild guess at around 1km^2, anyone done the maths?)

Edit: A 5km diameter spot illuminated from 600km altitude.

For Americans: this is roughly 3500 sqft.

Whoops, I overcooked my last minute edits while almost asleep. Yeah, I'm was off by 18x there.

Every colleagues watch face.

A gigantic source of light in the sky that lights up a part of the Earth and is too bright to look at is... the sun. I think we're all used to the sun.

I personally am _not_ used to seeing the sun after sunset and before sunrise.

Neither is nature, this sounds like an environmental disaster waiting to happen

Solar panels aren't nature. Shining lights on solar panels is not going to be an environmental disaster.

considering plants grow just fine with grow lights, they don't really care. same with co2, they LOVE CO2

> they LOVE CO2

Plants can absorb some more CO2 and it improves their growth slightly but saying they LOVE CO2 is an exaggeration.

They turn it into sugar, what's not to love?

Nature is more than just plants.

everyone’s seen ads before, mind if I put a giant ad in the sky for everyone to look at?

Don't give these ghouls ideas.

The idea of putting a PepsiCo or Coca-Cola ad on the moon dates backs to the 60's, when we first went there.

If one person owned the sun and could charge all humanity for access to its light then maybe that would be a relevant example

What do you think is being proposed, exactly? Some sort of alternative sun that's going to shine on the entire earth, that we'll all be forced to look at?

No. I used a rhetorical device to highlight a theoretical monopoly we assume would never exist. But imagine I launch a space sail that can cast a shadow on any part of earth I chose. I could block or unblock sunlight at will and grant access only for paying customers.

Is that something that should be permitted?

Wut? This has to be some sort of a scam. There's no way you're going to be reflecting enough light from hundreds of kilometers away.

I really hope it's a scam, because if not, and this is allowed to exist, we're fucked.

oh dear, the stakes are so high

It's not. USSR and Russia experimented with space mirrors and was able to light significant territory. It was a successful program, but in 1993 Russia had no money to continue the project, so it was wrapped up.

It works fantastically well for construction and military applications.

Based on what? You get the light of the moon for about 5 minutes.

I’m pretty sure the plan is to have tens of thousands of them so that they can hand off from one satellite to the next. I know this tech would have been fantastic when I used to work on oil rigs in super remote locations.

It still would only work close to sunrise or sunset. You cannot get hours of extra light this way.

Oh wow, that would pretty limiting. Thank you for that heads up!

I see that from the 400 miles altitude they filed with the FCC, you'd expect them to be able to provide maybe an extra 2 hours before + after sunrise/sunset near the equator. However, that appears to improve to almost 4 hours at 50 degrees latitude - assuming 30 degrees of elevation is sufficient for the light to not get too scattered through the atmosphere. If you assume a much more conservative 60 degree elevation requirement then it would be 3 hours before+after sunrise/sunset at 50 degrees latitude.

It also depends on the season, but this has a much smaller effect than latitude.

Shortening the night by a combined 6-8 hours might be quite useful for operations in Ukraine which occur near 50 degrees latitude.

That's really not correct. Do yoi work there or something? The whole thing is an obvious scam. None of what you say is realistically possible in practice.

I think this needs to be addressed with a crowd-funded projectile. This sort of stuff must be done on a planetary-scale consensus basis only.

What a terrible tyranny of the majority problem that would be. I reject this idea completely

> planetary-scale consensus basis

What a terrifying thought. My dad was in Bangladesh when Americans landed a man on the moon. The man next to him said he couldn’t believe the Americans had punched through the dome of the sky. You want to achieve a consensus with them?

> You'll be sad to know there's another mf trying to put a mirror to reflect sunlight near twilight

This has been approved:

* https://ca.pcmag.com/networking/16760/fcc-approves-reflect-o...

* https://news.ycombinator.com/item?id=48866452