13 Facts About Physicist Niels Bohr

Baron/Getty Images
Baron/Getty Images

Quantum physics might not be the most approachable topic, but there’s a good chance you’ve heard of some of its elemental parts, like atoms. In the early 20th century, Danish physicist Niels Bohr discovered the basic atomic structure—a positively charged nucleus surrounded by orbiting electrons—which laid the groundwork for how we understand atoms today. Here are 13 things you might not have known about Bohr.


Niels Bohr, born in Copenhagen in 1885, was brought up in a family that valued science. His father Christian was a physiology professor at the University of Copenhagen, and he often hosted fellow scientists at his home for lively discussions. Young Niels and his two siblings often listened in, which likely inspired the young student’s future studies. Though he never won, Christian Bohr was nominated for the Nobel Prize by one colleague in 1907 and by two in 1908, all for his research on the physiology of respiration.


Bohr enrolled at the Gammelholm Latin School at age 7 and did well in all of his classes except for composition. According to the Niels Bohr Institute at the University of Copenhagen, he once turned in an essay that contained just two sentences: "A trip in the harbor: My brother and I went for a walk in the harbor. There we saw ships land and leave."

But by secondary school, he was correcting errors that he discovered in his physics textbooks. He excelled in the majority of his studies, and he graduated first in his class. Later in life, he penned a number of philosophical writings on physics, having overcome his youthful aversion to exposition.


Bohr began his university studies in 1903 at the same institution that employed his father, the University of Copenhagen. While he initially studied mathematics and philosophy, he won a physics competition sponsored by the Royal Danish Academy of Sciences, and he soon changed his major to physics. Bohr studied other fields, including inorganic chemistry, perhaps less successfully: He earned a reputation for causing explosions in the lab, and eventually broke a record amount of glass at the school. He would, however, go on to earn a master’s degree in 1909 and a doctorate in 1911 in physics.


After graduating, Bohr continued his studies at Cambridge University under J.J. Thomson, who had discovered the electron in 1897. Thomson had turned his attention to cathode rays, which were then believed to be part of the ether—a theoretical, weightless substance found everywhere in the universe. But he eventually determined that the rays were actually particles even smaller than the atom by showing that they could be deflected by electricity. This led Thomson to propose the “plum pudding” structure of atoms, in which negatively charged electrons are embedded in a sphere of positively charged matter, like raisins in a English pudding. Bohr would later contradict the “plum pudding” structure with his atomic model.


After finding his work at odds with Thomson’s, Bohr joined the Manchester University lab of Ernest Rutherford, who had also studied under Thomson. Rutherford had discovered the atomic nucleus through an experiment in which he shot alpha particles at a thin sheet of gold foil. Because some of the particles bounced back instead of going through the gold, he determined the majority of the atom’s mass must be within a small, central nucleus, with the electrons orbiting around it.

This became the foundation of his work with Bohr. The pair studied the structure of the atom, and Bohr determined Rutherford’s model must not be entirely correct. By the laws of physics, the orbiting electrons should eventually crash into the nucleus and destabilize the atom. Bohr eventually tweaked Rutherford’s model by explaining that the electrons orbiting a positively charged nucleus can jump between energy levels, which stabilizes the atoms.


Based on his atomic research, the University of Copenhagen hired Bohr as a professor of theoretical physics in 1916 when he was just 31 years old. Soon after, he began pushing for a new institute for his field, which would allow researchers from all over the world to collaborate with Danish scientists at a state-of-the-art facility. He was granted approval, and the institute opened in 1921 with Bohr serving as director. (His mathematician brother Harald, a former Olympic soccer player, would go on to open the university’s mathematical institute next door nine years later.) In 1965 the university renamed the facility the Niels Bohr Institute, and today more than 1000 staff and students work and study there.


Bohr and Einstein were not only contemporaries; they were good friends who partook in a series of conversations on physics over the course of decades, most notably at the 1927 Solvay Conferences now known as the Bohr–Einstein Debates. They argued two very different positions regarding the observations of electrons behaving as a particle in some experiments and a wave in others, even though an electron shouldn’t be able to be both. Bohr theorized the concept of complementarity to explain the phenomenon—that is, something can be two things at once, but we can only observe one of those things at a time. In establishing a fundamental principle of quantum mechanics, Bohr argued that the act of observation of particles brings them into existence, which is known as the Copenhagen Interpretation.

Einstein, on the other hand, argued that particles exist whether or not we actively observe them. (Imagine a very complex version of the “if a tree falls in the forest” question.) Even with their opposing theories, both were awarded the Nobel Prize in Physics in 1922: Bohr for his atomic model, and Einstein for his work on the photoelectric effect (instead of his then-controversial theory of relativity). So how did the two physicists receive prizes for the same thing in the same year? Einstein was actually awarded the 1921 prize a year late, due to a technicality.


Danish beer giant Carlsberg, known for having its own laboratories to promote the study of natural sciences as they related to brewing, invited Bohr to live in its honorary residence, a house near its production facilities given to a deserving artist, scientist, or writer for life. It had a tap connected directly to the brewery for free beer. In 1932, Bohr and his family moved in, and stayed for the next 30 years.

