herid @herid@qoto.org
- Planet
- Earth
- Country
- Canada
Refugee from twitter. I am into math, tech, clean energy, EVs, COVID info, books, movies, music.
Based in Toronto. Support Ukraine.
Boosts=endorsements twitter:https://twitter.com/heridfan
Joined Nov 2022
@undefined @johncarlosbaez they generate the whole G_2. Lie subgroups of G_2 are well understood. as the set of inner automorphisms you describe is 6-dimensional the only possibilities we need to exclude is that it generates a copy of SU(3) which is 8 dimensional or a copy of SO(4) (all other proper subgroups of G_2 have dimensions <6). It should be easy to see that it's not SO(4) which is also 6-dimensional.
SU(3) can be excluded as follows.
All SU(3) in G_2 are known to come about as follows. G_2 acts on S^6=unit imaginary octonians and various SU(3) in G_2 are isotropy subgroups of different points in S^6. if all inner automorphisms were in an isotropy group of some point v in S^6 that v would be in the center of octonions. This is impossible and hence Inner automorphisms generate all of G_2.
@johncarlosbaez It is certainly can't be true that composition of inner automorphisms must be an inner automorphism for that would make it into a subgroup of \(G_2\), in fact, a closed subgroup and what you describe is certainly not that.
herid
boosted
What are the inner automorphisms of the octonions?
Of course this is an odd question. Since the octonions are nonassociative you might even guess the map
𝑓: 𝕆 → 𝕆
given by
𝑓(𝑥) = 𝑔𝑥𝑔⁻¹
for a nonzero octonion 𝑔 isn't well-defined! After all, maybe we have
(𝑔𝑥)𝑔⁻¹ ≠ 𝑔(𝑥𝑔⁻¹)
But in fact this is a red herring.
(1/n)
(Below we see my friend the physicist Nichol Furey, a big fan of the octonions, standing in front of the Fano plane, which can be used to multiply them.)
herid
boosted
herid
boosted
Companies like HR Block and Intuit have spent millions lobbying against free tax prep. It's money well spent, because tax prep makes billions for these companies. The biggest tax prep companies formed something called "the #FreeFileAlliance" that purported to offer free tax-prep to low- and medium-income Americans.
8/
@pluralistic yikes! do you know if the same is true for the Canadian H&R block?
herid
boosted
If you were unfortunate enough to e-file your US #tax using HR Block, Taxact or Taxslayer, your most sensitive financial information was nonconsenually shared with Facebook, where it was added to the involuntary dossier the company maintains billions of people, including people who don't have Facebook accounts.
1/
herid
boosted
You can define operations on [-∞,∞) depending on a positive real number called the 'temperature' 𝑇 in such a way that:
1) for any 𝑇 > 0, you get a rig isomorphic to [0,∞) with its usual + and × . (A 'rig' is a ring without negatives.)
2) in the limit 𝑇→ 0, you get a version of the 'tropical rig', where addition is min and multiplication is + on [-∞,∞).
Yeah, the terminology is bad: the 'tropical rig' is a low-temperature limit! They should have called it the 'arctic rig'.
(1/n)
herid
boosted
Our toddler has been testing positive on rapid antigen tests for more than 6 months. We’ve consulted many doctors and specialists and were told they are seeing a lot of “persistent viral shedding” in this age group. Guess what the advice was... STOP TESTING!
https://twitter.com/fitterhappierAJ/status/1594739187752013824?s=20&t=Rfqg1dKUHk16iI957NZMyw
herid
boosted
Epidemiologist @deonandan, on the efficacy of masks in light of surging numbers of respiratory diseases.
The short version: "Masks work. Of course they do. They work as imperfect personal protection and as highly impactful community protection."
A great deal of data and nuance in his post.
http://blog.deonandan.com/wordpress/2022/11/covid-19-do-masks-work.html
herid
boosted
Musk’s reign at Twitter has increased risks to users—especially those in crisis zones around the world who flocked to Twitter for expression during unrest—by unraveling guardrails against misinformation, harassment, and censorship. https://www.eff.org/deeplinks/2022/11/twitters-monetizable-users-not-human-rights-matter-most-under-musks-rein-leaving
PSA from our PM on twitter
Canadians can now purchase Ukraine Sovereignty Bonds. These bonds allow Canadians to provide direct support to Ukraine, so the Ukrainian government can keep providing essential services. Find out more here: https://bit.ly/3TUGmV2
@Pwnallthethings high profile accounts seem most hesitant to leave. which is sort of understandable. although I noticed that because relatively few of them moved those that did got pretty large followings here quickly. still not nearly as large as they had on twitter.
herid
boosted
An official Google social account is now on Mastodon https://ift.tt/3temu56 #ntt
@taz neither have I. was thinking someone might know a hacky way. using css perhaps.
stupid question but is it possible to adjust the width of columns in #mastodon advanced view?
This is in the browser.
herid
boosted
I also don't think it is a serious solution to tell people, especially those from vulnerable communities, to just go find a server that respects them / allows them to criticize racism, etc.
People are joining Mastodon in good faith, but if they encounter these problems once, twice or more, it starts to send them the message they're not welcome here. It becomes a real brand problem and platform integrity issue.
- Planet
- Earth
- Country
- Canada
Refugee from twitter. I am into math, tech, clean energy, EVs, COVID info, books, movies, music.
Based in Toronto. Support Ukraine.
Boosts=endorsements twitter:https://twitter.com/heridfan
Joined Nov 2022
