Dr. Rook Bridson
@rookbridson.bsky.social
she/her 🏳️⚧️🏳️🌈
Mathematician in metro Vancouver, working on VFX software in simulation/numerics/geometry. You may know me as the inventor of FLIP for incompressible flow, curl-noise, a very simple fast Poisson disc algorithm, my fluids book, cloth stuff…
Mathematician in metro Vancouver, working on VFX software in simulation/numerics/geometry. You may know me as the inventor of FLIP for incompressible flow, curl-noise, a very simple fast Poisson disc algorithm, my fluids book, cloth stuff…
Horrifying.
And yeah, that makes an absolute no to the idea of US travel for me until It Happens.
And yeah, that makes an absolute no to the idea of US travel for me until It Happens.
And here is my story: ‘Absolute hell’: Irishman with valid US work permit held by Ice since September
www.irishtimes.com/world/us/202...
www.irishtimes.com/world/us/202...
‘Absolute hell’: Irishman with valid US work permit held by Ice since September
Seamus Culleton has been in a detention facility in Texas for nearly five months despite having no criminal record
www.irishtimes.com
February 9, 2026 at 2:58 PM
Horrifying.
And yeah, that makes an absolute no to the idea of US travel for me until It Happens.
And yeah, that makes an absolute no to the idea of US travel for me until It Happens.
I am absolutely not a software developer, but working with developers I think I am finding my preferred approach to big new algorithmic features — thinking of my output as including an accurate whitepaper with full details of implementing the new algorithm (NOT a conference paper), …
February 3, 2026 at 5:05 PM
I am absolutely not a software developer, but working with developers I think I am finding my preferred approach to big new algorithmic features — thinking of my output as including an accurate whitepaper with full details of implementing the new algorithm (NOT a conference paper), …
When the bug is actually just in your test harness, not the code you're testing...
January 31, 2026 at 9:59 PM
When the bug is actually just in your test harness, not the code you're testing...
My roving curiosity and flexibility are absolutely things I love about myself, but from time to time I'm keenly aware of how I have Too Many Interests to possibly have the time and energy to develop them all. I could so easily be the proverbial jack of all trades, master of none ...
January 31, 2026 at 6:08 PM
My roving curiosity and flexibility are absolutely things I love about myself, but from time to time I'm keenly aware of how I have Too Many Interests to possibly have the time and energy to develop them all. I could so easily be the proverbial jack of all trades, master of none ...
Reposted by Dr. Rook Bridson
This is insane, but expected thanks to all that “clarity.”
January 27, 2026 at 8:42 AM
This is insane, but expected thanks to all that “clarity.”
Reposted by Dr. Rook Bridson
What he says here about liberal critiques of the culture war - "as if the terms of a fight can be determined by the person getting punched" - captures 98% of discourse about trans rights activism.
"You're losing public opinion" no shit sherlock, do you have a spare $200m a year to even the scales
"You're losing public opinion" no shit sherlock, do you have a spare $200m a year to even the scales
Ta-Nehisi Coates: With the killings of Renee Good and Alex Pretti, "Trump has clarified an inconvenient fact—the culture war is an actual war"
“The Homeland” Is War on America: The Blood-and-Soil Nationalism That Killed Renee Good and Alex Pretti
In the killings of Renee Good and Alex Pretti, Trump has clarified an inconvenient fact: the culture war is an actual war.
www.vanityfair.com
January 26, 2026 at 11:22 PM
What he says here about liberal critiques of the culture war - "as if the terms of a fight can be determined by the person getting punched" - captures 98% of discourse about trans rights activism.
"You're losing public opinion" no shit sherlock, do you have a spare $200m a year to even the scales
"You're losing public opinion" no shit sherlock, do you have a spare $200m a year to even the scales
the joy, and irritation, of continually finding intriguing new mathematical problems while trying to get a (good) working baseline solver going 😂
January 26, 2026 at 6:52 PM
the joy, and irritation, of continually finding intriguing new mathematical problems while trying to get a (good) working baseline solver going 😂
Reposted by Dr. Rook Bridson
Recently, a research team uncovered a strange exception to a mathematical rule: a pair of twisty, closed-up surfaces that are defined by the same local measurements, despite having completely different global structures.
Two Twisty Shapes Resolve a Centuries-Old Topology Puzzle | Quanta Magazine
The Bonnet problem asks when just a bit of information is enough to uniquely identify a whole surface.
www.quantamagazine.org
January 23, 2026 at 9:04 PM
Recently, a research team uncovered a strange exception to a mathematical rule: a pair of twisty, closed-up surfaces that are defined by the same local measurements, despite having completely different global structures.
