America has a uniquely powerful aircraft carrier fleet, however …
Let’s get curious together.
Galaxy M87, one of the largest galaxies in the Local Supercluster, is located about 54 million light years away. The supermassive black hole M87 * at its center has 6.5 billion solar masses and absorbs 90 Earth masses daily (one solar mass in about 10 years).
The explanation of points 1-4 can be read below.
1. The event horizon is an imaginary line beyond which nothing can return. The event horizon of a black hole has a characteristic size – the gravitational radius. Crossing it, all objects go beyond the observable Universe, disappearing into a singularity. The gravitational radius of the black hole M87 * is 0.019 light years, more than a hundred times the orbit of the Earth.
2. Accretion disk of matter falling into a black hole: accelerating and heating up, matter actively radiates in a wide wavelength range, allowing you to see, if not the hole itself, then its immediate surroundings. The accretion disk of supermassive black hole M87 * stretches 0.4 light years – thousands of times beyond Pluto’s orbit.
The bright side of the accretion disk is moving in our direction and thanks to the relativistic redshift becomes better visible. The disk of the black hole M87 * rotates at a speed of about 1000 km / s
3. Relativistic jets appear when the accreting plasma interacts with magnetic fields. Part of the matter at a near-light speed is ejected from the poles of the disk in two narrow oppositely directed streams. The supermassive black hole M87 * ejects jets up to 5,000 light years in length. One of them is directed in our direction and is visible in the optical range.
4. The photonic sphere is formed by light trapped in a circular orbit around a black hole. The position of the particles that have got here is unstable, and, having completed one or several revolutions, they inevitably fall into the depths of the hole or spiral into outer space.
The explanation of points 1–2 can be read below.
1. The shadow of the hole arises from the curvature of the trajectory of photons flying low over the sphere of the event horizon. Its dimensions are about 2.6 times the gravitational radius of the black hole.
2. The reverse side of the accretion disk is visible due to powerful gravitational lensing. Some photons from the opposite side of the black hole go around the sphere of the event horizon, and the far sides of the accretion disk – the upper and lower ones – become visible.
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TECHNOLOGIESHow to prepare oilOleg MakarovIt is impossible to imagine today’s world without oil. Land transport, aviation, polymer production – all of this critically depends on "black gold". It is just as difficult to imagine that a little over a century ago, very few people were interested in oil, and there were simply no modern technologies for its processing.
THE SCIENCEWhat are the possibilities of changing the DNA alphabet?Alexander PanchinAll living things on Earth – from bacteria to humans – have the same nucleotides in their DNA. More precisely, they were like that – until last year, when scientists made a scientific breakthrough and were able to add two new letters to the genetic alphabet.
THE SCIENCEHalf of the magnetVladislav Kobychev, Sergey PopovThe Standard Model (SM) of elementary particles describes 61 particles (the Higgs boson became the last one to be discovered). However, theorists have been actively working on various extensions of the Standard Model for a long time, usually leading to the prediction of new particles that experimenters are trying to discover. Sometimes these searches last for decades, as happened with the magnetic monopole.
TECHNOLOGIESWhat are artificial earthquakes for?Tim SkorenkoPeople have been afraid of earthquakes since ancient times. An angry planet is capable of destroying cities and turning entire countries into post-apocalyptic deserts – remember at least the recent tragedies in Haiti, Chile, Japan. But seismologists are engaged in artificially causing earthquakes.
WEAPONAll about the combat equipment "Ratnik"Sergey ApresovThe military equipment of a serviceman "Ratnik" is one of the most ambitious projects for the modernization of the Russian army. As applied to this program, the concept of equipment is so broad and extensive that it is almost impossible to describe all its elements in one article or depict in one photograph.
ARTIFACTBruce Gray Robot SculpturesAnton TeplovThere is noise in the workshop and sparks fly, behind which a large man in a welding mask is barely visible. Bruce Gray, a sculptor from Los Angeles, is building something. It is absolutely impossible to guess what he is doing, because it seems that there is no more versatile master than Gray in the world of technogenic art. Bruce can do anything.
