CosmicDefect's recent activity
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Comment on What are we in a golden age of? in ~talk
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Comment on What are we in a golden age of? in ~talk
CosmicDefect Link ParentWaterRamen is incredibly entertaining. Him eating his pets doesn't really bother me since I know buying seafood live at the grocery store is normal there and he treats them better than most...WaterRamen is incredibly entertaining. Him eating his pets doesn't really bother me since I know buying seafood live at the grocery store is normal there and he treats them better than most animals I eat get treated.
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Comment on What is the oldest file you still have? in ~tech
CosmicDefect LinkProbably my first reddit post to pics in 2010. https://www.reddit.com/r/pics/comments/dq3s3/i_got_bored_and_drew_a_guy_fighting_two/ I don't think I have anything from my older computers and it...Probably my first reddit post to pics in 2010. https://www.reddit.com/r/pics/comments/dq3s3/i_got_bored_and_drew_a_guy_fighting_two/
I don't think I have anything from my older computers and it was before I backed up stuff on the cloud. Maybe some images from Facebook might be older, but I don't have access to that anymore.
Edit: I realized I still have the game Deadly Tide on CD from 1996. https://en.wikipedia.org/wiki/Deadly_Tide
The cutscenes from that game still hold up imo.
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Comment on What is the oldest file you still have? in ~tech
CosmicDefect Link ParentThis is pretty awesome. I'm glad you were able to access them finally. Tbh, I'd consider printing and framing the first just as a conversational piece.This is pretty awesome. I'm glad you were able to access them finally. Tbh, I'd consider printing and framing the first just as a conversational piece.
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Comment on ‘Coyote vs. Acme’ snags no. 2 with $15.4m as ‘Spider-Man’ nears ‘Avatar 2’; ‘Dog Stars’ put to sleep in ~movies
CosmicDefect Link ParentIt's a shame that Bugs may go down the Mickey Mouse route which, if so, likely strips him of all personality and edge. It's fun that he's a self-aware jerk basically. Like, I don't recall who...There's not much financial opportunity with them, outside of using Bugs Bunny as a mascot.
It's a shame that Bugs may go down the Mickey Mouse route which, if so, likely strips him of all personality and edge. It's fun that he's a self-aware jerk basically. Like, I don't recall who Mickey actually was as a character outside a vague recollection of what happened in the sorcerer's apprentice bit in Fantasia. The Steamboat Willie incarnation is very odd to modern audiences and certainly overwritten as well.
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Comment on Any significant changes to Tildes are extremely unlikely in ~tildes.official
CosmicDefect (edited )LinkI haven't posted in awhile, since 2024, but came back on a whim and saw this post which immediately broke my heart a little. I still donate via GitHub despite my absence, and I think I'll continue...I haven't posted in awhile, since 2024, but came back on a whim and saw this post which immediately broke my heart a little. I still donate via GitHub despite my absence, and I think I'll continue that at least awhile longer because I respect the heck out of what you tried to accomplish here, and what was accomplished by you and the community. This website is frankly still beautiful to look at and use and I hope it lives out the "long defeat" a la Tolkien.
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Comment on Why and how I version my blog in ~tech
CosmicDefect LinkCommenting to read later. I use GitHub pages for my blog so I definitely have a mechanism to do versioning but not an overall philosophy to implement. This looks like a good marriage of versioning...Commenting to read later. I use GitHub pages for my blog so I definitely have a mechanism to do versioning but not an overall philosophy to implement. This looks like a good marriage of versioning as traditional software versus versioning as a living document.
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Comment on <deleted topic> in ~tech
CosmicDefect Link ParentThere's still substacks that I read and perhaps I even might open my own substack at some point, but I am definitely soured on the idea that a social media platform of any kind should necessarily...There's still substacks that I read and perhaps I even might open my own substack at some point, but I am definitely soured on the idea that a social media platform of any kind should necessarily cater to free speech ideals in some absolute sense. I think long-term I'll be more happy on platforms that have a moral center to them that is well telegraphed and everybody can get behind. Tildes is one such a place and I'm finding Bluesky is another.
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Comment on Proving that SU(2) is compact (and other group theory bits) in ~science
CosmicDefect LinkSo, as the blog post states right off: I am not a trained mathematician, but a physicist. I am secretly jealous of mathematicians though, and their ways, and have been trying to patch up my...So, as the blog post states right off: I am not a trained mathematician, but a physicist. I am secretly jealous of mathematicians though, and their ways, and have been trying to patch up my skills. What better method to improve than to pick a question that interests me and diving deep as I could and putting the results into writing. Corrections are welcome! This was also cross-posted to /r/math which has some really good discussion too.
