Why the number 137 is one of the greatest mysteries in physics

Famous physicists like Richard Feynman think 137 holds the answers to the Universe.

  • The fine structure constant has mystified scientists since the 1800s.
  • The number 1/137 might hold the clues to the Grand Unified Theory.
  • Relativity, electromagnetism and quantum mechanics are unified by the number.

Does the Universe around us have a fundamental structure that can be glimpsed through special numbers?

The brilliant physicist Richard Feynman (1918-1988) famously thought so, saying there is a number that all theoretical physicists of worth should "worry about". He called it "one of the greatest damn mysteries of physics: a magic number that comes to us with no understanding by man".

That magic number, called the fine structure constant, is a fundamental constant, with a value which nearly equals 1/137. Or 1/137.03599913, to be precise. It is denoted by the Greek letter alpha - α.

What's special about alpha is that it's regarded as the best example of a pure number, one that doesn't need units. It actually combines three of nature's fundamental constants - the speed of light, the electric charge carried by one electron, and the Planck's constant, as explains physicist and astrobiologist Paul Davies to Cosmos magazine. Appearing at the intersection of such key areas of physics as relativity, electromagnetism and quantum mechanics is what gives 1/137 its allure.

Physicist Laurence Eaves, a professor at the University of Nottingham, thinks the number 137 would be the one you'd signal to the aliens to indicate that we have some measure of mastery over our planet and understand quantum mechanics. The aliens would know the number as well, especially if they developed advanced sciences.

The number preoccupied other great physicists as well, including the Nobel Prize winning Wolfgang Pauli (1900-1958) who was obsessed with it his whole life.

"When I die my first question to the Devil will be: What is the meaning of the fine structure constant?" Pauli joked.

Pauli also referred to the fine structure constant during his Nobel lecture on December 13th, 1946 in Stockholm, saying a theory was necessary that would determine the constant's value and "thus explain the atomistic structure of electricity, which is such an essential quality of all atomic sources of electric fields actually occurring in nature."

One use of this curious number is to measure the interaction of charged particles like electrons with electromagnetic fields. Alpha determines how fast an excited atom can emit a photon. It also affects the details of the light emitted by atoms. Scientists have been able to observe a pattern of shifts of light coming from atoms called "fine structure" (giving the constant its name). This "fine structure" has been seen in sunlight and the light coming from other stars.

The constant figures in other situations, making physicists wonder why. Why does nature insist on this number? It has appeared in various calculations in physics since the 1880s, spurring numerous attempts to come up with a Grand Unified Theory that would incorporate the constant since. So far no single explanation took hold. Recent research also introduced the possibility that the constant has actually increased over the last six billion years, even though slightly.

If you'd like to know the math behind fine structure constant more specifically, the way you arrive at alpha is by putting the 3 constants h,c, and e together in the equation --


As the units c, e, and h cancel each other out, the "pure" number of 137.03599913 is left behind. For historical reasons, says Professor Davies, the inverse of the equation is used 2πe2/hc = 1/137.03599913. If you're wondering what is the precise value of that fraction - it's 0.007297351.

Stand up against religious discrimination – even if it’s not your religion

As religious diversity increases in the United States, we must learn to channel religious identity into interfaith cooperation.

Sponsored by Charles Koch Foundation
  • Religious diversity is the norm in American life, and that diversity is only increasing, says Eboo Patel.
  • Using the most painful moment of his life as a lesson, Eboo Patel explains why it's crucial to be positive and proactive about engaging religious identity towards interfaith cooperation.
  • The opinions expressed in this video do not necessarily reflect the views of the Charles Koch Foundation, which encourages the expression of diverse viewpoints within a culture of civil discourse and mutual respect.
Keep reading Show less

The biggest threat to America? Americans.

Pulitzer Prize-winner Jared Diamond explains why some nations make it through epic crises and why others fail.

Videos
  • "A country is not going to resolve a national crisis unless it acknowledges that it's in a crisis," says Jared Diamond. "If you don't, you're going to get nowhere. Many Americans still don't recognize today that the United States is descending into a crisis."
  • The U.S. tends to focus on "bad countries" like China, Canada and Mexico as the root of its problems, however Diamond points out the missing piece: Americans are generating their own problems.
  • The crisis the U.S. is experiencing is not cause for despair. The U.S. has survived many tragedies, such as the War of Independence and the Great Depression – history is proof that the U.S. can get through this current crisis too.
Keep reading Show less

10 new things we’ve learned about death

If you don't want to know anything about your death, consider this your spoiler warning.

Culture & Religion
  • For centuries cultures have personified death to give this terrifying mystery a familiar face.
  • Modern science has demystified death by divulging its biological processes, yet many questions remain.
  • Studying death is not meant to be a morbid reminder of a cruel fate, but a way to improve the lives of the living.
Keep reading Show less

Where the evidence of fake news is really hiding

When it comes to sniffing out whether a source is credible or not, even journalists can sometimes take the wrong approach.

Sponsored by Charles Koch Foundation
  • We all think that we're competent consumers of news media, but the research shows that even journalists struggle with identifying fact from fiction.
  • When judging whether a piece of media is true or not, most of us focus too much on the source itself. Knowledge has a context, and it's important to look at that context when trying to validate a source.
  • The opinions expressed in this video do not necessarily reflect the views of the Charles Koch Foundation, which encourages the expression of diverse viewpoints within a culture of civil discourse and mutual respect.
Keep reading Show less