Archive for the Science Category

An Incomplete World

Posted in computers, Science, Uncategorized with tags on December 9, 2015 by davidnm2009

I burnt out badly on science blogging several years ago, so I don’t do much of it now. But, this result is interesting, so I’m bending said rule a bit here:

http://www.nature.com/news/paradox-at-the-heart-of-mathematics-makes-physics-problem-unanswerable-1.18983

Basically the researchers have identified an applied physics problem, related to the structure of matter, that may actually be insoluble due to Godel’s incompleteness theorem.

What’s interesting about this is a) it feels weird (here’s something that happens in our universe that can’t be analytically-modeled) and b) by implication, we finally have a viable refutation for Simulation Theory. If parts of our basic physics can’t be analytically modelled, then also, we can’t be a ghost-world running on someone’s computer. Because said computer literally wouldn’t be able to perform the required maths, no matter how powerful its components.

(Also, apparently my blog doesn’t already have a category for “physics”? Bwuh … ? How did that happen?)

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Hot Earth Dreams, by Frank Landis

Posted in Books, Reviews, Science, Social Concern with tags , on December 1, 2015 by davidnm2009

Unfortunately, climate change is something that matters to all of us, and is going to matter even more as this century wears on. With this grim fact in mind, Hot Earth Dreams is a serious work of speculation on what the Earth’s warm, storm-ridden and wet future might be like.

The short version is, we’re completely and nightmarishly fucked. Things aren’t quite as bad as is conceivable, but there aren’t many grounds for optimism either.

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Unintended Extra Travels…

Posted in Astronomy, Science, SF with tags , on October 31, 2015 by davidnm2009

Just for once, I’d love to see a time travel story where the protagonists know their probe has worked because they see a starfield when it drops backward to 9,000 BC (or whenever).

This is a minor point that often annoys me with time travel stories: if you actually had a time machine or viewer, you’d better hope it’s a space machine as well. Why? Because the Earth (and the Sun) move.

And they’re actually quite fast.

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Sideways To Zero

Posted in Fanfiction, Personal, Science, Speculation, Writing with tags , , on December 29, 2013 by davidnm2009

I don’t think I’ve written anything about StZ yet, have I?

The funny thing is, the asari are one of my less-favourite aliens in Mass Effect. I’ve never tried ranking the various aliens by how interesting I find them, but I suspect they would be somewhere down the list. Certainly not at the bottom, but not very high up either.

(In case you’re wondering, the winner is the krogan. Headbutting FTW! Also I think krogan armour looks better than any of the others, with some of the turians as a close second. And the krogan have such a wonderfully tragic and compelling backstory, as well. Epicness and all of that.)

So, how come I’m trying to write a fic focused entirely on the asari?

Well. I do have something of a feeling of missed potential with them in the ME universe. There are interesting-sounding things we hear a lot about, but never really see. Asari democracy – just how exactly does it work? How do the various factions and interest-groups – Justicars, matriarchs etc., the various cities – all interact? What about asari science? We get told a lot about it, but never really see that much, even with Liara.

Instead, in ME1, the asari do sometimes feel a little bit like Fanservice: The Species. I often get the feeling that I’m some sort of six-sigma outlier as male gamers go, but actually, I would have preferred it if Liara had talked less about sex and more about her research. In fact, throughout 1, Liara is actually fairly vague about what it is she does. To be fair, this gets redressed a bit in ME3, particularly if you have the ‘From Ashes’ DLC. (Also, a minor grammatical gripe … shouldn’t that be ‘From the Ashes’?) I found this odd, as most real-world academics have a very hard time shutting up about their specialist subject.

The only asari world we see in detail is Illium, and the whole point of that planet is that it’s a freak. Its society is presumably entirely-abnormal, as are its governance arrangements. It is presumably relatively little of a guide to the more ‘normal’ asari lifestyle. Again, in fairness, one bit I did like was the conversation with the Tracking Officer on Illium, about Samara. The attitude she describes toward the Justicars did feel like something that had come out of an alien culture and an alien society, what with her evident surprise that anyone might consider the Justicars’ actions questionable and so forth.

