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Not really sure where this one's going. It's not an invention so much as a musing in search of a concept that's been bugging me for a few years now.
A photon does not experience time.
Think about that.
It doesn't matter that it took 4.5 billion years to reach your eye, to the photon it met
your retina at the exact same time it left its star or super nova or what have you, and if it reflects back the way it came and takes another 4.5 billion years to return to its origin... it's still the same instant it began its trip.
This hurts my head.
So... like all of the light in the entire universe exists in a perpetual state of 'now'.
There is no time, there is only light.
Somewhere out there is a photon which can never reach other galaxies which are receding faster than it can travel.
Like...
...ever.
Travelling for all of infinity, but its still just 'now' for the loneliest photon.
Kant
https://plato.stanf...ies/kant-spacetime/
[pertinax, Feb 01 2026]
Kant, but as a cartoon
https://existentialcomics.com/comic/597
[pertinax, Feb 01 2026]
Two Particle Photon
Two_20Particle_20Photon
The secrets of the universe lie in things that spin. [neutrinos_shadow, Feb 01 2026]
Single Photon Picture
https://www.reddit...._photon_looks_like/
(No picture of what a married one looks like) [Dub, Feb 03 2026]
The Lonely Photon
https://www.youtube...ncL5Q&start_radio=1
With cattle, the images of which are just photons. [doctorremulac3, Feb 04 2026]
Sun Sounds
https://www.nsf.gov...sts-listen-song-sun
[bs0u0155, Feb 05 2026]
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On a side note: Until a few days ago any posting I clicked on here would highlight red if I was the last person to annotate. Nothing highlights red anymore. |
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Is it site related, or is it my POS computer related? |
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I've never bought that crap. I am far from well enough versed in the science to explain why, but I don't believe photons "don't experience time". Time is time. I also don't believe that they always exist at a constant speed. Scientists CLAIM photons are already traveling at c the instant they're created, but that's as nonsensical as some of the crap religious leaders have been peddling. Logically, it MUST accelerate to get to that speed, unless it is created by a source that is already moving at c. There's so much crap scientists are just plain making up, it infuriates me. |
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//I don't believe photons "don't experience time".// |
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I am not a physicist, but ... what makes you think photons experience anything? If you could give them experiences then they would get time, in the Kantian sense, for free. If not, not. |
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They experience things in the same way all inanimate objects do, in that they are affected by it, however imperceptibly. |
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but... light has no increase in speed. It is instantaneous. |
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Can we all agree on this? or is it an issue? |
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//all inanimate objects do// |
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From Newton up until about the late nineteenth century, physics was about inanimate objects bouncing off each other in ways that we can all intuitively imagine. During the twentieth century, it gradually stopped being about those and became mostly about equations. Trouble is, the equations have predictive power about very large things and very small things, in ways that our easily-imagined objects don't. So you can call them crap if you like, but they're crap that works. |
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Never really thought about photons. Asked Grok if it was improbable due to the law of averages that a photon would travel 50 billion light years to reach Earth and never encounter even one object to block its path? Grock said that even though we see a lot of shit (not its words exactly) the universe is basically empty. |
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Grok will show you each photon being a tiny part of a naked underage girl and offer you a way of saving them in a secure digital bank. |
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So my next question on just a general web search was "What percentage of the universe is what's called "normal (baryonic) matter: Stars, gas, dust, and planets?" Got less than 5%. |
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So my question is still, at any given space with 5% photon blocking stuff, how the hell does it get through 50 billion light years of space without hitting a single rock? 5% is a lot, hell, I have 5% of the space on a pool table filled with other balls I'm not even gonna be able to shoot that ball to the other side if it was fifty feet long or so. |
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Okay, the photons might a lot smaller than the billiard ball, but the obstructions aren't. Seems like that would be some 3rd grade math to be able to figure out the maximum practical distance a photon could travel. |
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Okay, put that query back into another AI and got this: It's pretty long though. (that's what she said) |
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(Doc) this is a great intuition check — and your pool-table analogy is exactly where most people get tripped up. The short answer is: that 5% number is wildly misleading for this question, because it’s not “5% of space is filled with stuff.” Not even close.
