Los nuevos datos de la misión Gaia permiten vislumbrar qué aspecto tendrá el cielo nocturno a lo largo de los próximos 1,6 millones de años.
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In mice, it had a similar antidepressant effect to ketamine.
In 1913, Niels Bohr developed his famous atomic model. In this model, electrons rotate in circular orbits around the nucleus, occupying the lowest possible energy orbit, or the closest possible orbit to the nucleus.
However, the popular idea of an atom is, to a certain extent, a schematic distortion, a model of understanding for laymen... an approach that bears little or no resemblance to reality. Atoms are not as they are drawn in textbooks. In fact, atoms are far from all the same: They differ greatly from each other.
Densities and shapes
As explained Santiago Alvarez in the book Of women, men and molecules, the density of atoms can vary by two orders of magnitude from one element to another, more than the density of the Earth varies from the crust to the core:
If we calculate the densities of the electron cloud and the nucleus separately, in the case of helium we find values of 2×3 10
17and 3.52 x 10-5kg/m3, respectively. That is, the density of the nucleus is about 10twenty-onetimes greater than that of its surrounding electrons. We do not have references in the everyday world to gauge the meaning of these densities. Not even the air in the stratosphere has a density as small as that of the electron cloud. We would have to go up to the thermosphere, about 100 km above the Earth's surface, to find a comparable density. In the case of the core, only a neutron star has such a high density, surpassed only by that of black holes.
Nor are atoms always spherical.. And even less is an atom within a molecule spherical. Even atoms of the same element can differ in a series of attributes:
- Number of neutrons (in different isotopes).
- Number of electrons (in multiple oxidation states).
- Degree of pairing of electrons (in various spin states).
- Variable molecular environment in coordination number and stereochemistry that also affects shape and size.
Thus, we could affirm that the invariant property between the atoms of the same element is its atomic number (number of protons in its nucleus), the property that defines a chemical element, despite the fact that the chemical reactivity and its ability to Bond formation resides in the valence electrons.
Various atoms and molecules as shown in A New System of Chemical Philosophy by John Dalton (1808).
In this way, the writing of Margaret Lucas Cavendish, Duchess of Newcastle, in her book Poems and Fancies (1653):
- Pointed atoms make the Fire subtle, fast and dry,
- The Long ones fly like arrows in the air,
- The Round ones become water, moist,
- The Squares on Earth, with immovable Form;
- Square atoms make up hard Minerals,
- Soft vegetables appropriate round atoms.
However, we need models to understand reality, because reality is not understandable in its entirety:
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The news
The density of different atoms can vary more than the density of the Earth's crust and nucleus
was originally published in
Xataka Science
by
Sergio Parra
.
According to a new study, the mass of all our things (buildings, roads, cars, etc.) now exceeds the mass of all living things on the planet.
It is not surprising that this is the case if we take into account that the amount of new material added each week It is equal to the total mass of the almost 8 billion people on Earth (Humans constitute approximately 0.01% of the planet's biomass).
Prepared dough: exponential growth
In 1900, the mass of human materials was only 3% of the Earth's total biomass. Since then, materials have doubled approximately every 20 years..
The glut of concrete and asphalt began during the boom years between World War II and the 1973 oil crisis, when developed countries began building.
Meanwhile, total biomass has gradually decreased since 1900 due to deforestation and other reasons. The increase in human mass is driven by the use of geological resources: rocks, minerals and metals.
Human-created mass finally surpassed Earth's total living biomass this year. The timing of that transition depends on whether the biomass accounts for the water. If water is included, biomass will remain larger than human materials until about 2037.
Even so, the comparisons are very striking: Buildings and other infrastructure weigh more than the world's trees and bushes. And the mass of plastic is twice that of all animals.
The world can be divided into three kinds of matter depending on its purpose: dead matter, living matter and processed matter. Let's analyze how many billion tons there are of each type of matter in the world... and discover that There is more matter made from cows than from humans!:
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The news
Each week, the mass of all our material objects added to the world is equal to the mass of all the world's inhabitants.
was originally published in
Xataka Science
by
Sergio Parra
.
As is already the case with Twitter and its tendency to create sociological bubbles or informational echo chambers, YouTube's algorithms, according to a new study, also seems to be fueling the most radical ideas, the harshest positions, even conspiracy theories.
More of 330,000 videos on almost 350 YouTube channels were analyzed and classified manually according to a system designed by the Anti-Defamation League.
From least extreme to most extreme
By processing more than 72 million comments, the study showed that the three types of channels (Alt-lite, Intellectual Dark Web (IDW) and Alt-right) increasingly share the same user base; and? Users are constantly migrating from softer content to more extreme content.
The study's authors hypothesized that alt-lite and the Intellectual Dark Web often serve as a gateway to more extreme ideologies. They proved it by tracking down the authors of 72 million comments on approximately two million videos between May and July of last year.
The results were that more than 26% of people who commented on alt-lite videos tended to move on to alt-right videos and subsequently comment there.
