2026-04-25T16:49:06Z https://yabu.me Morgan Arnold https://yabu.me/npub1fp0024ns6k99e42eet6esd3c3n7rh6p2u0snkmdtcxm48rmmwrcsgvs4sx https://media.mathstodon.xyz/accounts/avatars/110/087/992/711/843/880/original/904683c7c9ff3158.png https://media.mathstodon.xyz/accounts/avatars/110/087/992/711/843/880/original/904683c7c9ff3158.png https://yabu.me/nevent1qqsdyhca95mxdc4wmrla2z90fszsghf023cfz4p34fqw7ga709xxkmgzypy9aa2kwr2c5hx4t890txpk8zx0cwlg9t37zwmd40qmw5u00dc0zpk8v8v In reply to <a href='/nevent1qqsfmklkanmvnqc2qwrszujy9xyse66hlmtqn5xfrqaszyw00cz0dsssagz7g'>nevent1q…gz7g</a><br/>_________________________<br/><br/>i wouldn&#39;t call myself an expert, but my master&#39;s degree is in mathematical general relativity. at a glance, this doesn&#39;t look like any paper i&#39;ve ever seen in mathematical general relativity. the researcher also appears to be employed by the research division of a mobile phone company, which makes me doubly suspicious. i can try to take a closer look later 2025-12-15T20:19:10Z https://yabu.me/nevent1qqsqsguf844ede9yay557qdae50zy4pn3twrnu7n6p9ngj8wm9lthfqzypy9aa2kwr2c5hx4t890txpk8zx0cwlg9t37zwmd40qmw5u00dc0z73djzh In reply to <a href='/nevent1qqs9mar2eee9mcjc53hy56f9cha0yrhzjc83k8jh68hare5hr6ewxyqaskwm9'>nevent1q…kwm9</a><br/>_________________________<br/><br/>okay, a couple of observations from computations. most probably aren&#39;t surprising.<br/><br/>first of all, light is blue-shifted rather than red-shifted. naturally, because there is no event horizon, there is no infinite red-shift at the event horizon.<br/><br/>as for orbits, the potential has no extrema, again somewhat unsurprisingly. although the singularity is naked, it isn&#39;t physically accessible, as the potential barrier goes to infinity near the singularity. gravitational lensing also isn&#39;t terribly surprising, although i struggle somewhat to visualise it! assuming the same impact parameter, you just get a sign change in the first-order approximation of the deflection, so instead of light rays being lensed around the black hole, they tend to be dispersed outward. maybe a better term here is gravitational mirroring? as best i can imagine, this sign reversal would make the black hole appear somewhat like a sort of weird spherical mirror. i wonder if i could hack into some computer simulation to better imagine what this would look like... 2025-09-28T14:46:13Z https://yabu.me/nevent1qqsw76w9hc2xyd0qgfrlc7dqxjcpvmgrf8nxjeq3d046gtamvscla6gzypy9aa2kwr2c5hx4t890txpk8zx0cwlg9t37zwmd40qmw5u00dc0zk0lrzp In reply to <a href='/nevent1qqs9t43r8j8at6mgwudm68gcvqutg96xsa4eattr3p4wklpzq730s2qdgnnks'>nevent1q…nnks</a><br/>_________________________<br/><br/>even if he doesn&#39;t succeed in cancelling existing grants, i can&#39;t imagine the chaos created by the fear and uncertainty. being canadian, i would really like to see our government move to make it easier for academics concerned about the trump administration interfering with their work to come to canada. i&#39;m thinking about writing an op-ed to a large newspaper to try to advance the idea, although i feel woefully underinformed to try to write such a thing 2025-02-14T08:24:18Z https://yabu.me/nevent1qqs8re9uac2zwwlxcqfpl433evuh5c2p5zztfhn5hka7z2kdg828gcqzypy9aa2kwr2c5hx4t890txpk8zx0cwlg9t37zwmd40qmw5u00dc0z02gvmq In reply to <a href='/nevent1qqsrsw20ugu69lcn9k9aqh853ak03e5l55c0k0rsjz0mur44xzmdfdsvmm7jd'>nevent1q…m7jd</a><br/>_________________________<br/><br/>this is enraging. i applied to the phd program at john&#39;s hopkins university last year (i was rejected, mind you, but anyway) specifically because i wanted to work with emily riehl. she&#39;s an incredible mathematician (and, i might add, an incredible asset to the american mathematical community)<br/><br/>i hope that she either finds a way to prevent the new administration from interfering with her work, or else is able to find a post as a university in a country in which ted cruz, who presumably hasn&#39;t has sat in a math class in thirty years, does not feel so confident as to claim that a grant supporting one of the foremost category theorists in the world is &#34;government waste&#34; 2025-02-14T07:29:35Z https://yabu.me/nevent1qqsrm9022nwxhfk95wr20rndj4rkvu8rlha8ge4vwmf8xvr6xldkagqzypy9aa2kwr2c5hx4t890txpk8zx0cwlg9t37zwmd40qmw5u00dc0zamtc54 In reply to <a href='/nevent1qqsd6zn6ckqmrnpz8phj8z4dx5p36x9eru3ljvvcaw3lwmvdtp7lrzgrykl7v'>nevent1q…kl7v</a><br/>_________________________<br/><br/>ah, what a shame! i don&#39;t really expect anyone else to pick up on (my) ilo, but if this is quite famous, it might be a good idea to rename. i&#39;m taking the names for everything from toki pona (the assembler is &#34;pali&#34;, the relocatable binary format is &#34;poki&#34;, and the linker is probably going to be called &#34;wan&#34;), but even then, &#34;ilo&#34; is a bit of an awkward name for an isa, since an isa isn&#39;t really a &#34;machine&#34; or a &#34;tool&#34; in its own right, so much as it is a specification or a set of rules. &#34;lawa&#34; might actually be a better name for the isa itself!<br/><br/>as a side note, uxn was a huge inspiration for me to start thinking about isa design. the implementation of uxn&#39;s isa that i wrote was actually the first emulator that i ever wrote! i spent three months this summer backpacking in japan, and i kept a little notebook for scribbling ideas in, and ilo ended up kind of coalescing in that notebook out of ideas that i assimilated from uxn, risc-v, and a bunch of other isas. i suppose that what i&#39;m trying to say is thank you for the inspiration that uxn provided! 2024-10-03T20:42:40Z