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An Essay on the Archaiology [sic] of Popular English Phrases and Nursery Rhymes - John Bellenden Ker

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jepler
21 hours ago
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Take the origin stories as you will, it's fascinating to see what terms we do and don't still use in English. (1834)
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Senior engineering & fantasy heroes

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I was talking to someone at work this past week about what I’d want out of a senior engineer, and found myself inventing characters I’d like to work with (and I already work with people who remind me of all of these, of course! <3). Maybe someone will find this bit of silliness enjoyable :). It’s about how fortune tellers do not necessarily also need to be cattle wranglers.

(apparently I think gardeners are fantasy heroes)

In very related excellence, Camille Fournier posted Rent the Runway’s engineering ladder in this blog post and spreadsheet which lays out engineering qualities they value in terms of strength/dexterity/wisdom/charisma <3

The fortune teller

The fortune teller can tell the future about your engineering project. You tell her a design decision you’re making; she tells you the problems you’re going to run into in 3 months. She saves you an incredible amount of engineering effort in bad directions.

The cattle wrangler

You have a team, and you need to standardize how your programs do an Important Thing. Everyone wants to standardize, and nobody can agree on what the standard should be. The cattle wrangler is amazing at working through the pros and cons, and getting everyone to feel heard & agree on a standard.

The spring of knowledge

Your company uses a lot of Java, and sometimes you need to know some obscure internal JVM detail. And all of your internet searching is bringing up… nothing. When you do, you go to the spring of Java knowledge, which tells you what you need to know.

(What you need to know is not always the answer to the question you asked)

The gardener

You built a project full of technical debt and spiky bits? You go to the gardener for help, and sheepishly ask them to help you clean it up a bit. They show you where the nastiest weeds are, suggest code that you could delete, and help you get to a better architecture in a reasonable amount of time. They’re great to have on your side at the beginning of a project, before you create the technical debt in the first place :)

If you have more characters you work with & love, tell me! @b0rk on Twitter.

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jepler
1 day ago
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I like to think of myself as the Spring of Knowledge, but not for java (yuck)
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expatpaul
1 day ago
I usually feel most like The Gardener. Cleaning up someone else's mess is is not always the most pleasant of activities.
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The Cry Life

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The Cry Life
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jepler
1 day ago
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what a terrible dream
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Seduction

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Seduction

New comic! Oskar knows how to work those paws. He knew exactly what he was doing.
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jepler
2 days ago
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this pretty much happened to a friend of mine
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Dark Matter Collisions

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The existence of dark matter is one of the coolest science stories of my lifetime. When I was growing up I was in love with pretty much every field of science, but particularly with astronomy, and at that time we had no idea that 85% of the matter in the universe even existed. We now know that the astronomy I was so fascinated with was actually the study of 15% of the matter in the universe. If you count dark energy, which makes up 68% of the universe, then dark matter makes up 27%, and everything that we thought was the entire universe is actually only 5% of the universe.

This story dramatically contradicts every crank and pseudoscientist who tries to tell you that scientists only support the status quo. In my lifetime we discovered 95% of the universe, without any prior theory telling us to expect this result. (Dark matter was hinted at in observations of galaxy rotation, but not generally accepted.) The discoveries were based on unexpected observations, that broke our models of how we thought the universe worked. Scientists met these new ideas with skepticism, but explored them further, and were slowly convinced by mounting evidence. Now dark matter and dark energy are generally accepted – because the evidence convinced the scientists. That is how science works, kids, so don’t believe the cranks.

Dark matter is a powerful idea, even though we currently don’t know what it is, because it not only explains observations that otherwise don’t make sense, it makes predictions. Predictions are the key to scientific progress. They provide the opportunity to test ideas against reality. If an idea does not make any testable predictions, right or wrong it’s just worthless. (Not even wrong.)

