Showing all posts tagged: science
Unfortunately, colonising Mars is not a great idea
23 September 2024
There’s the challenge. There’s the adventure, the pioneering spirit, of setting off to another planet. Not everything is, or should be, easy. But are those really the right reasons for wishing to establish a human colony on the fourth rock from the Sun, Mars?
Mars does not have a magnetosphere. Any discussion of humans ever settling the red planet can stop right there, but of course it never does. Do you have a low-cost plan for, uh, creating a gigantic active dynamo at Mars’s dead core? No? Well. It’s fine. I’m sure you have some other workable, sustainable plan for shielding live Mars inhabitants from deadly solar and cosmic radiation, forever. No? Huh. Well then let’s discuss something else equally realistic, like your plan to build a condo complex in Middle Earth.
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Another day, another problem with Voyager 1, solved
20 September 2024
Data the nearly fifty-year old deep space probe was returning to Earth earlier this year, was getting all scrambled up. But dutiful mission controllers sorted that out. This despite Voyager 1 being so far away that it’d take a day to reach, assuming we had a vessel that could travel at the speed of light.
More recently, Voyager 1 has been having have trouble using correcting thrusters that keep the probe’s antenna pointed at Earth. Fuel pipes to the aging thrusters have begun to clog up, rendering them inoperative. Mission controllers, at the Jet Propulsion Laboratory, in California, however have been able to re-activate another set of thrusters — unused in decades — and effect a fix.
As a result of its exceptionally long-lived mission, Voyager 1 experiences issues as its parts age in the frigid outer reaches beyond our solar system. When an issue crops up, engineers at NASA’s Jet Propulsion Laboratory in Pasadena, California, have to get creative while still being careful of how the spacecraft will react to any changes.
If you want a tricky problem solved, ask a mission controller from one of the automated space missions to help. And of course Apollo 13.
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astronomy, science, technology
Gravitational waves may reveal presence of warp drive starships
13 September 2024
Gravitational waves have been helping scientists and astronomers answer some of the big questions of the universe. But gravitational waves may be able to do something else: detect the presence of vessels with Star Trek like warp drive engines, as they move through the cosmos.
One problem with the warp drive space-time is that it doesn’t naturally give gravitational waves unless it starts or stops. Our idea was to study what would happen when a warp drive stopped, particularly in the case of something going wrong. Suppose the warp drive containment field collapsed (a staple storyline in sci-fi); presumably there would be an explosive release of both the exotic matter and gravitational waves. This is something we can, and did, simulate using numerical relativity.
I imagine a cloaking device wouldn’t be much help, if a vessel was trying to move about unnoticed. The gravitational waves generated by the ship’s warp drive would pretty much render it visible.
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Add new Australian volcanic activity to the list of worries…
6 September 2024
As if climate change, and the increasingly unstable weather it will bring, isn’t enough to worry about, parts of Australia may see an increase in volcanic activity. Not in the immediate future, thankfully, but at some point nonetheless:
It is much less likely that a volcano that has already erupted will start again. It is a lot more likely a new volcano will form somewhere else. That is almost a given. It is going to happen. The follow-up question is when is this going to happen? It may be in 100 years, or 5,000 years. We don’t know. We need to have more information to answer that question.
I’m unsettled by this lack of certainty here… one-hundred years isn’t really much. Nor, for that matter, is five-thousand years, speaking in geological terms. Let’s hope these new volcanoes appear later rather than sooner, or ideally, not at all.
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Vacuum decay, one more existential threat to lose sleep over
22 August 2024
Tooth decay. Entropy. Heat death of the universe. These are things to worry about, and we’ve known about them for a long time. But recently scientists have identified something else to lose sleep over: vacuum decay:
Vacuum decay, a process that could end the universe as we know it, may happen 10,000 times sooner than expected. Fortunately, it still won’t happen for a very, very long time.
There’s a lot of theoretical physics (I think) involved, which is way over my head, so there’s not more I can say about vacuum decay. The good news however: vacuum decay will not bring about the end of the universe anytime soon.
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The physics of running and keeping fit on the Moon
8 July 2024
Rhett Allain, writing for Wired, looks at the physics of this important question.
If humanity is ever to establish bases on the Moon, ways of keeping occupants fit in the low lunar gravity need to be worked out. A wall of death sort of gizmo, that’s a little like a stationary hamster-wheel, but turned on its side, that emulates Earth-like levels of gravity, may be a solution. But there might be more effective alternatives.
But check out the article’s artist impression of a suited up astronaut “jogging” on the surface of the Moon. Straight up running in this way is a fanciful keep fit option unfortunately, as simple as the idea may at first seem. It’s too bad though, because what a sight it would be to behold: Earth floating in the lunar sky, as you ran.
I doubt Earth would be quite as big as depicted in Nzoka John’s image, but it still be quite the spectacle. And on the subject of what Earth might look like from the surface of the Moon, a gallery of images by American illustrator and writer Ron Miller, depicting how other planets in the solar system would appear from Earth, if they were as close as the Moon.
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art, astronomy, illustration, physics, science
Potentially habitable Earth size planet forty light years away
4 July 2024
That’s the good news. Tory Shepherd, writing for The Guardian, says the recently discovered exoplanet, dubbed Gliese 12b, might be able to host liquid water. We all know what that means. If there’s water, there may be life. Gliese 12b is so named because it orbits a star called Gliese. Now for the bad news. Gliese is a red dwarf.
