Steve Trettel
@stevejtrettel.bsky.social
Math Prof: Geometry, Topology and Illustration at University of San Francisco. Minnesotan, from the occupied lands of the Dakota people.
Summers here - time to catch up sharing some of what I’ve been up to! First up - *gravitational photography* - using (simulated) black holes instead of lenses to focus an image onto a screen. Can you see the ghostly dinosaur? 1/n
May 20, 2025 at 9:29 PM
Summers here - time to catch up sharing some of what I’ve been up to! First up - *gravitational photography* - using (simulated) black holes instead of lenses to focus an image onto a screen. Can you see the ghostly dinosaur? 1/n
The regular hexagon can be rolled up isometrically into a flat torus in 4 dimensional space: here’s a stereographic projection of the result. (Can you see the hexagonal pattern in the spheres covering its surface? 😁)
January 20, 2025 at 10:12 PM
The regular hexagon can be rolled up isometrically into a flat torus in 4 dimensional space: here’s a stereographic projection of the result. (Can you see the hexagonal pattern in the spheres covering its surface? 😁)
Here’s a cute lil donut!
January 19, 2025 at 11:58 PM
Here’s a cute lil donut!
Fun pic from a new project! Drawing lots of donuts today 😁
January 19, 2025 at 11:26 PM
Fun pic from a new project! Drawing lots of donuts today 😁
Best of luck to all taking the Putnam today, from our team here at USF! 🤓🤘
December 7, 2024 at 5:13 PM
Best of luck to all taking the Putnam today, from our team here at USF! 🤓🤘
I have a second piece display at O'Hanlon Center for the Arts in Mill Valley CA this month, entitled "Julia". Here it is, and a short math-explainer of what we're looking at
December 6, 2024 at 8:13 PM
I have a second piece display at O'Hanlon Center for the Arts in Mill Valley CA this month, entitled "Julia". Here it is, and a short math-explainer of what we're looking at
This book is incredibly good
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December 6, 2024 at 6:50 AM
This book is incredibly good
My artwork "Many Paths to the Beach" is currently on display at O'Hanlon Center for the Arts in Mill Valley CA. here's a math explainer thread: what are we looking at here?
December 4, 2024 at 8:11 PM
My artwork "Many Paths to the Beach" is currently on display at O'Hanlon Center for the Arts in Mill Valley CA. here's a math explainer thread: what are we looking at here?
So honored to have some of my pieces on display at O’Hanlon Center for the Arts in their exhibition “Chaos” this month. This one is titled “Many Paths to the Beach” (explanatory thread to follow once I’m to my office)
December 4, 2024 at 7:30 PM
So honored to have some of my pieces on display at O’Hanlon Center for the Arts in their exhibition “Chaos” this month. This one is titled “Many Paths to the Beach” (explanatory thread to follow once I’m to my office)
Bay Area people: I’m really excited to have two pieces of mathematical art on display at O’Hanlon Center for the Arts in Mill Valley, for their exhibition “Chaos”. The opening reception is today 530-7pm! www.ohanloncenter.org/event/chaos-...
CHAOS Gallery Show Art Talk and Reception | O'Hanlon Center for the Arts
www.ohanloncenter.org
December 3, 2024 at 5:24 PM
Bay Area people: I’m really excited to have two pieces of mathematical art on display at O’Hanlon Center for the Arts in Mill Valley, for their exhibition “Chaos”. The opening reception is today 530-7pm! www.ohanloncenter.org/event/chaos-...
The hopf fibers corresponding to the vertices of a regular dodecahedron
December 2, 2024 at 11:26 PM
The hopf fibers corresponding to the vertices of a regular dodecahedron
Some points on the sphere and their preimages under the hopf map
December 2, 2024 at 8:41 PM
Some points on the sphere and their preimages under the hopf map
Some more good fibration - I really like how this one came out 😃
December 2, 2024 at 8:36 PM
Some more good fibration - I really like how this one came out 😃
Some fibers of the Hopf Fibration
December 2, 2024 at 8:04 AM
Some fibers of the Hopf Fibration
Here's what it would look like to travel in a distant orbit to two extremal charged black holes, which themselves are stationary (grav/electrostatic in balance). As you orbit you see one pass in front of the other and lens it; Ive colored light rays green/red which enter their respective horizons.
November 26, 2024 at 3:06 AM
Here's what it would look like to travel in a distant orbit to two extremal charged black holes, which themselves are stationary (grav/electrostatic in balance). As you orbit you see one pass in front of the other and lens it; Ive colored light rays green/red which enter their respective horizons.