The first hint of dark matters existence was in the observation of galaxy rotations. In short, the stars in the outer parts of galaxies are moving faster than can be explained by Newtonian gravity and the mass of observable stars. There were some preliminary observations to this effect, but it did not come to serious scientific light until Vera Rubin published her influential paper in 1980, based on her work over the previous decade plus. She showed, using the most accurate observations to date, that stars in spiral galaxies all orbited at roughly the same speed. This means that the mass of spiral galaxies increased linearly as you go out from the core, but this could not be explained by observable matter. Galaxies must be comprised of at least 50% invisible, or dark, matter.

An alternate theory, that of modified Newtonian dynamics (MOND), states that the gravitation constant is different at really large (galactic) scales and this explains the observations. This remains a minority opinion, and more recent observations seem to have killed MOND in favor of dark matter.

Those more recent observations indicate that dark matter is not just regular matter that is obscured by dust clouds or hidden from view for some other reason. Dark matter is actually a new and unknown type of matter, because it behaves unlike other known matter. The clincher comes from the observation of collisions between galaxy clusters. The first such observation was of the bullet cluster in 2006. 

Using the Chandra X-ray telescope, astronomers observed this collision of galaxy clusters. What they found was the the visible matter in the cluster slowed as they crashed into each other, as would be expected. This is because the matter in the two clusters interact with each other, causing the slow down. The astronomers also observed the gravitational lensing effect of the cluster. In essence, they could see the shape of the gravity of the colliding clusters. What they found was that the center of gravity of the two clusters had continued to move past each other, hardly interacting at all, even while the visible matter had crashed into each other and slowed down.

What this means is that dark matter, which contains most of the gravity, interacts very weakly with regular matter and with itself. It’s non-gravitational interaction is very minimal. In fact, astronomers could use the observation of the bullet cluster to set limits on this non-gravitational interaction of dark matter.

One data point is never satisfying to scientists, however. This brings us to a new study and the inspiration for today’s post. Astronomers have just published observations of 72 similar collisions of galaxy clusters. They write:

Using the Chandra and Hubble Space Telescopes, we have now observed 72 collisions, including both major and minor mergers. Combining these measurements statistically, we detect the existence of dark mass at 7.6σ significance.

The 7.6σ significance (or sigma) is a huge degree of confidence. Five sigma is generally considered to be the level of certainty in a data set where the results can be taken as true. This corresponds to a one chance in 3.5 million that the results were due to random chance. A result of 7.6 sigma is well beyond significant.

In other words – dark matter exists. It is a real thing. It is an unknown type of matter that has a strong gravitational field, but otherwise only very weakly interacts with other matter, including other dark matter.

We don’t know what dark matter is, but this new result gives us one more piece to the puzzle. The authors note that the results are, “disfavoring some proposed extensions to the standard model.”

I do hope I live to see this decades long science news story progress to the point where we know what dark matter actually is. But even if that discovery is still decades away, it has been an amazing ride. When I was born we thought we knew what the universe was made of, but our knowledge only encompassed 5% of the actual universe. Now, at least, we have a better idea of the extent of our ignorance, which is the beginning of discovery.

We now have very good evidence that 27% of the universe is made of an unknown type of matter that has gravity but otherwise only weakly interacts. We are gathering clues as to what this dark matter is and what it isn’t. Eventually we’ll figure out what it is. That knowledge will likely just create further mysteries for scientists to explore.

 

 

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jepler
2 days ago
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"In my lifetime we discovered 95% of the universe, without any prior theory telling us to expect this result"
Earth, Sol system, Western spiral arm
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From LPC810 to LPC812

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No, I haven’t abandoned the Micro Power Snitch!

But some projects are trickier than others, and this one didn’t want to play along when I tried it again on my new PCB design. I fixed one glaring wiring mistake so far, but there’s more going on. Since Mr. Murphy seems to be enjoying himself again, I’m going to let him enjoy his little “victory” for a while and come back to the MPS at a (slightly) later date.

Instead, let’s move up the ladder a little and experiment with another ARM µC:

DSC 4977

On the right: four times as much memory (both flash and RAM) and twice as many pins.

As you can see, packaging is everything – and bigger is not always more…

(For comments, visit the forum area)

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jepler
2 days ago
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good, an 8-pin device is WAY too limiting.
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