Showing all posts tagged: science
If there is life on K2-18b the K2-18 red dwarf star will kill it off
25 April 2025
News that traces of chemicals possibly indicating the presence of life on a planet, known as K2-18b, some one-hundred-and-twenty-four light years from Earth, resulted in a flurry of headlines the other week. Scientists find strongest evidence yet of life on an alien planet. Scientists claim they’ve discovered most promising ‘hints’ of potential for life on distant planet. And: Scientists Find Promising Indication of Extraterrestrial Life — 124 Light-Years Away.
Sure, it’s exciting. This is news many of us have been waiting for. Even if it’s not quite the definitive announcement we would have preferred. The problem though is the media outlets writing about the discovery of chemical “fingerprints” in the atmosphere of K2-18b, have not looked at the whole story. In fact, it seems they’ve only looked at the first few words. After all, why allow the full facts of the matter to get in the way of a click-bait worthy headline? The biggest — literally — part of the story is K2-18, the star the would-be life-hosting planet K2-18b is orbiting.
I’ve written about this before, but let’s revisit the subject, since it’s topical.
K2-18 is a red dwarf star. Red dwarfs — as the name suggests — are small. Some might only be a little bigger than Jupiter, the largest planet in the solar system. Red dwarfs are dimmer and cooler compared to a star like the Sun. They however have long lifespans, typically measured in trillions of years, rather than billions, as is the case for many other stars in the universe. At first glance, red dwarfs seem like ideal stars to host planets that might give rise to life. Their longevity gives lifeforms an eon to take hold and develop. But red dwarfs are not really life-friendly stars.
One problem lies in their size. Being so small, the habitable, or Goldilocks zone, the area of their solar system best suited for the fostering of life, that is neither too hot, nor too cool, is quite close to the star. Any planets in the habitable zone will be tidally locked. This means one side of the planet permanently faces the star, while the other is perpetually shrouded in darkness. In other words, the star facing side of a planet will be incredibly warm, while the dark side will be quite cold. Neither extreme may be particularly conducive to life, especially complex lifeforms.
But that’s not the worst of it. Red dwarfs also emit powerful flares that can render nearby planets lifeless. Some of these outbursts can be even more intense than those generated by the Sun. While one study of these flares found they might emanate from the polar regions of red dwarfs, rather than their equators, being the plane planets usually orbit a star along, the odds remain stacked against life here. None of this information is new, but has just about been completely overlooked in the recent news stories, about the possibility of life on K2-18b.
Here may be an unfortunate instance of a star that brings life into being, only to take it away later.
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astronomy, current affairs, science
Your time machine breaks down at the worst times in history
24 April 2025
Despite what you might think, the worst possible time for your time machine to breakdown is not 2025. Instead, in this Kurzgesagt imagining, you are variously trapped in three periods of time, some several million years after three separate mass extinction events.
The time machine taking you to the early Triassic Period (two-hundred-and fifty million years ago), the late Carboniferous Period (three-hundred-and_twenty million years ago), and finally, the early Devonian Period (four-hundred million years ago) is not so much broken down, as it acting with a mind of its own. Why else hone in on some of the worst times in the far distant past to visit?
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animation, education, history, science
Does the universe reside within a black hole?
17 March 2025
Good morning, welcome to the new week, and mind-blown Monday. Today we’re discussing life, the universe, the rotation of galaxies, black holes, and everything.
Data collected by the James Webb Space Telescope (JWST) has concluded about two-thirds of galaxies in the universe rotate in one direction, while the remaining third rotate the opposite way. In a supposedly normal course of events, the balance would be more even. Apparently.
But there is any such thing as normal in the cosmos? You know what they say. Truth is stranger than fiction. The universe is not only stranger than we can imagine, it is stranger than we can imagine. Two-thirds of galaxies might spin in one direction, because, you know, just because.
But there’s no just because in this universe. The imbalance in the rotational direction of the galaxies suggests to some astronomers that the universe was born inside a black hole. Since the black hole hosting our universe rotates in one direction, it follows that the majority of galaxies will spin in the same direction. Nikodem Poplawski, a theoretical physicist at the University of New Haven, describes this as the “simplest explanation” of the phenomenon:
“I think that the simplest explanation of the rotating universe is the universe was born in a rotating black hole. Spacetime torsion provides the most natural mechanism that avoids a singularity in a black hole and instead creates a new, closed universe,” Poplawski continued. “A preferred axis in our universe, inherited by the axis of rotation of its parent black hole, might have influenced the rotation dynamics of galaxies, creating the observed clockwise-counterclockwise asymmetry.”