The sweet real estate deal was not Carlsberg’s first interaction with the scientist. The brewery’s foundation helped Bohr pay for his research in England and funded the Institute for Theoretical Physics.


As the Nazis overran Europe at the height of World War II, Bohr helped scientists escaping the regime in Germany by providing them with funding, lab space, and temporary homes in Copenhagen. Bohr himself was forced to flee in 1943 after the Nazis overtook his country—Bohr’s mother was Jewish, and his entire family was persecuted. They fled Denmark on a fishing boat bound for Sweden, then Bohr and his son Aage were smuggled to England in the empty bay of a British Mosquito bomber plane. In London, he consulted with the Canadian and British governments’ ultra-classified program to develop nuclear weapons, code-named Tube Alloys.


In 1939, American officials had learned that Germany was attempting to build an atomic bomb. Five years later, the U.S. government invited Bohr to work on the Manhattan Project, its top-secret program to develop uranium- and plutonium-based nuclear bombs with the purpose of forcing the Axis nations to surrender. For two years, Bohr collaborated with American and British physicists at Los Alamos National Laboratory in New Mexico, using the name Nicholas Baker as a cover. In 1944, he wrote to British Prime Minister Winston Churchill with a progress report:

“What until a few years ago might be considered as a fantastic dream is at present being realized within great laboratories and huge production plants secretly erected in some of the most solitary regions of the United States. There a larger group of physicists than ever before collected for a single purpose, working hand in hand with a whole army of engineers and technicians, are preparing new materials capable of an immense energy release, and are developing ingenious devices for the most effective use of these materials. […]

“One cannot help comparing the situation with that of the alchemists of former days, groping in the dark in their vain efforts to make gold. Today physicists and engineers are, on the basis of firmly established knowledge, controlling and directing violent reactions by which new materials far more precious than gold are built up, atom by atom.”


He was a staunch believer in sharing the science behind nuclear weapons—a view not taken by U.S. and British leaders. Returning to Denmark after the war, Bohr directed his atomic research toward developing sustainable power rather than weapons. He and several colleagues established Risø, a research laboratory with a modern particle accelerator dedicated to developing nuclear energy for peaceful purposes, in the 1950s.

At the same time, Bohr co-founded the European Center for Nuclear Research (CERN), which held conferences and conducted research at Bohr’s Institute for Theoretical Physics for its first five years, prior to moving to Geneva, Switzerland, in 1957. The center now houses the Large Hadron Collider, the world’s largest particle accelerator, which generates electrical fields to speed up the movement of atomic particles and uses magnets to direct their flow. The collisions of the particles reveal information about their properties. Using the Large Hadron Collider, a team of researchers first observed a new type of particle, the Higgs boson, in 2012.


Bohr’s life wasn’t just focused on his work—he was a family man, too. He married Margrethe Nørlund in 1912, and they had six sons, four of whom survived into adulthood. His son Aage would follow closely in his father’s footsteps, becoming not only a physicist, but also the director of the Institute of Theoretical Physics (after his father passed away in 1962) and winner of the 1975 Nobel Prize in Physics for his research into the structure of atomic nuclei. The Bohrs are one of six father-son pairs to have each won a Nobel Prize (Niels Bohr’s professor J.J. Thomson and his son George Paget Thomson are another).


Bohr still contributed to physics after his death—in a way. In 1981, German researchers succeeded in creating a single atom of Element 107, isotope 262, the result of bombarding bismuth atoms with chromium atoms. They named it Bohrium. The highly radioactive element does not occur in nature and, so far, only a few atoms of it have ever been created in a lab.

5 Signs Humans Are Still Evolving

Lealisa Westerhoff, AFP/Getty Images
Lealisa Westerhoff, AFP/Getty Images

When we think of human evolution, our minds wander back to the millions of years it took natural selection to produce modern-day man. Recent research suggests that, despite modern technology and industrialization, humans continue to evolve. "It is a common misunderstanding that evolution took place a long time ago, and that to understand ourselves we must look back to the hunter-gatherer days of humans," Dr. Virpi Lummaa, a professor at the University of Turku, told Gizmodo.

But not only are we still evolving, we're doing so even faster than before. In the last 10,000 years, the pace of our evolution has sped up, creating more mutations in our genes, and more natural selections from those mutations. Here are some clues that show humans are continuing to evolve.

1. Humans drink milk.

Historically, the gene that regulated humans' ability to digest lactose shut down as we were weaned off our mothers' breast milk. But when we began domesticating cows, sheep, and goats, being able to drink milk became a nutritionally advantageous quality, and people with the genetic mutation that allowed them to digest lactose were better able to propagate their genes.

The gene was first identified in 2002 in a population of northern Europeans that lived between 6000 and 5000 years ago. The genetic mutation for digesting milk is now carried by more than 95 percent of northern European descendants. In addition, a 2006 study suggests this tolerance for lactose developed again, independently of the European population, 3000 years ago in East Africa.

