@LondonCityGirl
  @LondonCityGirl
LondonCityGirl | WHAT IS THE OBSERVABLE UNIVERSE? HOW BIG IS IT? @LondonCityGirl | Uploaded 6 years ago | Updated 4 hours ago
Hi Everyone,

Today we're exploring what we mean by the Observable Universe and how large it is.
---------------------------------------------------------------------------------
SUPPORT ME ON PATREON:
patreon.com/londoncitygirl

Even the smallest of amounts will help me create more and more content for YouTube and I’ll be forever grateful as you help me make my dream of becoming a full-time YouTuber a reality.
---------------------------------------------------------------------------------
DESCRIPTION
The observable Universe, as the name indicates is the Universe that we can observe from earth; that is light from the contents of the observable Universe has had time to reach our instruments on earth.

Assuming that the Universe is the same in all directions, the distance to the edge of the observable universe is the same in every direction, so the shape of our observable universe is a spherical ball with the observer at its centre.

The age of the observable universe is approximately 13.8 billion years. This number has been arrived at using two methods:

1). measuring how fast the Universe is stretching and working backwards and
2). analysing the age of the oldest star clusters in our Milky way

Light has travelled approximately 13.8 billion years to reach the observer at the centre of the Observable Universe.

Space continued to stretch while the light travelled the 13.8 billion years, and the region of space from where that light originated is now 46.5 billion light years away from the observer. The radius of the observable Universe is therefore 46.5 billion light years and the diameter of the observable Universe is 93 billion light years across.

The circumference of our known, observable Universe is called the Particle Horizon.

The particle Horizon is not to be confused with the cosmic event horizon.

The Cosmic Event Horizon is the region of the Universe from beyond which light emitted today can never reach us, because the space in between is stretching faster than the speed of light. The Cosmic Event Horizon is around 16 billion light years away from us.
WHAT IS THE OBSERVABLE UNIVERSE? HOW BIG IS IT?IS TIME TRAVEL POSSIBLE?CHINESE POLITICS EXPLAINED SIMPLY || WHY IS CHINA IMPORTANT?ALL OF HUMAN HISTORY IN 6 MINSPREDESTINATION (2014) - ILLUSTRATED TIMELINE EXPLANATIONWHY WE CRAVE A LIFE WE CAN’T AFFORD? || KEEPING UP WITH THE KARDASHIANSSTANDARD MODEL OF PARTICLE PHYSICS EXPLAINEDTop 10 Most Controversial Films EverTENET (2020) ILLUSTRATED TIMELINE & EXPLANATIONWhat happened to the cast of the Wonder YearsPRIMER (2004) - ILLUSTRATED EXPLANATIONTheory of relativity explained in 7 mins

WHAT IS THE OBSERVABLE UNIVERSE? HOW BIG IS IT? @LondonCityGirl

SHARE TO X SHARE TO REDDIT SHARE TO FACEBOOK WALLPAPER