i guess if you had some super crazy distant probe observing the black home and it’s memory bits were quantum entangled with a receiver device near us, we might know instantly-ish? but would need to wait millions of years for that probe to be placed to begin with and hope the systems don’t corrode or corrupt or fail in those millions of years. and what would you do with the info? tell everyone?
I thought FTL communication is just a fun typical science fiction understanding of quantum entanglement.
I thought we would still have to know what is going on at the probe via another means to know or decode the message sent by the entangled particles to their counterparts on Earth.
Kind of like putting two letters in two envelopes but we don’t know what colour they are, just that they will always be opposite colours. Even the person arranging them doesn’t know which colour they are. We don’t know if a red letter is sent to London or a green one is sent to LA or what colour they’ll be at all. But when we open the letter in London and see that it’s the red one we know the other one in LA is green.
So no matter where or when the person with the red letter is, they’ll always know the other person has the green one once they open the letter. But no information has been mysteriously transported across space and time, just the correlation between the two has been discovered.
This is correct. FTL communication using any form of quantum entanglement is provably mathematically impossible by the no-communication theorem. Most common sci-fi trope though.
How did I completely miss this, the video linked in another comment does a decent job of explaining. Is there anything like this currently going on for other research elsewhere? Would love to get involved.
EDIT: changed encryption / decryption to signing / veryfing. Thanks for the corrections
Not an expert, those who know more please correct me.
From what I understand, what they post is not a PGP key, but the same content published in clear text signed with their private key. That way anyone can verify it with the author’s public key to check it has been generated with the private one (that only one person should have).
In a digital signature system, a sender can use a private key together with a message to create a signature. Anyone with the corresponding public key can verify whether the signature matches the message, but a forger who does not know the private key cannot find any message/signature pair that will pass verification with the public key
You’re not though. You said encryption occurs with the public key and decryption occurs with the private. That’s the opposite of what happens and what the quoted text says.
From the same source:
In a public-key encryption system, anyone with a public key can encrypt a message, yielding a ciphertext, but only those who know the corresponding private key can decrypt
Funny story: you didn’t change the wrong info. The sad part is that you’re spreading misinformation and unwilling to hear otherwise. This is more dangerous than helpful.
How is Crul wrong in anything other than the terminology? You sign a document with your private key - generating basically a hash of the document entangled with your key information. Anyone holding the public key can then verify that hash with the public key - that the document contents are intact and unchanged (from the hash), and generated by the person holding the private key (entangled key information)
To help you with the terminology, the names for the two operations are “signing” and “verifying”. That’s it.
What can you do with…
public keyprivate keyEncryption:encryptdecryptSignature:verifysign“Signing” is not at all the same as “encrypting” with the keys swapped. It is a separate specific sequence of mathematical operations you perform to combine two numbers (the private key and the message) to produce a third - the signature. Signing is not called “hashing”. A hash may be involved as part of the signature process, but it is not strictly necessary. It makes the “message” number smaller, but the algorithm can sign the full message without hashing it first, will just require computation for longer time. “Hash-verifying” isn’t a thing in this context, you made that name up, just use “verify”.
@dohpaz42 is mad because you messed up your terminology originally, and thought you were trying to say that you “encrypt” a message with the private key, which is totally backwards and wrong. He didn’t know that in your mind you thought you were talking about “signing” the message. Because honestly no one could have known that.
Look at the words you used, encryption is not the same as a signature, with a signature you can prove that a person with access to the private key wrote the message.
What you’re talking about in your message is encryption, and you have it the wrong way around, messages gets encrypted with the public key, and can only be read with the private key.
what they post is not a PGP key, but the same content published in clear text encrypted with their private key.
So they are not excrypting it, but do we agree that with signatures the author uses their private key + the clear message to generate “something”?
That way anyone can decrypt it with the author’s public key to check it has been encrypted with the private one (that only one person should have).
… so then anyone can use the author’s public key to check that “something” against the clear mesage to confirm the author’s identity?
If that’s the case, then my error is that the operation to generate the signature is not an encryption. So, may I ask… what is it? A special type of hash?
Thanks again. I will edit my original comment with the corrections once I understand it correctly.
So they are not excrypting it, but do we agree that with signatures the author uses their private key + the clear message to generate “something”?
