00:00If you came to Earth from another planet, your rational mind would not understand how singing dunes and moving balls of lightning are scientifically possible.
00:10In my opinion, you would say that these things are only images taken from your favorite science fiction movie.
00:16I hope for you that you will never find yourself alone near the Rio Catatumbo in Venezuela during a storm.
00:23Because you must know that at this place, lightning works in both directions.
00:27That is to say that it can come from the sky as from the ground.
00:30It's terrifying, I know.
00:32Scientists think that the reason for this phenomenon is probably the strong presence of uranium in the sea rock.
00:39But it could also be due to the hot and cold air currents that meet in this area.
00:45The electric field is then charged and the lightning reverses, passing from the ground to the clouds.
00:50Scientists even have a sophisticated name for this phenomenon.
00:53Ascending lightning.
00:55This special place, the Rio Catatumbo, became famous because of its light shows.
01:02In fact, this name means house of thunder in the local language.
01:07This phenomenon occurs up to 160 nights a year.
01:10And it can last about 9 hours a day.
01:14When the scientists did the math, they realized that the region produced between 16 and 40 lightning per minute.
01:23You have probably heard of Marco Polo, a Venetian merchant of the 13th century and a great traveler.
01:29During one of his travels, he came across what he described as singing dunes.
01:35The dunes had literally grown larger, as if they were playing the drum.
01:39And he was so scared that he thought it was the work of evil invisible entities that were having fun tormenting him.
01:45Today, scientists have discovered how sand dunes produce these rumbles.
01:52A team of scientists studied a singing dune in Morocco.
01:55They chose a large crescent-shaped dune that makes noise all year round.
02:00If the wind is favorable, this dune can sing several times per afternoon.
02:06It turns out that the wind forces the sand to accumulate at the top of the dune,
02:10until the slope reaches a tipping point of about 35 degrees.
02:16This accumulated sand then falls like an avalanche.
02:19And that's what makes a sound.
02:21The sand must be dry enough for the song to occur.
02:25It's a kind of natural rhythm box.
02:27Pretty impressive, isn't it?
02:30The following image may be the most disturbing of all.
02:33First, you will see a flash.
02:35Then, a thunderbolt.
02:38And finally, a curious light floating in the air and bouncing on the surface like a white electric ball.
02:45Would you hide under your blanket if you were a witness to such a thing?
02:48This is what an old lady who has witnessed this phenomenon since her bed in her apartment in Chicago did.
02:54It turns out that people have been exchanging stories of light balls for hundreds of years.
03:00The report of an English monk dating from the beginning of the millennium could be the oldest version of these stories.
03:05It is a question of a flaming globe coming down from a storm cloud and falling into the sieve.
03:11Scientists are not entirely sure of the cause of this phenomenon.
03:15But a theory wants the lightning to strike a soil rich in silica.
03:19This can vaporize the silica and create tiny particles, linked together by an electric charge.
03:26When these particles react with oxygen, they produce luminous orbs that can last a few seconds.
03:33According to other theories, this phenomenon would be linked to miniature black holes or even hallucinations.
03:39But the explanation of silica is the most plausible to date.
03:42What is certain is that the ball lightning is often linked to stormy weather.
03:47If you wake up in the middle of a winter night and you see these lights,
03:51you will probably think that extraterrestrial beings are invading our world.
03:56Or you will feel like one of the lucky people who have seen a Boreal aurora during their lifetime.
04:02But this is not what it is.
04:04These magnificent pastel light beams were photographed by an inhabitant of Ontario, Canada.
04:10This phenomenon occurs when tiny flat ice crystals, which are usually found in the atmosphere, float closer to the ground.
04:18These beams are sometimes called violet light columns,
04:21and they reflect light from sources such as air lamps or cars.
04:26These reflections stretch to form large colored columns that seem to shine in the sky.
04:32But the most beautiful thing is that it is mainly an optical illusion.
04:36The columns do not really float in the air, they are just an effect of the light reflected by the ice.
04:42Somewhere near Buffalo, in the state of New York,
04:45you will find a surreal combination of fire and water elements.
04:49This phenomenon is called the fall of the eternal flame, because the flame never stops burning.
04:54Although it is very close to water,
04:56we owe this beautiful spectacle to a chemical reaction during which gas escapes from the ground and is consumed with air.
05:02It is one of the few hundred natural eternal flames in the world.
05:06But because of its location, it is probably the most beautiful.
05:10But how does it light up?
05:12In general, eternal flames can be ignited by lightning,
05:15human activity or what is called piezoelectricity.
05:19These are materials that produce electricity when you press or twist them.
05:24Scientists believe that the Amerindians lit these flames thousands of years ago,
05:29but this is only a hypothesis.
05:32Have you ever imagined taking a midnight bath
05:35when suddenly you find yourself surrounded by an incandescent blue mist?
05:39As if there were huge canons of light coming out of the bottom of the sea and arriving directly at the surface.
05:45This phenomenon is rare, but it is magical.
05:48This chemical reaction is known as bioluminescence and can occur in different situations.
05:54This is the case, for example, when tiny algae migrate near the shores.
05:59When these algae are disturbed, they try to defend themselves by lighting up and thus creating the most beautiful of the shows.
06:05There is a precise place in the world where you can observe a similar phenomenon, New Zealand.
06:11There are caves where thousands of glowing worms live.
06:15These are in fact the larvae of a mushroom, which have the particularity of being luminescent.
06:20If you have the chance to visit these caves, you will have the impression of floating in an underground galaxy.
06:25The sky can be the origin of a large number of different phenomena,
06:29of which this one, called lightning in a crown.
06:32It occurs in the form of a column of light that jumps or dances near the top of a cumulus, Nimbus.
06:38Cumulus and Nimbus are massive and imposing clouds that look like mountains.
06:44These are the clouds that usually announce storms, lightning and heavy rain.
06:49You will certainly say that these crowns of lightning look like a supernatural energy gate opening into the sky.
06:56But this is actually a very scientific phenomenon.
07:00It occurs when the light of the sun is reflected on tiny ice crystals inside a cloud.
07:06But the most interesting thing is that these ice crystals do not float by chance.
07:11They move under the effect of the variations of the electric field of the cloud.
07:15When the electric field changes, the ice crystals realign and the light they reflect moves as well.
07:23This is why the lightning in a crown seems vacillating or wavy.
07:28Lightning in a crown does not occur all the time.
07:31A cloud of storms must bring together the right conditions.
07:35A lot of sunlight, ice crystals and a powerful electric field.
07:40If you see one, consider yourself lucky.
07:44It's as if nature was showing you a rare magic trick.
07:48We sometimes see fire hills in science fiction movies,
07:52but this one is very real.
07:54Located in the Arctic region of Canada, the Smoking Hills are a unique site on our planet.
08:01And that's where things get a little more sensational.
08:04Some minerals found in these hills have only been found in a few rare places on our planet,
08:10and on the surface of Mars.
08:13The ground of the Smoking Hills has been emitting smoke for at least 200 years, without interruption.
08:19Explorers thought the region was home to an active volcano, but this is not the case.
08:25As explained by scientists, the ground of the region is made of sulfur and coal.
08:30When exposed to oxygen, it spontaneously ignites and emits a constant smoke.
08:36I warn you, do not plan to go there for tourism.
08:40This environment is extremely hostile to human life,
08:43because the smoke is toxic and the temperatures are dangerously high.
Comments