Showing all posts about science
What next after finding the goddamn Higgs boson particle?
14 July 2022
The Large Hadron Collider (LHC) is being fired up again after an extensive upgrade, and expectations are high the revamped particle collider will yield further of the universe’s secrets. Australian journalist Sherryn Groch has written about what scientists hope to learn in the next round of LHC experiments, as part of the Sydney Morning Herald Explainer series of articles.
For many people the LHC is most notable for finally confirming the existence of the elusive Higgs boson, nicknamed the goddamn particle by some scientists, on account of the difficulty they had finding it. The discovery though wasn’t quite the missing piece of the puzzle physicists expected it to be, says Dr Mitesh Patel, a lead researcher at CERN, giving rise to the possibility a fifth force of nature may exist, over and above the presently accepted four.
And then there’s the Higgs boson itself: it’s much lighter than expected. “It doesn’t really make sense on its own,” Patel says. “Everything about it tells us its mass should be much heavier. So, is something keeping it low? That’s what makes us think there’s something else.”
But the plot thickens. Shortly before the LHC was deactivated for upgrade, Patel and his team were struggling to make sense of data they had gleaned from older LHC experiments. What they were seeing didn’t stack up against the tenets of the Standard Model of physics, used to account for the four forces of nature, being electromagnetism, the weak force, the strong force, and gravity, even if the Standard Model does not actually explain gravity.
In the subatomic realm, particles interact and change all the time. And, according to the standard model, those known as beauty quarks should decay as often into muons as they do into electrons. But on the CERN team’s measurements, they became electrons 15 per cent more often than the muons, suggesting something could be tipping the scales.
Scientists are hoping further LHC experiments will also tell them more about dark matter, which coupled with dark energy, makes up ninety-five percent of the universe. But gravity remains the mystery. Standard Model does not account for it, and scientists are puzzled as to why it is far weaker than the other forces of nature. But they have some mind-boggling suggestions as to why:
[Some] speculate whether dark matter is really the effects of matter in another universe – gravity leaking through a multiverse into our own. It sounds like a Marvel film but Patel says “there are decent foundations” for the theory, namely that scientists still don’t understand why gravity is so much weaker than the other three forces of nature. “So people have speculated that maybe gravity behaves differently because it’s spread out in other dimensions in addition to our own”.
It is possible insights into these puzzles may be forthcoming sooner rather than later, once the LHC is up and running again. This I am looking forward to.
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When will the last human be born? Not as soon as you think
8 July 2022
When will the last human be born and how many people will there ever be?
With the way things are in the world at the moment, who can help but think the last human might be born sooner rather than later. But in taking on the question, Kurzgesagt argues we may be among the first humans born, especially if our species goes on to survive and flourish over the next billion years. A whole lot depends on that eventuality, but what’s wrong with some optimism?
The future of humanity seems insecure. Rapid climate change, political division, our greed and failings make it hard to look at our species with a lot of optimism and so many people think our end is in sight. But humans always thought they lived in the end times. Every generation assumes they’re important enough to witness the apocalypse and then life just goes on. This is a problem because it leads to short term thinking and prevents us from creating the best world for ourselves and our descendants. What makes this worse is that we actually may live at an extremely critical moment in human history.
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Absurd instances of the trolley problem by Neal Agarwal
8 July 2022
Most people have heard of the trolley problem. In short, you’re standing beside a rail line, near a railroad switch. A train is coming along the track, but there are five people tied to the track, in its path. You have the option to pull the switch lever, sending the train along a side line.
But another person is tied and bound to the side line. What should you do? Stand there, do nothing, and allow the train run over the five people? Or send the locomotive down the side line, where one person will be killed? Presumably there is not time to free any of the people, so you are left with the difficult choice. Do five people perish, or one?
This format of the trolley problem was created by Philippa Foot, a British philosopher, in 1967, while Judith Thomson, a philosopher at MIT, devised the quandary’s name. American creative coder and developer Neal Agarwal, meanwhile, has thought of a few more, absurd, trolley problem instances.
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Space bubbles a Dyson sphere like solution to global warming?
15 June 2022
Dyson spheres are hypothetical mega-structures highly advanced planetary civilisations might construct around their host star to harness as much solar energy as possible to power their needs. Seen from a distance, a Dyson sphere would look like a massive shell almost completely encompassing a star.
