No one will actually do that, except the few weirdos who think that it's a good idea.
Remember: "Reusable" containers also have an environmental cost. Each container will be used, on average, X times. Then it will break, or otherwise end its useful life, and end up in a landfill too.
Don't assume that a "reusable" container is better for the environment: My house is full of free, pristine, reusable water bottles that are gifts, souvenirs, ect. My kids go through about 2 reusable water bottles a year, each.
I mean, of course it's not perfect. But isn't 2 water bottles in a land fill orders of magnitude better than 300? Isn't the reduction of bulk trash the point? Why would the fact that a glass container can break make it not still a better alternative to 50 plastic ones?
So many barbies and barbie-like dolls have shown up, that they are often laying in a pile at the bottom of the doll castle.
I dread opening the doll castle because the sight of the dolls laying, stacked on the castle's floor, just brings back images I've seen of ethnic cleansing.
> The article is clearly not written by a parent because it barely touches on Buy Nothing Groups on Facebook.
The author very clearly indicates they have children. I don't think the author wants to make it an article about themselves.
Keep in mind: Toys just show up from well-meaning people. There's a lot of social momentum around gifting; I started dreading Christmas because it means a bunch of toys my kids won't play with.
And, not only am I drowning in toys, I'm drowning in books too.
pretty much the only toys i get for my kids to get are lego compatible bricks. with those it doesn't make a difference if you have 1 or 10 kg of them. just add to the pile.
no books in my house because we are moving to often. but i grew up in a library. my dad probably has 10-15m worth of bookshelves. from my granddad we inherited 3 or 4 times as much. but they were both collectors, curating their collections with care. still, sorting through those books to figure out whats valuable is a lifetime occupation. and i can see how a lot of books can be overwhelming if you are not into that.
a year ago i heard about someone passing away leaving behind a house with a collection of 75000 books. the cost to sort through them would be higher than the value of the collection, so instead it all goes to a landfill because i a not even sure it can be recycled or the cost of getting it recycled was to much too.
There are a few types of toys that my wife and I are still ok with getting and Lego is one of them. She's started using the phrase "more really is more" to describe the category. Basically, it's systems where you build something and the more you have, the more things you can do: Lego, Brio, Magna-Tiles, Hot Wheels track, etc. Even things like Pokemon cards (if your kid actually plays the game) can fall into this. You do have to be careful not to end up with too many of these systems, especially really similar ones.
We're also still ok with getting books. We have a few too many for our shelf space, but at their current ages, our kids are aging out of books about as quickly as they receive new ones. I just need to do a better job of giving away the old ones more regularly.
Yes! I've run out of ways to tell MY parents not to get toys for my kids for Christmas/birthdays. I can ask directly for no physical things; I can suggest tickets to shows or evens, memberships to museums or zoos, etc; I can point out every time they come over that there's not enough space for the things we already have; I can tell them what sorts of clothes the kids could use instead. They're still going to get each kid a "showstopper" (toy workbench, Big Wheel, something physically large) plus several cheap plastic trinkets... plus the clothes.
And that's just my parents. I can politely talk to them about not getting physical things for my kids, but then there's all of the extended family that loves to get them big, cheap plastic stuff, too. I know they're trying to be generous and don't really understand the fallout, but I'm starting to reconsider the whole "it's the thought that counts" idea.
I need to do a better job of helping the kids periodically go through and give stuff away, but 1) try explaining to a 3-year-old why giving away your toys is a good thing, and 2) the influx of new things always seems to outstrip the rate at which I can find time to get rid of stuff.
Is that connecting renewables to the grid is time consuming, and shouldn't be. A few years ago, I determined that they payoff of grid-scale batteries is extremely fast, BUT, connecting to the grid is so frustrating that I decided I didn't want to peruse the opportunity.
I would expect a company whose business is building and operating power plants, to be more adept at navigating the red tape surrounding the grid that they operate than you are.
> The answer, as best I can find it, seems to be related to the points about status.
> The second is the overly bulgy bit in front of their front legs, the brisket. And, also according to my research, when cattle are judged for competitions or prizes, the brisket is taken into consideration.
> Oh! Is that an artifact of Joint Stereo encoding ?
I personally don't understand enough of MP3's internals to explain that.
What I assume is that, because MP3 internally stores Fourier transforms in the frequency domain, instead of the time domain, it uses very few bits to store phase. This will result in phase shifts.
Hopefully, someone else can give a better explanation of this than I can.
Basically, think of it this way:
1: Imagine a frame of 64 16-bit samples. (1024 bits)
2: Than its converted to 32-bit floats: 64 32-bit samples.