I personally don’t have a problem with red dwarf, or M-type, stars. They’re actually kind of cool. And common. Up to seventy-five percent of stars in the cosmos are thought to be red dwarfs. The star nearest to Earth, Proxima Centauri, is a red dwarf. And while most stars in the universe have relatively short lifespans — for instance the Sun, which is about half way through its ten billion year life — red dwarfs live for trillions of years.
The last stars — as we currently understand them, at least — shining in the universe, will be red dwarfs. Go the red dwarfs. But, the problem is any planets orbiting in a red dwarf’s habitable-zone, will be tidally locked. That is, only one side of the planet will face its host star. That half of the planet therefore, in this case Gliese 12b, will be overly warm, while the other, dark side, will be rather cold.
This may not be particularly conducive to life. But some scientists have suggested life on planets orbiting red dwarfs in the habitable-zone, may take hold near the day-night terminator. This is where it will be neither too hot, nor too cold. But this would be an extremely narrow corridor, somewhat limiting the chances of life, especially intelligent life, developing.
Then there’s the red dwarfs themselves. They’re prone to regularly emitting intense radiation flares, which could have the effect of sterilising the surface of nearby planets. This points to the likelihood of Gliese 12b not being all that habitable at all. I think we need to reserve our excitement for the discovery of habitable Earth size planets, for maybe when they’re found orbiting other types of stars.
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Did the universe exist before the Big Bang? Maybe…
27 June 2024
What happened, or was there, before the Big Bang that is said to have brought the universe into being? Was there nothing, to which something came? It is the question of the ages.
In his recent documentary series, Universe, British physicist Brian Cox posits that the universe existed before the Big Bang. How long this pre Big Bang entity had been there, or its origins, remain unknown however. How fascinating these before-the-beginning sort of questions are.
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astronomy, philosophy, physics, science
The search for the distant Planet Nine continues
27 May 2024
Weird stuff is happening out on the remote boundary of the solar system. Beyond the orbit of Pluto. You name it, it’s going on out there. Irregularities. Anomalies. Clustering of apsidal lines. Perihelia. And — saving the best for last — a surprising prevalence of retrograde Centaurs.
These anomalies include the apparent clustering of apsidal lines of long-period trans-Neptunian object (TNO) orbits, the alignment of their orbital planes, the existence of objects with perihelia extending far beyond Neptune’s gravitational influence, the highly extended distribution of TNO inclinations, and the surprising prevalence of retrograde Centaurs. Collectively, these irregularities hint at the existence of a yet-undiscovered massive planet, tentatively named Planet Nine (P9), whose gravitational influence sculpts the outer reaches of trans-Neptunian space (Batygin et al., 2019).
But this is nothing new. Astronomers have been aware of this activity for some time.
Many postulate this weirdness points to the existence of an — as yet — undiscovered, large-ish planet, out beyond the known planets of the solar system. Some incredible distance out beyond the known planets. Planet Nine, if it exists, is thought to be orbiting the Sun at an approximate distance of twenty times that of Neptune to the Sun.
The gravitational influence of Planet Nine, combined with its extreme distance from the Sun, is enough to interfere with what would otherwise be predictable orbits of the numerous TNO objects, of which Pluto is one.
Planet Nine sort of comes along and displaces — sweeps aside, perhaps — these TNOs. While the presence of a larger planet therefore appears to be the logical explanation for the various irregularities and anomalies witnessed in the outer solar system, scientists are yet to clap eyes the elusive body. Or even calculate its position mathematically, for that matter.
If Planet Nine is found, here’s hoping one of Earth’s space agencies dispatches a probe pronto to go and take a good look at it.
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Build bases on the Moon, instead of going for a week
24 May 2024
NASA is dead set keen to return to the Moon. But their current plan, called Artemis, is dead set crazy, writes Polish-American entrepreneur and writer, Maciej Cegłowski:
You don’t have to be a rocket scientist to wonder what’s going on here. If we can put a man on the moon, then why can’t we just go do it again? The moon hasn’t changed since the 1960’s, while every technology we used to get there has seen staggering advances. It took NASA eight years to go from nothing to a moon landing at the dawn of the Space Age. But today, twenty years and $93 billion after the space agency announced our return to the moon, the goal seems as far out of reach as ever.
I only know what I know about NASA’s proposed Artemis crewed flights to the Moon, from the occasional glance at headlines on the subject. Needless to say, that knowledge isn’t much to write home about. That’s because the prospect doesn’t really excite me. Artemis seems like little more than a re-run of the Apollo flights of over fifty years ago.
If we’re to return to the Moon again, I’ve always thought it should be more permanently, and on a grander scale. As in bases on (or under) the lunar surface. Sending a couple of flights back there for a week’s stay, seems pointless. On top of that, the cost of doing so today has ballooned. But why? Is no one stopping to think about this?
If humanity is ever to progress, yeah, hmm, we need to set ourselves some pretty ambitious goals. But we need to think a bit bigger. Re-hashing the Apollo missions isn’t thinking big. Combatting climate, disease, and poverty, for instance, make for better goals. After that, what about reaching for stars, literally. Not just the nearest celestial body to Earth.
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