I wonder how far up and down the “levels” of universes residing inside black holes goes then? If our universe is indeed located within a black hole, it follows that other universes must reside within the plentiful black holes that populate our universe. And inside those universes will be yet more black holes, that will be home to further universes. And so on.
But where does our black hole universe sit in such a hierarchy? Near the top? In the middle somewhere. Or near the bottom? If such a thing exists, as there may be no limit to how how far down the progression can go. The same applies going up the other way of course, in theory.
It’s mind blowing stuff for sure. If, that is, you accept this two-thirds versus one-thirds split of galaxy rotation represents a significant imbalance in the first place. There might still be room for just because here. After all, weird things just happen in this wondrous universe of ours.
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No planet has two hundred and seventy plus moons, not even Saturn
15 March 2025
Saturn’s moon count leapt a few days ago, after the International Astronomical Union (IAU) decided to classify an additional one-hundred-and-twenty-eight objects orbiting the ringed planet, as moons. It must be quite the feat of achievement for Saturn to boast it has the most number of satellites, by far, of any other planet in the solar system.
These new moons now mean Saturn is possessed of two-hundred-and-seventy-four satellites. But let’s be serious here. No planet has that many moons, real moons. All of Saturn’s new “moons” are just tiny rocks. They count as moons though, because they have a “proven orbit” around Saturn:
Most of the moons are irregular and tiny, just a few miles across. By comparison, our moon has a diameter of 2,159 miles (3,475 kilometers). But they do have proven orbits around Saturn, which is a key element of official moon candidacy.
Former planet Pluto has a proven orbit around the Sun, yet it is now considered a dwarf planet. This because it no longer meets the IAU’s definition of a planet. We can have different types of planets, it seems, but a moon is always a moon, even it is pet rock size.
But if planetary bodies need to fulfil a certain criteria to be deemed a (real) planet, then a tighter classification of what constitutes a moon, a real moon, is long overdue. If we use our moon, the Moon, as a benchmark, then perhaps Saturn has half a dozen or so “real” moons. The rest would be, as I wrote of Mars’ so-called moons in 2014, merely captured objects.
ETA: on the subject of Saturn, the planet’s fabulous rings will seem to disappear later this month, as far as observers on Earth are concerned. This is because the rings will be edge-on to us, a phenomenon called ring plane crossing, something that happens about every fifteen years.
The rings will become become visible again later in the year though. Who knows, without the rings to distract astronomers on Earth, maybe another batch of moons will be found orbiting Saturn.
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Sending people to Mars will be challenging, for all the wrong reasons
25 February 2025
Maciej Cegłowski’s in depth (deep dive) articles on an array of topics are always worthy reading, even if I’m not always able to consume his pieces in one go. In his latest long form column, he takes on the prospect of sending an Apollo-like flight to Mars, complete with a human crew on board. But going to Mars is not even remotely like a jaunt to the Moon:
A trip to Mars will be commital in a way that has no precedent in human space flight. The moon landings were designed so that any moment the crew could hit the red button and return expeditiously to Earth; engineers spent the brief windows of time when an abort was infeasible chain smoking and chewing on their slide rules.
But within a few days of launch, a Mars-bound crew will have committed to spending years in space with no hope of resupply or rescue. If something goes wrong, the only alternative to completing the mission will be to divert into a long, looping orbit that gets the spacecraft home about two years after departure.
Sending people to Mars is not beyond the realm of possibility, but it will be difficult, incredibly difficult.
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A supermassive black hole is set to collide with the Milky Way
21 February 2025
It’s true: a supermassive black hole is on a collision course with our galaxy. But the happening is at least two billion years away.
And even then it may not be a black hole, but rather a “massive invisible object” thought to lurk within the Large Magellanic Cloud (LMC), a smaller galaxy that presently orbits the Milky Way, but which is slowly falling towards us. Once the LMC collides — though merge is probably a more apt word — with the Milky Way, the black hole, or whatever the invisible body that the LMC hosts, will make a bee-line for Sagittarius A*, the supermassive black hole at the centre of our galaxy.
