Archive for the String Theory Category

String Theory History

Posted in String Theory, Taz with tags , , , , , , , , , , , , , , , , on December 2, 2008 by tazspaz

A Brief “History” of String Theory

Here is a very brief “history” of the development of string theory.  These details are destined to fill many large volumes written by many people directly and indirectly involved in this research.

Some believe that string theory helps to explain the “Shadow” people.

Others, the existence of the one true “God” of all the universe…

Read on….

1921

Kaluza-Klein Theory

 

Electromagnetism can be derived from gravity in a unified theory if there are four space dimensions instead of three, and the fourth is curled into a tiny circle. Kaluza and Klein made this discovery independently of each other.

1970

String Theory is Born

 

Three particle theorists independently realize that the dual theories developed in 1968 to describe the particle spectrum also describe the quantum mechanics of oscillating strings. This marks the official birth of string theory.

1971

Supersymmetry

 

Supersymmetry is invented in two contexts at once: in ordinary particle field theory and as a consequence of introducing fermions into string theory. It holds the promise of resolving many problems in particle theory, but requires equal numbers of fermions and bosons, so it cannot be an exact symmetry of Nature.

1974

Gravitons

 

String theory using closed strings fails to describe hadronic physics because the spin 2 excitation has zero mass. Oops, that makes it an ideal candidate for the missing theory of quantum gravity!! This marks the advent of string theory as a proposed unified theory of all four observed forces in Nature.

1976

Supergravity

 

Supersymmetry is added to gravity, making supergravity. This progress is especially important to string theory, where gravity can’t be separated from the spectrum of excitations.

1980

Superstrings

 

String theory plus supersymmetry yields an excitation spectrum that has equal numbers of fermions and bosons, showing that string theory can be made totally supersymmetric. The resulting objects are called superstrings.

1984

The Big Year For String Theory!

 

This was the year for string theory! Deadly anomalies that threatened to make the theory senseless were discovered to cancel each other when the underlying symmetries in the theory belong two special groups. Finally string theory is accepted by the mainstream physics community as an actual candidate theory uniting quantum mechanics, particle physics and gravity.

1991-
1995

The Duality Revolution

 

Interesting work on stringy black holes in higher dimensions leads to a revolution in understanding how different versions of string theory are related through duality transformations. This unlocks a surge of progress towards a deeper nonperturbative picture of string theory.

1996

Black Hole Entropy

 

Using Einstein relativity and Hawking radiation, there were hints in the past that black holes have thermodynamic properties that need to be understood microscopically. A microscopic origin for black hole thermodynamics is finally achieved in string theory. String theory sheds amazing light on the entire perplexing subject of black hole quantum mechanics.

 For more information, and updated research items, visit wikipedia here.

Quantum Mechanics

Posted in String Theory, Taz with tags , , , , , , , , on November 24, 2008 by tazspaz

Here is the next installment of my thoughts on String Theory from the original post you can find here.

Through Quantum Mechanics it was found that there are two categories that particles fall into; bosons and fermions.

What are bosons you may ask?  Glad you did!  They are particles that transmit forces.  Bosons, most, can occupy the same place at the same time.

Fermions are a different type of particle; obviously.  Unlike bosons, fermions are not able to occupy the same place at the same time.  Only one fermion can occupy a given state at a given time.  This is why fermions are particles that make up matter.  Just think, if that had not been true you could have been walking through a wall while reading this.  Not that you’d be thinking about your head and a wall right at this moment.  *Starts banging head on wall.*

There is more information that you can find with a simple search on http://www.google.com (for instance) on Newton’s “Special Theory of Relativity” and “Relativistic Quantum Field Theory” also “General Theory of Relativity” and “Differential Geometry”.

With the next installment we will look at a brief history of String Theory. I will cover the basics from 1921-1996. Following that installment will be a brief overview of Black hole Entropy.

See, I DO have a twisted mind. Bet you didn’t know things like this were interesting eh??

String Theory, the Start of My Journey

Posted in String Theory, Taz with tags , , , , , , , , , , , , , , , , , on November 16, 2008 by tazspaz

So what happens when you decide to look up your old website content from ages long since past?  You find interesting tidbits for sure!

So here we go!  The start of my journey looking into String Theory:

What is string theory and why do you care?

Well lets look at that.  Lets just look at the basics of all of this.

Let’s start with theoretical physics. Sir Isaac Newton was the first theoretical physicist at a time when it was known as “Natural Philosophy” this was a time when algebra and geometry where in common use. But algebra and geometry could only be used to explain things that are still or not in motion. So Newton came up with another way. We now know this as calculus.

Now with calculus Newton was able to take his “Law of Motion” to explain the force of gravity. But his new theory did not only involve planets and stars but other objects such as weights and cannonballs. Seeing as Cannons were the weapon of choice at this time in Europe…wonder what that did for them hmm…

Being a theorist and an experimentalist Newton observed nature so that he might describe it better. As such Newton realized that his explained “Laws of Motion” were not some abstract laws that Nature was forced to obey but rather that it could be described through mathematics. Just a quick note, mathematics is the oldest language known to man.
Check back soon for more….

Next installment we will talk more about how “Strings” came into all of this…