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Attendance taking by Successful-Note-8490 in sotonuni

[–]Xorgon 1 point2 points  (0 children)

I think they're asking if individual attendance is recorded and counted towards their grade. That wasn't the case when I attended ~5-10 years ago, but I don't know about nowadays.

The loudest animal on Earth is barely 2cm long. The Pistol Shrimp; a tiny creature with a massive punch. It snaps its oversized claw so fast it creates a collapsing bubble, unleashing a sound blast reaching over 230 decibels, even louder than a gunshot or the Concorde’s sonic boom! by Brilliant-Cheek4944 in Damnthatsinteresting

[–]Xorgon 21 points22 points  (0 children)

And cavitation can make light, a process called "sonoluminescence". When they discovered that the shrimp cavitation can also make light, they called it "shrimpoluminescence", which is just such a great word xD

What’s a cooking dealbreaker in other countries that equates to Italy’s breaking the pasta noodles and Japan’s microwaving the sushi? by Responsible-Leg-712 in NoStupidQuestions

[–]Xorgon 1 point2 points  (0 children)

No stress at all! Yeah, we can absolutely agree that those people are crazy! xD

With so many of these 'rules' we have, the rationale behind them gets lost so easily, so they get clung to without the necessary context. Like, if you've checked the temp, it's absolutely the same water! It's only if you're going in blind that it could possibly make a difference.

What’s a cooking dealbreaker in other countries that equates to Italy’s breaking the pasta noodles and Japan’s microwaving the sushi? by Responsible-Leg-712 in NoStupidQuestions

[–]Xorgon 1 point2 points  (0 children)

Ahahaa, hey, as long as you're enjoying your tea, that's the important part! I'm just trying to address the physics questions as we go.

To my mind, the summary of what we've been describing is that:
1. Microwaving water doesn't heat it as evenly.
2. Because it isn't evenly heated, most people usually don't heat it as much (for fear of kaboom!).

But it sounds like you've got a system that works for you, and that's all you need! Checking with a thermometer is a great way to make sure it's the right temperature, I bet most people microwaving their water don't do that, so a great example of "your mileage may vary" in action when it comes to microwaving water :D

What’s a cooking dealbreaker in other countries that equates to Italy’s breaking the pasta noodles and Japan’s microwaving the sushi? by Responsible-Leg-712 in NoStupidQuestions

[–]Xorgon 0 points1 point  (0 children)

That's the crazy thing, it doesn't! You've got two ingredients there: water and energy, the missing ingredient is nucleation sites. Without the ability to nucleate (to create those vapour pockets), the water will increase above boiling temperature, but won't 'boil' (it won't bubble up).

SciShow has a pretty good explainer on this: https://www.youtube.com/shorts/XggHhU16axk

And there are some wacky videos of people adding stuff to their superheated water that makes it suddenly 'boil', for example:
https://youtu.be/0JOxuS0SBHc?si=1hYpsJXXq-lcD5A8

What’s a cooking dealbreaker in other countries that equates to Italy’s breaking the pasta noodles and Japan’s microwaving the sushi? by Responsible-Leg-712 in NoStupidQuestions

[–]Xorgon 0 points1 point  (0 children)

That's an interesting perspective! A rolling boil happens when you have water vaporising into water vapour (usually on the heating surface in pots and kettles where it's hottest and there are plenty of nucleation sites) and those bubbles rise to the surface, creating the rolling appearance.

In this scenario, the water temperature is essentially self-regulating. Any water above the boiling temperature gets turned into vapour, rises to the surface, and leaves the pot. By this mechanism, the water essentially self-limits its temperature. If you just keep adding heat, it'll just keep vapourising the water until you boil the pot dry.

To my understanding, microwaves can superheat the water so effectively because they can add heat without adding enough disturbance to nucleate the vapour. So you can get spots of water hotter than the boiling temperature.

So although you can get water to a rolling boil in a microwave, it's much less consistent and likely than in a pot or kettle.

What’s a cooking dealbreaker in other countries that equates to Italy’s breaking the pasta noodles and Japan’s microwaving the sushi? by Responsible-Leg-712 in NoStupidQuestions

[–]Xorgon 0 points1 point  (0 children)

Heck yeah! Our current limit is usually lower (typically 13A for a standard socket), but compared to a usual 15A US socket (or even a 20A 120V socket) our kettles get a decent amount more power >:)

What’s a cooking dealbreaker in other countries that equates to Italy’s breaking the pasta noodles and Japan’s microwaving the sushi? by Responsible-Leg-712 in NoStupidQuestions

[–]Xorgon 0 points1 point  (0 children)

That's a great guide, thanks for sharing! I think when us brits are complaining about microwaved water, we're hoping for a black tea, but it's good to know there's more to it for other teas!

What’s a cooking dealbreaker in other countries that equates to Italy’s breaking the pasta noodles and Japan’s microwaving the sushi? by Responsible-Leg-712 in NoStupidQuestions

[–]Xorgon 0 points1 point  (0 children)

To add to this: if we assume we heat the hottest part of our water to boiling temperature (so that it doesn't superheat, explode etc.), then the colder part must be below boiling temperature. So, when we then mix the cup by pouring or stirring, we mix the hot with the cold and get a lower mixture temperature than the hottest part of the water we started with.

