General Relativity

by | Oct 19, 2018

time-person-of-the-century-albert-einstein-8752070

Widely considered the greatest scientist in the history of mankind, Albert Einstein is famous for a number of theories, including the discovery of the law of the photoelectric effect, for which he won the Nobel Prize. What did Einstein do With His Nobel Prize Money? He is most famous for his two theories of Relativity (special and general), but did not win a Nobel Prize for either of those theories.

Special Relativity describes the relationship between space and time for non-accelerating objects and produced the world’s most famous equation E = mc2. Two prior IFODs delve into the theory of Special Relativity: The Strange Result of Light Speed Being a Constant and Is Speed of Light (or Faster) Travel Possible?

What Is General Relativity?

Proposed in a paper Einstein published in 1915, General Relativity states that what we know as gravity arises from the curvature of space and time (or spacetime). In other words, objects with mass (or energy) bend the fabric of spacetime and this curvature of spacetime is what causes what we perceive as gravity.

picsart_05-30-01-03-25-5970943
This image shows the Sun bending spacetime which causes the planets to orbit the Sun.

According to astrophysicist Pedro Ferreira of the University of Oxford, “although Earth appears to be pulled towards the sun by gravity, there is no such force. It is simply the geometry of space-time around the sun telling Earth how to move.” Thus, gravity is warped spacetime. Pretty mind-blowing.

0-h0eak8gouvj23brg-1468211
Bringing any mass into space distorts the space around it.

Moving objects, including orbiting bodies such as the moon, follow the straightest possible path in spacetime, even though the path doesn’t look straight to us. The moon is merely following the path in curved spacetime. In addition to solid bodies following the curvature of spacetime, light is  also bent as it passes through curved spacetime.

sxo2u-6246454

4 Comments

  1. Well, you can slice it either way. Gravity is curvature of space time or mass creates that curvature. What’s also interesting us that two physicists named Kalisz and Klein, shortly after A.E. released his theory of G.R. showed that if you add a 4th spatial dimension you could also explain electricity and magnetism as a curvature of space-time. Today, string theory adds the strong and weak nuclear forces into the geometrical picture by extending space time to 10 spatial dimensions and 1 time dimension. Is the universe 11 dimensional? Yes, perhaps, in which case we are 3+1 dimensional holograms in a bigger space-time.

    Reply
  2. how did you get those shapes to move around like that? Is that moving or am I?

    Reply
  3. So does that mean that an apple falling to earth is not affected by gravity but buy the geometry of space time?

    Reply
    • The point is that gravity is curved spacetime. Gravity definitely exists. It is one of the four forces of the universe.

      Reply

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Subscribe To The IFOD

Get the Interesting Fact of the Day delivered twice a week. Plus, sign up today and get Chapter 2 of John's book The Uncertainty Solution to not only Think Better, but Live Better. Don't miss a single post!

You have Successfully Subscribed!

Share This