Let’s unwind it carefully. The big misunderstanding: 5% ≠ 5% of the volume. That “<5% baryonic matter” figure means ~5% of the universe’s mass–energy budget, not its spatial occupancy. Almost all of that matter is crammed into stars, inside galaxies, in dense gas clouds. Meanwhile, most of the universe’s volume is deep intergalactic space, where the average density is about ~1 atom per cubic meter (roughly one hydrogen atom in a box the size of a washing machine). That’s not “sparse.” That’s criminally empty. If you shrank the universe to a pool table, almost all the balls would be crushed into a few microscopic specks, not spread evenly across the felt. Even atoms don’t “block” photons the way rocks block balls. Atoms are mostly empty space. If an atom were the size of a football stadium, the nucleus would be a marble at midfield, the electrons would be dust motes in the stands, and the rest is empty. A photon doesn’t need a “clear lane between atoms.” It needs to actually interact with one — and that requires hitting a very tiny target governed by quantum cross-sections. So even if a photon passes through an atom, it usually doesn’t scatter, usually doesn’t get absorbed, and just keeps going. Glass works because it’s dense and structured, not because atoms are big. The right tool is mean free path: the average distance a particle travels before interacting with something. For visible light in intergalactic space, the mean free path is billions to tens of billions of light-years. That’s not a coincidence — it’s measured. If photons couldn’t do this, astronomy wouldn’t work past our local neighborhood. Why the universe was opaque once is an important sanity check. Early universe: much denser, electrons everywhere, photons scattered constantly, result: opaque universe. At ~380,000 years after the Big Bang, electrons combine with nuclei, density drops, photons decouple. Those photons are now the Cosmic Microwave Background — and we see them perfectly, after 13.8 billion years of travel. If the universe were remotely “5% full” in a billiards sense, the CMB wouldn’t exist. Why your pool-table analogy feels right but fails: your brain assumes obstacles evenly distributed, obstacles solid, interactions guaranteed on contact. Reality: matter is clumpy, atoms are mostly empty, photons only interact via probabilistic cross-sections, intergalactic space is emptier than any vacuum we can make on Earth. So the photon isn’t threading a needle through rocks. It’s flying through a cathedral-sized void where the “walls” are light-years apart and mostly made of ghosts. The wild takeaway: what’s shocking isn’t that photons make it. What’s shocking is that anything ever interacts at all. The universe isn’t “mostly empty” in a poetic sense — it’s violently, absurdly empty. And yet here you are, sitting on a dense rock, reading photons that left a galaxy before Earth even existed. Which, honestly, is metal as hell. |
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Then asked the same question of Grok. Got basically the same thing only twice as wordy with a lot of mathy stuff. (Just putting it up to show how rambling it was) |
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You're spot on that the standard figure for baryonic (normal) matter is about 4.9% of the universe's total energy density—stars, gas, dust, planets, and all the atomic stuff we can see or interact with electromagnetically. (The rest is ~26% dark matter and ~69% dark energy.) But here's where the intuition breaks down: That 5% isn't about the universe being "5% filled" with blocking material like balls on a pool table. It's a measure of mass-energy contribution averaged over the entire vast volume of space. The actual density and distribution make all the difference, and space is so mind-bogglingly empty that photons have an ridiculously easy time threading the needle over cosmic distances.Why the 5% Doesn't Mean 5% "Blocked" SpaceIt's not uniform fill: If you took all the baryonic matter and smeared it evenly across the universe (which it's not), the average density would be about 0.25 atoms per cubic meter. That's not 5% of the volume being solid stuff—it's an ultra-thin gas. The "volume filling factor" (how much space is actually occupied by matter at any density) is way smaller, like 10^{-6} or less for galaxies and even tinier for denser clumps like stars or rocks.
Clumping rules everything: Matter isn't spread out; it's bunched up in galaxies, stars, and clouds, leaving enormous voids. The average distance between galaxies is ~2-3 million light years, and galaxies themselves are mostly empty space (stars are light years apart). A random straight-line path through the universe (like a photon's journey) is overwhelmingly likely to zip through voids without grazing anything substantial. The probability of hitting a galaxy along the way to a distant source is low, and even then, it might just skim the diffuse outer halo.