WEAPONAircraft carrier Queen Elisabeth: the queen of global politicsOleg MakarovBritain has not ruled the seas for a long time, the role of a global maritime power decades ago passed to its closest ally – the United States. America has a uniquely powerful aircraft carrier fleet, however … last summer, in the presence of the Queen, a bottle of whiskey was smashed against the side of the largest warship in British history. In 2020, the aircraft carrier Queen Elisabeth will become the flagship of Her Majesty’s fleet.
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MASTER CLASSWe build a motor from a candle and a glassTim SkorenkoThis classic candlelight experience was invented at least two centuries ago. He even has his own name – "Paraffin Motor". But with age, he does not lose either relevance or beauty. With the help of an ordinary table candle, two pins and two glasses, you can observe an interesting picture of self-oscillations.
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TECHNOLOGIESViking Grace: a luxury crossingTim SkorenkoThe ferry is essentially a floating bridge. Its task is to ferry people, vehicles and goods from one coast to another. The crossing usually does not last long, and the ferry provides minimal means of comfort – sometimes the drivers do not even leave their cars. But this does not apply to the ship Viking Grace, plying between Finland and Sweden. Basically, it’s not really a ferry. This is a liner.
THE SCIENCEEpigenetics: genes and something on topAlexey Rzheshevsky, Alexander VaysermanPerhaps the most capacious and at the same time precise definition of epigenetics belongs to the outstanding English biologist, Nobel laureate Peter Medawar: "Genetics suggests, but epigenetics disposes."
MASTER CLASSDIY hoverboard: building a levitating board layoutIgor EgorovAs we all know from the cult film trilogy "Back to the Future", this year we have to dress very unusual, fly in cars filled with garbage, watch "Jaws 19" in holographic cinemas. And most importantly, don’t forget to swap out skateboards for hoverboards that float a few centimeters above the floor!
WEEKDAYS OF THE EDITORIALRescue tug Shakhtar, drilling ice over Lake Vostok and other best letters of the monthThe author of the best letter of the month receives a SVEN GX-990 Gaming gaming mouse as a present. Heavy-duty design for a smooth ride the device is equipped with navigation buttons, a triple-click button and resolution switching at 1000/1500/2000/2500 dpi. You can expand the capabilities of the mouse using the software: adjust the sensitivity of the buttons, change the polling rate of the USB port, etc.
TECHNOLOGIESCrowd Survival RulesAnton FarbAbout a hundred shark attacks on humans occur annually; about 10% of these cases are fatal. How to avoid the attack of a sea predator? It’s easier than ever – do not swim in prohibited places. The human crowd is the same shark. Over the past hundred years, more than thirty episodes of mass stampedes have been recorded, in which from thirty to one and a half thousand people died at a time. Do you want to survive in the crowd? Just stay away.
STORYHow did reusable bag fasteners come about?The familiar "sealable" reusable bags (Ziploc) are now used almost everywhere: at home they put sandwiches in them, in stores – bulk products, in the garage – bolts and nuts.
WEEKDAYS OF THE EDITORIALThe smallest mammal, the Oort cloud and the differences between launch vehicles: "PM" answers readers’ questionsAsk your question and you!
Letter from the editor about the military travel bag and equipment "Ratnik"Sergey ApresovIt is a great honor and great pleasure to address readers from one of the first pages of the magazine. However, composing an "editor’s letter" also involves some responsibility, so sometimes it is very difficult to come up with what worthy thoughts to fill the cherished half-page with.
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Anastasia Shartogasheva"Popular Mechanics" # 1–2, 2020
Caves are the last corners of the planet where you can still become a discoverer. Basically, for this, people go to caves: for discoveries or out of purely sports interest. There is a wide choice: in Russia alone, more than five thousand caves are known, and many of them still have unexplored sites. Alexander Gusev, one of the creators of the Atlas of the Caves of Russia, a leading researcher at the Moscow State University’s GAISh, told us how to give our name to the newly discovered piece of sushi, for whom exploring caves is a serious hobby.
There are three ways to find a new passage in an already known cave, Alexander explained to us. The first is designed to expand the passage impassable for a person – the continuation of the cave is sometimes found behind the wall. You can also dive into the flooded part of the cave and search there or climb higher: if the upper vault of the cave is not fully visible, there is a chance to find a passage there to its unexplored part.
