Physics (part 2) - Flat Earth? It depends ...

Flat Earth/Wikidpedia

Flat Earth?

That's a throwback to medieval science, isn't it?  And didn't Columbus debunk the "flat Earth" when he "discovered" America? Or so says the myth.

But actually, the ancient philosophers and learned understood that the Earth was round, at least as far back as the ancient Greeks. [reference: Who Discovered The Earth is Round?]

Today, the term Flat Earther has become an epithet for someone who adheres to outmoded beliefs and ideas. And there really exists such a groups  as The Flat Earth Society.  And they still make the case ... you guessed it ... for a flat Earth.

Some may laugh. Flat Earth? That can't possibly be.  Well, ...

It depends ....

According to Einstein and the great scientists before him, such as Lorentz and Maxwell, the length - including the "flatness" of the Earth, for example - is not absolute, but depends on your reference frame.

The video below take a serious scientific look at the flat Earth:

(reference:  https://youtu.be/VNqNnUJVcVs )

Indeed, our latest knowledge of physics indicate, if you are going near the speed of light, the Earth is flat as a pancake.  And that point was made about 7 minutes into the video.

Again, here are the numbers, which could be the answers to homework problems given in any college modern physics course:

* For cosmic ray protons, for example, moving at 99.9999999999991% of speed of light, the Earth only appears 17 meters thick, essentially flat

But to us Earthlings, our reference frame, the Earth is ball shaped.  Yet, to cosmic travelers zipping along near light speed, it's a flat Earth. At least in their direction of motion.

Why does length contract?

I had a physic professor who said - and rightly so - there is no answer to why nature behaves as it does. All we have are descriptions.  And that's what all those equations are about. They describe phenomenon, make predictions of their behavior, and can be reproduced with the same results.  If they fail to do so, it's back to the drawing board. (And that can be a subject of another post.)

As for length contraction, here is a mini-lecture from a modern physics class describing its observed behavior: Physics: Length Contraction

Ball or Sphere?

But what of the claims of a Flat Earth, regardless of our reference frame?  Consider the philosophy of Ockham's Razor:

(reference: https://youtu.be/skcCu4RUkAg )

The salient point is this:

"when you have two competing theories that make exactly the same predictions, the simpler one is the better."
  [reference: What is Occam's Razor? ]

Simply put. Keep It Simple. And a spherical Earth does just that.

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Previous post in the series:

Physics (part 1) - Picking Feynman's Brain (2013)

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Photo from: Flat Earth/Wikidpedia

Christopher Columbus, Washington Irving, and the Medieval Church

Many Americans will celebrate Columbus Day this Monday- October 12, 2009.

In my school days, Christopher Columbus was presented as a hero (and rightly so), for he not only discovered America, but he proved that the world was round to the unenlightened medieval academia and potentates. And this myth was re-enforced in American culture, even humorously such as a favorite Bugs Bunny cartoon - Hare We Go - as Columbus argues with the King of Spain whether the earth is flat or round.

In my previous blog, Dan Brown's novel Angels & Demons integrated into its plot the Church's pressure on Galileo to recant his helio-centric theories. Hence to this day, Science and Religion are perceived to be poles apart.

We may cast medieval philosophers (scientists of their time) as superstitious, ignorant people, clinging to falsehoods like the flat earth. But the medieval Church never taught that the earth was flat. Medieval sailors knew the earth was round for they observed ships disappearing over the horizon. Much of that perception of the flat earth mentality comes from the fantasies of a 19th century American novelist, Washington Irving, best known for The Legend of Sleepy Hollow and Rip Van Winkle.

Irving's biography of Columbus, The Life and Voyages of Christopher Columbus, came out in 1828. Before the Great Voyage, a scene in this book describes how Columbus was confronted by the ignorance and bigotry of the Church authorities. They accused him of heresy for claiming the earth was round, when the Church taught that the earth was flat. Hence, Washington Irving's fantasy of Columbus portrayed a false picture that the medieval Church suppressed knowledge and suppressed those who taught to extend the boundaries of Science.

Yet, the philosophers of the Middle Ages saw the purpose of knowledge as useful if it brought them closer to understanding God. Therefore, Churchmen carried out scientific experimentation with the blessing of the Church. Roger Bacon was one of these remarkable Churchmen, who was 400 years ahead of Galileo and Newton in his discoveries. And this, Lord willing, will be the subject of my next blog.

Related links:
Photo from: everystockphoto.com
Replicas of the Santa Maria, Nina, Pinta: everystockphoto.com/photo.php?imageId=2036740