Pool table analogy tweak: Your pool table is a great 2D example, but space is 3D, and the "balls" (atoms or particles) are tiny compared to the gaps. If you scaled a pool table to cosmic proportions with 0.25 "balls" per cubic meter, the balls would be atomic-sized (cross-sections for interaction ~10^{-20} to 10^{-28} m²), and the gaps between them would average ~1.6 meters. Shooting a point-like "cue ball" (photon) across 50 feet wouldn't hit anything—it's like firing a laser through a room with a few dust motes floating around. Now stretch that table to 50 billion light years: The odds of a direct hit plummet to near zero because the obstructions are sparse and small. |
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The Math: Mean Free Path and Optical DepthYeah, it's basically 3rd-grade math once you plug in the numbers—multiplication and exponents mostly. The "maximum practical distance" a photon can travel before likely interacting (scattering or absorbing) is called the mean free path (λ), which is the average distance before a collision. It's λ = 1 / (n σ), where:n = number density of scattering particles (e.g., free electrons in the ionized intergalactic gas, since most baryons are in this diffuse plasma).
σ = interaction cross-section (for photons, often the Thomson cross-section for scattering off electrons: σ ≈ 6.65 × 10^{-29} m²). Using modern values:n_e (electron density in intergalactic space) ≈ 10^{-7} per cm³, or about 0.1-0.25 per m³ (this is the average; it's even lower in voids).
So λ ≈ 1 / (0.25 × 6.65 × 10^{-29}) ≈ 6 × 10^{28} meters.
Convert to light years: 1 ly ≈ 9.46 × 10^{15} m, so λ ≈ 6.3 × 10^{12} ly (about 6 trillion light years). The observable universe is "only" about 93 billion light years across (46.5 billion to the edge), so over 50 billion light years, the path is a tiny fraction of λ.To get the probability of making it through unscathed, use optical depth (τ), which is roughly distance / λ. For 50 billion ly:τ ≈ 50 × 10^9 / 6.3 × 10^{12} ≈ 0.008 (very small). Survival probability = e^{-τ} ≈ 0.992, meaning ~99.2% of photons zip straight through without interacting. The other 0.8% might scatter once, but even then, many still reach us indirectly or with minimal change.
If we use a slightly lower density (some estimates put n_e at 10^{-7} cm^{-3} exactly), λ jumps to 15 trillion ly, making τ even tinier (0.003).For "hitting a single rock" (like a planet or asteroid): That's even rarer. Solid objects have minuscule number densities—planets are confined to star systems, and the cross-section for hitting one over cosmic scales is like 10^{-15} or lower. Photons mostly worry about diffuse gas or dust, but even that is sparse enough for transparency.But We Do See Some BlockingNot every photon makes it—distant galaxies look dimmer and redder due to cumulative minor interactions (e.g., dust absorption in intervening galaxies or slight scattering). This is why the universe isn't completely transparent at all wavelengths (UV gets absorbed more), and we see effects like the Gunn-Peterson trough in quasar spectra for very high redshifts. But for visible/near-IR light from sources billions of ly away, enough photons arrive intact to form clear images in telescopes like Hubble or JWST.In short: The universe's "5%" is diluted over insane volumes, making collisions improbable. No 3rd-grade math predicts blockage over 50 Gly—it's the opposite. If it were denser, we'd live in a foggy cosmos, but observations confirm it's clear sailing for light. |
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Then after all that drivel I asked "What percentage of the SPACE of the universe is filled with photon blocking stuff and got the clearer answer I was looking for. "extremely small, on the order of far less than 0.000...1% (with many zeros)." |
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So guess I worded the questions wrong at first, and yes, the universe is basically empty. |
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Then I said "What was that you were saying about... hats?" (obscure movie reference, disregard) |
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//Logically, it MUST accelerate to get to that speed//
Yes, but a photon also has zero mass, meaning it can accelerate instantaneously (F=ma, a=F/m) regardless of what is initiating it's creation.
