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The Ph-word                

                                            Particles, cosmology and everything

Hi <<First Name>>. Thanks for reading the ninth issue of this newsletter!

To everyone's delight, I'll keep the personal intro and most of the rest of Ph-word brief today^^ Maybe it's due to the deadline-feeling accompanying mid-December, or maybe it's due to the feeling that everything is already good and fluffy enough which also accompanies mid-December. 
But research-related news can't hide, so let me say that a poster with my recent work went on display at the European Space Weather Week. Continuing previous work, it's about how the motion of planets seems to affect certain events on the surface of the sun. (Yes, space weather is a thing, is when solar events, or even others from further away, affect earth. Hey, space-age, baby.)

Let's jump to the rest, but first: if you have something to say back, use the line right below.

eleni@chapette.net
November '18: The latest in ph-word

Kilos change (but you still have to start preparing for the beach *now*)

As everyone's already heard, the kilogram has been rebranded. This received quite some publicity and the reason is that, in a sweeping move, experts redefined the kilo and a bunch of remaining measurement units so that they are now based on physical constants, instead of arbitrary prototypes (like the platinum-iridium prototype kilo guarded in a vault in Paris). Our measurements are now wholly calculable through constant quantities permeating the whole nature, such as e.g. the speed of light. It makes for a good philosophical leap, since it shows that humankind has both mastered the concept of physical laws and constants and has the technology to connect them to the everyday.

In a ceremony full of quotable statements (okay, it was a conference, but with many features of a ceremony) it was heard that this makes measurements "future-proofed", referring to that the prototypes will always undergo some change through the years while the constants are not actually supposed to. In other words, "if a fingerprint got on the kilogram prototype, all of you would lose weight" - now not anymore. Even more dramatically, it was heard that measuring based on the constants of nature provides a common ground between "cultures, even unearthly and non-human ones".

In the case at hand, given proper devices the "electronic kilo" can be derived from the notorious Planck constant. Named after physicist Max Planck, it is a "mark" of the indeterminacy inherent at the tiniest scales of the world, the scales where quantun mechanics reigns and totally counterintuitive things happen. If you are curious: it also relates frequency of light to energy, and by using electromagnetic fields for lifting small objects, the change in the field can lead to the calculation of their mass painstakingly (or happily, if you are a metrologist).

A dark matter hurricane

"Some" time ago our younger Milky Way fatally attracted a number of smaller galaxies. Gravitationally disbanded, they turned into rivers of stars streaming between "our own".

But how do we know? From the Gaia catalogue. The unmatched precision of the positions and motions of billions of stars released some months ago has let people spot a few such streams, moving obliquely against the rest of the firmament. And one of them might also lie at the figurative intersection of astrophysics and particle physics: you see, the S1 stream is found to cross path with the solar system!

This doesn't mean stars crashing with the sun any time soon (contrary to what several people would see as a good solution). What it means is some dark matter flowing around us in a markedly different direction and speed than the dark matter which moves along with us in the Milky Way. And if dark matter is made up of particles, then this discovery just increased the chances of detecting them now that we know what to expect; a study from last month showed the experiments that look for the two most popular candidates for such particles (WIMPs and axions) what to be on the lookout for.

New moons, Mars rover and winking stars 

Perhaps surprisingly, two more moons were confirmed to be in orbit around earth, albeit really thin ones. They are actually clouds of meteoric dust, caught at points where they are gravitationally locked on The Moon's orbit, and each spans a patch in the sky equal to about twenty "moons". And although unnoticed, they seem to be there since ever instead of being some Falcon 9 byproduct or other.

InSight is the latest craft to land succesfully on Mars, determined to study its interior and tectonic activity, and helping understand in general the formation and evolution of terrestrial planets. It's already sending back some nice martian-sepia selfies.

And, finally, 234 stars were found to exhibit “peculiar periodic spectral modulations”, that is pulses of light that look right like what we'd expect from ETs making signals by flashing ...stars. I'm not hopeful they'll turn out to be that, but it's really fit news for the tree decorating season.
The kickin' link: Gigapixels of Andromeda
(I often hear people say that sights like this one make them feel how tiny and insignificant humans really are. I've never felt that way looking at the sky. Personally, the sight always fills me with craving and awe for something that we're a proud part of.)
Previous Ph-issues are gathered here.
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...Till next year.
Eleni
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www.chapette.net

The city made of syllables.
(Shopping for Chinese printing elements.)
from my photoblog Blossom City Hotel
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