Tweet Archive 2020 03
Making light appear static in a 3D location in space. I wonder if there could be any applications of that..? https://twitter.com/tomscott/status/1234509808914632704
We had a collaboration with an artist when I was working on my PhD on 3D face shape. The communication, and the synergy, and the energy were very positive for our group. http://www.leeds.ac.uk/cath/ahrc/congress/2005/programme/abs/52.shtml
@JamieDJS ? https://twitter.com/ddiakopoulos/status/1234910583180259329
A parameter map for the Maginu reaction-diffusion rule. Thanks to Tiha von Ghyczy. da/dt = k1 * laplacian_a + alpha * (a - aaa) - b; db/dt = k2 * laplacian_b + epsilon * (a - gamma * b); For k1=k2=1, epsilon=0.5, alpha=[0.01,5] left-to-right, gamma=[0.01,3] bottom-to-top.
Replying to @tim_hutton
Kenjiro Maginu (1975) “Reaction-diffusion equation describing morphogenesis I. waveform stability of stationary wave solutions in a one dimensional model” Mathematical Biosciences Volume 27, Issues 1–2, Pages 17-98.
Replying to @tim_hutton
The region in the top-right is static, while at the bottom are dynamic wave fronts. The line between the static region and the advancing fronts we could call the Maginu line.
RT @sachgau: I’ve never wanted a cat and then I saw this video and now I want a cat
Replying to @tim_hutton
Animated version.
Ready file: https://github.com/GollyGang/ready/blob/gh-pages/Patterns/Maginu1975/maginu_parameter_map.vti
Replying to @FfKnighty
It’s showing channel ‘a’, with a linear map from [-1.3, 1.3] to [blue, red], as shown here:
Replying to @FfKnighty
Here are channels a and b, plus the magnitude and phase of a+ib, following your suggestion.
Replying to @xululululuuum
Over a much longer time scale most of the top part does actually change. I suspect all of it does but this pattern is quite hard to simulate numerically.
Run it yourself to explore: https://github.com/GollyGang/ready https://raw.githubusercontent.com/GollyGang/ready/gh-pages/Patterns/Maginu1975/maginu_parameter_map.vti
Replying to @xululululuuum
A zoom into the lower-right corner where things looked static, over an even longer time scale. Fascinating things going on here. @mrob_27 A vortex approaches the Maginu line and is destroyed.
All of this behavior comes from the differential equation given earlier.
The UK is just 13 days behind Italy but our government decided today to keep our schools and universities and nurseries open.
They had no time for experts when they were lying about Brexit. And now in power they have no time for experts when it comes to people’s lives. https://twitter.com/MarkJHandley/status/1237781162153717760
Replying to @AjdDavison
I didn’t but Jeremy Hunt on C4 news saying that the good news from the briefing is that we’re 4 weeks behind Italy, which is dramatically wrong.
Replying to @AjdDavison
Also reported here: https://www.theguardian.com/world/2020/mar/12/uk-moves-to-delay-phase-of-coronavirus-plan
Replying to @AjdDavison
Thanks, have watched it. Everything makes sense but the lack of immediate action stems from their claim that we’re 4 weeks behind Italy. This fundamental point seems to be contradicted by the data.
RT @JamieDJS: Our team in Cambridge is hiring! Our diverse team of highly talented CV scientists, SW/HW engineers, designers and artists ar…
One parent must have white with black stripes, the other black with white stripes.
(This is a reaction-diffusion joke, see https://www.nationalgeographic.com/science/phenomena/2010/09/07/spots-plus-spots-equals-maze-how-animals-create-living-patterns/) https://twitter.com/knotunknot/status/1238432945494515713
RT @hamish_todd: Here’s the interactive documentary I’ve been working on for 3 years! http://viruspatterns.com It’s about viruses, patterns,…
RT @johncarlosbaez: Italian doctors are begging other countries to institute a complete lockdown now.