3: Than its transformed
4: Now there are: 1 DC bias 32-bit float, where phase is 0, and 32 frequency amplitude floats, and 32 phase floats. (The other 31 frequency/phase pairs are duplicates and don't need to be stored.)
These floats need to be quantized so that there are many less bits. Some of it can happen by using very few bits to store phase, and some of it can happen by using less bits to store amplitudes. Again, someone else can probably explain this better than I can.
Interesting. In a quick internet search seems like people finds a small phase shift on MP3 enconding, but I haven't found details on why. Haven't had much time to find it, though...
It's because mp3 dramatically changes phase. As a result, merely mixing the inverted original won't leave you with what's filtered out.
That technique will work with simpler compression techniques, like companding. (Companding is basically doing the digital equivalent of the old Dolby NR button from the cassette days.)
What happened is that European disease created massive pandemics that killed most of the American Indians. No one was seduced by western culture, because, in general, American Indians had a better standard of living than the European colonists.
Where I live, (in Massachusetts,) the remaining American Indians integrated into European settlements because so few of them were left. I know its different elsewhere in the American continents; you can find out more if you read 1491 and its sequel 1493.
You've misunderstood something about Nyquist. A sample rate of, say, 44KHz, will capture ALL information below 22KHz and recreate it perfectly.
There are of course implementation details to consider, for example you probably want to have a steep filter so you don't wind up with aliasing artifacts from content above 22KHz. However it's important to understand: Nyquist isn't an approximation. If your signal is below one half the sample rate, it will be recreated with no signal lost.
I don't recall seeing Nyquist described with those requirements before. I think it is evident that in the real world, there are many practical signals which do not exactly meet those requirements, but which still yield nearly-exact reproduction.
I wonder, what are some examples of signals that fail to reproduce after sampling in a way that is "nearly Nyquist"?
If you look at the Wikipedia entry on the Nyquist Sampling Theorem, you should note that the summations to reconstruct the original signal go from negative infinity to positive infinity. In other words, that sum requires an infinite number of samples.
There are many signals of practical interest that can be approximately reconstructed with a finite truncation of the series. Note, however, that any signal that has only a finite length, eg has a uniformly zero amplitude after some time t_final, does not have a finite bandwidth, and cannot be exactly reconstructed by any sampling scheme. This is the case whenever you stop sampling a signal, eg it is always the case whenever you step outside the mathematical abstraction and start running real code on a real computer. So any signal reconstructed from samples is always approximate, except for some relatively trivial special cases.
Hm, yes, a function cannot have bounded support in both the time domain and the frequency domain…
What if you take a function that has bounded support in the time domain, and then turn it into a periodic function? Might the resulting function have bounded support in the frequency domain even though the original function did not?
I suppose doing this would force the Fourier transform to have discrete support? But under what conditions would it have bounded support?…
I guess technically a low-pass filter applied to a signal with finite support in the time domain, would result in a function which has infinite support in the time domain.
I suppose sinc(f t + c) doesn’t have bounded support, and it is unsurprising that a non-trivial linear combination of finitely many terms of this form would also not have finite support.
Still, such a linear combination could decay rather quickly, I imagine. (Idk if asymptotically faster than (1/t) , but (1/(f t)) is still pretty fast I think, for large f.)
Soon enough the decay should be enough that the amplitude should be smaller than the smallest that the speaker hardware is capable of producing, I suppose.
I think it is you who have misunderstood the Nyquist-Shannon theorem. Aliasing and noise are real concerns. Tim Wescott explains it very well [0] (Figures 3, 10 and 11). If your signal is below one half the sample rate but the noise isn't, you'll lose information about the signal. If your signal phase is shifted wrt. the sampling, you'll lose information. If your sampling period isn't representative, you'll lose information. These are not implementation details.
Anything close to N/2 is going to have varying magnitude that requires filtering and likely oversampling to remove.
How close to the Nyquist bandwidth you can get depends upon the quality of your filtering.
44.1KHz is a reasonable compromise for a 20KHz passband. 48KHz is arguably better now that bits are cheap-- get a sliver more than 20KHz and be less demanding on your filter. Garbage has to be way up above 28KHz before it starts to fold over into the audible region, too.
> Garbage has to be way up above 28KHz before it starts to fold over into the audible region, too.