Alexander Gusev is an employee of the Department of Extragalactic Astronomy of the SAI. A keen speleologist, author of several articles on speleology, co-author of the Atlas of Russian Caves, published with the support of the Russian Geographical Society
First ascents are not uncommon. Actually, for the sake of them, everything is usually started: among other things, this is an opportunity to leave your name or the names of your favorite characters on the map. The scheme of the Gorlo Barloga cave in Karachay-Cherkessia, for example, looks like it was drawn by Tolkien himself: its many manholes, palaces, halls and wells are named after his characters. In addition to the intricate toponymy, Barlog’s Throat is almost a kilometer deep – this is the deepest cave in Russia. Deeper only in neighboring Abkhazia – there are several of the deepest caves in the world.
Most of the caves in Russia are in the Caucasus and the Urals, and since 2014 also in the Crimea. Together with the peninsula, Russia received a large speleological school; before that, scientific work of this magnitude was carried out only in the Urals – in Perm, Yekaterinburg, in the Kungur of the Perm Territory, where one of the largest karst caves in Europe is located. In the Crimea and the Urals, they are mainly engaged in geological problems; in other places biospeleologists work – they study species inhabiting caves that have long existed in isolation from the rest of the world in the dark and cold. In some caves in Russia, the remains of ancient animals and people are found.
The Atlas of the Caves of Russia is a rare edition, with a circulation of only 500 copies, and it cannot be bought: it will be distributed to the authors, and the rest will be given to the Russian Geographical Society. But you can choose a cave to your liking in the database on the website of the Russian Speleological Union
But Russian cavers do not deal with the paleoclimatic direction popular in other countries: according to Alexander Gusev, there is not enough expensive equipment. It’s a pity: caves are a storehouse of information for those who know how to get it. Nothing ever changes in them, and everything that gets there remains there and is stacked in layers – hundreds, thousands, millions of years. Based on the composition of mineral growths, stalactites and stalagmites, conclusions are drawn about the climate of past years, the salinity of groundwater, and sea level. Even a mountain of bat droppings preserved in the cold of a cave can tell scientists a lot – about what mice ate thousands of years ago, about what plants were growing and what insects were flying, how brightly the sun was shining and what was the background radiation. A lot could also be learned from Russian caves, but so far they are needed mainly by tourists, geographers, biologists and athletes. For them and for all those who are interested there is a search system "Caves" of the Russian Union of Cavers. This year, on its basis, a unique book was published – "Atlas of Russian Caves" with descriptions of 176 of the most beautiful, longest, deepest and other remarkable caves.
Roman Fishman"Popular Mechanics" # 11, 2020
The more desperate the situation with the planet’s climate becomes, the more ideas arise on how to fix everything. Some projects are striking in their scale and the scale with which their authors are going to influence the life and energy balance of the Earth. As if all the past experience of mankind does not suggest that it is best not to interfere with anything.
The most reliable way to slow down the heating of the planet is to reduce the flow of energy that it receives from the Sun by shielding some of this radiation. Back in the early 2000s, Lowell Wood of Livermore National Laboratory calculated that for this, a mirror with a total area of about 1.5 million square meters would need to be injected into low-Earth orbit. km – three quarters of Greenland. Roger Angel of the University of Arizona proposed a technically less complicated option – an array of many smaller space mirrors "suspended" at the L1 point of the Earth-Sun system. Here, the gravitations of both bodies balance each other, and objects can remain in place without constant fuel consumption.
The array of mirrors located in L1 will not be visible from the Earth, but it will be able to screen 1–2% of solar radiation
However, as sometimes happens with such grandiose ideas, the consequences of their implementation may be unexpected. For example, German scientists tried to assess the effect of space mirrors on the planet using existing climate models and found that the temperature decrease would be uneven, leading to a reduction in cloud cover and large-scale droughts.
Swiss glaciologists, anxiously watching the destruction of the Alpine glaciers, are already resorting to extremely unusual measures. Thus, the famous Rhone glacier, which gives rise to one of the largest rivers in the region, is covered with a white cloth that reflects part of the sun’s rays and, according to measurements, can slow down melting by as much as 70%. Conservationists in Italy and Germany are also using such coatings, and Danish geologist Jason Box proposes to deploy them on one of the planet’s largest glaciers, Greenland.