When was the beginning of time?

Most scientists now think that time started with the beginning of the Universe. The Universe is everything in and on our planet and everything in outer space. It’s everything we know and everything we still haven’t discovered! Scientists are pretty sure that the Universe began about 13.7 BILLION years ago!

Written out completely, that’s “13,700,000,000.” That’s a huge number, and difficult to imagine! It’s more years than twice the number of people on the entire planet! How many birthdays have you had?  Well, the Universe has had 13.7 billion!

Since people have not been around for 13.7 billion years, scientists, called “astronomers,” who study stars and the Universe, had to get creative to figure out when time began. One of the many ways they did this was by figuring out how fast the Universe is growing.

Have you ever blown up a balloon with air or seen someone do it?  Just like a balloon, the Universe is expanding outward and getting bigger. Most scientists believe that the Universe began in an explosion! You may have heard of it before. It’s called the “Big Bang.”  Ever since that explosion, the Universe has been growing. By studying how the Universe is growing right at this moment, astronomers can guess how long it took to get to the size it is right now.

We are always learning more about the Universe, and the date that time began is always being updated. As we are learning, the seconds keep ticking, time keeps passing, and the beginning of time gets farther and farther away from today.

 

Here are just a few of the many big moments in the History of time! It’s important to know that some of these, especially the really old ones, are not believed by everyone. Some religions and even some scientists believe differently about when these events happened. Listed here are just the most common scientific estimates (as of 2009).

13.7 Billion years ago:  The Universe begins with a Big Bang!

4.55 Billion years ago: The Earth is formed in our solar system.

230 Million years ago: The first dinosaurs appear on Earth.

65 Million years ago: The last dinosaurs go extinct.

250,000 years ago: The first people begin to appear.

5,500 years ago: The earliest clocks, “sundials” are created. They use shadows cast by the Sun to tell time, but they only work in the daylight!

82 years ago: In 1927 German priest,  Georges Lemaitre proposes what would soon be called “the Big Bang Theory”.

19 years ago: The Hubble telescope is launched in 1990. This powerful telescope floats out in space and can capture images from incredibly far away. It has greatly helped out monitoring the changing Universe.

Since people have been on the planet, there have been many ways of keeping track of the past. People have written History books, they have told stories about the past, and they have painted pictures and taken photographs and video.

Have you ever kept a journal?  It doesn’t have to be much.  Find a notebook and once a day, write down what you did, or how you feel, or even just draw a picture of something that happened.  Always write the date.  That way, when you read your journal in the future, you’ll have a record of your past (and you won’t forget things)!