I have joked before about the apparent lack of life in the universe, that we are just living in unencrypted 'plain text' mode. But all the developed aliens have moved to encrypted space. ;)
This rough idea is the basis of A Fire Upon the Deep by Vernor Vinge. It has this idea of "zones of thought" where there's basically a speed limit on the speed of thought and advanced civilizations move up into the higher zone with a faster limit. It's an incredible book and well worth the read.
It's one of my favorite books. For those of us that came of age during the golden age of Usenet, there are a ton of jokes related to the communication throughout the galaxy. Because communication is so slow, it resembles Usenet, with it's relays, etc.
The AI stuff in the book is also really interesting.
Also, let's not forget that Vinge coined the term singularity.
Humans have went dark considerably over the years. I don't know the exact date when encrypted comms became the norm, but we rarely transmit plaintext out into the Universe anymore. We still leak plaintext, but the vast majority is encrypted now.
Compression is also of interest. A well-compressed file should resemble noise: if you can predict the next bit, you could have avoided sending it. As we've moved to digital formats, there's an increasing opportunity to save bandwidth through compression, making the 'plaintext' much less readable. You could theoretically backwards-engineer the mp3 format by seeing enough examples, but it's a harder problem than, say, playing back a record that someone velcro'ed onto the side of a space probe.
Both switched to digital broadcast format years ago. Looks like FM might be simulcast. And I am definitely not an expert so I can’t speak to the contents but I would assume encoded but not encrypted.
Naively, I guess that non-digital signal decoding is trivial compared to digital signal decoding where the signal might be indistinguishable from encryption without a reference spec or unencoded sample.
We have people smart enough to crack all kinds of signal encodings and actual attempts at encryption, and we're probably not even that advanced of a civilization. Also, I'm not an expert in EM signalling or whatever the field is called, but I understand that most physical encodings actually have a lot of structure that distinguishes them from random. I know for sure that plaintext signals tend to have a LOT of structure unless they're compressed, and that structure will be reflected to some extent in the physical encoding unless you take measures to stop it.
Meanwhile the usual standard for encryption is "indistinguishable from random"... which kinda just doesn't make sense at the physical level. I'd be very interested to know if anyone has figured out how to do physical encoding/encryption that's indistinguishable from physical noise.
I agree with most of what you’re saying but my thought was that digital broadcast signals are compressed and multiplexed so they’re likely to be much more complicated than analog FM transmissions. I think they also broadcast to equivalent range at lower power, so I assume they have checksum bits in the stream so the decoder can reconstruct or reject a weak or intermittent signal. Then, if an entity trying to decode the signal had no framework for human communication the difficulty would be significantly higher because it would need to approach the data using a pure information-theoretical approach. Meanwhile I can (theoretically :)) build a crystal radio that “decodes“ analog FM in an afternoon.
I suppose the shift into the other space would be motivated by shifting to a different set of physical laws? Maybe our 'plaintext' program ("machine code") actually is the underlying instructions for the "encrypted space".
> Dark matter is the mysterious, unknown substance that seems to make up the bulk of all the mass in the universe; for every 2 pounds (1 kilogram) of regular matter, there's roughly 10 pounds (5 kg) of dark matter.
The units here are pretty silly. They are only talking about proportions, so they could have gone with banana-equivalents, and it would still have worked.
The bananas you can buy in the West are all clones of each other. Their mass distribution is tight enough that it wouldn't make much of a difference given that the numbers in the article are only very approximate to begin with.
In any case, my point in the comment was that the unit is arbitrary, they are only talking about ratios. So any unit (or no unit at all) would do.
They could have just said "5 times as much" to save us the bother of doing the calculation ... which needs a tiny bit of care because of the dual units.
The calculation involves dividing 5 by 1; most people should be able to handle it.
Note that they've correctly not bothered with providing equivalent quantities in each unit - 5 kilograms is 11 pounds, not 10 pounds. This doesn't matter, because the ratio 10 to 2 is equal to the ratio 5 to 1.
But it does raise the question of why they provide pounds at all, and if they're going to, why not just say "for every pound (or kilogram) of matter, there are roughly 5 pounds (or kilograms) of dark matter".
> why not just say "for every pound (or kilogram) of matter, there are roughly 5 pounds (or kilograms) of dark matter".
Your suggestion is better writing. As for why? Likely the author and editors rushed the content or lack strong skills in this particular style of writing. The author Paul Sutter seems to have a strong background in writing. The original sentence is awkward enough that it looks like it was written by one person and edited by another.
> Dark matter is the mysterious, unknown substance that seems to make up the bulk of all the mass in the universe; for every 2 pounds (1 kilogram) of regular matter, there's roughly 10 pounds (5 kg) of dark matter.
