The cosmic horizon of our sight
The shape and geometry of space
Is there an edge to everything
The expanding cosmos and cosmic speed limits
Three ultimate fates of the universe
YOUR GOAL
Master of Is the universe infinite
artiteacher The Cosmic Horizon
Space is stretching out / billions of light-years wide / we're looking back in time!
artiteacher The oldest light we can see is the leftover glow from the early hot universe.
artiteacher The observable universe is a sphere centered on Earth stretching 46.5 billion light-years in every direction.
Cosmic time travel: Light from the Sun takes 8 minutes and 20 seconds to reach Earth, meaning we always see the Sun in the past.
The theoretical boundary marking the maximum distance from which light can reach an observer. Our current limit of visibility spans a diameter of roughly 93 billion light-years.
What is the name of the oldest light in the universe, dating back to 380,000 years after the Big Bang?
Which cosmic speed limit prevents us from seeing the entire universe instantly?
Which ancient Chinese philosopher wrote about the concept of infinite space around 400 BCE?