The alt-right They tend to sympathize with anti-Semitic, Islamophobic, anti-feminist, anti-communist, anti-capitalist, homophobic, racist, ethno-nationalist, traditionalist and neo-reactionary ideas. This type of ideology has experienced a boost from the development of social networks, the harsh opposition of the Republican Party during the presidency of Barack Obama and the impact of the Great Recession since 2008.
We still don't know much about YouTube radicalization: for one thing, we're not quite sure what exactly makes people switch from alternative material to far-right material. That's partly because YouTube restricts access to recommendation data.
The tension between individual freedom and collectivism It has not been resolved since it arose at the dawn of the 18th century. There is no answer. And probably both positions must exist so that neither positions definitively wins. The same happens with ideologies, and also with ideas that now seem radical to us (many of today's moderate ideas were, to a greater or lesser extent, radical in the past).
The problem posed by the study is whether, perhaps, YouTube would be catalyzing a transformation beyond reflection, a kind of evolution from a moderate positioning to a more radicalized one. not so much for the ideas themselves, but for the reinforcement of peers through the internet. After all, extreme political ideas They evolve due to the need to connect with others, which would also explain part of the current COVID-19 denialist movement:
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The news
YouTube's algorithm could be fueling extreme ideas and polarization
was originally published in
Xataka Science
by
Sergio Parra
.
The National Statistics Institute (INE) just made public the data of the first wave of coronavirus. Only in the first 5 months (actually 3, because the first two months there is no Covid): 50,000 dead. In 3 months.
That is to say: 45,684 direct deaths from COVID + 4,218 cases in which the cause of death was not directly Covid, but rather their death was mainly due to other causes, but the virus has contributed to the death of said people.
First cause of death
Seen this way, it is the leading cause of death in Spain in that period of time... as much as adding all the deaths from all types of cancer simultaneously. It has also been analyzed where people have died: almost 14,000 people in nursing homes.
However, in general terms, Infectious diseases (include #COVID19 identified virus and suspected COVID19) were the 2nd cause of death (20.9% of the total).
Deaths according to Cause of Death January-May 2019/2020
Infectious diseases (include #COVID19 identified virus and suspected COVID19) were the 2nd cause of death (20.9% of the total)
Press release👇https://t.co/WnnhEcgO2A
Results➡️https://t.co/626yXbopvW#INE pic.twitter.com/4DYLeNR9GJ
— INE Spain (@es_INE) December 10, 2020
These are almost definitive figures, apparently things still need to be refined, so the figure could increase over time. But, for now, In Spain, 231,014 people died between January and May 2020. About 43,000 above the average for the 2016-2019 period. 47,000 above the average if we only count the period from March to May.
As of May 31, the Ministry of Health identified 27,127 deaths from coronavirus with a diagnostic test. Not all people who died in the first wave of the pandemic in Spain were tested to detect the coronavirus: the INE now numbers them at 18,557. 50,000 compared to 28,000 for Health. Almost double.
Now Health says that we have about 18,000 deaths since August. Obviously, there are more. We don't know if it's double, but it's somewhere around there. If it were double, it would be 18,000 x 2 = 36,000. Which gives us a pessimistic total of 50,000 + 36,000 = 86,000 so far.
If we are optimistic and Health now counts its deaths better, perhaps there will be 10,000 fewer. If Health told the whole truth (or could do so, because technically it still cannot), then it would come out, as a hyper-optimistic figure: 68.000. So we are in an approximate range of 68,000 – 86,000. And there is almost a month left until the end of the year. The most pessimistic figure of all, although unlikely, could be close to 100,000 deaths from covid.
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The news
Deaths in Spain from COVID-19 according to new data (almost definitive) from the INE
was originally published in
Xataka Science
by
Sergio Parra
.
In reality, the International Space Station (ISS) moves around the Earth at about 25 times the speed of sound or about 10 times faster than a rifle bullet, so SpaceX's Dragon cargo ship docked autonomously to the space-facing side of the orbiting laboratory's Harmony module on Monday at 18:40 UTC. in a way that is difficult to imagine.
Fortunately, Space X has released images of the cargo Dragon's approach to an orbital complex moving rapidly around the Earth, as the ship approaches its docking position. You can see the video below.
Time-Lapse
Space X has released a video with spectacular images of the International Space Station taken from an approaching Dragon spacecraft that docked this week at the orbital complex. 28,000 km/h is a speed that is difficult to understand. We really can't even imagine that kind of speed. And it is not appreciated in the video, naturally.
So, when you see it, try to repeat that figure incessantly: 28,000 km/h.
Time-lapse of Dragon on approach – two Dragons now docked to the @space_station pic.twitter.com/I046jBmC7o
— SpaceX (@SpaceX) December 8, 2020
It is the first time that there are two Dragon ships docked at the Station: the other is a crew capsule.
The Dragon capsule It consists of a cone-shaped front cover, the traditional ballistic capsule and a non-pressurized charging module with two solar panels. The capsule uses a shield that protects the capsule during reentry even at speeds found in lunar or Martian missions.
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The news
Spectacular Time-lapse of Dragon approaching the International Space Station
was originally published in
Xataka Science
by
Sergio Parra
.