The Covid-19 virus may be extremely aggressive, but it is really very, very small. Christian Yates, a mathematician from the University of Bath (United Kingdom), thus had fun calculating the space that all the SARS-CoV-2 viruses currently in circulation would take if they were compacted to the maximum.
–
VIDEO" />You will also be interested
[EN VIDÉO] Visit the first self-sufficient “special Covid” city A Spanish architectural firm imagined an ecological city in wood autonomous in food, producing its water and electricity. A project intended for a new district in China, but which is intended to develop with epidemics. Guided tour in pictures.
—–
What if it was enough to put all the coronavirus of the world in a can of Invented in 1885 by John Stith Pemberton
Coca-Cola Invention
Contrary to the legend conveyed by the brand, the appearance of the … “data-image =” https://cdn.futura-sciences.com/buildsv6/images/midioriginal/9/3/1/9318904265_50037767_coca-cola -glas-mit-eis-02.jpg “data-url =” https://www.futura-sciences.com/sciences/definitions/chimie-coca-cola-11111/ “data-more =” Read more ” >Coca Cola before throwing it in the trash? It would still be very practical to get rid of it! Alas, this is drastically impossible on a practical level. But, in theory, it would indeed be possible to achieve this.
To reach this conclusion, Christian Yates has made some approximations. He first considered only viruses affecting humans (so exit aim, chats and other beasts infected with SARS-CoV-2). He then sought to know the number of viruses in circulation. According to the statistics site Our World in Data, about half a million people test positive every day for the Covid-19. But many people go undetected. The real figure would therefore be closer to 3 million, estimates theInstitute for Health Metrics and Evaluations.
–
A graphic demonstration of the calculation of the volume of coronaviruses in the world. © Vicki Martin, YouTube
–
How many viruses are there in a human being?
Second step: evaluate the maximum quantity of virus carried by a patient at a time T. Christian Yates was inspired by a study pre-published on the site MedRxiv who calculated the number of viral particles per gram of different tissues in infected monkeys and proportionally increased their size to be representative of humans. According to study estimates, peaks in viral load range from 1 to 100 billion virus particles per individual. To simplify, Christian Yates took the geometric mean of this interval, or 10 billion viral particles per person.
But that’s not all. We know that the viral load increases gradually from the infection to peak on the 6e day and then decrease. This means that it follows a bell curve. ” When we add up all the viral load contributions of each of the 3 million people infected in the previous days (assuming this rate of 3 million is roughly constant), we find that there are about 200 quadrillions of viral particles in the world at a time », Details Christian Yates in his article published on the site The Conversation. Either 200 million billion or 2 x 1017 virions.
This is roughly the same number as the number of grains of sand on the planet
—
« It sounds huge and it is. This is about the same number as the grains of Artificial Sand
Sand can also be obtained artificially, by … “data-image =” https://cdn.futura-sciences.com/buildsv6/images/midioriginal/4/e/9/4e957f8c38_92834_sable.jpg “data- url = “https://www.futura-sciences.com/planete/definitions/geologie-sable-6009/” data-more = “Read more”>sable on the planet », Attests the mathematician. But there is hardly enough to cover the beaches of the world, because the SARS-CoV-2 virus is much smaller than a grain of sand: it measures between 80 and 120 nanometers in diameter, 1,000 times thinner than a human hair. This is where another (big) approximation comes in, which consists of considering the virus as perfectly spherical. It is therefore sufficient to apply the simple formula for calculating the volume of a sphere (V = 4π /3x r3), taking an average diameter of 100 nanometers (nm). We then obtain 520,000 nm3 for a viral particle. It remains to multiply this figure with the number of particles, and we end up with a volume of about 120 milliliters (ml).
160 ml or 52 times the Earth-Moon distance
Be careful, it’s not over! Because, like when stacking oranges in a cardboard box, it is impossible to completely fill a space with spheres. It is therefore necessary to calculate the maximum proportion of the total volume occupied by the spheres. This very famous stacking problem, called conjecture de Kepler, however, was only demonstrated in 1998 by Thomas Hales. And again, its demonstration is so complex that no one dares vouch for its accuracy, Robin Jamet attests, from the mathematics department at the Palais de la Découverte. According to this theorem, a maximum density of about 0.74 is obtained; which means that we have 26% empty space in the container. This amounts to increasing the volume of viruses to 160 ml. “ Even taking into account the size of the roles of proteins
Proteins can perform a wide variety of functions within the cell or the body.
They may have:
a structural role (like actin or tubulin which … “data-image =” https://cdn.futura-sciences.com/buildsv6/images/midioriginal/4/6/e/46e94f9da7_50034188_actine-thomas-splettstoesser -cc.jpg “data-url =” https://www.futura-sciences.com/sante/definitions/biologie-proteine-237/ “data-more =” Read more “>protein peak, not all SARS-CoV-2 in the world would fill a can of Coca-Cola », Concludes Christian Yates. And if we aligned them end to end, we would arrive at 52 times the Earth-Moon distance.
While viruses are very small, they are still quite heavy. According to the MedRxiv study, the mass total of all these viruses is between 100 g and 1 kg. So much more than a can of Coca-Cola.
Interested in what you just read?
–
– .