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This kind of thing could replace some uses of blockchain. The pattern of clouds on earth every day is unique, so anything that needs a timestamp with 1-day reso
by dreamcompiler 8y ago
This kind of thing could replace some uses of blockchain. The pattern of clouds on earth every day is unique, so anything that needs a timestamp with 1-day resolution could just tie it to a hash of today's cloud image pixels gathered from many receivers around the world, each taken at noon from the POV of a given geostationary satellite. That way one could prove that an event took place no earlier than today, especially if you hash each cloud photo with the hash of the one from the day before, which creates a cloudchain. The chain's ordering is verifiable from multiple sources and created wholly external from any human agency or pseudo-random number generator.
Speaking of which, you could also use the pixels (or some permutation of them) as a random number seed that changed every day.
- mehrdadn 8y agoSo essentially instead of hash-based computer proof of work, you're suggesting looking at cloud patterns (say, as the sun's proof of work)? Sounds like a great way to save energy, if we can ensure image authenticity/integrity.
- dreamcompiler 8y agoThe vulnerability is the one satellite everybody is looking at. But that could be mitigated by having a network of ground stations looking up and asking "is it cloudy overhead?" With enough of these sample points scattered around the planet and correlated with the satellite's imagery, one could make hacking the satellite impractical.
- atoav 8y agoWhy not taking the clouds of Jupiter? Then you could use telescopes and multiple satellites alike because that far away parallax shouldn’t change a lot.
- dreamcompiler 8y agoJupiter's not always visible from Earth (sometimes it's behind the Sun). Earth is always visible from a geo sat (provided the satellite is working).
- atoav 8y agoLet's use the sun then :)
- saagarjha 8y ago> you could also use the pixels (or some permutation of them) as a random number seed that changed every day Except that would make your PRNG easy to guess, since this data is publicly available to everyone?
- dreamcompiler 8y agoIt wouldn't be useful for crypto (except maybe as a salt?) but it might be useful for repeatable random simulations.
- Erlich_Bachman 8y agoRepeatable random simlations that cannot for some reason just check the date and use the date (and some salt) for the RND seed? What simulations are we talking about here? Must be some obscure things?
- dreamcompiler 8y agoYeah I'm still trying to think of a good example for that.
- bdamm 8y agoThat's the point, it proves the day. I think there's still a challenge to solve which is mapping the points from which to construct the hash, because you need a low enough quality to agree on pixels but a high enough quality to get enough entropy to be strong as an time consensus authentication source.
- baddox 8y agoIs it any better than any other source of random or extremely difficult to predict data? Seems like you could just use data from the stock market or some radio antennas or telescopes.
- dreamcompiler 8y agoThe stock market is human-generated so somebody with enough money could nudge it in one direction or another. Radio antennas or telescopes could work too; I'm just not aware of anything they see that meets some definition of "random" except for maybe the surface of the sun, and the pattern of clouds on the earth.
- atoav 8y agoHow about clouds on another planet? Makes manipulation even harder and easier to observe from earth itself
- ttsda 8y agoIt's actually quite difficult to observe clouds on other planets from earth (or earth orbit) due to resolution limits of the combination of reasonably-sized telescopes and usable wavelengths.
- dreamcompiler 8y agoVenusian clouds are easy to see with earth-based telescopes. Problems: There's not a lot of variation -- it's solid cloud cover. And Venus has phases and we never see it as a 100% disc (the Sun is in the way).
- mkagenius 8y ago> with enough money could nudge it in one direction can only do for a limited period of time, no one can control the graph tick-by-tick for the whole day.
- akira2501 8y ago> Radio antennas or telescopes could work too Antennas are vulnerable to noise, anyone with enough effective radiated power placed near enough to it can nudge it one direction or another. > except for maybe the surface of the sun Perhaps, but overall the Sun follows 22-year cycles. [1] [1]: https://en.wikipedia.org/wiki/Solar_cycle https://en.wikipedia.org/wiki/Solar_cycle
- sbr464 8y agoTo your point of randomness, I always thought the cloudflare lava lamps were pretty interesting: https://blog.cloudflare.com/lavarand-in-production-the-nitty-gritty-technical-details/ https://blog.cloudflare.com/lavarand-in-production-the-nitty...
- dredmorbius 8y agoPressaged by SGI's LavaRnd: https://web.archive.org/web/19971210213248/http://lavarand.sgi.com/ https://web.archive.org/web/19971210213248/http://lavarand.s... https://en.wikipedia.org/wiki/Lavarand https://en.wikipedia.org/wiki/Lavarand https://www.wired.com/2003/08/random/ https://www.wired.com/2003/08/random/
- sbr464 8y agoTruly nothing new under the sun. I salute you, thx for sharing.
- mkagenius 8y agoCoincidentally I used weather information to generate a random number, I used {{PollenCount}}{{LowTempCelsius}}{{HighTempCelsius}}{{WindSpeedKph}}{{Humidity}}{{UvIndex}}{{SunriseAt}} I know this would collide eventually but hey its just a hack for my IFTTT applet [1] 1. https://imgur.com/y0PPH7E https://imgur.com/y0PPH7E
- mgamache 8y agoJust add a monotonically increasing number (like milliseconds from the big bang) that will eliminate the collision, but not add much entropy.
- mkagenius 8y agoTrue in general. But this IFTTT platform has some limited supply of types of placeholders, we are not allowed to insert arbitrary numbers.
- 420codebro 8y agoRelativity, bruh?
- alex_young 8y agoJust use any CCD with the gain turned up. People have been doing this for a long time :) http://www.lavarnd.org/lavarnd.html http://www.lavarnd.org/lavarnd.html
- eru 8y agoBlockchain timestamping are often more concerned with establishing that things happened no later than today. The bitcoin genesis block (https://en.bitcoin.it/wiki/Genesis_block https://en.bitcoin.it/wiki/Genesis_block) included a quote from the Times. The Times 03/Jan/2009 Chancellor on brink of second bailout for banks
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- Rexxar 8y ago> That way one could prove that an event took place no earlier than today I probably miss something, what prevent you from taking a old event and tag it with today hash ?
- dreamcompiler 8y agoIt would only work where there was no motivation to show an event happened earlier than it did, but rather as late as possible. Such as the proverbial kidnap photo where the victim is holding a copy of today's newspaper.
- jacobush 8y agoIf someone else also tagged the event, you can’t.
- nialv7 8y agoDo things this way creates a single point of failure (the weather satellite), which is one of the thing cryptocurrencies try to avoid.