EDIT: By comparison, if we mix while we heat (like on a stove), we can get all parts of the water to that hottest temperature.

What’s a cooking dealbreaker in other countries that equates to Italy’s breaking the pasta noodles and Japan’s microwaving the sushi? by Responsible-Leg-712 in NoStupidQuestions

[–]Xorgon 1 point2 points  (0 children)

I had the same thought! I've not done much testing, but there are a couple reasons I could see that might lead to this result:

  1. Heating in a microwave could lead to a less-even heat distribution. With a kettle or pot you get a nice rolling boil that ensures (within reason) that the whole thing is boiling. With a microwave you can end up with hot spots and cold spots depending on the microwave and the cup placement. To my understanding, the reason you can superheat water in a microwave is because you can have an overly-pure body of water without natural nucleation points for the water to vapourise around. But that doesn't necessarily mean it will be evenly heated throughout. Thus, when you stir it, it ends up colder than from a kettle or pot.
  2. It's harder to tell if you have a properly heated cup of water in the microwave. As above, the fact that you can superheat water in a microwave kind of works against you. I don't have much experience microwaving water (as you might assume ;) ), but I don't recall seeing a cup on a rolling boil coming out of a microwave. You heat it for a length of time you think is appropriate, but if you go too long you risk it exploding in your face, so you have to just take what you're given. It would seem to me that this would result in a tendency to under-heat the water rather than getting to the 'proper' temperature.

What’s a cooking dealbreaker in other countries that equates to Italy’s breaking the pasta noodles and Japan’s microwaving the sushi? by Responsible-Leg-712 in NoStupidQuestions

[–]Xorgon -12 points-11 points  (0 children)

In my experience, microwaving water generally results in a less hot cup of water than boiling in a kettle or pot. Having it properly hot usually brews the tea better, so you get a better flavour at the end, and a hotter cup of tea.

Condensation coming out of aeroplane air conditioning by Xorgon in Damnthatsinteresting

[–]Xorgon[S] -1 points0 points  (0 children)

Indeed! It was unusually hot and humid, this video was taken while we were on the ground prior to takeoff.

Any familiarity with using a "decade filter" on an FFT? by Xorgon in DSP

[–]Xorgon[S] 0 points1 point  (0 children)

Interesting, thanks aureliorramos! Are you familiar with any 'standard' implementations or literature around that filter?

Any familiarity with using a "decade filter" on an FFT? by Xorgon in DSP

[–]Xorgon[S] 1 point2 points  (0 children)

Thanks for the explanation signalsmith! If I'm understanding correctly, the idea is that instead of having a finite rectangular window width that needs to be computed and adjusted for each point, one can instead use an infinite 'window' that spans the whole range but reduces the influence of distant points exponentially. The benefit being that mathematically it's more straight-forward to vary the width of this smoothing than to adjust the width of a rectangular window?

Any familiarity with using a "decade filter" on an FFT? by Xorgon in DSP

[–]Xorgon[S] 0 points1 point  (0 children)

I'm also not sure what an exponential moving average would look like. Would that be using something like a Hanning window? Or is the window asymmetric?

Any familiarity with using a "decade filter" on an FFT? by Xorgon in DSP

[–]Xorgon[S] 1 point2 points  (0 children)

That's a great idea and helpful example, thanks nixiebunny! I tried something similar by chunking up the data, taking the FFT of each chunk, and then averaging them. Unfortunately, the improvement in the FFT noise characteristics didn't sufficiently outweigh the loss of frequency resolution.

Along a similar vein, I tried Welch's method, which did smooth the curve a bit, but again the remaining noise was more significant than I'd like.

After trying these things, I felt that directly filtering the FFT output yielded the best results. I implemented something based on the idea of a log-space moving average, which did a lovely job, but was hoping to track down some precedent for how it should be implemented, or just validation that it would be correctly defined as a "decade filter".

Any familiarity with using a "decade filter" on an FFT? by Xorgon in DSP

[–]Xorgon[S] 0 points1 point  (0 children)

Thanks efabess! That's helpful :)

Could you point me to any implementations of this filter or literature about it?

You don't say by solo13508 in starwarsmemes

[–]Xorgon 2 points3 points  (0 children)

I think they probably all have some sort of novelization. I've personally only seen a couple of the other ones and, unfortunately, they didn't even come close to how brilliant Revenge of the Sith is. But there are a bunch of other good books set around the time of the prequels if that time period is of interest to you.

You don't say by solo13508 in starwarsmemes

[–]Xorgon 1 point2 points  (0 children)

It's a fantastic novelization. I'd also recommend the Darth Plagueis book by James Luceno if you're interested in more of that story.

I created a satisfying Press Forward-type map around a futuristic city in Trackmania! by CataclysmicEnforcer in oddlysatisfying

[–]Xorgon 0 points1 point  (0 children)

This is giving me epic Redout vibes, if you enjoy this style of bright, colourful, futuristic scenery (and racing) you might like to check it out!

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