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“It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn't feel like a giant. I felt very, very small.” – Neil Armstrong (1930-2012)

Fresh Reads from the Science 'o sphere!

Saturday, May 17, 2008

John Stewart Bell: The Part-timer Who Proved Einstein Wrong

A letter written by Albert Einstein in 1954 has recently emerged and clearly indicates that he was not a supporter of religious beliefs.

Einstein is without a doubt one of the most brilliant physicists who ever lived, but his views on religion has always attracted controversy due to his (deliberately?) unclear stand.

Of course, as Prof. Larry Moran of Sandwalk observes correctly, what Einstein personally believed is not relevant to whether supernatural beings exist or not.

Besides, it's not as if Einstein was right about everything.

Einstein's strong "brand name" has given the public an impression that he couldn't possibly be mistaken about anything, but that is simply not true.

For example, in 1939 Einstein and Leó Szilárd co-wrote a letter to US President Franklin Delano Roosevelt - a letter that helped to spark off the nuclear arms race.

After realizing the magnitude of the horror that atom bombs unleashed in Hiroshima and Nagasaki, Einstein would spend his later years strongly opposed to nuclear weapons.

Just before he died, he revealed to Linus Pauling that:

I made one great mistake when I signed the letter to President Roosevelt recommending that atom bombs be made.

Albert Einstein is definitely a human being, with human desires and weaknesses.

Not everything that Einstein says outside of theoretical physics must be true.

In fact, not everything that Einstein says inside of theoretical physics must be true!

Fresh Brainz readers, you're in for a treat - this week's science story is both about counterintuitive science AND the second-best.

An amazing story about how a young man REFUTED one of the greatest minds in history (as a hobby!) ...

... and nobody cared.

Because the public didn't understand the significance of what he did.

To begin the story, let's turn the clock back to 1935.

Einstein, who recently achieved great success with his discovery of the photoelectric effect and the theory of relativity, has moved on to other interesting questions in physics.

He was embroiled in a long-standing dispute with a group of physicists (known as the Copenhagen theorists, most notably Niels Bohr) over the implications of the predictions generated by the brand new theory of "quantum electrodynamics".

Or quantum theory, for short.

Quantum theory predicts a bizarre phenomenon called quantum entanglement, where measurements performed on parts of a quantum system that are widely separated from each other can somehow have instantaneous influence on one another.

From the perspective of Einstein's theory of relativity, particle interactions cannot propagate faster than the speed of light, and thus two spatially separated particles can never affect each other instantaneously.

Therefore, Einstein considered the concept of quantum entanglement counterintuitive and unbelievable, coining the term "spooky action at a distance" to describe its absurdity.

Rather odd that an originator of one counterintuitive theory could find another counterintuitive theory so utterly unacceptable, but like I said, Einstein is human.

Together with Boris Podolsky and Nathan Rosen, Einstein published a paper in 1935, introducing a thought experiment called the "EPR paradox" that highlights the apparent weaknesses of quantum theory, including the concept of quantum entanglement.

Einstein himself said that:

Quantum mechanics is certainly imposing. But an inner voice tells me that it is not yet the real thing. The theory says a lot, but does not really bring us any closer to the secret of the 'old one'. I, at any rate, am convinced that He does not throw dice.

They concluded that quantum theory is an incomplete theory and postulated that "hidden variables" may be responsible for the observed results.

Einstein would maintain this position for the rest of his life, and the controversy would not be resolved until after his death.

Enter John Stewart Bell, a brilliant Irish physicist.

He was only seven years old when the EPR paradox was published.

In his early 20s, Bell became fascinated by this scientific controversy. In the beginning, he was a strong supporter of Einstein's view, stating that:

I felt that Einstein's intellectual superiority over Bohr, in this instance, was enormous; a vast gulf between the man who saw clearly what was needed, and the obscurantist.

A bizarre twist lay in the future.

By the 1960's, Bell's day job was working as a particle physicist and accelerator designer at CERN. However, his part-time obsession was quantum theory, especially with the "hidden variables" mentioned in the EPR paradox.

In 1963, Bell took a year's leave from CERN and was able to spend significantly more time on his pet obsession. He focused on working out a way to experimentally test the existence of these hidden variables.

Finally, he published Bell's Inequality (or Bell's Theorem) in 1964. Bell's inequality makes it possible to construct experiments to directly test if "spooky action in a distance" actually occurs.

Other physicists began to perform experiments based on his hypothesis. After numerous experiments using many different approaches, the result is clear.

Quantum entanglement is real.

There is no need to postulate any hidden variables to account for the results.

John Bell had single-handedly disproved the great Albert Einstein.

The parallels could not be more obvious - just as Einstein had once rendered the "luminiferous aether" irrelevant using the theory of relativity, so Bell has also rendered Einstein's "hidden variables" irrelevant using Bell's inequality.

Bell's inequality was hailed by fellow physicists as the "most profound discovery in science". In the late 1980s, Bell was even nominated for a Nobel Prize.

Unfortunately, Bell would never enjoy anywhere near the amount of fame and prestige that Einstein received.

On the 1st of October 1990, John Bell died suddenly of a stroke.

Had he lived longer, he would most likely have been awarded the Physics prize, and things might have turned out very differently.

Alas, because theoretical physics was inaccessible to the public at that time, most people never came to understand the importance of his work.

And so John Stewart Bell, the part-timer who proved Einstein wrong, was consigned to the footnotes of history.

Would you like to know more?

About John Stewart Bell:
John Bell and the most profound discovery of science

About other stories of the second best:
Swiss vs British Everest teams
Steve Jobs vs Bill Gates
Golgi vs Cajal
Wallace vs Darwin


Lona said...

Good post.

Lim Leng Hiong said...

Hi Lona,

Thanks and welcome to Fresh Brainz!