'I am discounting the reports of UFOs. Why would they appear to only cranks and weirdos?' - Theoretical astrophysicist Stephen Hawking (1942 - 2018)

Should we be content with being cosmic couch potatoes? In this interview, the late Professor Stephen Hawking lays out the case for continued and increased human space exploration, despite its cost and challenges.

In this comedic interview with John Oliver, Stephen Hawking discusses his groundbreaking work in theoretical physics, his views on AI, and Oliver's chances of dating Charlize Theron in the multiverse—all with his trademark voice and humorous tone.

After predicting black holes could evaporate and before undergoing a tracheotomy, Stephen Hawking conducted interviews in his voice, explaining phenomena like black holes and the Big Bang. In this clip, he explains how curiosity drives humans to become “masters of the universe.”

While TV and films offer common tropes for why aliens would invade Earth, many of those reasons aren't actually feasible. For example, a species with technology advanced enough to allow it to travel between planets likely doesn't need to enslave flawed humans to carry out its labor.

The Fermi paradox addresses this discrepancy between the lack of evidence of alien life despite the high likelihood of its existence. Physicist Brian Cox offers various theories, like the extinguished civilizations hypothesis, for why we have never found any extraterrestrial neighbors.

It describes the discrepancy between the high likelihood of life beyond Earth given the vastness of the universe and the lack of evidence for such life, since extraterrestrial civilizations have not communicated with us. However, quantum communication—a more information-dense and effective method than classical means—requires massive receivers and very narrow signals, which would easily miss Earth, making a lack of signals expected.

When renowned theoretical physicist Stephen Hawking did not rule out the possibility of time travel in his posthumous book Brief Answers to the Big Questions, many hopefuls got excited. But, unfortunately for them, Hawking believed that yet-to-be discovered laws of physics will prove time travel impossible. This piece outlines some practicalities about the speed of light and wormholes that lend way to Hawking’s prediction.

His theoretical work—especially on black holes emitting radiation, now known as Hawking radiation—challenged long-held ideas. He also brought complex physics to the public through bestselling books like "A Brief History of Time."

In 2009, Hawking hosted a reception but only sent out invitations afterward, hoping that time travelers from the future would attend and prove time travel possible. He later joked it was "experimental evidence" that time travel doesn’t exist.

"Do the impossible, because almost everyone has told me my ideas are merely fantasies."

The Pentagon made a splash in recent years with revelations of videos showing fighter pilots observing unknown aerial objects. Lindsey uncovers stories of still-unverified UFO sightings and addresses the likely possibility of life beyond Earth.

Hawking famously placed wagers on high-stakes questions in theoretical physics—such as the Higgs boson—for fun and to draw attention to science. When Hawking lost a bet about Cygnus X-1 being a black hole, he paid up with a magazine subscription.

The writer behind Mindless Algorithm, George McGowan, challenges various assumptions about aliens depicted in science fiction. One of those is that aliens are, like humans, individual entities that live, age, and die. McGowan suggests that the difficulty of intergalactic travel and the aliens' technological advancements make it more likely that they'd be an advanced form of AI or digital copies of biological entities.

Famous cosmologist Stephen Hawking—who lived for half a century after being diagnosed with Lou Gehrig's disease—delivered a final speech just before he died in 2018. In the video, Hawking talks about the importance of science and reason in...

Throughout his life, he appeared in numerous pop culture moments—from "The Simpsons" to "The Big Bang Theory"—showing his talent for comedy and his love of science outreach. He was the only person to play himself on "Star Trek: The Next Generation," even writing some of his own lines.

Stephen Hawking's PhD thesis mathematically showed that singularities—points of no volume and infinite density—are an expected feature of nature. It laid the theoretical groundwork for a model of the universe where everything originates from a single point.

Lucy Hawking details what it was like to be the daughter of the famed cosmologist and what his life looked like from her eyes. Among the anecdotes was Stephen's enjoyment of being on "The Simpsons" because production gave him a wheelchair with helicopter blades.

As UFOs make a resurgence in public awareness, take a trip back to the early decades of UFO research. This interactive shows the location and descriptions for some of the most fascinating incidents reported to a secretive Air Force team between 1947...

Diagnosed with ALS at 21 and told he had two years to live, Stephen Hawking went on to change our understanding of black holes and the universe, living 55 more years and defying every expectation.

