pglpm

cross-posted from: https://lemmy.ca/post/1721793

The article introduces a dynamic cosmological constant in the current ΛCDM cosmological model to account for some data from the James Webb telescope. The new model would have the age of the universe at ~27 billion years.

This is interesting. Unfortunately some popular science magazines are already presenting it as a fact...

cross-posted from: https://lemmy.ca/post/1721793

The article introduces a dynamic cosmological constant in the current ΛCDM cosmological model to account for some data from the James Webb telescope. The new model would have the age of the universe at ~27 billion years.

This is interesting. Unfortunately some popular science magazines are already presenting it as a fact...

The article introduces a dynamic cosmological constant in the current ΛCDM cosmological model to account for some data from the James Webb telescope. The new model would have the age of the universe at ~27 billion years.

This is interesting. Unfortunately some popular science magazines are already presenting it as a fact...

https://doi.org/10.1093/mnras/stad2032

Some large datasets are pushing memory and some functions I'm writing to the limit. I wanted to ask some questions about subsetting, of matrices and arrays in particular:

1. Does defining a variable as a subset of another lead to copy? For instance

x <- matrix(rnorm(20*30), nrow=20, ncol=30)
y <- x[, 1:10]

Some exploration with object_size from pryr seems to indicate that a copy is made when y is created, but I'd like to be sure.

2. If I enter a subset of a matrix/array as argument to a function, does it get copied before the function is started? For instance in

x <- matrix(rnorm(20*30), nrow=20, ncol=30)
y <- dnorm(0, mean=x[,1:10], sd=1)

I wonder if the data in x[,1:10] are copied and then given as input to dnorm.

I've heard that data.table allows one to work with subsets without copies being made (unless necessary), but it seems that one is constrained to two dimensions only – no arrays – that way.

Cheers!

There are two kinds of colours that appear in each torrent entry in Nyaa's listings:

• One for the rectangle in the "Category" column. I see many different colours there: purple, red, dark and light grey, green, orange, dark and light yellow...

• One for the whole row. Here I've only seen three different colours so far: white, green, red.

Do these colours, especially the second, mean anything?

Nyaa's Help page mentions the meaning of four "torrent colours": green, red, orange, grey. But they don't say where these colours appear. If they mean the row colour, then I've never seen an orange or grey one. So I'm very confused. Maybe the Help page is outdated?

OK, not a life-or-death matter, but I've been curious about this for a long time...

Something that struck me about recent "large language models" is how their answers resemble those of students who work (on purpose or unawares) by memorization. I mean students who learn that specific patterns, appearing in questions, require particular answers. Such students can be extremely skilled at this. But they don't really understand why those answers are meaningful or correct. Their lack of understanding appears clearly upon closer examination and some digging. Exactly as it happens with large-language-model algorithms.

(This is one reason why I personally don't consider these algorithms to have any genuine "knowledge"; not yet at least. But that's not my point here.)

Now those algorithms manage to answer almost correctly many questions from exams; I speak for maths and sciences in my country (Norway) at the bachelor level; but I think the same can be said for other subjects and in most countries (correct me if I'm wrong). In my opinion this shows that our current education and graduation system is focusing on the wrong thing: not knowledge, but parroting. As Gibson asked in 1964:

Do we, in our schools and colleges, foster the spirit of inquiry, of skepticism, of adventurous thinking, of acquiring experience and reflecting on it? Or do we place a premium on docility, giving major recognition to the ability of the student to return verbatim in examinations that which he has been fed?

I think this is a huge problem that has been with us, and we have been aware of, for a long time. But the current AI development emphasizes it very strongly. And it urges us to ask (again) some questions. This is what I'd like to hear your opinions and points of view about:

• Some institutions where I live are planning to use these AI algorithms to (help) generate or correct exams. I think this strategy completely misses the point: shouldn't we prepare exams that these AI cannot answer, which would mean they rely on understanding rather than language patterns?

• If we keep teaching and grading students based on memorization, won't they become unemployed in the coming years? Their "knowledge" can be obtained more cheaply and quickly from AIs.

• Assuming you agree at least partially on the theses above, then which education levels seem to be most affected?

• Doesn't the current packing and compression of lots of subjects into a very short time, at bachelor levels, make the situation even worse?

These are personal (though starkly held) views of course. I respect others and would be happy to hear arguments and counter-arguments!

I joined SDF very recently, and today I took a closer look at its logo. ...That's Macross! Exciting childhood memories come to mind, with engaging background music. Exhilarating!

Is there somewhere I can read about SDF's logo? I checked the FAQ, maybe not thoroughly enough, but didn't find anything.

While refreshing my memories about Macross I read that it was named Super Dimension Fortress – now I see the connection :)

To whoever designed that logo: you're on my "inspiring people" list now. Genius.

Imagine there's a sequence of items, it started somewhere in the past and will keep on going. The kind of items could be anything – say days, or football matches, or lectures, or widgets out of an assembly line.

I'd like to refer to the future item that will be, say, the 100th if I start counting them from now. I hope you understand what I mean: the 1st would be the next, the 2nd would be the one after the next, and so on.

How do I denote that future 100th item with a concise expression? I thought of "the next 100th item", but it doesn't sound right.

The problem is that if I just say "the 100th item", that refers to the number 100 since the sequence started, not the number 100 starting counting from now.

Example:

The last 10 widgets were red and blue; the 20th widget from now will be yellow.

Saying "the 20th widget from now" doesn't sound right – but maybe it is? Nor does "the next 20th widget" sound right.

As usual, if possible please also give some references. Cheers!

Very glad to see this community here. Does it welcome posts also about other TeX flavours such as XeTeX or LuaTeX etc? (Maybe this can be explained explicitly in the sidebar?)

A lot of debate today about "community" vs "corporate"-driven distributions. I (think I) understand the basic difference between the two, but what confuses me is when I read, for example:

...distro X is a community-driven distribution based on Ubuntu...

Now, from what I understand, Ubuntu is corporate-driven (Canonical). So in which sense is distro X above "community-driven", if it's based on Ubuntu? And more concretely: what would happen to distribution X if Canonical suddeny made Ubuntu closed-source? (Edit: from the nice explanations below, this example with Ubuntu is not fully realistic – but I hope you get my point.)

Possibly my question doesn't make full sense because I don't understand the whole topic. Apologies in that case – I'm here to learn. Cheers!