5 ms·
A Dyson sphere is just as much fantasy as physics, true of most of today's technology just 50 years ago. Solar and wind are needed today, but Starship could br
by gibolt 4y ago
A Dyson sphere is just as much fantasy as physics, true of most of today's technology just 50 years ago.
Solar and wind are needed today, but Starship could bring launch costs down enough that some highly optimized space solar panels with microwave power beaming could be viable within a decade.
- paulsutter 4y agoHow would capturing the beamed energy on earth be any easier than capturing sunlight directly? Maybe illuminate existing solar arrays during nighttime? Any other energy receiver would be so far behind PV on the price / manufacturing learning curve
- lovemenot 4y ago>> Maybe illuminate existing solar arrays during nighttime? I never thought about this. Is there some orbit where this becomes feasible?
- zardo 4y agoA sun synchronous orbit above the terminator would do it.
- gibolt 4y agoMain benefit is avoiding transmission losses through our atmosphere. Capturing the signal is easy (we have satellite communication already)
- Cthulhu_ 4y agoI believe the solar panel part, but not on the microwave power beaming; has that been proven to work already? How efficient is it? What is the effect on anything flying through or being near where said microwaves are received? Solar panels in space is the believable part; rays of concentrated energy being sent back to earth is what I'm skeptical about. Besides, solar panels have a limited lifetime; I don't believe space solar panels are a cost effective solution to solving the energy crisis.
- Tade0 4y agoThis idea keeps being brought up and people keep reminding everyone that for all intents and purposes this is the closest to a cartoon supervillain death ray that we can create.
- Aeolun 4y agoI think the important point is that we’re reasonably certain we can create it.
- taneq 4y agoYes but could we please not? Orbital death rays for power generation seem like a bad idea when we have options like rooftop solar and wind turbines.
- vegetablepotpie 4y agoRight, but what do we do when we’ve covered every surface of the earth with solar panels and wind turbines? We’ll need to move into space sooner or later if we want to continue exponential growth.
- taneq 4y agoWe'll just have to clear some area, I suggest the quickest way would be with the giant orbital heat beam! :D (100% agree that getting into space is important, and that if we want to continue exponential growth we'll need more than one planet. In fact, we'll need more than all the planets and we fairly rapidly (in cosmic terms) hit the point where the available volume of our light cone isn't enough. Maybe indefinite exponential growth isn't something we should feel entitled to...)
- gibolt 4y agoWe're nowhere close to that. Covering all land in solar would be ~100x our current energy needs, and then we still have ocean (most of the surface) available.
- vbezhenar 4y agoReceiving energy that was not supposed for earth will increase planet heat output (because electricity in the end will heat things). Who knows how that would affect the planet. The only way to preserve the Earth is smart planning, reducing energy usage and moving industry to the space. IMO Earth should be sanctuary for people to enjoy their origins and for some rich people inevitably. Most people should move to other planets or space objects where pollution does not matter.
- joebob42 4y agoWhy would we build a solar panel that has a microwave emitter instead of just building a mirror?
- aaronblohowiak 4y agoIs our atmosphere more or less transparent to some parts of the frequency spectrum than others? Is the diffusion different?
- gibolt 4y agoThis is the point. High energy needs to be transferred in a narrow beam, and be minimally impacted by all layers of our atmosphere
- wcoenen 4y ago> Is our atmosphere more or less transparent to some parts of the frequency spectrum than others? Yes. The frequencies that are not blocked are called "atmospheric windows". And there is indeed such a window for microwaves. These windows also exist for visible light and a range of IR, but those depend more on weather conditions. https://glossary.ametsoc.org/wiki/Atmospheric_window https://glossary.ametsoc.org/wiki/Atmospheric_window