• last week
Les scientifiques ont découvert un tout nouveau cycle naturel qui est extrêmement surprenant et sans précédent. Il s'avère qu'il existe un motif dans la nature qui affecte les écosystèmes, les climats, ou même la manière dont certaines espèces se comportent, mais que nous n'avions pas remarqué jusqu'à présent. Ce nouveau cycle montre comment différentes parties de la Terre sont plus interconnectées que nous le pensions, s'influençant mutuellement de manière incroyable. Ces découvertes pourraient totalement changer notre compréhension de phénomènes tels que les schémas météorologiques, les migrations animales, ou même la croissance des plantes. Ce qui est excitant, c'est que cette découverte ouvre tant de nouvelles questions pour les scientifiques à explorer. C'est un rappel que, même aujourd'hui, la nature a encore des secrets à révéler ! Animation créée par Sympa. ---------------------------------------------------------------------------------------- Musique par Epidemic Sound https://www.epidemicsound.com Pour ne rien perdre de Sympa, abonnez-vous!: https://goo.gl/6E4Xna​ ---------------------------------------------------------------------------------------- Nos réseaux sociaux : Facebook: https://www.facebook.com/sympasympacom/ Instagram: https://www.instagram.com/sympa.officiel/ Stock de fichiers (photos, vidéos et autres): https://www.depositphotos.com https://www.shutterstock.com https://www.eastnews.ru ---------------------------------------------------------------------------------------- Si tu en veux encore plus, fais un tour ici: http://sympa-sympa.com

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Transcript
00:00Salt gives a delicious taste to our chips and popcorn.
00:04But that's not all.
00:06It is used in household and industrial products,
00:09in cosmetics, fertilizers, water treatment and road asphalting.
00:14Every year, around 300 tons of salt are produced worldwide.
00:19But there is a problem.
00:21It's too much salt for our planet.
00:23You see, salt gradually rises to the surface
00:26from the oceanic rocks located deep down.
00:29And this process is quite balanced.
00:31Or it was, in the past.
00:33Man is disrupting this balance.
00:35Our demand keeps increasing
00:37and we throw too much salt into the soil,
00:39into the air and into the sea.
00:41And if this process continues uncontrollably,
00:44we could be faced with an existential threat.
00:47Yes, it's really serious.
00:49And a recent study by the University of Maryland confirms it.
00:53There is a phenomenon known as the natural salt cycle.
00:58It has existed for thousands of years.
01:00Salt rises naturally
01:02due to geological elevation
01:04and rock alteration.
01:06As a result, rocks disintegrate
01:09and release salt ions into the soil.
01:11Some of these ions are absorbed by plants and organisms.
01:15Others are carried by rivers
01:17that transport them to the oceans.
01:19Salt also penetrates the atmosphere
01:22through salt dust in dry regions
01:25and impurities in coastal regions.
01:28Salt is essential for man,
01:30animals and plants
01:32because our organism feeds on it.
01:34In short, we are a bit like electric systems
01:36controlled by salt.
01:38The soil needs salt to stay compact.
01:40Plants also need it in small quantities.
01:43It allows their metabolism to function properly
01:46to synthesize chlorophyll in sufficient quantities.
01:49However, an excess of salt is not a good thing.
01:52Nowadays, human activity disrupts the natural salt cycle
01:55because we bring it back to the surface of the planet
01:58much faster than before.
02:00This is the conclusion that researchers have come to
02:02after combining data from different sources,
02:05including the U.S. Geological Survey Mineral Annual Report
02:09and the world records on the composition of watercourses
02:12and salinity measurements.
02:15The main factor behind these changes
02:17is the extraction of the necessary salt,
02:19especially in the food industry.
02:21This is followed by acid rain,
02:23which accelerates rock alteration.
02:25These factors accelerate the production of salt
02:27on the surface of the planet.
02:29At present, the concentration of salt in the world is too high.
02:33The soil, plants and animals
02:35are not able to consume it completely.
02:38Worse still, some essential species
02:41cannot survive with this excess of salt.
02:44Their disappearance modifies biodiversity
02:46and could lead to the appearance of invasive species
02:49such as the common rose.
02:51This is a tall plant that invades coastal areas.
02:54There is also the zooplankton,
02:56an important oceanic species for the regulation of algae
02:59and which is extremely sensitive to salt.
03:02If this species begins to decline,
03:04it could disrupt global food networks.
03:07The excess of salt also turns agricultural lands into fridges.
03:11Recent reports have shown that
03:13about 13 million square kilometers of land
03:15are already affected.
03:17This is an area equivalent to four times the size of India.
03:21In some countries,
03:23huge areas become infertile because of this excess.
03:27In addition, excess salt is bad for health.
03:30Indeed, all this additional salt
03:32infiltrates underground waters,
03:34making them too salty for human consumption.
03:37This situation is particularly harmful
03:39to people who must follow a poor sodium diet.
03:43And I'm not just talking about table salt
03:45or sodium chloride.
03:46No.
03:47Other salts based on calcium and magnesium
03:49also infiltrate, generally,
03:51during the production of fertilizers and building materials.
03:54This gives us an awful chemical cocktail
03:56of different salts from various sources.
