HI version is available. Content is displayed in original English for accuracy.
Advertisement
Advertisement
⚡ Community Insights
Discussion Sentiment
54% Positive
Analyzed from 2170 words in the discussion.
Trending Topics
#don#more#light#night#power#solar#satellite#need#satellites#earth
Discussion (56 Comments)Read Original on HackerNews
Even if you ignoring how much drag these must have, and hence how much electrical power you'd need for an ion drive just to keep them up, each spot being a few km across (and only getting light while the satellite is over your horizon) is just not compelling.
Given most people don't have any reason to illuminate several square kilometres at once, for realistic scenarios it will take a lot of satellites before you beat the cheap battery-powered floodlights in my local Aldi or Kaufland, and the batteries in those lasts a lot longer than the 10-15 or so minutes each of the satellites will be over the horizon, and reflectors like these can only supply sunlight close to sunset otherwise the earth blocks the sun from them.
In the list of things which, if you could make them at all useful, would also be relatively easy to redesign as weapons.
There is a fiction I've read years ago that mentioned satellites becoming makeshift weapons by overheating exposed objects (think reactors, gas trucks, oil refineries) by acting as a solar furnace [1] via mirrors.
Not sure/don't recall how it deals with practical issues such as clouds and distance/intensity, but good enough for a story I guess.
[1]: https://en.wikipedia.org/wiki/Solar_furnace
I thought this was interesting because it doesn’t really seem like an applicable top level claim, surely this is referring to a specific furnace, not all solar furnaces?
Then this got me thinking if there is some universal upper bound constraint to these temperatures. E.g. if I recall a telescope can’t make a source object brighter than it actually is, and this just seems like a thermal telescope, so I wonder if that principle applies here or not.
It applies, but also in practice the maximum temperature is lower than the theoretical upper bound.
https://what-if.xkcd.com/145/
Obviously this satellite isn't viable, but all things start small. Large tracts of land could be illuminated.
But of course, I question the logic of redirecting more sunlight, especially such large amounts, onto a world already warming uncontrollably.
Still, it could be useful for the polar caps on Mars?
These seem like unlikely things though.
My guess is it's probably easier to make a bunch of greenhouses on the surface? But the scale is so huge that which is best will be affected by technology invented after you start.
X Wing: Wedge’s Gamble (1996) by Michael Stackpole shows the rebel alliance using similar tricks during the battle of Coruscant.
I'm far more concerned about the people who own/build stuff like this using it as you suggest (or any of the government pets that they own) than I am about "hackers" doin' such things (although, you're entirely right to have that concern as well, because there's obviously those type of folks out there doin' bad things even with the technology we have already).
see: https://youtu.be/lkjyeI0ykGM
This strikes me as another hand-waved scifi/fantasy inspired investment, where everyone is so caught up in proving they can achieve this (spoiler: this is obviously possible) that no one has stopped to ask does that achievement lead to a real benefit outside of VC wealth transference?
And a satellite isn't going to provide "hours" of extra light unless it's a very much higher orbit than current proposals. At 600 km altitude, you're talking 20-30 minutes even with an unbounded number of satellites (and 10-15 minutes when you've only got a few satellites). Same reason as sunset itself happens: Earth just gets in the way.
If this is somehow an actual problem, it is far more solvable with tethered blimps or drones, battery pack in a container on a truck, a spool of wire, and light banks as big as you want. AND that isn't subject to clouds (but would be subject to high winds, which would also be more likely to cancel/postpone the event than clouds).
Meanwhile, they go beyond the already massive disturbance of existing terrestrial lighting and overwhelmingly screw up the biologically critical light signals used by every plant, insect, animal, and human in the zone, and do it at multi-kilometer scale.
Edit: Even if the revenue potential is actually huge, it is no justification. For any intelligent person, the actual sponsorship message will be "Tonight's lighting brought to you by [Insert_Company_From_Which_I_Will_Never_Buy_Anything_Again]
This level of stupidity is beyond evil — the kind of lunacy to make a good argument that humans should not exist.
I saw a presentation by one of the founders where he talked about several use cases where the benefit is just phenomenal.
They don't fool me for a second, however. The end goal of this is to build a weapon that can fry people/places on demand (but only the bad guys, of course).
The military application would just be illumination.
It sounds too coarse-grade in terms of its area to be anything other than disruptive socially and ecologically.
Sporting and cultural events? Not really (extending the hours of sunlight over a city does have marginal value for a major celebratory event I suppose, but there just aren't that many of these).
Farming? Don't plants need night too? Does harvesting need the sun anymore?
But being able to illuminate a war zone with spontaneous sunlight you can switch off at will, that is a weapon, not least because if you are the only one with the power, your opponents will have to act knowing they may not have the cover of night.
It's not as dangerous as allowing Elon Musk to launch so many more satellites that he ends up with de facto control over access to earth orbit, but it's pretty dangerous.
I think so, but even then it's a heck of a lot of work to make it useful for that.
> Farming? Don't plants need night too? Does harvesting need the sun anymore?
Mostly limited by other things, hence why there's only limited farming in the Sahara, relatively little phytoplankton in the North Atlantic Gyre.
> But being able to illuminate a war zone with spontaneous sunlight you can switch off at will, that is a weapon, not least because if you are the only one with the power, your opponents will have to act knowing they may not have the cover of night.
Even then, nah. Militaries have had night vision for ages. We can make a wall-penetrating radar work as heartbeat/breathing sensor out of kit fairly close to (but not close enough to be a software patch from) a WiFi base station.
I just don't really get it.
And as this is optical, won't go through clouds. This is why beamed power discussions often talk about converting to microwaves instead, though that comes with an even bigger spot size on the ground.
It's not going to be full daylight, is it?
Can everyone just stop with all the LOTR references already why the fuck is this such a thing.
But it is such a shame that it has started to become the brand of dark-side (militaristic/authoritarian) Silicon Valley: Palantir, Anduril, this… Tolkien would be so very sad.
PS: Palantir is at least rather fitting and honest, it’s literally an evil crystal ball (at least the one shown in the movies).
At least, best I can make out over this UI choice: https://imgur.com/gallery/bad-ui-5t0O0SH
(Why, of all the things, would someone use a fire as their example for this? Fire is famously a light source. Also, famously, smoke is a thing that blocks out light from above).