Imagine being told that your TV had an aspect ration of ":16"

We kind of have that with people talking about a screen or image being "2k" and then expect you to infer what the actual resolution and aspect ratio is from context.

4:3 only makes sense to you because you know which is length and width a priori. I for example, always have to recheck that. So if it was written as 1.33 or 4/3 it makes the same difference to me, and is similar in that way to dB

Ratio is just a single number. 4:3 can be expressed as 1.3333~ and it just says how much bigger one number is compared to another.

RE: Yes, I was able to read and understand the article. I also have 8 years of EE. Ratio is still a single number in the end. You can have an actual size of a monitor 1600 x 1200 and the ratio of sides is 1600/1200, which is just a single number. You can express it in multiple ways. You still need at least one size + understanding of what the aspect ratio is used to describe in a particular situation (units (mm, px, ...), ...) to be able to calculate the complete dimensions of a monitor screen.

Same issue with % or ppm, or whatever.

You always need a defintition to understand what the numbers are abstracting in any particular situation.

Nothing better than spending hours encoding something, only to discover you got one of those wrong.

Yep you have dB for a ratio, and dB SPL as a physical unit. Just as the article says.

And yeah, the issue is when people forget to use physical units, like if they say it's 30 degrees outside amd not saying C F or K or latitude.

The historical context is a bit meaningless as well since the main application for the OG dB is 101 classes.

Stop saying "one of two possibilities". It isn't. A dB is a power ratio. The fact that you can describe that in terms of voltage ratio is a simple reflection of the fact that power ratios can be described as a voltage ratio squared. When talking about voltage ratios directly from dB you're just short circuiting the necessary square root.

Coulomb? In a discussion about units, leaving out the degree word or symbol made me initially try to parse it as that you must mean it literally, though context quickly makes clear that isn't the case ^^'

> Look at Fahrenheit, for example. I’m American, and I still think it’s absurd, but because I’m extremely used to it, it feels natural.

What do you find absurd about Fahrenheit?

If it is that its 0 point is not absolute 0 then I think you can make a good case, at least for scientific work. It's a bit harder to make the case for absolute 0 being the 0 point a scale for ordinary day to day use since all temperatures most people deal with will be 3 digit numbers (and making you degree large won't help because people will still need 3 digit number--they just won't be integers any more).

If you find it absurd compared to Celsius then I think it is hard to make a convincing case. They are both scales with a 0 point way above absolute 0, differing only on where they put their 0 point and the size of the degree. (They originally differed on direction, with Celsius putting 0 at the boiling point of water and setting the degree size so that water froze at 100, but Celsius soon came to his sense and flipped so the numbers went up as it got hotter).

Fahrenheit set 0 at the coldest temperature he could make in his lab and tried to set 100 at body temperature. Celsius (once he got the direction fixed) set 0 at water freezing and 100 at water boiling.

That gives Fahrenheit a smaller degree and puts the range of temperatures most people deal with most of the time above 0.

Celsius made it easier to memorize two temperatures that are very significant in many human activities, namely the freezing point of water and the boiling point of water (although the latter is probably less important...generally most people only deal with boiling water when they are trying to boil water and don't need to care about the temperature. It's not like freezing which can happen naturally and so people often need to monitor temperature to find out if there is danger of freezing).

But that 0 point in Celsius means that a lot of people have to regularly deal with negative temperature which is a little annoying.

The metric system chose Celsius, but I've not been able to find any compelling technical reason for that. A metric system with Fahrenheit would have fine too.

Note that unlike mass, length, area, and volume units pre-metric systems generally only had one temperature unit. There was nothing in temperature like miles, yards, inches, feet, furlongs, etc. for length and gallons, pints, cups, etc. for volume. A system that went with one single length unit (the meter) and one single volume unit (the liter) and then derived larger and smaller units from those using consistent ratios and prefixes that were the same across different types of units was a massive simplification.

I asked an LLM why metric went with Celsius and got a lot of circular reasons. For example it cited that various thermodynamic forumals would not work with F degrees because the Boltzman constant is defined in the SI system using K. But the Boltzman constant is defined that way because SI uses the metric system. In an F based metric system the Boltzman constant would be defined in R and everything would work fine.

The non-circular reasons it suggested were also not satisfactory. One was that C was more common than F in Europe at the time the metric system was created, which technically does answer the question I asked but then raises the question of why C became more common pre-metric.

It also suggested that having water freeze at 0 and boil at 100 fits in better with a decimal system which doesn't really make a lot of sense.

As for why C became more popular than F pre-metric it suggests that the 0 and 100 points were easier to reproduce. Fahrenheit's choice of body temperature for the 100 point was definitely a mistake as it is too fuzzy (it was even dumber than metric's initial choice for the meter as 1/10000000th of the distance from the distance from the North Pole to the equator along the meridian passing through Paris).

Freezing and boiling of water do take some care to use (you need to control pressure and contaminants) but are going to be more consistent that body temperature.

