For the first time, physicists have observed a quantum property that makes water so unique

    Researchers "saw" how water molecules move close to each other, "framing" the hydrogen bond

    He is about to end up run over, his mother saves him

    Water, the most common liquid, the one that makes us live, is also the most "strange" in the Universe. A research group from the SLAC National Accelerator Laboratory, Stanford University (USA) and Stockholm University (Sweden) has "seen" for the first time how water molecules move close to each other, managing to frame the fascinating mechanism of hydrogen bonds.





    Water is a molecule formed by two atoms of hydrogen and one of oxygen (H2O) and due to its particular structure it forms very strong molecule-molecule bonds, much stronger than other bonds between molecules of different types, called 'hydrogen bonds '. These atoms in fact "bridge" creating a dense network of molecules when water is in a liquid state. This mechanism, at a microscopic level, is due to the different electron density of oxygen and hydrogen.

    In fact, oxygen is the second most electronegative element of the periodic system, that is, it has a very high capacity to attract electrons to itself. On the contrary, hydrogen has a much lower "attractive force" and therefore a sort of "imbalance" is formed in the water molecule so that only one H2O, even if neutral, is a magnet with a positive pole (the hydrogen atoms ) and a negative one (the oxygen atom). In fact, technically it is said that water is one polar molecule. The network is therefore formed by the attractions positive part-negative part.

    And - it seems incredible to say - but it is this structure that has it generated and ensure life on Earth. In fact, when the water becomes solid, therefore ice is formed, the molecules are much less free to move, but to keep the hydrogen bond a little "alive" they move away, causing the system to increase in volume.

    This is why ice floats on water, having a lower density, and this is why aquatic life has been able to develop and evolve. But the even more incredible thing is that this behavior is truly unique in its kind, because normally the solids are more "concentrated" and therefore denser (be careful, however, to put water bottles in the freezer, because this extraordinary behavior of water causes even explode the glass if the water inside freezes).



    Today researchers have "seen" all of this, which is actually a quantum phenomenon. In particular, they made the first direct observation of how the hydrogen atoms in water molecules pull and push neighboring ones when excited by laser light.

    For the first time, physicists have observed a quantum property that makes water so unique

    © Stanford University

    These findings reveal effects that could underlie key aspects of water's microscopic origin and could lead to a better understanding of how it helps proteins perform their functions in living organisms.

    Although it has already been speculated as this so-called nuclear quantum effect is at the center of many of the strange properties of water, this experiment marks the first time this has been observed directly - comments Anders Nilsson, co-author of the work - We now wonder if this quantum effect could be themissing link in theoretical models that describe the anomalous properties of water.

    Experimentally, the team created jets of liquid water 100 nanometers thick (about 1.000 times thinner than the width of a human hair) and vibrated the water molecules with infrared laser light. Then it blew up the molecules with short pulses of high-energy electrons.

    This generated high-resolution snapshots of the changing atomic structure of the molecules which, put together, created a film that tells how the network responded to light. The movie of life.


    The work was published in Nature.

    Sources of reference: Stanford University / Nature


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