Hmm... if a photon experiences no time, then it is (from it's point of view) at both it's source AND it's target at the same time; it is a line across space, not a "point".
[steam cannon]'s "Two Particle Photon" post relates to some of this too (linky). I'm a fan of this theory. |
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It's even stranger though, isn't it? Because the universe’s expansion is accelerating, some photons can never reach their destination. Furthermore, a photon cannot return to its emission point. |
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But luckily for them, photons don't actually experience anything. |
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//can we all agree on this?// |
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By no means! It is absolutely an issue for me, it's nonsensical groupthink, an accepted Canon, a dogma. |
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Can light be slowed? YES. |
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What is light made of? PHOTONS! |
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Can photons be slowed? NO! |
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It's pure fucking nonsense. |
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"But photons are massless!" You say, but light is also massless, and if massless light can exist below c, then logically, so can the massless particles it's made of. |
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I read the single electron theory recently. But a single photon I suppose is unlikely |
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It's not meant for puny beings like you and I to understand. |
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The most amazing and brilliant thing about truths revealed or discovered by science and maths is that it makes no difference whether you believe them or not. They are still true and real |
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Think of it this way:
All of science is but a model of reality.
It's the best model we currently have.
If you don't like the model, come up with a better one, that:
a: answers all the questions the current model does
AND
b: solves some of the problems/missing bits of the current model.
Otherwise, we stick with the current model, because it (mostly...) works. |
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As for "photons can't slow down", my (vague & unrefined; I also haven't asked the internet about this...) hypothesis is, when light enters a medium (ie. not a vacuum), it's the interactions of the photons & the particles that "slow it down". The photons, when NOT interacting (moving through the empty space between or inside atoms) DON'T slow down (ie. continue at c); it's the electron shell jumps etc that create the effect of the refractive index. |
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(that weird "double-post & can't delete" glitch... at least I can edit) |
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If I remember correctly the speed of light has been slowed down to 7 km/hr in one experiment, thing is though, as soon as the light crept its way through the medium it instantly attained light speed again when released. |
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I imagine that would be absolute torment to a photon, y'know, if a photon could experience torment.
Forced to experience time without actually terminating by illuminating some physical object the way God intended. Seconds would then feel like eternity to an entity outside of the bounds of time and three dimensions. |
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It'd be like the worst seven seconds Ever! |
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Side note: Things are highlighting red again. Weird glitch. |
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In case it matters, other recent glitches within the same time frame, which just seemed to have magically Herbie'd themselves in the last week or so consist of; |
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...all of the icons on my computer disappeared so that if I wanted to find this site I had to search for it.
...youtube became absolutely generic. Anything any sort of algorithm had been showing me reset to default like I was suddenly twelve or something.
...any site I was once permanently logged into, including this one, I had to log into every time even if I'd just gone to another site in the same window. |
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There were a couple more week-or-so long glitches but they all seemed to fix themselves today without my intervention. |
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//Is it site related, or is it my POS computer related?// |
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My first guess is, it has something to do with cookies; it's as if your browser temporarily lost sight of its cookies. |
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As for how it might lose them and then find them again, I dunno. |
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If you have your computer (or browser) configured to auto-install security patches, then that might have something to do with it. |
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I'm in contact with [Jutta]. She asked me to clear cache. |
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I tested can I delete this?