When those two objects eventually collide — an event that will unfold at a likewise cosmologically glacial pace — the result will be the formation of an even more monstrous black hole.
While the black hole merger process may be drawn out, assuming a black hole indeed resides inside the LMC, it will no doubt be a bumpy ride for whatever interstellar objects lie in the path of the two, as they fuse together. Perhaps the solar system will find itself in harm’s way here. The only consolation there is it’s something we won’t be around to see.
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Could these extraterrestrials build and pilot flying saucers?
7 February 2025
Kurzgesagt speculates on what extraterrestrial life might look like on planets elsewhere in the galaxy. But this may not be quite what we were expecting…
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Gravastars and black holes, a weird cosmic double act
2 January 2025
The concept of gravastars (or gravitational vacuum stars) is a fascinating alternative to the idea of black holes, although if their presence were ever proved, they would not rule out the existence of black holes. Proposed by Pawel O. Mazur and Emil Mottola some twenty years ago, these objects are consistent with Albert Einstein’s general theory of relativity.
Gravastars, like black holes, form in the aftermath of some supernova explosions. They are relatively small, their size might be similar to London, capital of the United Kingdom.
In terms of appearance they are black, and a little like balloons, having an extremely thin shell, consisting of matter scientists do not yet understand. Their interior is filled with a vacuum, or dark energy, bustling to break out, but unable to do so. Gravastars sound like an incredible phenomena, but in a universe some think is devoid of dark energy, I wonder if they could actually be present.
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Albert Einstein, astronomy, physics, science
Time, not dark energy, may be causing the universe to expand
27 December 2024
Dark energy does not exist, and the universe, while continuing to expand, is not doing so in a uniform fashion. In other words, the cosmos may look more like a potato, rather than a sphere. This according to recent research by astronomers and scientists at the University of Canterbury (UC), based in Christchurch, New Zealand.
As if that’s not startling enough, things become truly mind boggling when we look at the nature of time in a universe that may be devoid of dark energy. Time, you see, is moving at different speeds, depending on the location. Within our galaxy, the Milky Way, a clock ticks more slowly than one that might be situated elsewhere in an empty region of the universe, say the mid-point between our galaxy and the Andromeda galaxy, which is two and a half million light years distant.
The model suggests that a clock in the Milky Way would be about 35 percent slower than the same one at an average position in large cosmic voids, meaning billions more years would have passed in voids. This would in turn allow more expansion of space, making it seem like the expansion is getting faster when such vast empty voids grow to dominate the universe.
Because there is more gravity inside a galaxy than outside, clocks will be slower. This is a concept called gravitational time dilation, which Albert Einstein predicted when he published the theories of special relativity and general relativity, early in the twentieth century. Differences in clock speeds may not be surprising then, but the UC research illustrates just how stark these variations might be.
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Albert Einstein, astronomy, physics, science
Shoot for the stars: Tim Teege wants to run a marathon on the Moon
20 December 2024
Hamburg, Germany, based web developer and long distance triathlete, Tim Teege is super keen to run a marathon the Moon. So much so, he wants you to ask any space agency worker type acquaintances you may have, to help him achieve his goal. Ask, and you shall receive, and the like.
Not to put a dampener on Teege’s aspirations, I wonder if he’s read Rhett Allain’s Wired article on the subject:
You can’t go out and jog around the Sea of Tranquility—you’d just start bouncing and floating.
But, as they say, where there’s a will, maybe there’s a way. The laws of physics notwithstanding. Yet here, at the quarter way point of the twenty-first century, the act of somehow being able to run on the Moon, should really be Teege’s only significant challenge.
Getting to the Moon — in this post 2001: A Space Odyssey world — should be as easy as boarding what ought to be regular commercial flights to Earth’s satellite.
The journey might cost a pretty penny, but that’s what crowdfunding is for. Instead, however, in what’s almost 2025, about all we have in terms of reaching the Moon, is NASA’s troubled Artemis program, which seems like a re-run of Apollo, yet appears not to be going anywhere fast.
With 2025 essentially only days away now, I shouldn’t be so indifferent. Big shoot for the stars ambitions and goals are what we need right now. Especially for this particular new year.
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