It’d be like constructing a giant display case for the Sun. Needless to say building a Dyson sphere is no small undertaking, and would require an enormous quantity of resources, technological smarts, plus an unprecedented level of international cooperation. A single superpower could not take on an engineering feat of this scale alone, it’d be a team effort.
Dyson spheres have been in the news relatively recently. Fluctuations in the light of Tabby’s Star, located about 1,470 light-years from Earth, were puzzling astronomers, and the existence of a Dyson sphere was advanced as a possible explanation, though later ruled out.
While Dyson spheres, something late British American mathematician and physicist Freeman Dyson first wrote about in 1960, are unlikely to feature in our future anytime soon, the concept may help us combat global warming.
A team of MIT scientists have devised a solar filter of sorts, they call space bubbles. In short, a small structure made up of numerous of these space bubbles could be used to form a shield, deflecting a small, though sufficient amount of solar radiation away from the Earth.
The MIT scientists propose placing the space bubbles at the Lagrange point between the Earth and the Sun. Put simply, a Legrange point, is an area between two celestial objects, say the Earth and the Sun, where the gravity of both objects balance each other. For example if a satellite were placed at this Legrange point, it would stay put, and wouldn’t fall towards either the Earth or Sun.
Once in place, the space bubbles would act like an eclipsing body, in this case permanently blocking, or more like filtering, a small amount of the Sun’s rays reaching the Earth. While the proportion of solar radiation “blocked” would be minuscule, the MIT team say if just under two percent of “incident solar radiation” was deflected, current global warming could be fully reversed.
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astronomy, climate change, science
In ten billion years the universe will double in size
28 May 2022
The Hubble constant expresses the rate at which the universe is expanding. The problem is though, no one has been able to nail down a precise value for the constant. That is, until now.
When the Hubble Space Telescope was launched in 1990 the universe’s expansion rate was so uncertain that its age might only be 8 billion years or as great as 20 billion years. After 30 years of meticulous work using the Hubble telescope’s extraordinary observing power, numerous teams of astronomers have narrowed the expansion rate to a precision of just over 1%. This can be used to predict that the universe will double in size in 10 billion years.
That’s mind blowing. To say the least. The already enormous cosmos will one day be twice its present size. Too bad no one here today will be around to see it. But what does it matter anyway? Well, you’d be surprised. Given some two point two million new books are published every year, one can only imagine how many more publications there’ll be in ten billion years’ time.
With a much larger universe by then, it’s comforting to know there will be space to put them somewhere…
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Time’s absence may make the universe easier to understand
19 April 2022
Writer’s on a tight deadline might disagree, but some physicists are beginning to believe that time may not exist. It’s a heady concept that there’s no such thing as lunch at one o’clock, because there’s no such thing as time, but when scientists talk about time, it’s on a cosmic scale, not a human one, says Dr Sam Baron of the Australian Catholic University, writing for The Conversation.
In the 1980s and 1990s, many physicists became dissatisfied with string theory and came up with a range of new mathematical approaches to quantum gravity. One of the most prominent of these is loop quantum gravity, which proposes that the fabric of space and time is made of a network of extremely small discrete chunks, or “loops”. One of the remarkable aspects of loop quantum gravity is that it appears to eliminate time entirely. Loop quantum gravity is not alone in abolishing time: a number of other approaches also seem to remove time as a fundamental aspect of reality.
The absence of time in this context though may account for discrepancies in some of the theories that scientists use to understand the universe, such as general relativity, quantum mechanics, and string theory.
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How the rings of Saturn were formed
23 March 2022
From BBC Earth Lab. Many millions of years ago, one of Saturn’s erstwhile moons, strayed a little too close, crossed a line, the Roche Limit, and shattered into billions of pieces, having been torn apart by the immense gravity of the Solar System’s second largest planet.
Saturn’s incredible ring system was the result of this cataclysmic event, once the remnants of the moon, some seventeen trillion tons of icy material, spread out in orbit around the planet. It would have been an incredible spectacle to witness, had anyone been around to see it all happen.