Reposted by Dr. Rook Bridson
lol: that is, or in principle could be, amusing
actual lol: I have produced a sound, contrary to social convention
lmao: I appreciate the humor of the situation
actual lmao: nearby strangers are becoming concerned
rotfl: that is genuinely funny
actual rotfl: emergency services are already en route
actual lol: I have produced a sound, contrary to social convention
lmao: I appreciate the humor of the situation
actual lmao: nearby strangers are becoming concerned
rotfl: that is genuinely funny
actual rotfl: emergency services are already en route
January 23, 2026 at 12:49 PM
lol: that is, or in principle could be, amusing
actual lol: I have produced a sound, contrary to social convention
lmao: I appreciate the humor of the situation
actual lmao: nearby strangers are becoming concerned
rotfl: that is genuinely funny
actual rotfl: emergency services are already en route
actual lol: I have produced a sound, contrary to social convention
lmao: I appreciate the humor of the situation
actual lmao: nearby strangers are becoming concerned
rotfl: that is genuinely funny
actual rotfl: emergency services are already en route
Reposted by Dr. Rook Bridson
I read The Anxious Generation and once I saw he compared being trans to a contagion it immediately cast not only the rest of the book in doubt but everyone who has bought what he's selling hook line and sinker
It's incredible how effective transphobia is as a litmus test for SO many issues. Every time I find a new pro-surveillance tech stooge, they're transphobic. I think people need to understand how tightly the belief that the internet is turning everyone trans is bound up w mass surveillance efforts
Jonathan Haidt Promoted a Fringe Theory on Trans Youth — Assigned
The author of “The Anxiety Generation” told Margaret Hoover for PBS that young people become trans due to peer contagion effects. There is no evidence for this claim.
www.assignedmedia.org
January 23, 2026 at 1:11 PM
I read The Anxious Generation and once I saw he compared being trans to a contagion it immediately cast not only the rest of the book in doubt but everyone who has bought what he's selling hook line and sinker
I have a remarkable memory for things which intrigue me or engage my reasoning in some way — which is perfect for a mathematician in a niche where she often is bridging a few specialities across computational physics, computational geometry, numerical linear algebra etc
BUT…
BUT…
January 23, 2026 at 5:38 PM
I have a remarkable memory for things which intrigue me or engage my reasoning in some way — which is perfect for a mathematician in a niche where she often is bridging a few specialities across computational physics, computational geometry, numerical linear algebra etc
BUT…
BUT…
When it’s working (close enough to solution) full Newton beats Gauss-Newton for nonlinear least-squares
but you can also see it from the angle of constrained minimization, where if you translate the problem to:
minimize |y|^2 with a constraint y-f(x)=0,
but you can also see it from the angle of constrained minimization, where if you translate the problem to:
minimize |y|^2 with a constraint y-f(x)=0,
January 21, 2026 at 1:22 AM
When it’s working (close enough to solution) full Newton beats Gauss-Newton for nonlinear least-squares
but you can also see it from the angle of constrained minimization, where if you translate the problem to:
minimize |y|^2 with a constraint y-f(x)=0,
but you can also see it from the angle of constrained minimization, where if you translate the problem to:
minimize |y|^2 with a constraint y-f(x)=0,
Once again I have run out of meaningful letters to assign to mathematical quantities, without ambiguous double uses. Occasionally I wonder why papers on a given topic will choose different letters to represent the same quantity — surely it would be better to pick one as a universal standard?...
January 19, 2026 at 8:45 PM
Once again I have run out of meaningful letters to assign to mathematical quantities, without ambiguous double uses. Occasionally I wonder why papers on a given topic will choose different letters to represent the same quantity — surely it would be better to pick one as a universal standard?...
It’s … enlightening? to discover there are an awful lot of men out there who will group a perfectly normal headshot photo of me, like my profile picture here, together with explicit hardcore porn simply because I am trans.
January 17, 2026 at 12:37 AM
It’s … enlightening? to discover there are an awful lot of men out there who will group a perfectly normal headshot photo of me, like my profile picture here, together with explicit hardcore porn simply because I am trans.