2. We're losing our wisdom teeth.

Our ancestors had much bigger jaws than we do, which helped them chew a tough diet of roots, nuts, and leaves. And what meat they ate they tore apart with their teeth, all of which led to worn-down chompers that needed replacing. Enter the wisdom teeth: A third set of molars is believed to be the evolutionary answer to accommodate our ancestors' eating habits.

Today, we have utensils to cut our food. Our meals are softer and easier to chew, and our jaws are much smaller, which is why wisdom teeth are often impacted when they come in — there just isn't room for them. Unlike the appendix, wisdom teeth have become vestigial organs. One estimate says 35 percent of the population is born without wisdom teeth, and some say they may disappear altogether.

3. We're resisting infectious diseases.

In 2007, a group of researchers looking for signs of recent evolution identified 1800 genes that have only become prevalent in humans in the last 40,000 years, many of which are devoted to fighting infectious diseases like malaria. More than a dozen new genetic variants for fighting malaria are spreading rapidly among Africans. Another study found that natural selection has favored city-dwellers. Living in cities has produced a genetic variant that allows us to be more resistant to diseases like tuberculosis and leprosy. "This seems to be an elegant example of evolution in action," says Dr. Ian Barnes, an evolutionary biologist at London's Natural History Museum, said in 2010 statement. "It flags up the importance of a very recent aspect of our evolution as a species, the development of cities as a selective force."

4. Our brains are shrinking.

While we may like to believe our big brains make us smarter than the rest of the animal world, our brains have actually been shrinking over the last 30,000 years. The average volume of the human brain has decreased from 1500 cubic centimeters to 1350 cubic centimeters, which is an amount equivalent to the size of a tennis ball.

There are several different conclusions as to why this is: One group of researchers suspects our shrinking brains mean we are in fact getting dumber. Historically, brain size decreased as societies became larger and more complex, suggesting that the safety net of modern society negated the correlation between intelligence and survival. But another, more encouraging theory says our brains are shrinking not because we're getting dumber, but because smaller brains are more efficient. This theory suggests that, as they shrink, our brains are being rewired to work faster but take up less room. There's also a theory that smaller brains are an evolutionary advantage because they make us less aggressive beings, allowing us to work together to solve problems, rather than tear each other to shreds.

5. Some of us have blue eyes.

Originally, we all had brown eyes. But about 10,000 years ago, someone who lived near the Black Sea developed a genetic mutation that turned brown eyes blue. While the reason blue eyes have persisted remains a bit of a mystery, one theory is that they act as a sort of paternity test. “There is strong evolutionary pressure for a man not to invest his paternal resources in another man’s child,” Bruno Laeng, lead author of a 2006 study on the development of blue eyes, told The New York Times. Because it is virtually impossible for two blue-eyed mates to create a brown-eyed baby, our blue-eyed male ancestors may have sought out blue-eyed mates as a way of ensuring fidelity. This would partially explain why, in a recent study, blue-eyed men rated blue-eyed women as more attractive compared to brown-eyed women, whereas females and brown-eyed men expressed no preference.

Now Ear This: A New App Can Detect a Child's Ear Infection


Generally speaking, using an internet connection to diagnose a medical condition is rarely recommended. But technology is getting better at outpacing skepticism over handheld devices guiding decisions and suggesting treatment relating to health care. The most recent example is an app that promises to identify one of the key symptoms of ear infections in kids.

The Associated Press reports that researchers at the University of Washington are close to finalizing an app that would allow a parent to assess whether or not their child has an ear infection using their phone, some paper, and some soft noises. A small piece of paper is folded into a funnel shape and inserted into the ear canal to focus the app's sounds (which resemble bird chirps) toward the child’s ear. The app measures sound waves bouncing off the eardrum. If pus or fluid is present, the sound waves will be altered, indicating a possible infection. The parent would then receive a text from the app notifying them of the presence of buildup in the middle ear.

The University of Washington tested the efficacy of the app by evaluating roughly 50 patients scheduled to undergo ear surgery at Seattle Children’s Hospital. The app was able to identify fluid in patients' ears about 85 percent of the time. That’s roughly as well as traditional exams, which involve visual identification as well as specialized acoustic devices.

While the system looks promising, not all cases of fluid in the ear are the result of infections or require medical attention. Parents would need to evaluate other symptoms, such as fever, if they intend to use the app to decide whether or not to seek medical attention. It may prove most beneficial in children with persistent fluid accumulation, a condition that needs to be monitored over the course of months when deciding whether a drain tube needs to be placed. Checking for fluid at home would save both time and money compared to repeated visits to a physician.

The app does not yet have Food and Drug Administration (FDA) approval and there is no timetable for when it might be commercially available. If it passes muster, it would join a number of FDA-approved “smart” medical diagnostic tools, including the AliveKor CardiaBand for the Apple Watch, which conducts EKG monitoring for heart irregularities.

[h/t WGRZ]