Skip to main content
  1. Home
  2. Emerging Tech
  3. Legacy Archives

New study says time travel is impossible

Add as a preferred source on Google

Even if you get your hands on a suped-up DeLorean and a Flux capacitor, you can’t travel back in time.

That’s what Hong Kong physicists say they’ve determined, thanks to a study of the speed limits of photons.

Recommended Videos

According to researchers at the Hong Kong University of Science and Technology, Albert Einstein’s theory that nothing can move faster than the speed of light holds up for even a single photon — the most basic unit of light. The study was led scientist Du Shengwang, who sought to measure the ultimate speed limit of a photon, which some believed could travel at faster-than-light speeds.

“Einstein claimed that the speed of light was the traffic law of the universe or in simple language, nothing can travel faster than light,” stated the university on its website. “Professor Du’s study demonstrates that a single photon, the fundamental quanta of light, also obeys the traffic law of the universe just like classical EM (electromagnetic) waves.”

“The study, which showed that single photons also obey the speed limit c, confirms Einstein’s causality; that is, an effect cannot occur before its cause,” reported the university.

Published in American scientific journal Physical Review Letters, the study was intended to end debate on the possibility of time travel, but let’s face it: we’re going to need to time travel if we’re ever going to defeat Skynet. Don’t stop believing, scientists!

Rick Marshall
Former Contributing Editor, Entertainment
A veteran journalist with more than two decades of experience covering local and national news, arts and entertainment, and…
AI turned a disgraced President under house arrest into a live avatar for another election campaign
Bolsonaro found an AI-shaped route back onto the campaign stage
Face, Head, Person

Jair Bolsonaro is barred from Brazil’s 2026 presidential election, being confined to house arrest and restricted from communicating publicly. But an AI-generated version of the former president still managed to take the stage at his son’s campaign launch.

The synthetic Bolsonaro appeared in a video at the launch of Senator Flávio Bolsonaro’s presidential campaign in São Paulo. It openly identified itself as AI-generated before endorsing Flávio as the person chosen to carry forward his father’s political movement. Flávio is running against incumbent President Luiz Inácio Lula da Silva in Brazil’s October election.

Read more
AI can turn a cloud of scuba bubbles into an early warning for divers
An underwater robot can estimate breathing rates from video, although the research stops short of proving that it can diagnose stress or distress
Nature, Outdoors, Water, Scuba

University of Minnesota researchers have taught an AI underwater robot to estimate a diver’s breathing rate by watching the bubbles released with each exhalation.

The contactless system, detailed in a peer-reviewed study published in The International Journal of Robotics Research, works with ordinary camera footage. Divers don’t need to squeeze another sensor into an equipment loadout that is hardly lacking for accessories.

Read more
Microsoft wants AI to catch hackers before they even attack
Red team, blue team, green team: Microsoft just gave its AI a full security squad.
Microsoft Project Perception

With AI now capable of writing exploits and running attacks at machine speed, the security tools built for a slower, human-paced world are starting to show their age. Microsoft thinks it has the answer, and it's calling it Project Perception.

So what exactly is Project Perception?

Read more