Misconceptions About the Universe • 2014 Veritasium

Category: Astronomy
Download:

The expanding universe is a complicated place. During inflation the universe expanded faster than light, but that's something that actually happens all the time, it's happening right now. This doesn't violate Einstein's theory of relativity since nothing is moving through space faster than light, it's just that space itself is expanding such that far away objects are receding rapidly from each other. Common sense would dictate that objects moving away from us faster than light should be invisible, but they aren't. This is because light can travel from regions of space which are superluminal relative to us into regions that are subluminal. So our observable universe is bigger than our Hubble sphere - it's limited by the particle horizon, the distance light could travel to us since the beginning of time as we know it.

Veritasium • 2014 • 2 episodes •

Can You Solve This?

How do you investigate hypotheses?

Math

Misconceptions About the Universe

The expanding universe is a complicated place. During inflation the universe expanded faster than light, but that's something that actually happens all the time, it's happening right now. This doesn't violate Einstein's theory of relativity since nothing is moving through space faster than light, it's just that space itself is expanding such that far away objects are receding rapidly from each other. Common sense would dictate that objects moving away from us faster than light should be invisible, but they aren't. This is because light can travel from regions of space which are superluminal relative to us into regions that are subluminal. So our observable universe is bigger than our Hubble sphere - it's limited by the particle horizon, the distance light could travel to us since the beginning of time as we know it.

2014 • Astronomy

You might also like

Comets

Scientists are only now starting to unravel the secrets of comets. Often referred to as dirty snowballs, they contain ice and elements from the very start of the universe. Some theorize that a comet, crashing into our planet, brought with it the organic material that started life on Earth. Spacecraft continues to offer new information on their makeup, from bringing back samples from a comet's tail to direct contact when a NASA-launched craft slammed into the comet Tempel-1.

Planet Science • 2007 • Astronomy

The Journey

The trek from earth to Mars is fraught with difficulties, from surviving radiation en route to landing in a space craft not yet designed. Mars One founder Bas Lansdorp attends the Mars Society Convention in Washington, DC, to debate the risks and rewards with scientists from around the world.

3/5Destination Mars • 2015 • Astronomy

Open for Business

After we reached the moon, NASA refocused energy on mastering routine spaceflight and living in earth orbit. With the retirement of the Shuttle program, we explore the massive contributions Low Earth Orbit operations have brought to our lives and watch the new guys in town spread their wings, ready to take their place in space history

3/4Space Voyages • 2013 • Astronomy

Mercury

Mercury is the closest planet to the sun. It has no atmosphere and is, as such, covered in craters. It's also incredibly hot but, surprisingly, has water ice hiding beneath its surface.

13Crash Course AstronomyAstronomy

The Plot Against Gravity

The story of how a large aerospace company, BAE Systems, began a secret project to counter the force of gravity while NASA simultaneously ran a similar 'Breakthrough Propulsion Physics' program.

S1E6Space's Deepest Secrets • 2016 • Astronomy

Planet Hunters

Planet Hunters follows the astrophysicists – many of them Canadian – at the forefront of the search for Earth's twin, and tells the little-known story of the two Canadians who invented the technique that made modern planet-hunting possible. Gordon Walker and Bruce Campbell also detected the first exoplanet ever discovered. But that's not what the history books say.

S52E04The Nature of Things • 2012 • Astronomy