atmospheric lensing

David Kipping presents his proposed Terrascope, a telescope that uses Earth's atmosphere as a lens to achieve enormous magnification. He covers the history of telescopes and his path to the idea, plus Sol-scope and Jupiter-scope variants.

Veritasium explains what a black hole should look like, using J.P. Luminet's 1979 work and a cardboard 3D model to show how light bends around it. It was made just as the first black hole image was released.

Explains the proposed NASA JPL plan to use the Sun as a gravitational lens, sending solar sail craft to its focal region to image an exoplanet's surface. It covers the distances involved, how imaging with the Sun would work and the mission design.

PBS Space Time explains the proposal to use the Sun's gravity as a giant lens, sending a train of small light-sail spacecraft to the focal point roughly 550 AU out. It covers how such a telescope could image exoplanets in surprising detail and the engineering challenges involved.

Sabine Hossenfelder explains how the greenhouse effect actually works, given that infrared is mostly absorbed low in the atmosphere already. She walks through why more CO2 still warms the surface.

PBS Space Time asks whether dark matter could be made of primordial black holes. It walks through the observational constraints that limit this idea.

Veritasium examines whether food has become less nutritious, weighing soil depletion, selective breeding and rising atmospheric CO2. It evidences nutrient decline even in weeds over a century and ties it to faster plant growth.