Reposted by Dr. Rook Bridson
You're telling me a woman was forced to give up her trophy to a biological male
María Corina Machado on her meeting with Trump: “I presented the president of the United States with the Nobel Peace Prize”
January 15, 2026 at 9:53 PM
You're telling me a woman was forced to give up her trophy to a biological male
It has been almost two years of she/her pronouns, after two years of they/them, and to be honest I am only just getting used to hearing other people use them for me
They/them feels more natural still, at some level — even before realizing I’m trans, I had preferred that on feminist grounds, …
They/them feels more natural still, at some level — even before realizing I’m trans, I had preferred that on feminist grounds, …
January 15, 2026 at 5:57 PM
It has been almost two years of she/her pronouns, after two years of they/them, and to be honest I am only just getting used to hearing other people use them for me
They/them feels more natural still, at some level — even before realizing I’m trans, I had preferred that on feminist grounds, …
They/them feels more natural still, at some level — even before realizing I’m trans, I had preferred that on feminist grounds, …
We traded in our old minivan for a used Prius yesterday (empty nesting began this school year!), and while doing all the documents I realized it was the first time I have seen Ms. Rook Bridson written somewhere — another little moment of transsexual joy! 🥰
January 15, 2026 at 5:34 PM
We traded in our old minivan for a used Prius yesterday (empty nesting began this school year!), and while doing all the documents I realized it was the first time I have seen Ms. Rook Bridson written somewhere — another little moment of transsexual joy! 🥰
Remembering as a kid when there were so many distinct computer systems out there and I had a special interest in reading about their details (despite having zero expectation of ever using them), and keyboards with lots of function keys seemed so cool
i don’t think i have ever used a function key 🙂
i don’t think i have ever used a function key 🙂
January 14, 2026 at 8:39 PM
Remembering as a kid when there were so many distinct computer systems out there and I had a special interest in reading about their details (despite having zero expectation of ever using them), and keyboards with lots of function keys seemed so cool
i don’t think i have ever used a function key 🙂
i don’t think i have ever used a function key 🙂
I thought I had learned my lesson in this work problem — where I had jumped to 3D and gotten hopelessly stuck in the complexity, then went back and did the 2D case and saw how I could simplify expressions much earlier.
So I went back to 3D with those lessons, but still got stuck in complexity
So I went back to 3D with those lessons, but still got stuck in complexity
January 14, 2026 at 7:12 PM
I thought I had learned my lesson in this work problem — where I had jumped to 3D and gotten hopelessly stuck in the complexity, then went back and did the 2D case and saw how I could simplify expressions much earlier.
So I went back to 3D with those lessons, but still got stuck in complexity
So I went back to 3D with those lessons, but still got stuck in complexity
this is also freaking me out, for fires, for water supply, for a changing insect/pest/disease environment when no freezing weather allows creatures from gentler climates to survive here
It's the middle of winter in Vancouver, there hasn't been a single snowflake since last winter, and some of the cherry blossoms just started to bloom. I can feel the wildfire season from here.
January 14, 2026 at 6:23 PM
this is also freaking me out, for fires, for water supply, for a changing insect/pest/disease environment when no freezing weather allows creatures from gentler climates to survive here
Just was shown this gem of a tool and associated research!
Herbie: Automatically Improving Floating Point Accuracy
herbie.uwplse.org
January 8, 2026 at 7:36 PM
Just was shown this gem of a tool and associated research!
“Too many projects” feels like my life motto, not just in research terms but also (simultaneously) tackling transition and multifaceted mental illness and somehow also new passions like dance, alongside existing efforts in music and art. While parenting four kids to adulthood.
January 7, 2026 at 2:11 AM
“Too many projects” feels like my life motto, not just in research terms but also (simultaneously) tackling transition and multifaceted mental illness and somehow also new passions like dance, alongside existing efforts in music and art. While parenting four kids to adulthood.
With the emails and invitations coming in for SIGGRAPH 2026, it’s hitting that I do have to make a choice about travel to the US next year
I think the probability of a bad event for me (either with the border or generally in LA) is very tiny, but it’s not zero & the consequences could be awful…
I think the probability of a bad event for me (either with the border or generally in LA) is very tiny, but it’s not zero & the consequences could be awful…
December 30, 2025 at 5:00 PM
With the emails and invitations coming in for SIGGRAPH 2026, it’s hitting that I do have to make a choice about travel to the US next year
I think the probability of a bad event for me (either with the border or generally in LA) is very tiny, but it’s not zero & the consequences could be awful…
I think the probability of a bad event for me (either with the border or generally in LA) is very tiny, but it’s not zero & the consequences could be awful…
A really great thing to check in both papers and code simulating physics is whether formulas make dimensional sense, or if they purposefully don't* you are sure you understand why.
Sometimes this reveals an actual mistake or bug, sometimes it indicates to you that you _should_ pick a scaling.
Sometimes this reveals an actual mistake or bug, sometimes it indicates to you that you _should_ pick a scaling.
November 27, 2025 at 11:12 PM
A really great thing to check in both papers and code simulating physics is whether formulas make dimensional sense, or if they purposefully don't* you are sure you understand why.
Sometimes this reveals an actual mistake or bug, sometimes it indicates to you that you _should_ pick a scaling.
Sometimes this reveals an actual mistake or bug, sometimes it indicates to you that you _should_ pick a scaling.