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Not the centre of the Earth that Jules Verne saw
10 February 2022
The long held notion that the centre, or core, of our planet consists of solid iron, may have been up-ended by a recent study suggesting Earth’s inner core is made up of a solid iron sublattice and liquid-like light elements:
A joint research team led by Prof. HE Yu from the Institute of Geochemistry of the Chinese Academy of Sciences (IGCAS) has found that the inner core of the Earth is not a normal solid but is composed of a solid iron sublattice and liquid-like light elements, which is also known as a superionic state. The liquid-like light elements are highly diffusive in iron sublattices under inner core conditions.
Well that differs somewhat from nineteenth century French author Jules Verne’s depiction, in his 1864 novel Journey to the Center of the Earth.
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NASA finds seven earth size planets, but are they anything like Earth?
24 February 2017
After days of keeping us in suspense about a new discovery, NASA let the cat out of the bag, in the early hours of yesterday morning. The TRAPPIST optic robotic telescope, located in Chile, recently identified a dwarf star, about forty light years distant from Earth, that is host to seven planets around about the same size as Earth.
Come on now, you didn’t think NASA was going to announce that an alien civilisation had been found, did you? This is still a significant discovery though.
Particularly as three of the seven bodies orbiting TRAPPIST-1 — the star also takes its name from the Belgian operated telescope — are within its star system’s so-called Goldilocks, or habitable zone. This is an area around a star capable of supporting life, that is neither too hot, nor too cold.
It is this bit that is especially of interest, as it means these planets may harbour water in liquid form, and, as a result, potentially life of some sort. And that is obviously an exciting prospect. But talk that we may one day be able to emigrate there is well wide of the mark, to say the least.
There’s a big difference between a planet that is earth-like, and one exactly like Earth. Such bodies are called an Earth twin, or Earth analog. For example, Proxima b, an exoplanet within the habitable zone around Proxima Centauri, the nearest star to the Sun, is considered to be earth-like, as it is a rocky, or terrestrial planet.
It might have some sort of atmosphere, and possibly there could be liquid water on its surface. But Proxima b may be far from habitable, at least as far as humans are concerned. As Proxima Centauri is a red dwarf star, which are relatively cool, Proxima b would need to be quite close to the star, to be within the habitable zone.
With that sort of proximity however, Proxima b would be tidally locked, meaning the planet’s rotational period matches the time it takes to orbit the star. The result here is only one side of the planet would ever face the star.
Therefore, the day side of Proxima b would be quite warm, whereas the night side would be extremely cold. The only spots that might be conducive to life, would be near the day-night terminator. Red dwarf stars themselves pose problems for any planets they host. For instance, they are prone to emitting powerful flares, which may have the effect of sterilising nearby planets.
Not so earth-like, after all. So while some form of life may manage to eke out an existence there, the environment would hardly be suitable for human occupation. The same conditions could well apply to the planets within the Goldilocks zone of TRAPPIST-1, given it too is a relatively cool dwarf star.
I think we might be waiting a long time indeed for news that a planet as habitable as Earth is found. In the meantime we should give thought to taking greater care of our own Earth. Clearly we’re not going to be rocketing off anywhere else in any hurry.
Originally published Friday 24 February 2017, with subsequent revisions, updates to lapsed URLs, etc.
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Life on Earth is premature: that is why we are alone in the cosmos
4 August 2016
Since the Fermi Paradox intrigues me. Life on Earth is premature. A fluke perhaps. The universe is still relatively young, that’s why we haven’t detected signs of intelligent life elsewhere.
If we compare the present age of the universe, against its projected lifespan, possibly twenty trillion years, then it has an age comparable to an eighteen day old child, who would be expected to live for seventy years. Eighteen days. That’s pretty young.
The cosmos isn’t yet mature enough to be teeming with life.
The dominant factor proved to be the lifetimes of stars. The higher a star’s mass, the shorter its lifetime. Stars larger than about three times the sun’s mass will expire before life has a chance to evolve. Conversely, the smallest stars weigh less than 10 percent as much as the Sun. They will glow for 10 trillion years, giving life ample time to emerge on any planets they host. As a result, the probability of life grows over time. In fact, chances of life are 1000 times higher in the distant future than now.
Originally published Thursday 4 August 2016, with subsequent revisions, updates to lapsed URLs, etc.
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