You brick-wall everything at 20 kHz (with an analogue filter) before you sample it; that's part of the CD standard, and generally also what all other digital CD-quality audio assumes. This ensures there simply is no 28 kHz garbage to fold. The stuff between 20 and 28 in your reconstructed signal then is a known-silent guard band, where your filter is free to do whatever it wants—which in turn means that you can design it only for maximum flatness (and ideally, zero phase) below 20 kHz and maximum dampening above 28 kHz (where you will be seeing the start of your signal's mirror image after digital-to-audio conversion), not worrying about the 20–28 kHz region.
Your comment is mutually contradictory-- what is it, a brick wall (impossible) analog filter or a more gentle rolloff as things fold over?
What you really do, these days, is you sample at a higher frequency; you can have an exceptionally gentle analog filter (which will help you make it linear, too). E.g. if you sample at 96KHz, you just need to roll to near zero by 75KHz. Then you can digitally downsample/decimate to 44.1KHz or 48KHz.
Also note for CD audio, it's more like 24KHz where you get worried, not 28KHz.
You're mixing up the two filters. The pre-sample filter (before ADC) is defined to be a brickwall (of course impossible in practice, so in reality, it will have to start going off a bit before 20 kHz); the reconstruction filter (after DAC) has a roll-off.
I've not been talking about the reconstruction filter at all during any step of this discussion. Reading your comment more carefully, it seems you were trying to.
I'm saying that if you oversample, it's easier to get appropriate rejection from your pre-sampling filter and it's easier to make it appropriately flat as well.
E.g. sample at 384KHz; you need to reject stuff over 360KHz. You probably have negligible energy up there to begin with. A 3rd-order filter with -3dB at 30KHz might get the job done.
It's pretty easy to make this flat in phase and amplitude up to 20KHz, and things like capacitor nonlinearity are much less of a concern.
In turn, filtering down to 20KHz and rejecting from 22050 and up is easy in the digital domain. 512 taps gets me a filter flat to 0.15dB up to 20KHz and >63dB rejection over 22KHz.
My point was, this is a little better at 48KHz, because we can choose to e.g. pass 21KHz and have a wider guard band (14% vs 10%). With 384 taps, numbers are more like flat to 0.1dB and -67dB, benefitting both from the wider guard band and 48KHz being a factor of 384KHz.
Sure, you can implement the pre-sampling filter as a multistage filter, of which some of the stages are digital, if you wish. (I don't know where you get “rejecting from 22050 and up” from, though. For the pre-sample filter, you should reject from 20000 and up, and for the reconstruction filter, you should either reject from 24100 and up or 28000 and up, depending on whether you ended up sampling in 44.1 or 48.) But I don't think your argument makes much sense; if you're already in a domain where you have enough resources to sample at 384 kHz and run a 384-tap FIR filter over it, then surely you're high-end enough that you can't say “nah, who cares about the most common sample rate out there”.
You should pass all below 20KHz, as flat as possible. You definitely should stop 24.1KHz and up. How bad 22.05KHz to 24.1KHz is, is debatable.
> then surely you're high-end enough that you can't say “nah, who cares about the most common sample rate out there”.
I didn't say "don't support 44.1KHz" -- I'm saying there's good reasons to prefer 48KHz.
All being equal (same number of filter taps, etc)-- just a slightly higher sample rate offers a lot more performance because you can get a bit more frequency response and a lot flatter passband.
But they still interact with frequencies lower than 20khz right?
Think about it like this - I have a single steady saw wave at 10khz. If I started playing waves above 20khz, would I be able to detect any disturbance in that 10khz wave?
No, 44 kHz is because you want to reconstruct the (20 kHz) bandlimited signal and it's (much) easier to realize such a filter if you have a bit of a transition band.
> You've misunderstood something about Nyquist. A sample rate of, say, 44KHz, will capture ALL information below 22KHz and recreate it perfectly.
Let's do a thought experiment. Imagine a digital image where the pixels are the exact minimum size that you can see.
If a line is exactly 1-pixel-wide, it'll display perfectly when it aligns perfectly with the pixels.
But, if the 1-pixel-wide image doesn't align with the pixels, what happens?
You can see this in practice when you have a large screen TV, and watch lower-resolution video. Smooth gradients look fine, but narrow lines have artifacts. IE, I recently saw a 1024p movie in the theater and saw pixels occasionally.
The same thing happens in sound, but because a lot of us have trouble hearing high frequencies, we don't miss it as much.
Remember: "Reusable" containers also have an environmental cost. Each container will be used, on average, X times. Then it will break, or otherwise end its useful life, and end up in a landfill too.
Don't assume that a "reusable" container is better for the environment: My house is full of free, pristine, reusable water bottles that are gifts, souvenirs, ect. My kids go through about 2 reusable water bottles a year, each.
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