Why talk about Einstein? Why Einstein matters?

Two weeks ago I wrote a post of “Einstein: A brief introduction”.  This post talks about the impact of his theory of general relativity upon the frontier research in physics over the past 100 years.  I have lost counts of how many Nobel laureates it has produced; just two days ago (Feb. 11, 2016) an earth-moving event was announced, again, to prove he has been right all along.

 
A solution of Einstein’s equations led to the concept of black hole

Einstein formulated the two postulates of special relativity in 1905.  The most famous formula of E = mc² was also published in 1905.  He presented the equations of general relativity, adding gravity to it, before Prussian Academy of Science in March 1916 (announced in Nov. 1915).

While serving in the Eastern (Russian) front during WWI in 1916, Karl Schwarzschild derived the first exact solution of Einstein’s equation while calculating artillery trajectory.  This led to the initial concept of black hole.

1983 Nobel Prize in Physics: Mathematical theory of the structural evolution of the stars and black hole

There is no way I can understand Chandrasekhar’s Nobel Lecture, but I can tell it can be traced back to Einstein’s general theory of relativity.  In the section of “The mathematical theory of blacks holes," he said,

“. . . the conclusion is inescapable that black holes will form as one of the natural end products of stellar evolution of massive stars; and further that they must exist in large numbers in the present astronomical universe. In this last section I want to consider very briefly what the general theory of relativity has to say about them. . .”

This is how he concluded his Nobel Lecture,

The mathematical theory of black holes is a subject of immense complexity; but its study has convinced me of the basic truth of the ancient mottoes,

The simple is the seal of the true,

Beauty is the splendour of truth.

Chandrasekhar

Chandrasekhar (an Indian American) gave a Ryerson Lecture of “Shakespeare, Newton and Beethoven, or Patterns of Creativity” at the University of Chicago in 1975, eight years before he was awarded the Nobel Prize.  One of the most intellectual talks I ever encountered; it is saved in my FileMaker file.  He is truly a Renaissance Man.

Toward the end of the lecture, he said,

“May I allow myself at this point a personal reflection? In my entire scientific life, extending over forty-five years, the most shattering experience has been the realization that an exact solution of Einstein’s equations of general relativity, discovered by the New Zealand mathematician, Roy Kerr, provides the absolutely exact representation of untold numbers of massive black holes that populate the universe . . . this incredible fact that a discovery motivated by a search after the beautiful in mathematics should find its exact replica in Nature, persuades me to say that beauty is that to which the human mind responds at its deepest and most profound.  Indeed, everything I have tried to say in this connection has been stated more succinctly in the Latin mottos:

Simplex sigillum – The simple is the seal of the true

Pulchritudo splendor veritatis – Beauty is the splendor of truth.

2011 Nobel Prizes in physics: The discovery of accelerating expansion of the universe

In his Nobel Lecture, Saul Perlmutter (one of the three laureates) said,

“For most of human history, this sort of question [is the universe expanding?] was a truly philosophical question. It wasn’t until the 20th century that we began to have a scientific version of this question. This is partly because Einstein’s theory of general relativity gave us some new conceptual tools that made it possible to think about this topic in a more rigorous way. But it’s also because Edwin Hubble (1929) measured an expansion of the Universe, which meant that we started to see in more concrete terms what we could mean by the fate of the Universe.”

Edwin Hubble was the one first discovered the universe was expanding and the universe goes beyond our Milky Way galaxy.  It is of interest this discovery was first published in New York Times before presenting to his professional society meeting.  He was never awarded a Nobel Prize as the Nobel committee didn’t consider astronomy as worthy of its recognition during his lifetime.

The Big Bang theory and the theory of general relativity

To connect these two theories is beyond the scope of this post.  Einstein’s general relativity gave birth to modern cosmology.  Several Nobel Prizes in Physics are related to the Big Bang theory.

The 1978 was for “the cosmic microwaves background radiation,” considered a relic of the explosion at the beginning of the universe 18 billion years ago.

In his 2006 Nobel Lecture, John Mather began the statement of “In the beginning was the Big Bang. So we now say with great certainty.” 

The discovery of the gravitational waves confirms Einstein’s general relativity

Einstein first predicted gravitational waves based on his theory of general relativity in 1915-1916, although he did waffle on a few occasions.

Einstein went back and forth on whether his theory suggested gravitational waves. He wrote in early 1916 that, “there are no gravitational waves analogous to light waves.”  He had a different thought and published a paper about gravitational waves in late 1916. A colleague pointed out a miscalculation in the equation in that paper; he then published an improved version, “On Gravitational waves” in 1918.

In 1921, Einstein delivered a series of lectures at Princeton University, a comprehensive review of his special theory of relativity (1905) and general theory of relativity (2015), during which the gravitational waves were not mentioned at all.  Until his death in 1955, Einstein was never convinced the gravitational waves can be measured if it were indeed present. 

On September 14, 2015 the Lasr Interferometer Gravitational-Wave Observatory (LIGO) picked up a faint signal that proved to be the unmistakable traces of the ever elusive gravitational waves.  It took two months for the scientists at LIGO to convince themselves it was real.  It was announced on Feb. 11, 2016.  This is an earth-moving (驚天動地) event; some said it is more important than the discovery of Higgs boson in 2012.  This is definitely a Nobel Prize work, if they can decide who (up to three persons are allowed the share the prizes) should get the most credits.

LIGO

The gravitational waves are supposedly generated by the collision of two humongous black holes about 1.3 billion years ago.  The existence of which was suggested by observing a pulsar circling neutron star in 1970s, resulting the Nobel Prize in Physics in 1993. 

The Higgs boson (the elemental particle of the Standard Model of particle physics) was discovered by the scientists at the CERN’s Large Hadron Collider in July 2012.  Peter Higgs and Francois Englert were awarded the Nobel Prize in physics next year (2013).  They theorized the presence of this long-sought particle more than 50 years ago; Robert Brout should share the prizes, but he has since passed away. 

None of the scientists actually discovered the Higgs boson particle at the CERN shared the prizes.  The case of gravitational waves is different.  Einstein should get it, but Nobel Prize is not given posthumously (with one exception), so there is still hope for the scientists at LIGO.

Nobel Prize or not, right now the scientists are thrilled in exhilarating mood, one scientists said, “We are pretty much at the moment when Galileo was beginning to see the first objects around Earth.  It will have such a huge impact on the field.