Still having fun with Majumdar Papapetrou black holes over here :) This animation shows six such black holes arranged on the vertices of an octahedron, and traces a null geodesic from a nearby observer. The trajectory, and which BH it enters, depends very sensitively on the initial condition
November 25, 2024 at 6:44 PM
Still having fun with Majumdar Papapetrou black holes over here :) This animation shows six such black holes arranged on the vertices of an octahedron, and traces a null geodesic from a nearby observer. The trajectory, and which BH it enters, depends very sensitively on the initial condition
@mseri.me introduced me to Majumdar–Papapetrou black holes through his+collaborators paper on the chaotic trajectories of light around 3 or more such black holes. Here's some intrinsic raytraced views of the N=3 case, where light rays falling into each are colored red/green/blue respectively.
November 24, 2024 at 7:05 PM
@mseri.me introduced me to Majumdar–Papapetrou black holes through his+collaborators paper on the chaotic trajectories of light around 3 or more such black holes. Here's some intrinsic raytraced views of the N=3 case, where light rays falling into each are colored red/green/blue respectively.
Recently learned about Mamjudar-Papapetrou solutions in GR: masses attract but like charges repel, so if you throw enough charge into a collection of black holes they can remain static! Here's such a collection of BHs arranged cubically, and a (numerically found) closed null geodesic.
November 24, 2024 at 6:39 PM
Recently learned about Mamjudar-Papapetrou solutions in GR: masses attract but like charges repel, so if you throw enough charge into a collection of black holes they can remain static! Here's such a collection of BHs arranged cubically, and a (numerically found) closed null geodesic.
One of my fav GR pics for you blueskiers! A bit outside the horizon of a nonrotating black hole lies the photon sphere - a “point of no return” for infalling light. Here’s a light ray that makes a brush with death - skimming the photon sphere, doing a loop, then continuing on its merry way
November 19, 2024 at 5:44 PM
One of my fav GR pics for you blueskiers! A bit outside the horizon of a nonrotating black hole lies the photon sphere - a “point of no return” for infalling light. Here’s a light ray that makes a brush with death - skimming the photon sphere, doing a loop, then continuing on its merry way
Just got into Orange County - beautiful morning for a walk into UC Irvine to talk about mathematical physics!
November 18, 2024 at 5:43 PM
Just got into Orange County - beautiful morning for a walk into UC Irvine to talk about mathematical physics!
Heading down to Southern California today to visit UCI and talk about Newtonian physics in the presence of curvature . So here’s a fun fact: there is no Galilean relativity in curved space ! You can do experiments to determine your precise velocity
November 17, 2024 at 6:06 PM
Heading down to Southern California today to visit UCI and talk about Newtonian physics in the presence of curvature . So here’s a fun fact: there is no Galilean relativity in curved space ! You can do experiments to determine your precise velocity
Hello all! I’m bad at keeping up with multiple social medias but as people move here figured I should reintroduce myself 😃 I’m a mathematician at the university of San Francisco who has gotten himself too deep into a computer graphics hobby. Here’s a couple algebraic varieties to cheer up your day ☺️
November 15, 2024 at 8:40 PM
Hello all! I’m bad at keeping up with multiple social medias but as people move here figured I should reintroduce myself 😃 I’m a mathematician at the university of San Francisco who has gotten himself too deep into a computer graphics hobby. Here’s a couple algebraic varieties to cheer up your day ☺️
I’ll also try to advertise my talks here 😁.
Bay Area math lovers - ever wonder why black holes look like this? I’m giving a public talk on curved space and general relativity at the Castro Valley public library tonight (Wed. Oct 25) at 7pm.
Register (free!) here:
wonderfest.org/curved-space...
Bay Area math lovers - ever wonder why black holes look like this? I’m giving a public talk on curved space and general relativity at the Castro Valley public library tonight (Wed. Oct 25) at 7pm.
Register (free!) here:
wonderfest.org/curved-space...
October 25, 2023 at 5:23 PM
I’ll also try to advertise my talks here 😁.
Bay Area math lovers - ever wonder why black holes look like this? I’m giving a public talk on curved space and general relativity at the Castro Valley public library tonight (Wed. Oct 25) at 7pm.
Register (free!) here:
wonderfest.org/curved-space...
Bay Area math lovers - ever wonder why black holes look like this? I’m giving a public talk on curved space and general relativity at the Castro Valley public library tonight (Wed. Oct 25) at 7pm.
Register (free!) here:
wonderfest.org/curved-space...