Answer: I can't. |
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"have "people" do it. Knowing what happened when to whom would probably help" |
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//the universe is basically empty// |
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yes. Also matter as you experience it is basically empty. |
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//What percentage of the universe is what's called "normal (baryonic) matter: Stars, gas, dust, and planets?// |
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Percentage mass-energy. Not Volume. There are some extremely massive things out there with 0 volume. Stars and planets are incredibly dense. A really really basic calculation puts the percentage of solid stuff in the universe at somewhere in the 0.(30x zero)1% range |
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//put that query back into another AI and got this://
Oh, good job I'm only LARPing as a physicist. |
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//Yes, but a photon also has zero mass, meaning it can accelerate instantaneously (F=ma, a=F/m)// |
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Including zeros in formulae is one of the first ways you see that Newtonian physics starts to break. |
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//it's the electron shell jumps etc that create the effect of the refractive index// |
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I work with light a lot. I really should understand how it interacts with matter. I have tried. I don't. Likely won't, unless I stumble upon the right person who can use clumsy words to get the concepts across. |
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//Oh, good job I'm only LARPing as a physicist// |
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As far as this crazy light / wave / particle / ghost / demon or whatever thing, don't 100% discount that we're might be a simulation and the brat that made us for a science fair project is just messing with us. Okay to discount it 99.99999..% with a Googleplex of 9s but nothing's for sure. |
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The Lonely Photon would make in interesting instrumental piece. |
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Think of the atoms in the material as little pendulums (oscillators) dangling in a line from a string. Pluck the string; the first pendulum resists motion, then passes it along to the second pendulum, etc; the overall speed of the travelling wave is slower than if there were no pendulums. They are 'coupled oscillators', i.e. coupled by the string. |
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//The Lonely Photon would make in interesting instrumental piece// |
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If you convert light wavelength into Hz, then middle A is 440nm, a rather pleasant blue. The problem with visible light is that it's only one octave, the next A at 880Hz would be a deeep red. We have a LOT more range of hearing than sight. |
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We'd probably have to apply more artistic license than physics to make it work. |
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hmmm if light waves had sounds it would be synesthsymphonics. |
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Heh, try saying synesthymphonics five times fast. |
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You could translate the sun's* visible output spectrum <link> to sound. The spectrum is quite mid-heavy in the middle of a very middle-of-the range single octave. It would be likely quite annoying. You'd be better mapping the entire EM radiation spectrum across, which is, I assume how this kind of thing is done <link>. Maybe if they weren't messing about in the recording studio the NSF would have some money left over to fund my most recent grant on I.D.-ing fundamental mitochondrial pathology phenotypes. I needed one data scientist and a modest amount of server time, not that I'm bitter.** |
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* or any other star for that matter
** I am actually quite bitter. |
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I would be bitter too, pardon me but millions for transgender studies in Rwanda but real science takes a back-seat?... |
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All of science is being betrayed. |
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Maybe there is something written in some several thousand year old book which can help science on its way. |
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No financing for you you entitled capitalist pig. |
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You probably have blue eyes you fascist nazi oppressor. What were you even thinking? |
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Can't function without them. |
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All of science is being betrayed. // |
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It's not helping itself, sadly. |
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The reproducibility crisis is decades deep now. There's somewhere between 2-6 fold too many PhDs per year leading to over supply downstream in post-docs etc. Almost all are imported, because the money isn't enough to recruit domestically. It's not improving quality. There's been massive data inflation in publications - there's at least 4 fold more per paper now than the 90's say, all while techniques have grown in complexity. Failure to produce more, faster in an ever more competitive environment carries life-altering consequences. Incentives for good, careful science are absent. |
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A few things could start to fix the situation: |
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Pay people properly. If that means fewer labs, so be it. |
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Scale back PhD programs. The whole concept was for a subset of very bright, curious people. Universities have expanded the whole thing with a growth/business mindset. The wrong people are suffering as cheap labor. |
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Section off a significant amount of government science funding for reproducibility studies. 10% seems a good starting point. You should be able to write a grant application along the lines of: "This paper represents a major step in xyz research, our lab possesses overlapping capabilities and is well placed to confirm the results with similar and complementary techniques" |
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Figure out some sort of journal reform. Academic publishing is clearly ridiculous. You submit a paper, it's peer-reviewed (voluntarily, for free think of the incentive structures there). If accepted, you pay $1000's to publish and do all the formatting etc. yourself (there used to be professionals at the journals who did this). Then the journal charges you $1000's/year to access that work. Government funding pays to publish, pays to access work it already paid for. Financial incentives only push more papers in more journals, not better. |
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When I become Benevolent Planetary Sovereign you've got the job of cleaning up that mess if yo want it. Pay's good. |
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According to Feynman photons don't move at all. All of spacetime is like a 3d Newton's cradle and when light propagates it's like releasing the initial marble. What we think of as the speed of light is the transfer of energy along an infinite number of marbles and that wave itself travels at C, not the photons themselves.
Fascinating. |
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