The Thessia mission in ME3 is more frustrating than enlightening. The implications of the Prothean beacon on Thessia are staggering; perhaps the real reason that Liara is having trouble with her career in 1 is actually because real asari ‘science’ actually consists of going and asking questions of the magic beacon, and interpreting the results? A sort of glorified tea-leaf reading, or a 40K-style intellectual cargo cult. One can imagine a scenario where the senior matriarchal academics are quietly laughing at all the young grad students and post-docs, who are running around trying to do that ultimate oxymoron, original research… But again, this is only explored to a limited extent. (Also, the Thessia mission turns into yet another annoying Cerberus event – it was never really about the asari, it turns out. Rather it’s just another platform for the dreadful Kai Leng to put on a performance, and for TIM to be irritating/tedious in public once more. Sigh.)

Also, how exactly did a supposed direct democracy manage to keep a secret like this for so long? It does seem to imply some sort of fundamental contradiction, lurking somewhere inside asari society. And where are the Justicars in all of this? Do they have an opinion? Would they have an opinion? Or would they consider something like this ‘above their paygrade’? We never get told.

All of these things have bugged me.

Plus, I have a mental image stuck in my head. (I kind of wish someone would paint it.) When the first asari came onto the Citadel, and they found the Relay Monument, how did they react to that? What did they see? What did they say? How did they feel? (For that matter, relatedly, when the Reapers harvested the Protheans, how come they didn’t recognise the Relay Monument for what it was? They of all people have no excuse for not recognising a mass relay! Bad cuttlefish, no biscuit.) None of these things get developed in any detail.

So these questions are a lot of what’s driving ‘Sideways’. In addition, I also have an interest in the more general theme of ‘science and society’. Here in the Real World(tm), our whole attitude toward science and technology is a contradictory mess. We seem to want the shiny consumer toys, but not the theoretical knowledge under them. Except when we do, in the sanitised ‘gosh and wow’ form that TV documentaries pretend to give you. And then there’s the whole confusing, festering mess that is the collision between scientific and religious ideas. Being a former scientist, I’m interested in exploring this theme. And the asari, with their purported technological advancement and supposed super-consensus democracy, seem to offer one means of doing so.

So yes; these are the ideas that are going on underneath ‘Sideways to Zero’. I hope that I’ll be able to develop them further over the New Year. I’ll probably fail – when was the last time I finished anything? – but it’ll be a fun process 🙂

And (you knew this was coming, didn’t you?), here’s the link to the fic. If any of this sounds interesting, please feel free to have a look!

Sideways To Zero, Chapter 1: A Failure of Funding.

The Eocene in Antarctica

Posted in Science with tags , , on August 2, 2012 by davidnm2009

I’ve just become aware of what I think is a very interesting paper, albeit one from outside of my field: Persistent near-tropical warmth on the Antarctic continent during the early Eocene epoch (Pross et al 2012).

The executive summary, as it were, is that Eocene-era Antarctica (55-48 million years ago) may have been a lot warmer than is generally reckoned. It’s been known for quite a while that the southern-polar continent hasn’t always been glaciated, and certainly has been forested in the distant past. However, the impression I’d got (from what I’ve read, here and there) was that the general opinion was that non-glaciated Antarctica was still a fairly cold place. Intuitively, given its extreme latitude, that would seem to make sense.

This study is arguing that simple intuition is wrong in this case.

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L and T and OBAFGKM and Oh My!

Posted in Astronomy, Science, Space with tags , , , on April 4, 2012 by davidnm2009

As regular readers might have noticed, I’ve recently discovered the ‘Mass Effect’ series of games (yes, I know, late to the party, as usual!). I’ve recently started on Mass Effect 2 – I think I’m now about halfway through it, as best I can tell. So far I can honestly say that the entire thing is made of pure awesome, from an interesting storyline to well-drawn and entertaining characters. Also, it’s quite refreshing to come across a game series where I don’t have to simply turn off the science-nitpicking part of my brain, as the series is actually rather well-researched. (We’ll take the plot-devicium oxide that is Element Zero as a given for the time being, of course.)

Anyway, imagine my surprise when I discovered that one of the first missions in ME2 involves a star system that contains a brown dwarf! Obviously this got my attention, as I have more than a passing interest in these failed stars…

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Astronomical Mystery #5: Revenge of the Mascons

Posted in Astronomy, Science, Space with tags , , , on February 7, 2012 by davidnm2009

The Moon. Astronomically, it’s quite nearby; close enough that it shows a disk even with the naked eye. Close enough that you can just about read a book by it at night, at least when it’s full. Close enough that its nature has been debated throughout history. Close enough that’s it’s even been physically-travelled to by actual, living human beings – the only celestial body for which this is true, aside from the Earth!

