[He] did not belong
to the types who bubble with ideas... His strength lay in another talent...the
unremitting critique of the reliability of physical observations and measurements.
William Wien on the occassion of Roentgen's death in 1923
When you saw the screen
shining ,"What did you think?", asked a reporter. "I did
not think, I investigated." was the reply from Roentgen. "What
is it?", the reporter pressed. "I don't know," was the reply.
In a few days I was
disgusted with the whole thing. I could not recognize my own work in the
reports any more. For exactly four full weeks I have been unable to make
a single experiment! Other people could work, but not I. You have no idea
how upset things were here.
Roentgen in a letter a month after sending his report around Europe
from the turn of the century.
ONE OF THE WELL KNOWN STORIES
in physics is the tale
of the discovery of X-rays. While the null search for the ether indeed
ushered in the modern physics world, the connection between that phenomenon
and the rapid understanding of the fundamentals of matter comes much later.
The accepted birth of modern physics of matter begins in the remarkable
few years between 1895 and 1898. In Germany, England, and France, laboratory
surprises occurred which have promoted Michelson's ill-timed comment about
the future of physics to embarrassing prominece for its wrongheadedness!
The stage for the first surprised was set by
Philipp Lenard [1862-1947], who was an assistant of Hertz's (and
a later ardent Nazi and an embarrassment to his former scientific colleagues).
In 1892 he managed to coat the end of a Crooke's tube with a very thin
layer of aluminum...through which he was able to transmit the cathode
rays into air beyond the tube. Now, this was quite spectacular: the cathode
rays penetrated what was presumed to be an opaque, solid wall of metal.
It was this experiment that led a careful and rather unspectacular German
professor to world-wide recognition.
William Roentgen-The First Nobel
Roentgen [1845-1923] in the 1890's
was a middle aged professor of Physics at Wurzburg. He had been transfered
within the German university system four different times and was not likely
to go much higher. At Wurzburg, he lived upstairs from his laboratory
and from there, he continued his pedantic and careful work. A competent
experimenter, he made good measurements of standard quantities in electromagnetics
and materials. Indeed, Lorentz dubbed a pheonomenon
that Roentgen had painstakingly discovered and characterized as the "Roentgen
Current" (the observation of a magnetic field generated by a moving
dielectric placed in a homogeneous electric field). He was productive,
an author of 48 careful, unspectacular papers at the age of 50 when lightening
The year that Babe Ruth was born was the turning
point. During the evening of November 8th, 1895 Roentgen was working alone
in his laboratory, studying the Lenard effect, the penetration of cathode
rays through different materials. In his darkened room, he covered his
Hittorf tube (a variant on the glow tube of Hertz) with black cardboard.
Quite by accident, on the wall six feet from the end of his tube, was
a sheet of paper which had been treated with the salt barium platinum-cyanide
which he used as a screen for other experiments. Because it was dark he
noticed that the paper was glowing, flourescing. Further study demonstrated
that this flourescent glow originated from the tube and that it exibited
amazing properties! He knew from his earlier work that source of the glow
could not be the cathode rays themselves, as they seemed unable to penetrate
the tube's glass wall and the cardboard. Rather, they were of unknown origin, so he called
He fussed for some time in his little lab.
He moved the screen away....it continued to glow. He turned the treated
side to the wall....it still glowed. He changed from a Crooke's tube to
a Lenard tube. He started to put various objects between the tube and
the paper and most materials appeared to actually be transparent: the
screen continued to glow. The rays coming from the end of the tube were
even capable of discharging electrified objects placed in their path.
But, when he inserted his hand in the beam...he saw his bones!
(The photograph is actually Rontgen wife's hand and her ring).
Roentgen Has Gone Crazy...
You can imagine how incredible this must have seemed.
Imagine standing in the dark in your basement realizing that you knew
something that nobody else had evern known...that it would likely raise
a ruckus. Because of this, he was careful. For weeks afterwards, he secretly
kept repeating the experiments, telling nobody but his wife. He told her
that he was doing something so strange that if people learned about it
they would say that "Rontgen has really gone
crazy." Finally, on January 1st, 1896 he sent numerous copies
of a report of his findings, with a picture of the bones of his hand,
to various labs around Europe. Then he waited.
One of those to receive his mailing was
Henri Poincare [1854-1912],
who hastened to transmit it the French Academie des Sciences
on January 20, 1896. Roentgen's paper was quickly reprinted in Nature,
Science and other journals within weeks. He received letters of
congratulations from around the world. Rutherford wrote about his boss
to his fiancee in late January, 1896, "The Professor
[J.J. Thomson] has been very busy lately over the new method of photography
discovered by Professor Roentgen...nearly every Professor in Europe is
now on the warpath."
The reaction, world-wide was proportional to
the magnitude of this discovery: five more observations were reported
in a week of the Paris announcement. Within three more weeks, X-rays were
used to set the broken arm of a young boy in Dartmouth, New Hampshire.
Within a year, a thousand papers were published on the phenomenon.
Roentgen only gave one talk on his discovery.
In late January of 1896, he addressed the Physical-Medical Society from
his home institution where he was received with tumultulous applause.
Inexplicably, Rontgen, himself, published only two more papers on the
subject, returning instead to his previous work. In 1900 he moved to Munich
where he became the director of the Institute for Experimental Physics
and then received the first Nobel Prize for Physics in 1901. Shy about
public speaking and the publicity that his work had generated, he literally
snuck out of Sweden to avoid having to give the Nobel Lecture. While Nobel
required a speech on the subject of the prize, the specific requirements
did not require that speech to be given at the ceremony, as it is traditionally
done now. Rather, Roentgen managed to substitute his single Physical-Medical
The rest of Roentgen's life was not a storybook
tale. He suffered terribly during WWI, as did many in the institutes around
Germany. He never allowed himself to profit financially from his discovery
and died in poverty during the post-war inflation at the age of 73.