If I had to guess, I bet it only originally had one set of units and an editor added converted units to match some style guide. I doubt that Paul would have originally gone with
> for every 2 pounds of regular matter, there's roughly 10 pounds of dark matter.
Because 2:10 ratio is not a natural thing to write. He's an astrophysicist who did post-doc fellowships in Paris and Italy, so most likely he submitted an article with SI units:
> for every 1 kilogram of regular matter, there's roughly 5 kilograms of dark matter.
And I bet a livescience.com editor changed that to pounds to match a US-centric style guide.
My favorite works to date regarding a mirror universe answering cosmology open questions is the stuff Neil Turok's been spitting out over the last decade:
Along similar lines, I've been wondering (I am not a professional) about what would happen if charge wasn't always conserved. What would violating that symmetry do? If such a bias was in one direction, like the matter-antimatter near-symmetry appears to be, what would the universe look like if there was a small non-zero charge density everywhere that couldn't be fully cancelled out?
Alas, my understanding of physics is only enough to look like a kook, which almost entirely prevents serious answers from people capable of providing them.
I'm not smart enough to say more than this, but it'd be interesting to see what Noethers theorm would imply about a universe with no conservation of charge.
> Remember that voltage is always expressed as a "potential difference." You can't measure the absolute value of voltage because everything is invariant when you add a constant voltage everywhere. That expresses a symmetry just like time translation invariance.
> When you bring in the magnetic field this invariance or symmetry can be generalised to a bigger gauge invariance transforming the electromagnetic potential as a vector field. Charge particles are also described by fields such as Dirac spinors, which are multiplied by a phase factor under the action of this symmetry, making it a U(1) invariance. Electric charge is the conserved quantity that Noether's theorem gives for this symmetry.
It sounds like violating this would mean that there was an observable difference between "zero electrical potential" and "nonzero electrical potential".
Temperature is another quantity that is usually measured solely in terms of the difference between two states, but -- apparently unlike electrical gauge -- in that case there is an absolute zero point which is distinguishable from other points.
It might be interesting to ask what would be conserved, but isn't now, if there were a temperature invariance analogous to gauge invariance.
Without symmetry, such as in conservation of momentum, you’d be able to create and destroy energy arbitrarily. Maybe like magic? Let’s say there were no proton/electron charge symmetry. That could mean atoms would be unstable. Maybe do some imagineering from this point!
I’ve wondered what it would take to be able to create energy arbitrarily. Gravity and mass and light seem to be suss in that context. I’ve been having a laugh to myself about the aether, a comment in here mentions Hinduism also. But if there’s some big goo of stuff, then could it be that the ‘perfection of the universe’ (sorry I know that’s a loaded phrase but chill) is what can emerge into reality from that goo?
If there wasn’t symmetry or whatever, then it couldn’t get to us. Kind of like the atoms that make us would have remained as mud instead of standing up and looking around?
As someone else says encrypted vs plain space. Figure out some suss things like what’s going on with light and some kind of arbitrary infinity awaits? And those things are suss because they’re operating at the interface/affected by both ‘worlds’, like flying around in atmosphere; suddenly there’s sound barriers and what not. Which is why (I think) we scratch our heads and wonder like, what’s the deal with electrons?
> A special combination of physics led to a proton having roughly the same mass as a neutron; perhaps in the dark matter mirror, that combination of physics played out differently, causing the "dark proton" to evaporate and leave behind a sea of "dark neutrons" — what we identify as dark matter.
I don't think I misread the article. Currently we expect dark matter to be neutral. So if we assume the statement is correct, what would then happen to the positrons and it's charge?
This is the same website that publishes stories with ignorant, idiotic headlines like "There's an asteroid out there worth $100,000 quadrillion. Why haven't we mined it?". Um, don't write about economics if you don't understand it.
Doesn't HN have a policy mandating original sources?
That headline sounds like it could start a really interesting discussion on economics, actually. Of course, worth is meaningless when you get to quantities that large. But there are costs, and benefits, of mining it. And analyzing weird interactions and schools of thought from classical economics on those would be super interesting
thats the most surface level, obvious concequence. Thats why I said " worth is meaningless when you get to quantities that large." But how much? how much would it have to drop to make the cost of launching too high, when it might give you monopoly power over the supply of an entire fundamental chemical element. How much would you be able to exploit that monopoly ? political consequences?
even outside of anticompetetive practices, When the price of a fundamental good drops like that, new industries and new uses become viable. Sometimes the market then grows to the point that you make more money than you might expect
There are non-mainstream explanations for how what keeps the universe going that have a much simpler model and a much better track record on predictability. There are six prevailing different incompatible theories for black holes and if you ask someone which of the six theories they are talking about when they insist that black holes do exist it's very rare that they will be able to tell you which.
