Blake Pi • Physics & Cosmology

Animated physics and cosmology.
Former physicist · Johns Hopkins APL & NASA GSFC
Full videos on YouTube ↓

[Blake Pi • Physics & Cosmology @BlakePierpoint]

Farther away usually means smaller. Past a certain distance, galaxies start to look bigger again, because the light we see left them when the universe was smaller and they were closer to us.

Watch "Why the Most Distant Galaxies Look Bigger" on YouTube!

[Blake Pi • Physics & Cosmology @BlakePierpoint]

Update: a preprint posted after this script was written found 2026 ED138 on photographic plates from 1954, and maybe on one from 1937. The 2016 in the video is from Dark Energy Camera images.

[Blake Pi • Physics & Cosmology @BlakePierpoint]

The day Pluto was discovered in 1930, this dwarf planet candidate was closer to the Sun than Pluto. Nobody recognized 2026 ED138 until this October, in Rubin Observatory images. #DwarfPlanet #Pluto

[Blake Pi • Physics & Cosmology @BlakePierpoint]

Research: Hollands et al. (2026), RASTI. https://t.co/mjnOaSLyrs
The research team reports it is the first star found that would look green up close. The colour shown is calculated from the researchers' atmosphere model. The star is animated.

[Blake Pi • Physics & Cosmology @BlakePierpoint]

Astronomers have found the first green star.

WD J1330+6435 is a white dwarf that swallowed rock from its own planets. Calcium absorbs its violet light, sodium its orange, and what's left looks green.

Sources in the replies. #Astronomy #Space

[Blake Pi • Physics & Cosmology @BlakePierpoint]

Music: "Signal to Noise" by Scott Buckley - released under CC-BY 4.0. https://t.co/ZQHVACFF9v https://t.co/hdEDTrcXfY (edited for this video)

[OpenAI @OpenAI]

GPT-Rosalind surfaced a new lead for drug discovery: could restoring cholesterol transport protect neurons from degeneration?

DCTN1 is a gene linked to Perry syndrome, a rare neurodegenerative disorder. In mouse-brain data, disrupting it increased expression of genes involved in making cholesterol. GPT-Rosalind suggested a possible explanation: cholesterol may not be reaching where neurons need it.

That gives scientists a specific mechanism to test and, if confirmed, a direction for developing new treatments for neurodegenerative disorders.

With @perturbai_tx and @scrippsresearch, a team of thousands of GPT-Rosalind agents worked in parallel, connecting gene-expression results from millions of mouse brain cells with scientific literature in just 32 minutes. We’re now expanding this collaboration to identify new drug targets.

https://t.co/oHdF3ELsMj

[Blake Pi • Physics & Cosmology @BlakePierpoint]

A distant galaxy can look bigger yet fainter. Its surface brightness scales as 1/(1 + z)^4, counting all wavelengths.

Full film: https://t.co/6L7R2UqcSY

[Blake Pi • Physics & Cosmology @BlakePierpoint]

https://t.co/m3ARv92stD

[Blake Pi • Physics & Cosmology @BlakePierpoint]

Farther away usually means smaller. Past a certain distance, galaxies start to look bigger again, because the light we see left them when the universe was smaller and they were closer to us.

Watch "Why the Most Distant Galaxies Look Bigger" on YouTube!

[Blake Pi • Physics & Cosmology @BlakePierpoint]

The full film, "Why the Most Distant Galaxies Look Bigger", follows the light all the way home.

Watch the 12-minute explanation, with chapters and sources in the description!
https://t.co/6L7R2UqKIw

6/6

[Blake Pi • Physics & Cosmology @BlakePierpoint]

Some of that light initially got farther from us while still moving toward us locally at light speed.

Expansion grew the gap faster than the photon could close it. Later the gap shrank. The curved path here shows distance changing through time. 4/6

[Blake Pi • Physics & Cosmology @BlakePierpoint]

Bigger on the sky doesn't mean brighter.

Expansion lowers photon energy and slows their arrival. A distant galaxy can cover more sky yet be far fainter. Real early galaxies are also typically smaller than today's: the same-size comparison matters. 5/6

[Blake Pi • Physics & Cosmology @BlakePierpoint]

Trace the light reaching us today back through time. Plot its distance from us at each moment and you get this teardrop: our past light cone.

Its widest point was about 9.7 billion years ago. Earlier than that, the cone narrows again. 3/6

[Blake Pi • Physics & Cosmology @BlakePierpoint]

The key is the distance when the light left the galaxy.

Beyond the turn, that earlier distance gets smaller while today's distance gets larger. The same-sized galaxy covers more of the sky. 2/6

[Blake Pi • Physics & Cosmology @BlakePierpoint]

Past a certain distance, galaxies stop looking smaller and start looking bigger.

Compare galaxies of the same physical size: their apparent size bottoms out around redshift 1.6, then rises.

Here's why. 1/6

[Blake Pi • Physics & Cosmology @BlakePierpoint]

@girlcumlover For jumps generated by a and a†, the n versus n+1 rate factors connect the ladder algebra to these trajectories. I made a visual derivation of the underlying oscillator states and ladder operators, if useful as background: https://t.co/a6s141Enc3

[Blake Pi • Physics & Cosmology @BlakePierpoint]

@smartserghash @MaureenNeesp6k For the oscillator, normalizability forces the residual power series to terminate, leaving a Hermite polynomial times a Gaussian. I animated that derivation, alongside the ladder-operator route: https://t.co/a6s141EV1B

[Blake Pi • Physics & Cosmology @BlakePierpoint]

@SciencesKL The n nodes in ψ_n are a useful bridge between this energy-level diagram and the Hermite polynomials. I made a visual derivation of the spectrum and wavefunctions, using both power series and ladder operators: https://t.co/a6s141Enc3

[Blake Pi • Physics & Cosmology @BlakePierpoint]

I made an animated derivation of the quantum harmonic oscillator: the power series, ladder operators, and what the states actually do in time! #manim #QuantumMechanics #physics
https://t.co/a6s141Enc3