6 ms·
Sadly, the combination of "wide cone" and "detectable from light-years away" implies some fairly prohibitive energy requirements.
by teraflop 5y ago
Sadly, the combination of "wide cone" and "detectable from light-years away" implies some fairly prohibitive energy requirements.
- deleted 5y ago[deleted]
- MerelyMortal 5y agoThat's according to our knowledge and understanding. It may not be the same for a civilization that is advanced enough to send such a probe.
- ajuc 5y agoConservation of energy is pretty fundamental. If we can't rely on that, then there's no point assuming anything at all, certainly not alien intentions.
- chii 5y agoi would imagine intentions could be derived from resource scarcity or abundance. If aliens intend to invade over resources, the cost of such an invasion (from an energy consumption perspective) is so prohibitively high, that harvesting from a closer body seems way more feasible. If aliens intend to invade over not resources, but some other factor, then we cannot guess it. May be there's what amounts to religion and the invasion is a defacto purging or converting of alien species over to their "god". Or to exterminate any possible future competition (aka, darwinianism at the galactic scale).
- ajuc 5y agoHow can you assume resources scarcity if energy isn't conserved? At this point all bets are off. How do we know that traveling closer in the same time takes less energy than traveling further? We can't assume that anymore. And so on. This is my problem with most sci-fi. They take some crazy assumptions and ignore most of the consequences so the world is recognizable. This is like people in ancient Greece hearing that one city in 21st century has more population than the whole world in their time and wondering how we feed our horses :)
- benibela 5y agoOr they needed a lot of paperclips
- sliken 5y agoDunno, take say 1 gram of matter and convert it to energy. Then assume something 100x better than the JWST, add in a few more decades of signal processing, encoding, etc. Add in the possibility of receiving from more than a single solar system. After all some random ham in 2005 set a record of 13M miles per watt. That's in 2005, with an standard radio (elecraft k1) and not any exotic receivers like say something 100-1000x better than the JWST that's I'd expect earth to have over the next few decades, let alone some other civilization that's sending sensors to likely millions of solar systems if they found us. That's only 400kw for a light year, not that much assuming you are slinging sensors into other solar systems.
- teraflop 5y agoWell, the energy requirements for wireless communication go up with the distance squared. So even if you can transmit 13 million miles per watt, that's equivalent to about 200GW for 1 light year.
- sliken 5y agoAssuming omnidirectional transmissions, yes.
- Armisael16 5y agoIf you spread the energy out it will spread in a shape with area proportionate to the square of the distance. You can focus more of that power into a particular area, but the fundamentals here are not particularly negotiable.