From the most shocking accounts of abductions and UFO sightings to an interview with a Harvard professor about these claims, dive into fascinating stories about run-ins with ETs that have continued to be told for decades.

Think you know everything about black holes? You might be surprised. Thought of as massive vacuum cleaners sucking up everything in their cosmic path, black holes actually accrete matter at an incredibly slow pace. Yet, some black holes existed when the universe was only a few billion years young. Learn more in this BBC report.

In his last broadcast interview, Stephen Hawking comments on detecting gravitational waves from the collision of neutron stars. The event may serve as a new means of measuring cosmological distances and help identify revisions to general relativity.

Given the vastness of the Universe, detecting alien life may require technological progress beyond the limits of what is sociologically viable and physically possible. Although interstellar civilizations are unlikely, messaging techniques and probes may improve the odds of successful communication with other intelligent life.

Even for math-y types, some numbers are incomprehensible. This article dives into several kinds of numbers more complicated than even irrational numbers with endless decimals like "pi" or Euler's number: Noncomputable numbers. Read the bizarre...

The former resulted from analyzing the motion of galaxies in the Coma Cluster, a subset of the approximately 30,000 galaxies he cataloged during his life. When hypothesizing an origin for observed high-energy particles called cosmic rays, Zwicky and colleague Walter Baade thought they could come from exploding stars, or supernovae—a term he coined—which would leave behind a collapsed star made entirely of neutrons.

Could aliens destroy us from light-years away? The team at Kurzgesagt imagines the impact of a highly sophisticated alien civilization setting out to crush humanity and considers the real-world logistics for warfare conducted across the Universe.

- Author Malcolm Gladwell (1963 - present)

Conspiracy theorists believe NASA is preparing for the gravity blackout under a classified operation called "Project Anchor." They speculate that the purpose of the secret project is to test whether Earth can survive such an event. NASA has rejected the claim. Considering the physics of a gravity blackout, the outcome would likely be chaotic but not total destruction.

- Philosopher Marshall McLuhan (1911-1980)

Stephen Hawking co-wrote "George’s Secret Key to the Universe" with his daughter, Lucy, to introduce young readers to big questions about the cosmos. In the first book, the protagonist rides a comet and discovers that black holes aren’t black.

The James Webb Space Telescope understandably received a lot of coverage in 2022. This astrophysicist wants to highlight ten major studies published last year you might have missed.

Hawking radiation is Stephen Hawking's theoretical prediction that black holes emit radiation and eventually evaporate. Applied to known black holes, their radiation is so weak that it would take vastly longer than the current age of the universe for them to disappear.

Traditional physics breaks down at the moment of the Big Bang, but quantum theory suggests that “empty” space is never truly empty. In 1973, physicist Edward Tryon proposed that our universe began from a quantum energy blip in the quantum vacuum.

The 1964 discovery of Cygnus X-1 provided the first strong candidate, but it took decades—and a famous bet between Stephen Hawking and Kip Thorne—before scientists were certain it was a black hole. Hawking's thumbprinted concession was delivered after breaking into Thorne's office.

- Pablo Picasso

He states that conducting research online cannot replace consulting with scientific experts who have spent their entire lives intimately studying a field. The former science education show host argues that deepening cynicism towards scientific institutions has been fueled by leaders embracing debunked and unsupported claims.

In 2003, philosopher Nick Bostrom published a paper in a journal arguing the technological possibility that humanity is living in a simulation. The argument, while popularly mocked (or cheered), is presented seriously in the paper. This podcast episode explores the contours of the arguments in an accessible way.

Stephen Hawking relied on a voice synthesizer after losing the ability to speak due to complications with ALS. Despite technological advances, he refused to change the "Perfect Paul" voice, making it a cornerstone of his public identity.

Olbers' paradox asks why the sky would ever appear dark if the universe is full of stars in all directions emitting light everywhere. Light from the farthest stars requires more time to reach our skies than the universe's age.

Hawking radiation may not have been discovered without Jacob Bekenstein first convincing Stephen Hawking that black holes follow the laws of thermodynamics. The graduate student showed that black holes could shrink, setting the stage for Hawking's most significant contribution.

If a fish screams as it falls down a cascading waterfall accelerating to ridiculous speeds, will his fish friends above hear him scream? This analogy, odd as it is, has become an essential tool in the astrophysicists kit for learning how enigmatic black holes operate. Lab experiments mirroring the so-called sonic black hole have achieved insights for their cosmic counterparts. Read how it works in this brief piece.