But there is no reason I can see that the fuzziness in Fahrenheit's 100 point couldn't have been fixed by simply changing the defining points from 0 and 100 to water freezes at 32 and boils at 212. Yes, it is not as easy to memorize as 0 and 100 but does let us have a scale where most temperatures dealt with by most people most of the time are 2 or 3 digit positive integers.

this

if a TV seller went bonkers and only said "it's 10:16", can you guess the actual size of that TV?

But the base value is well defined, qualitatively (“a quiet room”), which is fine for what we are talking about which is “experienced loudness”. Once you go past log(3) it really doesn’t matter what the noise was at log(0).

Nothing to do with decibels but the thermostat on the water heater might be set too high. If one lowers the overall temperature the ratio of cold to hot will balance.

We have a unit for that. It's dBm and very easy to grasp. 0 dBm is 1 mW, every 10 dBm is an order of magnitude more (10 dBm = 10 mW).

dB is only confusing if people omit which quantities they are relating. If it's clear like in the case of dBm which relate to 1 mW, it's an awesome tool.

You can't take the log of a quantity with units like watts. It would be log of some ratio of powers, and then it doesn't matter what unit of power you use because they cancel out. Instead, it matters what the denominator in the ratio is so we're back at needing something confusing like dB :(

That would be dishonest. You don’t adjust input power - you adjust attenuation

EDIT if you did let’s say approximate power, or measure and present the consumed power (as some systems do) you would still be in a situation about how to present this data. Do you present your users with a simple 1-10 (logarithmic) or a 10 digit display which sweeps over vast ranges of uninteresting values.

If you opted for a more compact scientific notation … well guess what that’s also logarithmic but in two parts LOL

This doesn't make any sense to me. Isn't this completely backwards? Wouldn't this behavior be expected from a logarithmic knob, and not a linear knob? I know what a logarithmic curve looks like, it rises quickly and then it tapers off, exactly the behavior you describe. But then you attribute that to a lineae knob! The parent comment confuses the hell out of me too, I am just really not putting 2 and 2 together here.

No I’ve never had one of those LOL

Pots do log and lin scales but they only have a limited angular range.

A properly designed volume control affects the sound power output logarithmically, but is labeled linearly (with 1-11 or 0-1 or something like that) to reflect how humans perceive the effect.

People in the field get this wrong all the time — for instance, the volume control on ChromeOS appears to be a linear multiplier, yielding a control with huge perceived steps in the output between 0 and 3, and negligible perceived change in the output between 7 and 10.

I suspect that the confusing design of the dB contributes towards how often such mistakes get made.

It's not that arcane, it's referenced to a sound pressure level of 1 pascal. Which, yes, is still arbitrary in that it all ends up back at the arbitrary values of things like metres, seconds, kilograms, etc.

Volts per pascal might make sense in some contexts (like your input buffer power supply), but log volts per pascal makes sense in others, particularly for audio applications where you stack gains and attenuations onto an already-logarithmic domain.

Sure, log scales are done quite often with SI prefixes for absolute (non-ratio) data that doesn't have a standard reference (which is the case for component datasheets). But dB can be more convenient when you want to present logarithmically-varying ratios, particularly for gain or attenuation (which are relative to unity) or when you have a commonly-accepted reference of your absolute data that is a useful standard to compare against. This gives your 0-point typically at the top or bottom of the axis a standard meaning across all graphs in a particular domain, and then datapoints typically have about a couple significant digits above the "." of the dB datapoint that you generally are interested in.

I grew up in a metric country too, but still it is much easier to speak of 0 to 100 or so of decibels with decades of power being in increments of 10 rather than having to say 10, 100, 1k, 10k, 100k, 1M, 10M, 100M, 1G, 10G, etc of gain or 100m, 10m, 1m, 100u, 10u, 1u, 100n, 10n, 1n, 100p, etc of attenuation. Especially when gains or attenuations would be multiplied, then decibel makes it really easy to just add and or subtract in decibels. For an example, a signal with 10M of gain (or that is 10M times some reference) that gets passed through 100m attenuation would result in a 1M signal (which takes my brain some fiddling with those letters and numbers), but in decibel we are just dealing with simple addition & subtraction: 70 dB minus 10 dB equals 60 dB.

No, changing definitions was exactly how we ended up with SI units. That was a very good (and necessary) thing and definitely not the sky falling down.

This mindset is why the US is still using barley seeds as a standardized unit of measure.

Glad we never changed them and still drink in hogshead, use the original foot reference, and never resolved what base is a megabyte. ;)

At first I was going to contradict you but then I realised 10 mm of rain is actually a measure of volume or mass, corresponding to 10 kg, right?

And of course, people use it mainly as a rate, i.e. 10 kg per hour, or per four hours, or six hours, or 24 hours.

And it gets worse when we start talking about snow, the density of which can vary a lot!

Could you elaborate on this?

If 10mm rain falls, and you have an open collection container, then the depth of the water in that container would be more, less, or the same as the thickness of the branch?

Moles still work without knowing that atoms exist. The quantity being called "amount of substance" not "number of things" reflects that. However, they are still a redundant over-complicated legacy that doesn't need to exist.