Science fiction writer and futurist Arthur C. Clarke once said, “Any sufficiently advanced technology is indistinguishable from magic.” Though he was talking about technology, science itself can sometimes seem so strange and unbelievable that one might wonder if it can be distinguished from magic either. The same can be said to apply to nature and natural phenomenon. Here are ten such science facts that we believe will elicit the same sense of wonder from you as they did from us.

1 An average cloud weighs 1.1 million pounds, and an average storm cloud weighs 105.8 million pounds. 

Weighing a cloud might seem like an impossible task, but all you need is its approximate volume and density which can be easily determined. Scientists have measured that the cumulus clouds, the white fluffy clouds that we see on days with good weather, have a density of 0.5 gram per cubic meter. Measuring the shadow a cloud casts on land at midday will give us its width, which, according to Peggy LeMone, a researcher at the National Center for Atmospheric Research, is typically a kilometer.

Cumulus clouds are roughly cubical and a kilometer high on an average. So, the average volume of a cumulus cloud is roughly one billion cubic meters. That makes its weight 500 million grams or 1.1 million pounds. That’s about equivalent to 100 elephants, 2,500 donkeys, or 33 apatosauruses. Storm clouds are much denser than cumulus clouds and weigh as much as 105.8 million pounds. A typical North American hurricane weighs 108 billion pounds. (source)

2 Humans possess the protein cryptochrome in their eyes that can detect magnetic fields, but our brains are not equipped with the ability to understand that information. 

Cryptochrome is found in the retina of most birds, some animals like foxes, cows, and deer, as well as bats, mole rats, turtles, ants, sharks, and rays. This helps them determine direction and recognize places if there are no landmarks. In humans, there are two types of cryptochromes – CRY and CRY2. While they are involved in controlling our body clocks, CRY2 can also work as a magnetic sensor according to Lauren Foley of the University of Massachusetts.

Foley introduced CRY2 into the retinas of Drosophila flies with the result that it was possible to train them in an artificial magnetic field to move in a specific direction to get food. According to Roswitha Wiltschko, one of the scientists to discover magnetic sense in birds, though CRY2 is very active in the human retina as a light sensor, it might be no good when it comes to detecting magnetic fields. This is because there are no known “pathways that communicate magnetic information to the brain.” Even though there were, it is unclear what use the information could be for humans, unlike the use the information gives to other animals and especially birds. (source)

3 Pure distilled water is not electrically conductive. It is actually the salts and impurities with negative and positive charges that make normal water such an excellent conductor. 

“Pure” water is water that has been thoroughly filtered or processed to get rid of impurities through distillation or deionization as in laboratories. Common methods currently used for purifying water include reverse osmosis, carbon filtering, ultraviolet oxidization, electrodeionization, microfiltration, ultrafiltration, and capacitive filtration. Employing a combination of these methods results in ultra-pure water with trace contaminants as low as a few parts per billion or trillion.

For water to be an effective conductor of electricity there must be positively and negatively charged ions which usually come in the form of salts and impurities present in regular water. When these are removed, the water’s conductivity drops as low as 5.5 × 10^−6 S/m (Siemens per meter) and its resistivity goes up to 18 MΩ·cm (megohm-centimeter). The little bit of conductivity is due to the OH^– and H₃O⁺ ions that form due to self-ionization of ultra-pure water.

Water of such high purity has various industrial applications, especially in semiconductor, cosmetics and pharmaceutical industries. It is also used to top off lead-acid batteries, cleaning cars and windows as it doesn’t leave spots after drying, in aquariums after adding minerals to keep fish from disease, as well as in aircraft engines when mixed with methanol to extend performance. (source)

4 Scientists believe it was the egg and not the chicken that came first. The first chicken egg was laid by a bird that was not a chicken. 

The “chicken or the egg” dilemma is an ancient folk paradox which Aristotle concluded to be an infinite sequence with no true origin. Strictly speaking, however, it is a false dilemma that was presented to have an either/or answer. It becomes much clearer when the Darwinian principle is taken into account.

Before life became terrestrial, most animals laid eggs in the water which prevented them from drying. As more animals began living on the land, the eggs became amniotic over 312 million years ago. These eggs have three layers that protect the embryo and provide nutrients as well as a hard shell encasing everything. So, if the question refers to all eggs in general, then the egg came first as it evolved to survive outside of water.

But if the question specifically refers to the chicken egg, then the answer gets a little more complicated. Scientists don’t clearly know when the mutations in the eggs of domesticated wild jungle fowl caused it to become a chicken. But at some point, after many generations of interbreeding and domestication, an animal similar to a chicken (aka proto-chicken) laid an egg that became the modern chicken. So, according to Neil deGrasse Tyson, “Which came first: the chicken or the egg? The egg – laid by a bird that was not a chicken.” (1, 2)

5 Your shoelaces come undone when you run because the knots experience forces up to 7G that gradually loosens them up. 

A research team at the University of California, Berkeley consisting of mechanical engineer Oliver O’Reilly and his colleagues used slow-motion videos of a volunteer running on a treadmill to find out what exactly happens with the shoelaces. What they found is that when the foot strikes the ground, the shoelace experiences a force seven times that of gravity which stretches and relaxes the knot a little. Next, when the foot swings, the tips of the shoelace experience an inertial force and acts like a whip. Together, these two forces unravel the knot.

The team experimented further and found that the rate at which the shoelace becomes undone increases with every stride. They also found that a square knot is far more efficient than a granny knot and fails only half the time while the latter failed every time. (source)