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Proving that SU(2) is compact (and other group theory bits)
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Comment on Can we ever detect the graviton? (No, but why not?) in ~science
CosmicDefect Link ParentI have to admit my heart kind of fell in love with kaluza Klein theory back when I first learned about it several years ago and that love has persisted since. I'm always on the lookout for a...I have to admit my heart kind of fell in love with kaluza Klein theory back when I first learned about it several years ago and that love has persisted since. I'm always on the lookout for a reasonable theory that adds more dimensions.
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Comment on Can we ever detect the graviton? (No, but why not?) in ~science
CosmicDefect Link ParentThat's not a really a compelling case. We can't see radio, but it's just as much a legit form of light as any other wavelength. Our human experience is quite limited and is often a poor source for...Because it's the set of dimensions we experience
That's not a really a compelling case. We can't see radio, but it's just as much a legit form of light as any other wavelength. Our human experience is quite limited and is often a poor source for physics intuition. In contrast, there's a lot of similarities between the degrees of freedom that arise from spatial dimensions and the degrees of freedom in the gauge fields, including the fact curvature in both are defined analogously. You might then naturally ask; are they actually separate things?
We already expanded Euclidean 3-space to include time as a dimension from relativity:
- xi = (x,y,z)
- xμ = (x,y,z,t)
We're then tempted to include the photon Aν gauge field. - Xa = (xμ,Aν)
We can add even more of the fields until we have a unified geometry of all interactions. Now, with all this said, the "project" of doing this in physics in incomplete and success is not guaranteed, but it's a cool idea. All theories of extra-dimensions (including String Theory) start with thoughts like these.
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Comment on Can we ever detect the graviton? (No, but why not?) in ~science
CosmicDefect Link ParentTo a certain extent, we already see that it does defy expectations by being difficult (or impossible) to quantize in a manner as satisfying as say electromagnetism. But a different point is that...It seems intuitive that the physics of gravity wouldn't conform to expectations derived from our understanding of the other forces?
To a certain extent, we already see that it does defy expectations by being difficult (or impossible) to quantize in a manner as satisfying as say electromagnetism.
But a different point is that you don't have to formulate general relativity as spacetime curvature (the geometrical interpretation). It is perfectly alright to consider a background of special relativity on which the gravitational field acts. From this perspective, gravity is then an additional dynamics field like any other (electromagnetism, electroweak, etc.) living on top of special relativity.
The flipped perspective is to LEAN into the geometrical interpretation. Gravity is the spacetime curvature of our base reality, but so are the other forces! The electromagnetic field tensor F is a curvature tensor for the gauge field we call the electromagnetic field in the same way the Reinmann curvature tensor R is for spacetime. From this perspective, you write all the interactions (gravity, electromagnetism, electroweak, strong, etc.) as geometric curvature. Our reality is then not just spacetime, but spacetime plus all gauge fields. Why give spacetime a preference when mathematically it is a dimension just like any of the others?
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Comment on Can we ever detect the graviton? (No, but why not?) in ~science
CosmicDefect Link ParentThank you for the kind words. It occurs to me I should have perhaps motivated the dimensional analysis better so one could follow why the cross section is proportional to the combination of...This was a really fascinating article to read as well, and though I agree with the other posters in being unable to follow the chain of derivation, the results are very clear. It never occurred to me that there could be such a stark difference in the detactability of quantum particles, but a distance of 85 orders of magnitude is nothing to sniff at!
Thank you for the kind words. It occurs to me I should have perhaps motivated the dimensional analysis better so one could follow why the cross section is proportional to the combination of constants in each case, but that'd require either some pretty strong (and likely unsatisfying) hand-waving or a crash course into the Feynman rules for quantum fields.
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Comment on Can we ever detect the graviton? (No, but why not?) in ~science
CosmicDefect Link ParentThe other answers you got cover the gist, but here's some more reasons why we expect gravity to be quantized. I'm quoting a reddit comment I made some time ago: Why does gravity have to be quantum...The other answers you got cover the gist, but here's some more reasons why we expect gravity to be quantized. I'm quoting a reddit comment I made some time ago:
Why does gravity have to be quantum in the first place? Since nobody can figure it out, maybe gravity is just classical. Maybe Einstein got it right the first time and we're just spinning our wheels. The above seems like a reasonable argument, but I want to elaborate on why we should expect gravity to be quantum in nature.