So, given all this closeness, you’d think we know the Moon pretty well, wouldn’t you?

Well, no, actually. We don’t. The Moon has its mysteries and some of them are rather baffling. In fact, the Moon’s mysteries are made all the more frustrating by the fact that it’s so nearby. One particular case is that of the ‘mascons’, or ‘mass concentrations’.

Basically, the Moon’s shape is broadly spherical, but its structure is lumpy. There is, in fact, some evidence that’s visible to the naked eye; the Moon’s so-called ‘seas’, the maria, are mainly located on the Earth-facing hemisphere. The maria, of course, aren’t bodies of water but are plains of frozen lava, darker in colour than the relatively-brighter, heavily-cratered lunar highlands. At some point billions of years in the past, the maria would have been true seas of a sort, albeit seas composed of red-hot molten rock. Those oceans of magma, however, quickly froze as they radiated their heat into space. These vast, volcanic outpourings were only a temporary phenomenon. The Moon is too small to have held much of its internal heat, and its mantle is solid and frozen. (Thanks to seismic data returned by remote landers and the Apollo missions, we actually have a relatively good knowledge of the Moon’s interior – although the keyword is ‘relatively’!)

Now, the side of the Moon that faces away from the Earth has far fewer maria. The ones that it does have are much smaller, and they seem to be confined mainly to the floors of big craters. It’s as if the far-side maria were actually produced when big impacts punched through the lunar crust, rather than through volcanic eruption. The reason for this appears to be partly that the Moon’s crust is thicker on the far side – it’s almost as if the entire Moon was actually several miles off-centre. In numbers, around 1% of the far side of the Moon is covered by maria, whereas 31.2% of the near side is covered in maria. The hemispheres have a clear, geological difference between them.

Yes, the Moon is weird.

But what, you may ask, does this have to do with the mascons? And what are they?

Well, in April 1972, Apollo 16 placed a small satellite in a close orbit around the Moon. This satellite, unromantically dubbed PSF-2, was intended to study the local environment around the Moon – charged particles, magnetic fields, that sort of thing. But the little satellite’s mission didn’t go to plan. The satellite’s orbit rapidly became unstable. It was originally meant to get no closer than 52 miles above the lunar surface. Instead, within two and a half weeks, PSF-2 was descending within six miles of the lunar surface. Six miles – that’s getting uncomfortably close to the height of some of the Moon’s bigger mountains! And all this instability developed in such a short space of time.

Needless to say, it didn’t take much longer for PSF-2 to crash headlong into the Moon’s rocky surface.

It turns out that the Moon’s crust contains some remarkable concentrations of matter. These dense lumps – the ‘mascons’ – also make the Moon’s gravitational field lumpy and uneven. The variance is surprisingly big, as much as half a percent. (For a gravitational field, this is a huge variation – for comparison, the Earth’s varies by less than one part in a thousand.) It would actually be easily-measurable to human astronauts, were any to land close to the relevant regions. Near the edge of a mascon, a pendulum or plumb-line would hang about a third of a degree off of vertical, with the tilt being oriented toward the mascon.

The biggest mascons are also located in the same area as the centres of the bigger lunar seas, so they are evidently related in some manner. That much at least, we do know. The positions of the mascons have been determined quite reliably, from measurements of satellite orbits. They have the effect of making low lunar orbits unstable, hence the unfortunate end of poor PSF-2. (The Apollo modules were sufficiently high so as not to be greatly-affected, thank heavens.) The mascons are presumably also much denser than normal lunar material, since they are massive enough to distort the Moon’s gravitational field. There is also a strong suspicion amongst planetary scientists that they were formed either through the volcanic upwellings of the maria themselves, or through large impact-events that ‘injected’ pockets of denser matter into the lunar crust, or some mix of both processes.

However, the truth is that we don’t really know.

Even within the above model, there are a lot of unknowns. For instance, there are demonstrably fewer mascons on the Moon’s far side, and those that exist are generally weaker too, despite the greater rate of impact on the far side. (The near face is shielded to an extent from impactors by the Earth.) Also, there do exist some mascons that aren’t obviously associated with maria. So, although we know of their existence, and we understand some of their properties, their full nature remains very much a mystery.

The Moon, it seems, guards her secrets closely.