Salindurthas

Salindurthas t1_j9gybl3 wrote

When I was a kid, I borrowed a friend's copy of Pokemon Snap.

He told me not to overwrite his save (duh), so I played through the game only pausing and not turning off the console.

The problem was when I beat the game this way, and it autosaved at the end!

He was not impressed.

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Salindurthas t1_j6p8zn2 wrote

Space and time are related. We call them together 'spacetime'.

You have a limited and fixed speed through spacetime.

If you are statioanry, then all your speed goes into time. You get to go the maximum rate through time. We'll call it aging 1 second per second.

If you move, then you have to split your speed between time and space. If you move slowly through space, then you might age 0.999999 seconds per second, which is hardly a ntoicible difference. If you move very fast through space, then you might age 0.10 seconds per second, which is a very noticible.

Some objects move just fast enough, and need precision timing enough, that we notice it. Like software that works with GPS satellites needs to account for the tiny time dilation between them, because that tiny difference would make a difference in where the GPS believes you are.

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Salindurthas t1_j6ljwa2 wrote

Your sister is aboslutely allowed to watch it herself in her own time, and now watch it with the family. If she wants to watch it herself because she prefers to watch it in silence and to watch the intro, that's fine too.

It's also totally fine for her to share that opinion with the family.

If you and your parents prefer skipping the intro and to discuss it to explain things while it is on, that's fine too.

But your sister is rude to raise her voice or get annoyed at the rest of you watching it differently.

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Salindurthas t1_j6l5p30 wrote

Normally your brain and nervous-system activate your muscles.

External sources of electricity also will activate your muscles, even if your brain doesn't want to.

Generally the electricity tends to 'tell' all your muscles to tense up.

Your 'close hand' muscles are stronger than your 'open hand' muscles, so they'll win this fight and 'succeed' in closing your hand.

Your brain has no say, really, because any orders it gives are overpowered by the external source of electricity.

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Salindurthas t1_j6l059o wrote

Companies pay dividends to their shareholders.

Companies that have some money lying around might normally try to invest it in opening new stores, or developing new products/services, or advertising, or hiring more staff, or upgrading their building, etc etc. This would be 'investment'.

However, sometimes companies can't find a good investment. They judge that there isn't enough demand for a new store, or that they are investing enough into produt developement, or that more advertising wouldn't help because they've already reached their target audience.

They could instead "Invest in themselves" so-to-speak by buying their own shares back. This effective destroys those shares since they issued them, so getting them back basically makes them cease to exist. This has a few effects:

  • They are aiming to profitit the shareholders buy directly paying out the ones they buy these shares from.
  • The spike in demand from them buying back the shares, and the reduced supply of shares, concentrates them in the hands of those who kept hold of them, so that also tries to help the profit of shareholders.
  • They could pay out less in dividends (i said they shares are essentially destroyed, but if you still imagine them holding onto their own shares, then they are just paying the dividends to themselves, i.e. not having to pay them for those shares), which is like saving money, i.e. the 'investment' into themselves pays off.

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It can sometimes be seen as a poor business move. Shareholders might like share buybacks since it is kinda diretly trying to give them value, but something they believe the business should expand, rather than consolidate like that.

It can be seen as greedy, because the money could instead go to employees or reducing prices, rather than aiming to help the shareholders.

It can be seen as corrupt, as the executives and board members that might have a say in this decision, might own some of the shares, and so might directly profit in some scenarios. e.g. they have an opportnity to buy up shares before the company does a buy-back, hence preempting the spike in demand and maybe getting an unfair gain.

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Salindurthas t1_iybms9m wrote

>Why couldn’t you just write it 5 x 12 + 2 and solve it all left to right?

Well, what if you are writing down the eggs you see, as you see them?

What if you spot 2 eggs, so you write that down, and then spot 2 cartons of a dozen, so you write that down.

Oh, dang, now you've written 2+ 5x12, and under your convention, that isn't what I meant (I've written 7x12, but I mean 2 more than 5x12).

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Or, what if you have a formula like: "D = 2*x/y + 5*z^2"

You might be working in a lab, , and your assistant tells you "I've measured x & y, they are 7 and 3.5 respectively."

You're waiting for them to measure z, and figure that you'll simplfiy your equation, and you work out the left term happens to be 4 (2*6/3.5=4).

So you write "D = 4 + 5*z^2" to keep your equations easy to read and lined up.

Oh, dang again! That isn't what you meant, you need to change the order around!

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I think it is better to have a convention where the order you write addition in doesn't matter, so that you can add things as you discover them/calculate them, rather than needing to reorder your equation every time.

You *could* do it, but I think if society did, we'd have more errors than using our current convention.

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Salindurthas t1_iyblyns wrote

On one hand, we simply decided to use it that way. It is just a convention we agreed upon.

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On the other hand, when people were deciding on the convention, surely they had *some* reason, right?

I think they did, and that there is some underlying logic to it.

The mathematical operations have some sort of inherent order to them, basically about how 'strong' (in a sense) they are.

  • You may have heard that multiplication is repeated addition. (e.g. 3x4 = 3+3+3+3 by definition).
  • Exponentiation (taking a 'power') is repeated multiplication. (e.g. 3^4 is 3x3x3x3 by definition).
  • So, in a sense, by being repeated versions of another operation, Exponents are stronger than Multiplication, and Multiplication is stronger than Addition (and Addition is stronger than Counting, for what it is worth).

We don't have to do operations in the order of most 'strong' to least 'strong', but it feels natural to do so, and so we formally choose and decide to do so.

So do exponents (aka powers) first, then multiplication, then addition.

But we've forgotten some operations, so let's add them in. Division is just as 'strong' as multiplication, because is the opposite, and can therefore undo exactly what multiplication causes. Subtraction is similarly the same strength as addition. So, in standard ways of listing the order of operations (like BODMAS/PEMDAS/etc), we obey that ordering.

I'll reiterate that despite this reasoning, it isn't lot as if we are logically forced to use this convention. It is just a fairly natural one to use.

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Salindurthas t1_iuk82sb wrote

I vaguely recall readig a claim that there are 2 sorts of dreams.

Supposedly, some are boring simulations of realistic simulations. Like waiting at traffic lights or eating meals.

While others are wild combinations of crazy factors (which probably have that 'dreamlike quality' to them).

The former ones are your brain practicing old scenarios, and the latter ones are imagination and preparation for new scenarios.

You get them in roughly equal amounts of time, but you don't always remember your dreams so your personal experience may be different.

I don't know where I read this though. It might be just an idea by a blogger, or it might be an opinion of a neuroscientist. (And even if it is the opinion of a neuroscientist, it might only an opinion/hunch of theirs, and I probably haven't remembered it 100% correct.)

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Salindurthas t1_itngh5y wrote

>Supply and demand have to match every second

This can be somewhat automated though. Like the signal for needinging more/less energy gets sent to the control-electronics in the power-plant, which then control the water/gas/air flow, or disconnect/reconnect solar panelts, etc.

Now, whether that means it lasts for twice as many minutes as you guessed, or for hours or days, is unclear to me. But it is plausible to me that it could last substantially more than mere minutes.

And even if things start to trip, that can be limited in scope. Like maybe one suburb gets a black out at peak time due to not enough manual upkeep, but the rest of the grid might continue ok.

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