Youth and Dust A cloud—only not the soft, gentle, and fluffy kind, but dangerous and unsettling, similar to a mountain ridge exposed to the ruthless forces of nature. Its wild, rough shape is the result of massive ultraviolet radiation emitted by young, hot stars of enormous sizes. They can’t be seen in the photo, they’re out of shot. The radiation isn’t there either, only its effect—it has expelled dust and gas from the top, compressing, rumpling, and creasing the cloud below.
When masses of dust and gas crash into each other and mix together, they instigate and hasten—and sometimes slow down and eliminate—the birth of new stars. The photo is a portrait of a tempestuous, wild cosmic youth. Some of the stars glittering within the cloud have just come into being, others are still being born. Everything is new, everything is sudden; in the process of becoming and taking shape. Planets might already be there, far apart, but there’s still much in store for them: orbit changes, collisions, bombardments, intense volcanic processes. The final shape of these worlds is yet to emerge from the ocean of possibility. In its widest place, the distance from the bottom of the shot to the edge of the cloud is about seven light years, which means that it would take seven years for light to travel the distance. Against such enormity, a human being is as tiny as a water particle in the Pacific Ocean. Still, this particle (not one of them, of course, but many) managed to create this magnificent image. Naturally, one could say that when we look at a cloudless night sky somewhere far far away, our vision encompasses much larger expanses. However, the precision and sharpness of insight offered by this photograph—taken by the James Webb Space Telescope—is without precedent. The use of infrared allows it to penetrate into the interior of dust and gas clouds, where events take place that have been hitherto hidden from the human eye, such as the birth of new stars. Cosmic dust itself is also worthy of examination. It used to be considered only a hindrance for astronomers wishing to look at the stars. Today it is known that it is a vital part of the cosmic puzzle—and a quite mysterious one, too, because there’s much more of it in the universe than calculations would suggest. “We are stardust,” sang Joni Mitchell at Woodstock (and she never lies). So, when we look at this photo, it’s really stardust looking at itself.
Fruitless Listening
Chinese scientists have joined the exciting search for radio signals from extraterrestrial civilizations. Since 2016, they have had at their disposal the world’s best tool for the job—the gigantic FAST radio telescope with a 1,600-foot diameter dish, situated in a natural depression of the mountainous terrain in Guizhou province. In June 2022, scientists even announced that this giant had allowed them to record a signal transmitted by intelligent life from another planetary system. However, specialists from the West are of the opinion that the Chinese scientists haven’t found anything, and the signal they received originated from Earth, or from one of the artificial satellites orbiting our planet. Either way, its ultimate source is probably people, not aliens. “If you’re kind of new in the game, and you don’t know all these different ways that interference can get into your data and corrupt it, it’s pretty easy to get excited,” said University of Berkeley, California’s Dan Werthimer in an interview with the website Live Science. Searching for communication from extraterrestrial civilizations is full of traps and paradoxes. Picking up signals from distant stars requires ultra-sensitive telescopes, but this characteristic also means that they easily register faint signals from Earth, which have to be skilfully filtered out. Furthermore, the very technological advancement that makes this search possible is its largest obstacle —as time goes by, humans are filling more and more radio wave bands.
Western scientists have more experience than their Chinese counterparts in searching for aliens via radio—they have been doing it since the 1960s, after all. This experience, however, is of a specific kind: it is not really about finding extraterrestrial life, but about capturing promising signals, analyzing them, and then realizing that their source is from Earth. For example, in 1998 the radio telescope at Parkes Observatory in Australia started to receive regular signals that nobody was able to explain. It wasn’t until 2014 that the facility’s employees noticed that the signal always occurred at lunchtime. This was when they identified the transmitter: it was the microwave. Maybe in the future there’ll be a breakthrough, but for now the search looks like this: we want to find aliens, but instead we find ourselves, in our most prosaic form. This might be funny, it might be tragic—or perhaps it is precisely this message about ourselves that we need to understand.
A Particle Called WIMP
As the name suggests, WIMPs are weakly interacting massive particles. Not much more is known about them. It’s not even completely certain that they exist, because no WIMPs have been found yet. It is presumed, however, that they’re widespread in the universe, because they are the basic ingredient of the hypothetical dark matter. To be sure, WIMPs are anything but. The dark matter that they make up outnumbers normal matter five-fold, and without it galaxies would disintegrate into dust, deprived of their gravitational binding agent. We wouldn’t want that now, would we, so let’s speak of these particles with respect. It is true that WIMPs are relatively slow—much slower than light—and photons might consider them a little sluggish. But photons would do well to stop smiling so disdainfully and consider that, unlike them, WIMPs not only have mass, but a considerable one—ten times that of a proton. It really isn’t easy for a banger like this to gather speed, and it has no chance of reaching the speed of light, because the theory of relativity would intervene. Out of the four fundamental interactions—the gravitational, electromagnetic, strong, and weak—WIMPs are only familiar with the first and the last. This means that these particles might seem extremely anti-social to electrons and protons, but should not be looked down on. Electrons and protons could instead self-reflect and consider whether the electromagnetic hullabaloo that they constantly generate is really more essential to the world than the quiet, gravitational work of the reticent WIMPs. The question remains of whether an interaction with these particles will ever be recorded. Scientists are doing all they can. They have placed containers of thousands of tonnes of xenon in deep subterranean tunnels and are waiting for a WIMP to crash into an electron or proton within that noble gas, so that the event can be noted down and proudly announced. But WIMPs haven’t let themselves be caught so easily. They’re obviously cleverer than their name suggests.
