galaxies

A short video built around an animation of the roughly 10,000 galaxies in the Hubble Ultra Deep Field, placed at their measured redshift distances. It gives a brief history of deep field images and ends with a 3D fly-through.

A short Nature video on the discovery that our home supercluster is Laniakea, redefined by mapping the flow of galaxies rather than their density. It names the structure with a Hawaiian word meaning 'immeasurable heaven'.

ScienceClic explains why the rubber sheet analogy for general relativity is misleading and offers a new visualization that includes the curvature of time and shows gravity as motion through curved spacetime.

A visual scale comparison of stars and cosmic objects, from planets up to some of the largest known stars, set to music. It is meant to convey the vastness of the universe.

Veritasium explains, with expert input, that in general relativity gravity is not a force and objects follow straight paths through curved spacetime, including why standing on the ground means you are accelerating.

Cody's Lab builds a 200-billionth-scale model to show how far away the nearest stars are, using parallax and light speed. A short astronomy explainer on interstellar distances.

Kurzgesagt explains stellar engines such as the Shkadov thruster and Caplan thruster, which could move the Sun and solar system across the galaxy over millions of years to avoid hazards and reach new regions.

A PBS Space Time episode explaining how space and time swap roles inside a black hole's event horizon. It is part of the channel's black hole series.

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.

Kurzgesagt lays out a speculative plan to terraform Venus, covering its hostile atmosphere and how it might be made Earth-like, with a sources page linked.

A minutephysics explainer showing that the Moon's path around the Sun is not a spiral but closer to a 12-sided polygon with curved corners. It argues the Moon arguably orbits the Sun rather than the Earth.

A PBS Space Time episode asking whether Venus would be a better colonization target than Mars. It covers Venus's habitable altitudes, floating balloon habitats, and the term surfacism.

PBS Space Time explains the Hubble constant tension, in which two precise, independent methods of measuring the universe's expansion rate disagree. It covers why this calls some standard cosmology into question.

PBS Space Time introduces Miguel Alcubierre's warp drive, explaining how spacetime itself could be warped rather than moving a ship through it, and whether it is physically possible.

A PBS Space Time episode hosted by Gabe Perez-Giz on the nature of spacetime and whether space and time are fundamental. It builds up reference frames and causality in a short, dense format.

PBS Space Time explains what happens as you approach and cross a black hole's event horizon, using Penrose diagrams and light cones as the tool for understanding spacetime there.

PBS Space Time explains Stephen Hawking's prediction of Hawking radiation and how black holes can emit radiation and slowly evaporate. It goes beyond the common particle-antiparticle analogy.

Astrophysicist David Kipping presents the halo drive, a proposed way to propel a starship to a good fraction of light speed by gaining energy from a black hole. The video is based on his peer-reviewed paper and explains why energy is the main obstacle to interstellar flight.

A PBS Space Time episode asking what black holes really are and whether events can happen inside them. It covers event horizons, time dilation and common misconceptions about black holes.

PBS Space Time examines the interstellar object 'Oumuamua and the popular theories about it, including the light-sail hypothesis. It argues that a natural rock is the likeliest explanation.

Isaac Arthur examines the Dark Forest theory, Cixin Liu's proposed solution to the Fermi Paradox in which civilizations stay silent and may destroy any that reveal themselves. He tests the theory's underlying assumptions and arguments.

A short Kurzgesagt animation explaining the Great Filter, the idea that finding alien life might be bad news because it implies something usually destroys civilizations. It connects the concept to the Fermi paradox.

A PBS Space Time episode explaining the holographic principle: the idea that our 3+1 dimensional universe may be described by information on a lower-dimensional boundary. It walks through black hole entropy and the AdS/CFT correspondence.

Veritasium explains in detail how LIGO detects gravitational waves, with a laser interferometer measuring displacements smaller than a proton. The video focuses on the extreme precision and the techniques needed rather than the general discovery story.

Kurzgesagt introduces the Fermi paradox: with so many stars and planets, why do we see no sign of aliens? It sets up the question and what it might imply for our own future. It is part 1 of 2.

PBS Space Time explains how spacetime geometry and light cones determine the order of events and what can cause what. It visualizes causality in special relativity.

Sabine Hossenfelder explains how her opinion on dark matter has shifted, weighing the evidence for and against it and the case for modified gravity. It runs through what dark matter is and why it has not been detected.

PBS Space Time episode on the black hole information paradox, covering how black holes seem to destroy information, the no-hair conjecture and the proposed role of the event horizon. It is part of a series on black holes.

Verge Science's pilot of its Trial & Error series follows amateur scientist Jon Larsen on a hunt for micrometeorites. It shows how tiny space rocks can be found on rooftops and confirmed under a microscope.

A PBS Space Time episode asking whether the universe's information can ever truly be lost, tying quantum mechanics, determinism and black holes together. It sets up the black hole information paradox.

A PBS Space Time episode explaining why faster-than-light travel is equivalent to travelling back in time, using relativity and Minkowski diagrams for different observers.

PBS Space Time explains Roger Penrose's conformal cyclic cosmology, in which the far future of our universe becomes the big bang of the next. It explores what could come after the universe ends.

Kurzgesagt explains black hole stars, a hypothesized kind of giant star with a black hole at its core that could be a route to early supermassive black holes.

ScienceClic explains why nothing can go faster than light by treating motion through space and time together, so everything moves at the speed of light through spacetime. It uses animated visuals to cover relativity basics in 12 minutes.

Rational Animations explains Robin Hanson's grabby aliens model, which argues that humanity looks suspiciously early in cosmic history. Expanding civilizations set a deadline that explains our timing and bears on the Fermi paradox.

Minutephysics compares how efficiently different processes convert mass to energy per E=mc^2, from fire and fission to fusion, antimatter and black holes, which can convert a large fraction of mass to energy.

Kurzgesagt explains the black hole bomb and how far-future civilizations might extract energy from spinning black holes, including Dyson-sphere-style ideas.

Kurzgesagt explains why, even with science-fiction technology, most of the universe is permanently out of reach because of cosmic expansion and finite resources.

ScienceClic visualizes what you would see falling into a black hole, from the approach and the accretion disc to crossing the horizon, in 15 minutes.

A PBS Space Time episode asking whether time began at the Big Bang. It explains that the Big Bang is not what most people were taught and what 'start' of the universe really means.