Yeah sure, and I think the person you are arguing with is saying as much as well, it’s just that this is not encrypting it, when you encrypt something you obfuscate it in a way that is possible to deobfuscate, think the caesar cipher as a simple encryption, a hash/signature on the other hand is something that is generated from the clear text using your private key, which is not possible to decrypt, think very simplified that the person would just put the amount of each letter of the alphabet used in in the text, then add the length of the thread, and then multiplied by your private key. This way it’s proven that the holder of the private key is the person writing the text, and that the text hasn’t changed since the signature was generated.
… so then anyone can use the author’s public key to check that “something” against the clear mesage to confirm the author’s identity?
They can confirm that the person holding the private key (not identity, just that they have the key) and also that nobody changed it since they signed it (like the person adminning the forum or a moderator or something)
If that’s the case, then my error is that the operation to generate the signature is not an encryption. So, may I ask… what is it? A special type of hash?
For signing, it’s backwards - you encrypt with the private key, and then everyone else can decrypt with the public key. If that doesn’t work, they know that the message wasn’t signed by the private key paired with the public key they have, and therefore is invalid and is not to be trusted.
Signing proves authenticity (only the private key holder can sign), encryption provides privacy (only the private key holder can read)
I can not answer this question, but I suspect, that actual answer is yes and no. Due to the swpc they relay solar storm info to earth before it hits due to sensors.
Webwoupd need yo send probes out further yo.grab that data first
Any data is sent at or below the speed of light. Solar storms are charged particles (mostly protons) being ejected from the sun and eventually hitting the earth’s magnetic field, causing disruptions in the field (and potentially cool auroras).
Since these storms are just particles traveling from the sun to the earth, they travel slower than light speed, so our distant sensors can warn us in advance at/near the speed of light. This won’t work if the sun were to instantly disappear or change color though, that information would travel at light speed and the probe signals would arrive at the same time.
The short answer is no. A bit longer of an answer is that with the public key, anybody can encrypt data. Only the owner(s) of the private key can decrypt the data. That is a key point: encrypted data by itself is meaningless. If you were to attempt to decrypt random data (or change one single character of valid encrypted data), you’d get literal garbage output. But, valid encrypted data and the corresponding private key can always unencrypt back into the original format.
This is why emphasis is always made to never share or expose your private key. Couple the private key with the always-available public key and you’ve got a man-in-the-middle (MitM) attack. This is where an attacker could decrypt the data with the private key, change it, re-encrypt it with the public key, and send it along to the destination without anybody knowing it was altered.
No, as both gravitational and em waves travel at the speed of light, the “we’re all screwed” things we could ever observe would only ever be slowed-down/distorted (by things that could even do such a thing like a black hole) as they approach us.
So it’d be a happy little surprise (short of worm-holes or tachyons existing), on year 26,000.
That’s not too say life as we know it would end immediately. We might make it generations before the real chaos affected us on earth. On a smaller scale, if the sun blipped out of existence, sure, we’re 💯 doomed and we’d know it after 8.3 minutes, but some of us might make it a solid week before all life on earth was expunged 😅.
You are behind the times on physics advancements buddy! Thanks to the recently discovered concept of relativistic time dilation, a 5000 light year trip at the speed of light will take literally 0 seconds of your lifespan. More practically, travelling in a starship that accelerates at 1G to the halfway point, turns around and decelerates to the destination, you can reach ridiculous distances within a single human lifetime:
shipboard timedistanceearth time1 year.263 LY1.05 Y2 years1.13 LY2.37 Y3 years2.82 LY4.35 Y4 years5.80 LY7.50 Y5 years10.9 LY12.7 Y10 years166 LY168 Y15 years2199 LY2201 Y20 years28.8 kLY28.8 kY25 years380 kLY380 kY50 years149 GLy149 GY100 years22.8 ZLy22.8 ZYThis is the formula to calculate the distance and time:
Nah, it’s actually super hard to maintain that acceleration. Not to mention all the fun of radiation, avoiding random obstacles and I assume the interstellar medium will become more dense to an accelerated observer.
We have idea on how to do it, but the engineering is far from it yet.
But what about the bit about not hitting anything whilst travelling at that speed? Even a speck of space dust would do massive damage at those speeds, right?
Oh yeah, it’s like flying the wrong way down the tube of the Large Hadron Collider. The tougher challenge though is like @MuThyme said maintaining 1G acceleration. Following the rocket equation, which is logarithmic, a 50 year multi-stage rocket will be bigger than the universe itself, even if you use some kind of nuclear propulsion 10000 times more efficient than our chemical rockets.
What you are doing is exporting your key. Your public key is indeed something you can (and should) share as it enables others to verify that you are indeed who you claim to be (or more accurately, that you’re in control of the private key that’s linked to that public key). So while you should share your public key, your private key must remain private.