"The invisible substance called dark matter remains one of the biggest mysteries in cosmology."
Gee I wonder why. Maybe it's because your goofy dark matter model is so broken you're borderline just making s** up.
"Dark matter is the mysterious, unknown substance that seems to make up the bulk of all the mass in the universe; for every 2 pounds (1 kilogram) of regular matter, there's roughly 10 pounds (5 kg) of dark matter."
...
"This symmetry would help explain why dark matter and regular matter have roughly the same abundances."
So 1 is "roughly the same" as 5, or is this an orders-of-magnitude comparison?
It seems that yes, they're saying that 1 and 5 are roughly the same. Basically, why is the matter in the universe ~20% "non-dark", and not 1%, or .001%?
There’s that old joke that computer scientists think any numbers within a power of two are equal, physicists think any numbers within a power of 10 are equal, and mathematicians only distinguish between finite numbers and infinity.
Edit: and engineers are as precise as they are paid to be.
Having proved the contribution of these second and third order terms are between plus 10 and 20% over the range of interest we will multiply by a constant 1.15
> Mathematically, the 80/20 rule is roughly described by a power law distribution (also known as a Pareto distribution) for a particular set of parameters. Many natural phenomena distribute according to power law statistics. It is an adage of business management that "80% of sales come from 20% of clients." [1][2]
Could you elaborate on how this is related? To me, the 80/20 rule and the 1:5 matter ratio seem like entirely separate concepts that coincidentally share the same ratio.
Though really the issue with the comparison is that it implies that 80% (or ~83.3%) of the <something> is correlated to the light matter, and the other 20% (or ~16.7%) of the <something> is correlated to the dark matter. Maybe eventually we'll learn enough about dark matter and discover that, yeah actually, 1/6 of the life, or unobtanium, or whatever, is actually in the dark matter. But for now, I agree that the Pareto principle seems pretty irrelevant.
Since no one knows what dark matter is, there's no known connection between it and real matter, so 1:5 seems coincidental if it's free to be anything within the range 0 .. infinity. But there's no reason to think there is or isn't any connection, since nobody knows what it is.
Cosmology error bars can be very big, depending on the measurement. 500% difference is certainly bigger than some, but since the vacuum energy density appears to differ by a factor of 10^60 from prediction, it's not necessarily a show stopper. Arguably the biggest discovery in cosmology in the last few decades is how much we do not understand at all.
In astronomy and cosmology, 1 and 5 are the same number. Only the orders of magnitude matter when talking about large things. At atomic scales and in photon length the precise numbers do matter.
> In astronomy and cosmology, 1 and 5 are the same number. Only the orders of magnitude matter when talking about large things. At atomic scales and in photon length the precise numbers do matter.
"I am not interested in a more accurate value." said no scientist ever.
It's just easier to measure small things using big tools than to measure big things using small tools, hence astronomy has a disadvantage. Another one is that it isn't easy to create any experiments.
Well, I would say social sciences arent exact, economics might be a hard science of rules, but the outcomes are subject to too many factors to predict precisely, but it is still a science. Though, well, I am not really qualified to speak on such things, but I would imagine we are fairly precise in the field you guys are talking about.
Thats kind of what I said, the rules are hard, supply and demand, time preference, marginal utility, those are forces that cant be argued with, but it doesnt mean they have precise predictive power.
Every scientist is painfully aware that their field of science is “wrong”. That’s why they are employed. It’s just the least wrong thing anyone has thought of yet.
Unrelated, but somewhat interesting in Hindu cosmology and ancient scriptures the edges of the bubble of the universe store everything happening, that has happened and is to happen.
Same in actual cosmology, it is called the holographic principle. The concept is that 3D bodies can be losslessly represented on a distant 2D plane which envelops them or alongside the spherical perimeter of a black hole if they are squished to it
It is not all that applicable, but it is interesting to think about and there are people studying it
Only spiritual beings on other planetary systems can, who have "siddhi" (powers beyond mundane earthly humans). The message of the Gita however is tapping into all of this is a waste of time as you want to escape from it (moksha/salvation/liberation)
The idea of metaphysics isn't foreign to science, as I see. Once the science acknowledges that 90% of our universe is invisible something, and that something has a structure, it's one step from the hypothesis that there are lifeforms in that "dark mirror" universe.
At least the abstract says some experimental verification is possible. When physicists start proposing innumerable parallel universes that can never be proven nor falsified, they may as well be proposing a religion.
