im lazy to give a full explanation on what he does in the multiverse.

Buchite on Scoria matrix

Locality: Emmelberg, Üdersdorf, Daun, Eifel, Rhineland-Palatinate, Germany

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“A compact, vesicular or slaggy metamorphic rock of any composition containing more than 20% vol. of glass, either produced by contact metamorphism in volcanic to subvolcanic settings or generated by combustion metamorphism.

An uncommon metamorphic rock type composed mostly of glass, formed by the melting of a sedimentary rock or soil by extreme heat from an adjacent lava flow or scoria eruption, or the burning of an underground coal bed. Buchite is a product of a special type of metamorphism, called pyrometamorphism (contact type, high to very high temperature, low pressure, often connected with coal fires). Buchites are often confused with obsidian, which is a volcanic glass rather than metamorphic glass. The so-called para-obsidian is a buchite with small amounts of mullite and tridymite forming microlites. Rarely, buchites can be colorful and transparent, and faceted as gemstones, as for example a few blue-green gems from the Eifel hills in Germany.

The original description of buchite was for partly fused, glassy sandstones associated with basalts (in Germany). Now the term also covers more pelitic rocks. The first described buchite contained relic, cracked quartz with tridymite overgrowths and inclusions, feathery or needle-like clinopyroxene, magnetite, cordierite crystals, tiny crystals of a spinel, small voids, pores interfilled with goethite and brown glass.

According to Grapes (2006), buchite also occurs as xenoliths and within contact aureoles.” - https://www.mindat.org/min-50131.html

Basically what this means for this rock, is that there was a scoria eruption (a volcanic eruption with lots of air bubbles in the magma) that came into contact with some sandstone.  The intense heat of the magma was able to melt some of the sand, which then rapidly cooled and became glass.  You can even still see the darker bands beneath the glassy layer, displaying this xenolith’s sedimentary origins!

This is my first time playing with the “Read More” function in order to provide some more information or an explanation, so please let me know if you read it and/or it is something you’d like to see more of in the future!

A Very Short Fact: On this day in 1905, German philosopher of science, C.G. Hempel was born in Oranienburg, Germany. He is famous for his contributions to the philosophy of science and explanation. He is known best for the “raven paradox,” which challenges our intuitions about what constitutes evidence for our beliefs.

“Hempel noted that scientific explanations are usually given in response to what he called ‘explanation-seeking why-questions’. These are questions such as ‘why is the earth not perfectly spherical?’ or ‘why do women live longer than men?’—they are demands for explanation. To give a scientific explanation is thus to provide a satisfactory answer to an explanation-seeking why-question. If we could determine the essential features that such an answer must have, we would know what scientific explanation is.

Hempel suggested that scientific explanations typically have the logical structure of an argument, i.e. a set of premises followed by a conclusion. The conclusion states that the phenomenon which needs explaining occurs, and the premises tell us why the conclusion is true. Thus suppose someone asks why sugar dissolves in water. This is an explanation-seeking why-question. To answer it, says Hempel, we must construct an argument whose conclusion is ‘sugar dissolves in water’ and whose premises tell us why this conclusion is true. The task of providing an account of scientific explanation then becomes the task of characterizing precisely the relation that must hold between a set of premises and a conclusion, in order for the former to count as an explanation of the latter. That was the problem Hempel set himself.” — From ‘Philosophy of Science: A Very Short Introduction (2^ndedition)’ by Samir Okasha

[Pg. 37 — From ‘Philosophy of Science: A Very Short Introduction (2^ndedition)’ by Samir Okasha.]

Image via Wikimedia Commons

Studying black holes … with water

Let’s continue the fun with analogies! Below we expand on the use of a particular analogy from science which we briefly discussed in a recent article.

The image above depicts the supermassive black hole M87*, which sits at the centre of the M87 galaxy some 55 million light years away. It was compiled from radiofrequency signals collected across several telescopes over two years. It is the first of its kind.

In the image we are given direct evidence of Einstein’s theory of general relativity. The black hole is dark, as predicted, since radiation cannot escape black holes once it’s within their boundaries. Moreover, the accretion disk (bright) around the black hole, from which radiation is emitted, is of a lopsided-doughnut shape. This varied brightness results from intense gravitational warping. And, because of rotation, there’s a kind of relativistic Doppler effect going on: radiation is boosted in the direction of rotation towards Earth.

Now, here’s a funny thing of relevance to us: some scientists and philosophers claim we can study black holes by investigating … [drum roll] … plain old water. One argument goes like this.

Inanalogue experiments, involving surface-water waves, something about black holes is realisable in surface-water waves’ ‘white holes’. Therefore, black holes can be modelled by analogy because their models and the models of white holes are related by the assumptions they share.

The analogy is not defined by a material relation. Nonetheless, thermal aspects of Hawking radiation (named after Stephen Hawking), which is released at black-hole boundaries, can be simulated in water. The analogy owes itself to ‘syntactic isomorphism’ between models, whereby the relation is confirmed in a ‘Bayesian sense’.

‘Analogue simulation’ is still a powerful experimental tool which can be used in a similar sense to computer simulation. Isn’t this cool? Or are such analogies fraudulent in some way because they only offer crude and opaque approximations via models which are often proven incorrect?

(Picture credit: Event Horizon Telescope project.)

The Philosophy of Analogies

InThe Republic—after introducing ‘the analogy of the sun’, in which the idea of goodness ‘illuminates’ truth, and ‘the analogy of the divided line’—Plato presents ‘the Allegory of the Cave’ (depicted above).

Prisoners in an underground cave are chained by the neck and legs, their eyes fixed towards a wall onto which shadows are cast. Trusting their senses, these two-dimensional figures mark the prisoners’ reality. But this imaginary world does not represent the intelligible reality above it: the ‘world of ideas’.

Like the prisoners, we can only hope to understand reality by ascending out of the cave. Plato’s analogies are powerful. But is each story, the source, really consistent with its accompanying theory, the target of the analogy?

Read more here.

iridescentpsychoart:

Note: This isn’t an insult/sassy come back to people to asking valid questions/statements (well maybe a bit sassy lol), none of it’s meant to offend people that are calmly trying to educate themselves to lgbtq+. Questions are always welcome!

Absolutely love this explanation cartoon series, thank you so much for sharing <3 It helps to explain asexuality to people who aren’t asexual in an open informative manner. 

It has helped me learn a bit more about my brother’s situation, much appreciated