A century ago in a German physics journal, “Annalen der Physik,” was a series of papers from the then young – and unknown to the scientific community – Albert Einstein.
In that one year, Einstein uncovered the nature of light, created the framework for experiments that would prove matter is composed of atoms, and also developed a theory of relativity, which forced us to radically change our view of mass, energy and time. The year 1905 has since become a year of legend, making Einstein an international icon.
“In 1905, Einstein had this miraculous year. He was incidentally a 26-year-old unknown with a day job,” Physics Prof. Dan Amidei said.
These papers paved the way for the next century of physics and has given rise to our current scientific understanding of the world.
To celebrate Einstein’s 1905 papers and the subsequent accomplishments in the field of physics, the United Nations and the American Institute of Physics declared 2005 as the World Year of Physics.
The University is celebrating the year by having a theme semester called, “100 Years Beyond Einstein”, which will include a series of lectures on physics topics.
“It is an international year of physics – and here at Michigan, since we have these theme semesters, it seemed like a great idea to get on the bandwagon and join in the festivities” Amidei said.
The theme semester will not only reflect on Einstein’s discoveries and the discoveries in physics that have occurred since 1905, but also the future direction and unsolved problems of the field.
The chair of the physics department, Myron Campbell said, “Einstein himself was a larger-than-life character.”
Of the four papers, the first was on the photoelectric effect.
During Einstein’s time, light was mainly thought to be made of waves, similar to sound propagating through air in a wave-like manner. Through his paper, Einstein was able to explain discrepancies between photoelectric experiments and the wave-like concept of light. This culminated in his argument that in addition to light having a wave-like property, it is also comprised of particles called photons.
This work led to a 1921 Nobel Prize in physics and contributed to the development of quantum mechanics, which is the field of physics that addresses the behavior of microscopic objects like molecules, atoms and even smaller particles.
His second paper was on Brownian motion. On a microscopic level, all objects randomly move in a vibrating motion. This is due to surrounding atoms and molecules striking the sides of an object. The phenomenon was named after botanist Robert Brown when in 1827 he observed the random jiggling pollen suspended in water. But, until Einstein, no scientist had given a convincing explanation of the random motion.
With his 1905 paper on Brownian motion, Einstein suggested that the erratic motion of objects could be explained by the idea that invisible objects, later identified as atoms and molecules, were continuously bombarding the object. At the time Einstein published his Brownian motion paper scientists were still unsure if atoms and molecules even existed. But Einstein attempted to put the debate to rest by arguing that Brownian motion resulted from the existence of atoms.
Physics Prof. Leonard Sander, who will be giving a talk on Nov. 2 called “Brownian Motion and Beyond,” said it was not until physicist Jean Perrin’s work was published did the scientific community finally accept the existence of atoms.
“The outgrowth of Einstein’s work – ultimately convinced the last holdouts, and they were influential holdouts, that the molecular theory of matter was correct – that there were atoms and molecules, that you had to believe in them and that they had macroscopic consequences” Sander said.
After these two remarkable papers, Einstein had two more in 1905 – one was on special relativity, which showed that time, mass and space change at relative speeds and that nothing could move faster than the speed of light.
Einstein’s other paper was on the consequence of the special theory of relativity, his famous E = mc2 equation.
“The most important contribution that Einstein made – relates to defining and making clear the intimate connection between space and time – the fact that we don’t live in a universe which has a spatial extent and an independent clock ticking along, but that those two things, space and time, are really inextricable coupled,” Physics Prof. Timothy McKay said.
Sander said, “The significance of his papers in 1905 were that they basically made the modern world. It’s not too big of an exaggeration to say that they made the modern world.”
Einstein’s subsequent work in the field of physics would also elaborate on the theory of relativity while also attempting to create a grand unified theory of physics. But Einstein asked many questions that he could not solve before his death in 1955.
“I hope that some of the speakers at least will carry forward the clear impression that this is not finished – There remains deep and fundament questions which are unsettled,” McKay said.
For a schedule of events, go to www.lsa.umich.edu/lsatheme/einstein100.