The Cosmic House Has Many Rooms
Some people admit that they’re terrified by the enormity and indifference of the universe. This is a completely justified reaction. The diameter of the universe amounts to over ninety billion light years, while a human has no chance of traveling even one light minute throughout their life, even if they drive a bus for a living. When, in the 16th century, the eminent Danish astronomer Tycho Brahe attempted to calculate the distance between Earth and the stars, he found the results absurd—so large that it was impossible (and he’d severely underestimated it, too). He then rejected the Copernican model and looked for solace in good old geocentrism and excellent Czech beer. When it comes to the universe’s indifference, it equals its size. One need only remember that—in a display of brazen apathy—the meteorite which crashed into Earth about sixty-five million years ago killed both fierce T-Rexes and gentle sauropods in one fell swoop, not bothering to differentiate between them. So the universe is enormous and indifferent. Let’s consider, however, whether we’d really like it to change. Would it be better if it was small, the size of Great Britain, or even that of a small town? Perhaps for a moment it would be nice, but in the long term rather suffocating and intolerable, even if that town was a lovely little English spa. The universe’s indifference is a similar case. If meticulously aimed meteorites fell out of the blue and eliminated the worst of all sinners, we might initially feel satisfied, but in time we’d probably be plagued by anxieties and uncertainty. A neutral universe has its merits. One should also note that the catastrophic, predatory, and explosive image of the universe that dominates the media is only partly accurate. Explosions and cataclysms do happen in the cosmos, but the general governing rule is “many a little makes a mickle.” Enormous objects are formed very slowly, out of smaller ones. The Milky Way probably came into being as small galaxies merged. This process is ongoing—intense talks are in progress with various dwarf galaxies and they’re bound to be successful, because gravity is an argument that’s not easily rejected. Yet unifications like these happen completely peacefully: the stars don’t collide, don’t swarm, don’t crowd, don’t fight for priority. Each one lives in its own way and there’s enough space for everyone, because the universe is enormous and indifferent.
Gluttonous Jupiter
Certain unpleasant facts have come to light about the past of Jupiter—the biggest and most highly esteemed planet of the solar system. To be clear and direct: it turns out that in its youth, Jupiter used to gobble up small planets. Admittedly, this wasn’t recently— it was around 4.5 billion years ago—but the evidence is very strong. This might come as a surprise considering Jupiter’s stolid, even jovial image—such shenanigans would be more suited to the eccentric Saturn. It’s obvious, however, that one shouldn’t judge a book by its cover. Jupiter used to devour smaller celestial bodies and this truth must simply be faced and not repressed. Proof was, in this case, provided by a probe called Juno: it knows Jupiter better than anybody. As it orbited the giant, it collected extremely detailed data about its gravity. On that basis, scientists from Leiden University in the Netherlands calculated that there are lots of heavy elements in the gas giant’s belly: they form three to nine percent of the planet’s mass. At first glance this doesn’t seem like a lot, but after considering the enormity of Jupiter, it turns out that this small percentage corresponds to eleven to thirty times the mass of Earth. And these are precisely those devoured planets! Eek… The mere thought makes you shiver. Scientists had already guessed that this might be the grisly truth. They knew that Jupiter started its life as a small, rocky planet, and it wasn’t until later that it grew a layer of gas blubber. Initially there were two conflicting hypotheses about how this rocky starter could have come into being. The first one theorizes that it was made up of small cosmic boulders; the second, that the material was small planets, known in scientific lingo as planetesimals. When—thanks to Juno’s observations—the scientists calculated the content of rocky substrate within Jupiter, they concluded that only planetesimals could have created so much of it. According to the team, Jupiter even swallowed up planetesimals as a quite large gas planet—small boulders wouldn’t have been able to penetrate into its interior at that point, barred by pressure. Of course, one can lament the fact that the planetesimals devoured by Jupiter never developed into full-sized planets. On the other hand—it’s not nothing to help create the largest globe in the solar system. Yes, the planetesimals have been swallowed up, but in adding their weight to the giant’s mass they made it easier for it to devour other similar objects. And because Jupiter started its career as a rocky planet which amassed nearby gas, its image as a gluttonous gas ball—greedy for small, innocent celestial bodies—does not really reflect the truth. All in all, it looks like the case isn’t morally clear-cut and a deft lawyer might be able to clear Jupiter of the charge of planet-eating.
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