Nuclear physics is a little over a century old as a science, but it has already generated quite a series of puzzles and mysteries.
As we are about to see, many have been answered during this time, but some at the cost of creating fresh problems for scientists to solve.
10. The Rope Trick Effect
The nuclear bomb tests of the middle of the 20th century provided scientists with a great opportunity to study various phenomena related to nuclear physics.
But one of the earliest mysteries turned out to have a rather unspectacular explanation. See, you’d normally expect a nuclear blast to be largely symmetrical, so at first nobody knew what the spikes coming out the explosion were.
A scientist called John Malik eventually noticed that the spikes corresponded to where the cables which held the bomb in place were located. To test this, he covered the cables in different kinds of paint and even aluminum foil.
When photographed, they appeared in reverse color: black cables were white and light cables were dark. This could be explained by the fact that dark shades absorb more heat than light shades, shining brighter as a result. Malik named this phenomenon the Rope Trick Effect.
9. Radiation rain
After decades with the looming threat of nuclear annihilation in the back of everyone’s mind, it’s somewhat understandable why a lot of people have developed a certain fear of radiation and everything related to it. This fear is, however, mostly unjustified.
After the widely reported Fukushima disaster, many people on the other side of the Pacific, on the North American West Coast, began posting videos showing higher than average Geiger counter readings on the beaches or after the rain. However this wasn’t from the damaged nuclear power plant half a world away!
In fact, radioactive elements like uranium and thorium are relatively prevalent in West Coast states like California and Oregon. What people found with their instruments was naturally occurring and harmless radon gas (a by-product of uranium decay) or thorium.
8. The abundance of lithium
Astrophysicists have a pretty good understanding of how the elements formed. Most hydrogen and helium (the two most common elements in the Universe) appeared immediately after the Big Bang, while the rest were formed mostly as a result of powerful stellar explosions called supernovae. However none of these could account for how much lithium there is in the Universe.
Just a few years ago, astronomers examining a stellar event called Nova Delphini 2013 stumbled onto what is possibly an answer to this conundrum: the lithium-7 isotope, which cannot be accounted by supernova explosions or cosmic ray interactions, could have been formed as a result of the decay of another element called beryllium.
What exactly happened to all the beryllium after this process is another mystery, however we’ll just stick to the lithium for now!
7. Project Faultless
During the height of the Cold War, Nevada was one of the most active nuclear bomb test sites in the world. This caused some serious problems for hotel owners in nearby Las Vegas, who didn’t exactly appreciate the fact that the ground would shake as often as once every three days! One of these hotel owners was particularly influential: billionaire Howard Hughes.
The oil and aviation magnate actually sent letters to presidents Lyndon Johnson and Richard Nixon and reportedly even tried sending bribes to Washington officials in order to get the testing to stop.
Eventually, Project Faultless was set up: a nuclear detonation at a depth of 3,200 feet which was supposed to test whether a bigger detonation farther away from Las Vegas would reduce the shaking there.
The explosion actually caused the earth to sink 8 feet and opened gaps 3 feet across, but unfortunately it didn’t solve the problem of shaking in Las Vegas, either.
6. An ancient spike in carbon-14 levels
According to tree ring data gathered from old Japanese cedars, there has been a spike in the concentration of the isotope carbon-14 during the latter decades of the 8th century.
The only other time such a fluctuation has been recorded was during the heavy open-air nuclear bomb testing during the mid-20th century! So what could have caused this anomaly?
According to Jonathon Allen, a biochemistry major at the University of California, Santa Cruz, the source could have been a supernova described in an old Anglo-Saxon text as a “red crucifix” which appeared in the sky in the year 774.
This event could have generated enough high-energy radiation to form the relatively scarce carbon-14, thus providing a plausible explanation for this mystery.
5. Japan radioactive mushrooms
The Fukushima nuclear disaster was the most prominent event of its kind in decades. Radiation from the meltdown spread to the surrounding areas, contaminating the food to some extent or another.
Mushrooms in particular have been affected, since they act as natural radiation magnets (so much so that they have even been proposed as a way to clean up radiation from the fallout).
The Japanese government immediately banned the selling of wild mushrooms until they could be deemed safe, however tests showed that the radiation in the mushrooms wasn’t coming from the Fukushima nuclear power plant.
Remarkably, the radiation was decades older, dating back to the nuclear tests from the 1940s to 1960s. There was even radiation sourced to Chernobyl!
4. Manganese irregular decay rate
The half life of an element is the time it takes for half of the atoms in a sample to undergo radioactive decay. This is supposed to be a constant, a rather important one at that, since the phenomenon is used, among other things, to determine the age of things (the famous carbon-14 dating method).
However scientists have recently found an anomaly, namely the decay rate of certain elements (most notably manganese-54) would sometimes vary. This puzzling fact was eventually correlated to the presence of solar flares, however scientists still can’t explain the causal connection.
It has been speculated that neutrinos from the Sun tamper with the decay rates of the elements, but no definitive explanation or proof has been put forth yet.
3. Nuclear bomb testing confirms formation of new neurons
Scientists used to think humans don’t make any new neurons during their lifetime, but an experiment only made possible by the above-ground nuclear testing that went on between 1945 and 1963 proved this assumption wrong.
As we’ve mentioned earlier, the concentration of carbon-14 in the atmosphere is generally really low, but there have been a few spikes throughout history.
Living things incorporate this isotope which they get from the atmosphere, so you could actually tell when a cell was created depending on its carbon-14 concentration. A team of scientists led by Jonas Frisén at the Karolinska Institute found that new neurons were being produced in a hipponcampus, with an annual turnover rate of about 1.75%.
2. The radioactive cloud over Europe
One of the last things you want to hear on the news is that there’s a cloud of radiation hovering above the place where you live. Many Europeans had to deal with this unsettling piece of news in 2011, as authorities across the continent began registering higher than normal levels of radiation.
The source was initially thought to be Fukushima, which had recently been damaged by a huge earthquake and tsunami, however this proved not to be the case.
The most likely culprit was probably an entity in Budapest which manufactured isotopes for the healthcare system, research facilities, and private companies.
Yet even though the levels of radiation were far from being harmful to humans, it is still highly unlikely that single institution could have emitted all that radiation. Little comfort to the millions of people living under a thin radioactive cloud, we imagine.
1. How do elements form?
As late as the first few decades of the 20th century, physicists had no idea how the elements formed. Some, like British scientist Arthur Eddington, argued that the centers of stars could be something like cosmic furnaces in which the elements were being forged, but the problem was that classical mechanics could not provide an adequate explanation for this phenomenon.
A few years later, however, Hans Bethe, one of the scientists who played a significant role in the Manhattan Project, showed how nuclear fusion reactions could turn hydrogen into helium. Similar processes would eventually be found which forge everything up to iron, while all the other, even heavier elements are formed during supernova explosions.