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There appears to be four fundamental forces in the universe (five if you include the Higgs, though it's not a gauge boson). Of these, all but gravity, are quantum in nature. It would be strange if all of physics except gravity obeyed the rules of quantum mechanics.
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Where quantum mechanics and gravity are both important (most famously black holes), there are calculations that are contradictory, or can only be done approximately. This means that physics must be incomplete. The "Black hole information paradox" says BHs do not preserve information via their decay into Hawking radiation. This is a paradox because quantum mechanics (which predicts Hawking radiation) requires information to be preserved which is a feature called "unitarity." Unitarity is a VERY important feature of quantum theory and we're reluctant to give it up.
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Instead of adding quantum fields to curved spacetime, we ask: "Can classical gravitation fields be made from quantum matter?" The simplest form of this "semi-classical gravity" (i.e. G = <T>) where <T> is the "averaged" quantum matter is also inconsistent and leads to incorrect predictions. This doesn't mean gravity can't be classical, but it does mean both classical gravity and quantum mechanics can't be simultaneously true. Either quantum theory or gravity needs to change.
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Effective quantum gravity actually works well. If you keep to low energy situations, quantum theory and gravity are actually very compatible. In this domain, you can do everything classical gravity does through the language of quantum theory. Calculating the precession of Mercury using quantized gravity is a graduate student level homework problem. Effective quantum gravity also clearly predicts quantum corrections to Newtonian gravity, though today there's no clear way to measure such corrections.
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String theory, despite recent negative buzz and bad PR these days, is a theory of quantum gravity. The problem is well-understood (and well behaved) string theories do not describe our gravity in our universe. We seem to have made math for quantum gravity for somebody else's universe! This is akin to stumbling upon Paris, Kansas instead of Paris, France. It's still Paris however, so maybe there's hope.
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Comment on Can we ever detect the graviton? (No, but why not?) in ~science
CosmicDefect (edited )Link ParentMy pleasure, thank you for reading. The main problem with detecting gravitons as a scattering process is that the cross-section is always proportional to either G_N or (G_N)^(2) which is tiny as...Thank you for sharing your write-up!
My pleasure, thank you for reading.
Have scholars speculated upon any additional processes the graviton participates in with higher cross-sections that might be more readily measured?
The main problem with detecting gravitons as a scattering process is that the cross-section is always proportional to either G_N or (G_N)^(2) which is tiny as an interaction strength. As far as alternative theories, there's a whole zoo of model building we could do out there. Dozens of models. One example which comes to mind is the search for the Randall-Sundrum (RS) graviton which is a massive heavy excitation of the graviton that is predicted by some theories involving extra dimensions. We wouldn't see these gravitons as a scattering process because they are heavy and wouldn't propagate easily (same reason W and Z bosons aren't long range) but there is the possibility we produce them in energetic collisions.
The LHC has excluded RS gravitons of mass up to a few TeV, but they could easily be heavier than that.
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Comment on Can we ever detect the graviton? (No, but why not?) in ~science
CosmicDefect Link ParentWhat gravity has going for it, is that all charges are always positive and attractive.And how insanely weak it is, yet so dominant in the Universe.
What gravity has going for it, is that all charges are always positive and attractive.
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Comment on Can we ever detect the graviton? (No, but why not?) in ~science
CosmicDefect LinkFull disclosure, I did this little writeup but thought folks here might find it interesting. It was fun to use dimensional analysis to understand the order of magnitudes involved in graviton...Full disclosure, I did this little writeup but thought folks here might find it interesting. It was fun to use dimensional analysis to understand the order of magnitudes involved in graviton detection.
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Can we ever detect the graviton? (No, but why not?)
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Comment on Balatro Mobile coming to Google Play, Apple Arcade and App Store on September 26th 2024 in ~games
CosmicDefect LinkNon-zero chance I pick this up for mobile. I adore the Steam version and have played many hours on my Steam Deck.Non-zero chance I pick this up for mobile. I adore the Steam version and have played many hours on my Steam Deck.
Saaaaammeee. Despite the world, my own life has so much going for it that I have to be grateful.