03:58And scientists do not yet know
04:00the effects that such a mixture can have on us,
04:03humans.
04:05Do you think it's time
04:07to reduce your salt consumption?
04:10Well, but do not completely eliminate it.
04:13In the 1930s,
04:15Dr. Robert Mackenz
04:17of the Department of Experimental Medicine
04:19at the University of Cambridge
04:21asked four volunteers
04:23to go completely salt-free for 10 days.
04:26They first had to sweat to evacuate the salt
04:28that remained in their bodies.
04:30Then, the scientist literally
04:32desalted everything they were allowed
04:34to eat and drink.
04:36Shortly after,
04:37the participants began to experience
04:39strange sensations.
04:41They realized that there was no longer much taste
04:43in what they were eating.
04:46The situation worsened.
04:48They began to feel tired,
04:51then they were quickly too exhausted
04:53to eat.
04:55They began to show signs of hyponatremia.
04:57This is when the sodium concentration
04:59in the blood is dangerously low.
05:01The blood cells thicken,
05:03the blood no longer managing to regulate
05:05the amount of water a cell must consume.
05:09If this problem is not treated,
05:11it can not only lead to epilepsy,
05:13but also have much worse consequences.
05:16At the end of the trial period,
05:18the participants received salty food.
05:21Miraculously,
05:23within a few minutes,
05:25they regained their sense of taste
05:27and their energy was restored.
05:29To tell the truth,
05:31all this is a bit terrifying.
05:33If this is what 10 days without salt means,
05:35imagine the disaster that would occur
05:37if there was no more salt at all.
05:39We would not last long,
05:41that's for sure.
05:43And it would be an endless drama,
05:45not only for us,
05:47but also for plants and animals.
05:49Because they need as much salt as we do.
05:51If our oceans suddenly lost all their salt,
05:53the underwater algae would disappear,
05:55which would reduce almost half
05:57the photosynthesis on the planet.
05:59The terrestrial plants would follow the movement.
06:01Shortly after the disappearance of salt,
06:03we would be confronted
06:05with a size problem.
06:07Too much carbon dioxide
06:09and not enough oxygen.
06:11Our climate would begin to fluctuate,
06:13with extremely hot and cold temperatures,
06:15and hurricanes would become
06:17incredibly powerful
06:19and destroy everything in their path.
06:21Fortunately, we still have salt in our stores,
06:23and its natural cycle
06:25could become more or less stable.
06:27Humanity knows
06:29and has been using salt since the dawn of time.
06:31It was used, for example,
06:33to make and preserve mummies
06:35in ancient Egypt.
06:37It was a product of value
06:39that was exchanged between the Phoenicians
06:41and other peoples of the Mediterranean.
06:43In ancient China,
06:45people knew more than 40 types of salt
06:47that they used for medicinal purposes.
06:49In medieval Europe,
06:51Venice became powerful
06:53thanks to its monopoly on salt.
06:55Its production and transportation
06:57favored the appearance of new cities
06:59and the construction of roads.
07:01Salzburg, the city of salt in Austria,
07:03is an excellent example of this.
07:05Today,
07:07salt continues to surprise us.
07:09For example,
07:11researchers from the Rosensteil School
07:13of Marine and Atmospheric Science
07:15at the University of Miami
07:17have recently discovered rare deep-water
07:19salmon pools in the Gulf of Aqaba.
07:21This is a northern extension
07:23of the Red Sea.
07:25These salty underwater lakes
07:27could reveal to us the secret
07:29of the formation of oceans
07:31millions of years ago.
07:33They could also give us clues
07:35about extraterrestrial life.
07:37Deep-water salmon pools
07:39are among the most extreme environments
07:41on Earth, and yet,
07:43despite their ultra-high salinity,
07:45their somewhat exotic chemistry
07:47and their total lack of oxygen,
07:49they are full of life.
07:51Researchers have even found
07:53bioactive molecules
07:55with potentially anticancer properties
07:57in the Red Sea.
07:59These oxygen-deprived pools
08:01are located near the coast
08:03and could contain information
08:05about tsunamis, earthquakes
08:07and sudden cruises
08:09that took place in the Gulf of Aqaba
08:11thousands of years ago.
08:13Salt even arrived in space.
08:15Finally, in a way.
08:17The Moon is like a comet
08:19that crosses the cosmos.
08:21Our natural satellite
08:23has a thin line of irradiated matter
08:25that our planet crosses
08:27directly once a month.
08:29However, according to a study
08:31published in the journal J.J.R. Planets,
08:33this lunar line
08:35would be made up of millions of sodium atoms.
08:37And as you already know,
08:39the chemical formula for salt
08:41is sodium chloride.
08:43These atoms
08:45are expelled from the lunar soil
08:47by meteorites, then pushed
08:49thousands of kilometers downstream
08:51by solar radiation.
08:53Several days a month,
08:55when the new moon is between
08:57the Earth and the Sun,
08:59the gravity of our planet
09:01drags this line of sodium
09:03into a long beam
09:05that wraps around our atmosphere.
09:07The line itself is harmless
09:09and invisible to the naked eye.
09:11But during these few days,
09:13the most powerful telescopes
09:15can detect the faint orange glow
09:17in the sky.

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