primary key: the thing that is guaranteed to identify a row in a table. it might be a single column that's an incremental number (an identity column), or it might be something like a guid, or it might be two columns that together make a unique value, but might not be unique in themselves.

foreign key: when one table links a column or columns to the primary key in a different table. this is good for referential integrity, you can't put a value into the foreign key columns unless they actually refer to a row in the other table. and that row is prevented from being deleted if something references it. (or you do a cascading delete, that deletes all records pointing to the initial record you're deleting).

clustered index: the columns in the table that define the order that data is stored in. normally it's the primary key. sometimes it can be useful to have that as a timestamp, so records from similar times are all kept together in storage.

natural key: sometimes the data you're given has a key that uniquely identifies the record already available in it. a (bad) example might be your social security number. that uniquely identifies you from everyone else in the usa. isn't good for foreigners tho. the chassis number on a car might be another natural key.

surrogate key: if there's no natural primary key in your data, you'll need to give it one. if you just number the first inserted record as 1, the next as 2, etc, that key is not part of the natural data you're storing, it's surrogating for a natural key that isn't present.

i don't think this question will stay, but I'll have a go at it.

then and than do not sound the same when spoken, they sound similar, but not the same. the 'e' in 'then' is a more closed sound than the 'a' in 'than'.

you might want to compare other words with the same sounds:

• ben, ban
• send, sand
• lend, land

'then' tends to be used when talking about sequences. "i do this, then i do that", it can also be logical sequences: "if you rob a bank, then you will go to jail"

'than' tends to be used more for comparisons: "I'd rather have a nice car than a small payrise", "there's nothing more satisfying than spending the night with your friends".

although I'm not a linguist so I'm probably missing a lot of uses.

I'm smiling now, smokey! ❤️

best pup ❤️

here's a not very satisfactory explanation that i found when playing with genetic algorithms at uni:

if you don't age, you end up competing for resources with your offspring. the best way to win that competition is to generate offspring that are worse than you. this leads to genetic stagnation and makes your population vulnerable to changes in the environment.

we all like naps too, Dyno! ❤️

best dog ❤️

that's beautiful

best pup ❤️

best doggo

she looks very swish

Humans are slightly special because of the baby's head, which is as big as it can be at birth. women's hips are as wide as they can really be without causing skeletal issues.

other animals haven't generally gamed their evolution in that particular way, we get more of an advantage from our brains than most. which makes our birthing process particularly traumatic for the mother.

other animals do get complications, as noted by others, but we're right on the cusp in terms of complications vs brain size optimisations.

dammit, short loop. i was hoping for a nice wholesome progression, ending in success

wobble dogs. not sure it qualifies as a bad game cos it's adorable, but you'll see what i mean

mobile phones got quite boring just before smart phones came along and changed the landscape. we're still trying to work out how to deal with being able to talk to anyone on the planet and survive as a society. ai hasn't even woken up yet and it's changing the landscape of text and image generation.

Even if that rule was useful, i don't know how you'd enforce it.

it would require everyone who worked with AI to abide by this rule at every point in time. It would only take one researcher or even home user to break the rule to cause trouble.

It would require everyone who used an ai to not generate another ai with its code.

And how would you know that the safeguards you're putting in place are secure? if you're making a general purpose ai, it's basically a massive search algorithm, so you'd better be damn sure that every single way it could improve itself is locked out.

I don't know if you've found it but there's some great discussions on ai safety by Robert Miles on both his own channel and the computerphile channel: https://youtu.be/w65p_IIp6JY

it's pretty bleak 😅

carrier command 2 👀

up vote for the word "shlumped"

thanks you for your feedback.

yes, telescopes can pick up and recover sound by registering the distortion on objects in the room. this used to be done with lasers but even that isn't necessary now.

and you might notice that i said in reality we couldn't have a telescope that did that, but we could communicate and see the effect in other ways. like flashing lights at each other.

that's kind of important. we can imagine what we would see, and describe the effects, without worrying about what the physical limitations are. visualising the situation can help with understanding.

my point was that our experience of time doesn't change, but the time we see pass for others does.

I'm sorry if you found the explanation confusing, however.

the gills are very delicate structures that rely on being "fluffed out" to have enough surface area to absorb the oxygen.

this is fine while underwater, but when you take them out into the air, their gills hang down all matted.

it's like your hair that floats freely underwater but straggles down in wet clumps when you surface.

the water also forms a barrier preventing circulating air from touching the gills. so until the gills are dry and fluffed out again, there's no chance of absorbing any fresh oxygen at all.

even then the surface area just isn't enough to sustain life. we enclose our oxygen absorbing surfaces inside our chest and our lungs fill the majority of our chest. that's a whole lot of absorbing area and mechanics to move a lot of air across it.

so basically, the fish suffocates before the gills dry. but they're too small and not structured properly to sustain life in air regardless.

let's imagine you're hanging out near a black hole (but not in it).

one thing to keep in mind, you would not notice time slowing down. your time as far as you're concerned would feel exactly like it is now. you'd look at your watch and it would tick at the same rate. you'd still be breathing, your heart pumping as normal. you'd hold normal conversations with the people next to you.

but, me, hanging out over here on earth, i could watch you through a telescope. and I'd see you moving in slow motion. your watch would tick more slowly than mine. your conversations would be lower in pitch and take longer. if you looked at me through a telescope, I'd be sped up. my watch would tick faster, my voice would be sped up like a cartoon character.

the closer you get to the event horizon the more extreme this effect. the most likely impact of this would be communications. in reality I'd never have a telescope that could view you. but you could flash a really bright light towards me, and communicate in morse code (or more likely a digital computer protocol). I'd see your flashes going very slowly. if i knew how fast you were flashing your light from your perspective, i could tell exactly how close to the horizon you were. weirdly, your light would get more and more red as well, for the same reason your voice would seem lower to me.

conversely, if i flashed a light at you, you'd see it flashing faster and more blue.

this effect is actually seen in our gps satellites. time goes slightly different for them (i think faster, as they're not in our gravity well, but there's other aspects that affect this too, like speed). so we need to account for the different clocks for gps to be accurate.

new goal, make music that affects people so viscerally that they're curled up on the floor shaking

not a scientist, but this is my understanding of things too.

the "big bang" was originally coined as a pejorative way to describe the idea. it just stuck because it's catchy.

our physics goes so far back, to a certain point. and it looks like the math would go back to a zero size point. which is how we get to fractions of a second after the big bang. but that's just using similar math to: a plant is growing 1cm a day, it's 10cm now, so 10 days ago it must have been 0 size.

our physics doesn't describe the early universe beyond a certain point, so we can't actually tell what it was like. and we know there's 4 big problems in current physics, all of which would affect this:

• quantum mechanics and Einstein don't align
• quantum mechanics does not describe what collapses the wave function
• we don't know what dark matter is
• we don't know what dark energy is

and these are just the "known unknowns".

however, "the big bang" remains the most plausible model, describing the cosmic microwave background and the current expansion and distribution of matter within the universe.

some of the big things we know we don't know about it:

• what happened at t=0 and just after, if t=0 really was the start of everything or just some inflection point
• why we appear to have mainly matter and not matter + antimatter

I'm sure there's a bunch more things we don't know. but your characterisation seems accurate to me.

best dog!