Clem Tillier

Do vehicle intrusion barriers still work if installed backwards?

I always thought under-slung BART wouldn’t fit through the Golden Gate Bridge towers, but it turns out BART is small and the bridge is huge. Here is a mockup in 1/100 scale, BART fits easily.

Shadow of the future

@worldbollardassoc.bsky.social did you send the check

Extreme dahlia today

Now out! Part 2 on the Geary metro, discussing its East Bay connection, downtown alignment, and yard location.

Umberto Boccioni’s “Unique Forms of Continuity in Space.” I had to walk around it three times to understand how it moved without motion. en.wikipedia.org/wiki/Unique_...

One of the neatest observations made by lightning mappers: we clocked this meteor fireball at ~57 kilometers per second (125,000 mph). That is FAST!

This nicely explains why SpaceX valuation is unmoored from the laws of thermodynamics. Cooling GPUs without conduction or convection is not the “no brainer” they claim.

New on the blog: how @caltrain.com could accomplish level boarding soon, fast and cheap. This is their most important capital project.

I spent the last month obsessed with finding colors that can't be displayed on a conventional screen. This is what I found. moultano.wordpress.com/2026/06/19/w...

On weekends, I like how you can use Caltrain like a horizontal elevator, just push a city’s button and whoosh, there you are, ding!

A bolide exploded high above New England in Earth's atmosphere on Saturday afternoon, creating a loud booming noise that was heard across the region. The flash of the exploding meteor was detected from the GOES-19 weather satellite's GLM instrument.

Progress! The more I work on this, I’m thinking it will be a shame to cover it with the road deck. Maybe a transparent deck? During construction, the girder seen here was painted with giant letters “McClintic Marshall,” the name of one of the steel suppliers. Thought about it, but it’s too cryptic.

Oil and gas might go the way of whale blubber sooner than we think!

"the dramatic cost declines in batteries have now made 'firm renewables' — solar or wind paired with batteries — cheaper than fossil fuels in many parts of the world." This is game changing.

This is a brilliant way to think about infrastructure: “for every obstacle encountered: is this a rock, or is this a person?”

After mixing up a fresh batch of International Orange (not a standard Tamiya color) this subassembly is almost ready to install on the bridge tower.

GLM has been game-changing for the community that monitors meteors. Great example! It’s also one of the many new capabilities that would be lost in the current plan to stop flying a GLM-like instrument after the current fleet reaches end of life.

Reverend Jesse Jackson called on each of us to be heralds of change, to be messengers of hope; to step forward and say “Send me” wherever we have a chance to make an impact. How fortunate we were that Jesse Jackson answered that call. What a great debt we owe to him.

How to identify American fascists as stated by our own US government in March of 1945.

This is the way

Whoa we’re bombing Venezuepstein!

Hard to believe a FIFA Peace Prize laureate would do this.

@jeffwise.bsky.social watching your vids, it bugs me that you assume mh370 was in a pristine state (no malfunctions.) This underpins the idea that the sequence of events was weird. It is only weird for a pristine system that behaves according to docs & design intent, which damaged systems may not!

🚨🔥 Warmest Christmas on record for the Contiguous U.S.! The average high of 57.9F and the average low of 36.6F each broke the Christmas record by a full 3F. 🔥🚨

New blog post by @ctillier.bsky.social. I'd be curious to learn more about proposal #4 for improving trip time, modular/quick-build platform height increases, and about comparable examples.

From the hang time (~10 seconds from apex to ground), looks like this fountain is almost 500 meters high. Easily clears Eiffel Tower.

California shut down its last coal plant last week and nobody even noticed, it made so little little difference. Meanwhile solar is up 17% and gas is down 17% from 2024. I have a few highlights... www.climatecoloredgoggles.com/p/ding-dong-...

Alrighty, ready to see something really cool? (and maybe a little nauseating) The evolution of Hurricane Melissa's mesovortices at peak strength.

A display of pure power from Hurricane Melissa today. Remarkable satellite imagery.

Magnitude 8.0 upzoning - 0 km from Sacramento, CA - 2025-10-10 17:00:00 UTC - TSUNAMI of SB 79 housing expected in all urban areas of California. Nice new apartments will reach 6 stories over normal housing heights. RECOMMENDED ACTION stay in CA to enjoy affordable housing with great transportation

MAJOR NEWS: @GavinNewsom signed SB 79, my bill allowing more housing near public transit — rail, subway, rapid bus. It’s a huge step for housing in California. It’ll create more homes, strengthen our transit systems & reduce traffic & carbon emissions. Thank you, Governor!

@governor.ca.gov it’s time to sign SB 79. Are you a governor of the people, or of the landed gentry? Tell us.

They were sooooo close to getting it 🤪

London Underground greebles