“As long as the rate of increase…
RT @AdamRutherford: From the British Society of Immunology:
1) more social distancing measures to limit COVID-19 cases in the short term,…
RT @statto: The Government’s advice is based on the idea that people will get bored of constantly avoiding public places and not seeing the…
RT @glynmoody: “For suppression, early action is important,and interventions need to be in place well before healthcare capacity is over…
RT @panlepan: @HumanEarthPig @tessellationfan Nice !
RT @AnthonyHopkins: Niblo is making sure I stay healthy and demands I entertain him in exchange… cats 🤷🏼♂️
Hey The Bread @FermentDC, now that we’re all quarantined, can you teach us all to make bread?
We promise to submit our photos for judging.
China now has an exit strategy: lots of testing, instant regional lockdowns when needed, relaxed lockdowns where possible. Then wait for a vaccine.
https://www.theguardian.com/world/2020/mar/19/china-reports-no-domestic-cases-of-coronavirus-for-first-time-since-outbreak-began
Replying to @tim_hutton
Their strategy of strong lockdowns has been completely vindicated. If Europe had been paying attention we would have locked down much sooner.
Replying to @yaneerbaryam
And yet the UK’s chief medical adviser is saying today about social distancing measures: “If you do them too early you get all the negatives but almost an immeasurable impact on the epidemic.”
Why would he say such a thing?
https://www.theguardian.com/politics/live/2020/mar/19/uk-coronavirus-live-boris-johnson-london-lockdown-williamson-refuses-to-rule-out-government-putting-london-in-lockdown-by-weekend?page=with:block-5e735dd68f085e564ad8710b#block-5e735dd68f085e564ad8710b
RT @jonathanfly: NeRF: Representing Scenes as Neural Radiance Fields for View Synthesis
Input is images with known camera poses. Can’t wai…
I’m seeing criticism of Boris’ “12 weeks to turn the tide” comment but it took just 8 weeks of strict lockdown in Wuhan to stop the spread.
The Platform is so topical it hurts.
RT @DanielZeichner: NHS Volunteer Responders launches. A quarter of a million healthy volunteers are needed to help the NHS for shopping, s…
Day 14: It is such a relief to know that the cats are doing all my paperwork and replying to all the emails.
A parameter map of Stephan Rafler’s SmoothLife, showing behavior at nearby parameters. The original SmoothLifeL is at the center, with parameters s1 and s2 varying across the image.
Replying to @farty and @Flexi23
It’s almost a reaction-diffusion system -the neighborhood is non-local (discs) but quite small.
Systems with long-range effects like gravity would be a bit weird. Might be fun to think about what it would mean to have the gravitational constant vary across space.
Replying to @SoftologyComAu
Many thanks for writing this up. Now implemented in Ready too. https://github.com/GollyGang/ready/blob/gh-pages/Patterns/Kobayashi1993/dendrites.vti
Replying to @roice713, @HypercubicPeg and @marctenbosch
Just need to bend space a little. It only takes a little curvature to make the tetrahedra fit. http://timhutton.github.io/hyperplay/index_sliders.html?f0=1.732&f1=1.633&f2=0.618 (third slider)
Laplacian growth.
m = alpha / pi * atan(gamma(teq-b)) da/dt = D_alaplacian_a + a(1-a)(a-0.5+m)/tau db/dt = D_blaplacian_b + kda/dt
Thanks to @SoftologyComAu and @nervous_system for showing the way.
Runs in real time in Ready: https://github.com/GollyGang/ready
Replying to @Anno0770, @HirokiSayama, @SoftologyComAu and @nervous_system
A constant. Details can be found via: https://softologyblog.wordpress.com/2020/03/29/dendritic-crystal-growth/
To run the system yourself, there’s a Ready file here: https://github.com/GollyGang/ready/blob/gh-pages/Patterns/Kobayashi1993/laplacian_growth_3D.vti
Replying to @tim_hutton
Some gorgeous images here, from when Nervous System was exploring this kind of system: https://n-e-r-v-o-u-s.com/projects/albums/laplacian-growth/
Replying to @tim_hutton
https://youtu.be/B8jUH-2AP14