Extremely high-energy particle detected falling to Earth
theguardian.com
theguardian.com
One of my pet theories is that the Fermi paradox is due to cloaking of extraterrestrial civilisations. We’re not entitled to observing them, and as a result the mass and energy of the universe doesn’t add up. Hence black matter and black energy.
Aside: dark matter and dark energy are pretty distinct concepts by my reading [2]. Dark matter interacts only gravitationally and is currently the leading explanation for things like galaxy rotation curves (visible mass is far too low to support observed disk rotation speeds, so non-luminous, i.e., "dark" matter must exist to make up the difference) and gravitational lensing by galaxies (again, visible mass is too low to produce observed lensing). Dark energy is, well, something that accelerates the expansion of the universe.
[1] https://en.wikipedia.org/wiki/Dark_forest_hypothesis
[2] https://science.nasa.gov/astrophysics/focus-areas/what-is-da...
Humans also have been broadcasting EM out into space for a bit now.. so either these hostile aliens are on their way right now, they are too far away to have detected us yet, or they don't exist.
Visual observations exists much longer, but they are limited to just our galaxy, Milky way (more distant sources are not bright enough to see them with naked eye).
And even most obvious mask ideas (and development), which we see on our current sci-tech stages, very fast move spectrum to infrared, which is near impossible to observe via thin atmosphere. And even now, I hear about developments of laser cooling, which could emit extreme amounts of heat into some direction, where nobody will see it.
For example, now Earth communications conversed to Ultra high frequencies and very high gain antennas (3G, 4G, 5G, emit only very narrow beam to receiver and are very short range), and to fiber-optic communications, which emit just infrared from heat. Also, Ultra high frequencies very quickly absorbed by moisture, so also effectively converted to heat infrared.
So, right question should be, how much time industrial civilization emit observable to others emissions.
And imagine, what could alien civilization learn about Earth from locations, where clouds are rare, as others they could not hear :)
Not exact. For so weak technologically civilizations such our Terrestrial, now could not detect many distant objects which does not emit EM spectrum.
For example, only small fraction of known planets outside our Solar system, seen on telescopes directly, most others detected by indirect means - measuring difference of speed of star (by Doppler shift), or measuring changes of brightness of star, when big planet eclipse star (most cases partially).
In many cases, planets orbits are not so fortunate to us to detect them, and these planets for us are dark matter also.
To be exact, for us "normal" matter are only classic stars and some other objects like Black holes when they "eat" something.
Astronomers already made calculations, based on assumption, that Solar system is more or less typical (we know approx weights of matter of Sun, Planets, Asteroids, Star dust, etc), and seen, that all we know could been about half of dark matter, but other half we could not explain, and this is huge number.
"Dark matter" has a technical meaning in astronomy, and this is not it.
For ASTRONOMY, dark matter is just what they could not see, but have gravitation features. And as I said, for astronomy, ~50% of dark matter is nothing special, but for example, only extreme models could suggest tens of thousands Black holes (to fill 50% of emptiness), because of this, they conclude, that exists something other matter which we don't know.
For PHYSICS, technical meaning of dark matter is special type of matter.
Good that we found understanding on this.
Also, how do they erase their early radio signals after they have been emitted? Civilizations don't go from zero to dark mater cloaking capable without a few intermediate steps...
> as a result the mass and energy of the universe doesn’t add up
wouldnt something smart enough to put up a cloak know that they should put up something to replace the missing data?
i mean... i would hope...
Even recent stealth technologies know from late 1970th, how to hide from radio waves reflections and how to hide visual reflections and how to hide infrared emissions (slot nozzle, directed where no observer).
What kind of technology would produce such ultra high energy particles?
What would they use such technology for?
Can a technological source be inferred from the data we already have?
It could also 'just' be a new particle which behaves differently than anything on the board. (Would still be a VERY strange particle though for sure, and still leaves open the question of what produced it.)
> Some charged particles in the air shower travel faster than the speed of light
Better article: https://attheu.utah.edu/facultystaff/cosmic-ray-2023/
Science paper for those with access: https://www.science.org/doi/epdf/10.1126/science.abo5095
The Guardian article says:
> Some charged particles in the air shower travel faster than the speed of light, producing a type of electromagnetic radiation that can be detected by specialised instruments.
> One such instrument is the Telescope Array observatory in Utah, which found the Amaterasu particle.
The Telescope Array actually has two different types of instrument for detecting the particles. Fluorescence Telescopes and Scintillation Detectors.
According to the paper the "fluorescence detectors were not operating at the time (owing to bright moonlight)". Instead the particles were detected by the plastic scintillator surface detectors.
I have found more information about the surface detectors here: http://www.telescopearray.org/index.php/about/surface-detect...
It gets weird because you see evidence of these mesons or whatever way down below the part of the atmosphere where cosmic rays impact. Like, if you multiply the half life of the meson with the speed of light, you get a result that should be way shorter than the actual distance you see mesons (or what have you) actually traveling. Depending on how you look at it, it's like the mesons are traveling faster than the speed of light given how far they're going before decaying.
It turns out these particles are traveling so close to the speed of light that the passage of time is different for the particles than an observer on earth. Their half-life duration occurs within their frame of reference, which is different than ours. So even though the particle was traveling at (fake numbers) 1 kilometer a second and traveled 3 kilometers, it only had a lifespan of 1 second. It plays out this way because 3 seconds on earth transpired during the particle's 1 second in its own frame of reference and thus we saw it travel 3 kilometers during the particle's own 1 second, despite the speed of light being just 1 kilometer per second. So depending on how you look at the numbers it can seem like it was 3x faster than the 1km/s speed of light.
I realize this almost of creates more (and bigger) questions than answers.
This journal is published by "American Association for the *** Advancement of Science ***". Jesus. You can't make up this sort of irony. Open collaboration, peer efforts and all that altruist nonsense requires you having the access. No access - no science for you. Beat it.
Yes I know the arguments they used to defend their choice but I don't find them convincing.
You are respectfully wrong.
And it worked!
Any particle physicist that could answer, what would happen if such a particle would make its way through the atmosphere and hit a person in the head?
Looks like he survived the incident and even completed his PhD in following years. He did lose hearing on one ear and was partially paralyzed though.
Now the particle mentioned in the article was million time more energetic so...
One extremely-high energy particle is way, way less dangerous than a bunch of billions of less energetic particle... repeated every 25 nanoseconds!
If you don't slow them down, they'll just traverse other uranium nuclei and the reaction will only proceed with its natural speed (half-life of billion of years).
That's why you need a minimum mass of uranium for a nuclear explosion: you need neutrons to traverse a certain thickness of material before it gets slow enough to excite other nuclei
And if it does interact in your head... nothing at all! At such an energy, it is so tiny that at most one electron or one nucleon (i.e. proton or neutron) will get the thrill of its life and find itself leaving precipitously your body in order to smash, a few nanoseconds later, into the planet behind you. You won't notice, and the Earth won't either.
It's a bit like how the depth where the energy is deposited of radiotherapy gets deeper with increasing energy. Past a certain energy (hundreds of MeV), most of the energy ends up being delivered somewhere behind you. This particle is hundreds of billions times more energetic than that radiation.
Add on question: can dark matter emit high-energy particles?
For first, most current answer, we just know, something exists in Universe, which we could not see directly, but have mass and so emit some gravitation, which influence moving of other objects, which we could see.
For second, even worse. We only know, we cannot SEE anything in void, but this just mean, something could be there, but we cannot detect it with our current technology, nothing more.
When we cannot se anything, and we have not before encountered such phenomenon, we could only speculate on fantastic theories.