What these people on the dark web are doing is one step further: they sign their messages with their private key. This creates a cryptographic signature that’s different for each message (changing a single character in the message will generate a wildly different signature). Anyone with the public key can simply copy that message including the signature and validate it. If even a single character of the message was changed, the signature will not be valid. Thus ensuring others that the person who posted the message is indeed in control of the private key.
Signing is different from encrypting: while encryption renders your message totally unreadable to anyone without the correct key, signing doesn’t change the message itself. It simply appends a signature allowing others to check that the message wasn’t tampered with.
Not my field, but I don't think it's even possible to really pinpoint "the" most recent evolutionary step, not to mention being able to define "step" in an incredibly slow variable with multiple layers of continuity (individual, population, and whole species levels).
But I would say that it is very recent for sure, as lactase persistence is a trait that really only started (above "noise" level stochastic mutations in the population) when we started using dairy some 6000 years ago because of selection pressure.
Try recreating that spin with a fidget spinner and slowly turn it around like the moon turns to face earth. You’ll find that it wants to turn in a way where it spins around the same axis it’s orbiting.
Since the moon has no hand preventing it from doing that, it aligns its spin with the orbit, so the forces described in the article bring that rotation to a halt.
It’s kind of interesting to think of society like a videogame. Like we put our stats in oil and tech. But not much in biotech. The different style of civilisation advancement we are missing out on could be wild. But we can’t go back and play the game from the start again, so we’ll never see what that’s like.
Could be computers built off of nerves instead of wires. Computers that grow and multiply. I wonder if it could lead to a new understanding of the nature around us and how we all fit and play a role in the galaxy.
Maybe our desire to explore space is immature. There may be whole other types of space that we can’t see because we don’t have the tech.
We already have a lot of biotech and even some biocomputers. The main issue is that bio structures are fragile for our common use cases.
We also have self replicating machines, 3D printers for example. They are as much as alive as viruses as both require some input from the hosts for full replication cycle. It’s just that most people don’t think about 3D printers as alive and self replicating beings.
Built a machine that can repair itself. Send it to a nearby planet. Give it the ability to manufacture human embryos from our genetic code using only inorganic material. Make at least 2 ; let’s call them Adam and Eve. Keep this machine somewhere hidden and near them so to guide them and their offsprings for a few milleniums. Someday, if they are mature enough, tell them what happened.
Ha, thanks … not available freely online yet it is : en.m.wikipedia.org/wiki/James_S._A._Corey
James S. A. Corey (June 27, 2023). How It Unfolds. The Far Reaches. Vol. 1. Amazon. ASIN B0C4R4V6KN
I’m sure there’s a physical answer as to why a spherical lens can’t focus the entire image (or maybe it can, physics is not my area and I think it shows haha).
But the biological explanation is that your retina isn’t uniform, instead you have a very small region called fovea where the vast majority of your cone cells are concentrated. If you could take an instantaneous snapshot of your vision, like a picture, you’d be scared to see that everything is grossly blurry and distorted save for a very small circle where the image is very clear - that’s the fovea. Your brain takes multiple images where different parts of a scene are focused on the fovea to create a composite end result that looks better. The rest of your eye still captures light, but with less detail, and therefore it’s mostly dedicated to getting broad positioning of objects, noticing fast changes in movement, tracking peripheral motion, and so on - not on focusing on text or small details.
Curiously, you also have a circle that would be completely black if your brain didn’t fill it in - it’s the blind spot left by the insertion of the optical nerve, where your retina can’t capture anything.
you’d be scared to see that everything is grossly blurry and distorted save for a very small circle where the image is very clear
This is what interests and distresses me about the mysteries of the human body. I once saw a video about capturing a person’s recollection of his memory of a video clip by scanning his brain activity. The result was really obscured and blurry, but it actually did resemble the clip, which was deeply disturbing. I would have never known my actual vision is vastly different from what my brain makes me perceive to be.
What you perceive is vastly different than a continuous filmstrip. Have you ever tried to watch unstabilized footage from a person jogging? Totally unwatchable! But your brain smooths it out better than the best steadicam. Tilt your head from side-to-side: what you perceive stays upright. And of course you know hat your eyes don’t smoothly pan from subject to subject but are constantly “saccading” around, but your brain processes that all away.
