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It's funny to have to think about cosmic variance with regards to an RNG.
Love to read someone analyze the feasibility of satellite based attacks on this rng
A discretely hovering UAV/drone would be cheaper and more targetable.
Why use satellites when you can use Microwave Oven Leaks?
This is absolutely awesome. We've been discussing this idea for quite some time at out blocckhain devshop.

Combining the CMB Radiation with an accurate measure of redshift you could create an accurate and immutable way of measuring time, essentially a new type of Proof of Work without the work.

This sounds interesting, however I don't think I fully understand how those two things would create a way of measuring time.

Could you expand a bit on this?

Assuming I'm on the same, erm, wavelength, one could extrapolate the passage of time as a function of cosmic radiation since any observation into deep space is also an observation of time (a planet one light-year away looks to us today as it did one year ago).

I think it's a fascinating premise. We don't really know what time is, and if we never figure it out and how to control it, all of existence will vanish when entropy gets the last laugh. That is, if human conflicts don't do us in first...

Bitcoin is effectively an oracle service. It creates a random state which is dependent on a previous random state. Generating the state is NP hard, verifying it is P (can be verified in polynomial time). The oracle output state is used for sequencing state (meaning the blocks and who gets to sign off on the latest block). So POW is an independently verifiable method of sequencing state among unknown signing members (i.e. the miners).

The Microwave Background Radiation is a perfect candidate for both NP state as well as universal (really, anywhere in the universe!) time keeping. It is NP hard to "generate" the state which will be observed at a certain time in the future, but immediately verifiable as long as you are online to observe it at that time.

That said, it does not solve the "problem" of deciding on who creates the next block in a truly distributed system, it only makes immutability of state possible.

At our devshop we have come to the conclusion that current "blockchain" implementations are practically useless in the real world. There are several reasons for that, the main one being that it makes zero sense for state transition to happen outside of the state machine which created that piece of information in the first place. An example of such a wrong implementation would be Ripple, where IOUs are being state transitioned by nodes who do not issue the IOUs in the first place. It's like tracking IOUs on a huge Google spreadsheet, it makes no sense. All state should be stored and state transitioned on it's own blockchain because the finality of the transition depends on the issuer anyways, and the blockchains need a common input/output based protocol for reconciling, sequencing, and verifying each other's state.

The future is a bit like adding Git to a database and adding a cryptographic reconciliation protocol so the databases can talk to one another.

Very nice explanation. Thanks a lot!

So if I understand correctly this would be somewhat akin to having a "universal clock" that is ever increasing, and that can be read/seen by anyone (like you said, universally). So you only need to know the "time" on the clock, when you do something, so that afterwards you can verify that indeed the "timestamp" happened.

Is this somewhat of a correct analogy? At least that's how I understood it.

In any case, it does seem interesting to be able to have a universally verifiable time keeping "signal". I'm guessing there must be other uses as well.

> So if I understand correctly this would be somewhat akin to having a "universal clock" that is ever increasing, and that can be read/seen by anyone (like you said, universally). So you only need to know the "time" on the clock, when you do something, so that afterwards you can verify that indeed the "timestamp" happened.

As long as you where online during that time, or as long as you trust a third party to record the CMB radiation for you, yes.

The really cool thing is that this wold apply not just anywhere in the universe, but because nothing travels faster than light any communication being done between blockchains between planets would always be in sync. The CMB Radiation simply reaches the other planet at the same time the communication does.

Can you elaborate on how this could replace proof-of-work in a blockchain context? Certainly I can use records of astronomical observations to prove a message was sent after a certain date, but the double-spend risk is mainly mitigated by the ability to prove that a message was sent before a certain date.
What if CMB is not random? Time to break out the idea pad for planning my next science fiction story.
It's been done to an extent - a flashed message in the CMB appeared in Three Body Problem, here's the excerpt http://www.tor.com/2014/09/23/the-three-body-problem-the-uni...
Stargate Universe (small spoiler alert) was also investigating a message in the CMB before it was canceled.
That's a very captivating story!

I want more...

On my list!! It's the Nebula winner so I've heard of it but still on hold at the library! Thanks for the mention!
This time "awesome" really applies.
What advantage does this technique have over measuring radioactive atoms?
Very interesting. Atmospherics might also be useful as an RNG or possibly a trustworthy public randomness beacon.

"There are an average of 45 lightning flashes per second around the world. [...] The radio signature (like a fingerprint) of a lightning strike can be detected around the world [...] [R]eceiving ELF/VLF waves allows us to determine the exact location of most lightning strikes on the whole planet, with just a small number of ELF/VLF receivers [...]"

http://vlf.stanford.edu/research/introduction-vlf

http://vlf.stanford.edu/research/global-lightning-geo-locati...

There's a great project blitzortung.org that I think uses that technology to create a real time map of lightnings.
Based on Penrose's work there may be non randomness in the CMB, with better imaging tech we may find that this is not a good source of randomness: http://arxiv.org/pdf/1302.5162v1.pdf
This is mainly Gurzadyan's work, and it shows such a complete lack of understanding for basic statistical analysis it's not even funny. They basically assume that if you have an i.i.d. random vector x, then a linearly transformed vector z = Q x, with Q some linear map, should also have coeffients without correlations.

For a start look here: http://arxiv.org/abs/1105.5051 -- beyond explaining the fallacies it has references to 3 independent analyses that failed to reproduce the result on the same data set.

The only interesting discussion to be had here is one about journals and peer review practices (i.e., how A&A could let something like this slip through).

That said, the randomness (or nature of randomness) in the CMB is actively researched (such a how close the random signal is to Gaussian). And anything you think is "CMB" run the risk of being foregrounds or systematics which would not be "random" in one sense.