Visual processing is amazingly complex. Its also interesting that our other senses have different levels of processing. Our sense of smell is nothing compared to a dog’s, our sense of hearing is nothing compared to a whale’s, etc. A metaphor I heard once (don’t know how accurate it is) is that when a human walks into a kitchen they might smell that a stew is cooking. A dog would smell both the overall smell but would also smell the individual carrots, peas, chunks of meat, etc.
I think a useful way to think about it is that your perceptual brain isn’t in the business of making you see, or hear, or anything like that - it’s in the business of giving you an accurate-enough-to-be-useful idea of what’s around you. You see the world as being sharp and stable and consistent even though the literal visual signals going from your eyes to your brain aren’t… because the world is sharp and stable and consistent. Or at least it’s enough those things that it was useful for the brain to evolve to generate that specific perceptual experience. The signals coming from your eye are just (some of) the information the brain uses to generate that experience.
Essentially the issue with this question is that the usual ways you’d answer that question all seem unsatisfactory, and the key to “answering” the question is to understand not magnetism, but why magnetism seems mysterious and all the answers seem unsatisfactory. Like, actually understanding magnetism in the sense of having read and understood the Feynman lectures definitely helps but that’s no good to a layperson.
And the answer to that as I understand it is that we always understand things in terms of other things we understand. When you see a process you don’t understand and learn how it’s caused by a process you do understand, you will feel satisfied, like you understand the process. If you don’t understand a very weird thing but you find a good analogy to something you are familiar with, you will feel like you understand the thing. The thing is, that’s all a feeling. Hopefully the feeling correlates to having an internal model of the thing that’s closer to its nature than your previous internal model, and to being able to make better predictions about the thing’s interactions, and it usually does because the brain is well-made, but it’s still two different things and you can have a feeling of understanding without an improved model or predictions and vice-versa.
And the issue with magnetism is that unlike most other physical things we run into in daily life, it’s a fundamental force that has macroscopic effects our brain didn’t really evolve to be familiar with, and the best explanations for those effects require going directly to the fundamental force, and the fundamental forces is something that’s very very unfamiliar to anyone who hasn’t done university-level physics. If I say “electromagnetism explains how solid objects don’t just go through each other” your response won’t be “but I don’t understand electromagnetism!”, it will be “wait, did we need an explanation for why solid objects don’t go through each other?”. We have an innate sense of how solid objects interact at our scales that feels like it requires no extra explanation. And any behavior of solid objects that does require extra explanation usually involves explanations just one level deeper in the causal chain, which is close enough to what we are familiar with that we can understand it. And as explanations go deeper the causal chain things become weirder and weirder, but as a student of physics you go gradually, get used to each step and when a step becomes familiar enough it helps you “understand” the next one. So at some point you may end up feeling like you understand electromagnetism as a fundamental force, but it took a lot of work to get there (and that feeling my be fairly fleeing and changeable).
We don’t have an innate sense of how magnetism works, and the actual explanations for how it works aren’t just one step removed from things we do have an innate sense of. It’s legitimately the case that the answer to “Why do magnets work like that” is “electromagnetism”, and if you don’t understand electromagnetism (which, as a layperson, you don’t) you’re screwed. There is no phenomenon or analogy that you have an innate sense of that’s enough like magnetism to provide understanding. You straight-up have to do university-level physics until the concepts in question start becoming familiar.
In a way your question is even worse, because look:
What does it mean for them to be composed of “lines of force”? What is the mechanism of that force? What is actually going on in a magnetic field that the space outside of a magnetic field lacks?
You’re kind of asking “what component parts is the fundamental force of magnetism made of and how to they interact to make it behave that way”, aren’t you. And the issue with this is that in the current standard model, there are no such component parts and causes; that’s what “fundamental” means. Now, we know physics isn’t a solved field so in practice there may indeed be extra explanatory steps out there to be found. But 1) they’ll be even weirder than the current thing you’re asking about is. They won’t help you understand, they’ll just confuse you further and seem like worse ad-hoc gobbledlygook than “fields” and “force” do. They’d only help you understand if you’d studied enough quantum physics for it to feel familiar and maybe almost-understood. And 2) at some point we kind of do have to hit an explanation that has no further explanation, something that’s not made of something else. Maybe it’s worth it for you to think about what that might be like. You’ll probably still feel the urge to ask “but what is that basic thing made of, what explains that explanation?” but you’ll have to accept that this question is that of a brain that evolved in an environment where everything is made of something else and things have nigh-infinite causal chains explaining that they are what they are. It just might not be very good at thinking about a situation where that’s not the case.
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