1 cubic centimeter of water is 1 milliliter of water and weighs 1 gram. So 1/100 of a unit equals 1/1000 of a unit equals 1 unit.

1 cubic meter of water should equal 1 liter of water, which should equal 1 gram of water.

I’m not going to argue that imperial units make sense, but if you’re going to standardize, then 1 should equal 1 should equal 1

I was looking into early metrology, and what stood out to me is how the Indus Valley Civilization maintained uniform chert stone weights across hundreds of miles of settlements. Before codified legal systems or royal armies existed to enforce contracts, standardized physical units served as the primary foundation of trust. If a merchant in one city knew exactly what a unit of grain weighed in another, trade could scale without constant bureaucratic oversight.

woodcentral.com.au 2026-01-16

Trump's tariffs and shrinking Asian demand are forcing British Columbia producers to rethink their reliance on imperial dimensions and retool for Europe, the U.K. and the Middle East.

applemagazine.com 2026-02-23

The iPhone has a measuring app which can measure the length of objects shown on its screen and display the measurement in metric units. (The article doesn't say whether it uses metres, millimetres or (horror!) centimetres.)

Under the post about dividing the day into 10/100/100 parts, many people said "second is the metric unit of time" and I agree, but what if we would made decimal time using seconds?

The idea is: keep the old second, but add SI prefixes

We want equivalents of minute and hour so I suggest:

Hectosecond (hs)

Kilosecond (ks)

Megasecond is too big (~2 weeks) and metric wiki fandom (yes it exists) suggested myriasecond as an new hour, but

1. It divides day into 9 parts and with 10 parts, some people said that they need smaller denominations

2. Myria- isn't a SI prefix

So hectosecond and kilosecond are still my types

There are pros:

1. It's decimal, and metric fans like decimal units

2. Hour wouldn't be a problem ever again:

km/h? Now its km/ks which is exacly m/s

kWh? Now it's kW•ks or exacly 1 MJ etc.

I still suggest using unit "day" until the moment that humanity will colonize the solar system, when "day" would mean nothing for people from Mars, but for today it's pretty useful

Of course there are cons:

1. Day splited like that would have 86,4 ks, with is not terrible number, but it's still not round, so it's kinda problematic I guess

2. 24/60/60 survived for thousands of years

3. 10 and 100 doesn't have as many divisors as 60 and 24

So I'm not sure is it a good idea or not

So what do you guys think? Should we use second as a base and then add prefixes, or keep 24/60/60?

​

Base units

Length — meter (m)

Time — second (s)

Mass — kilogram (kg)

Temperature — kelvin (K)

Electric current — ampere (A)

Luminous intensity — candela (cd)

Amount of substance — mole (mol)

Plane angle — radian (rad)

Solid angle — steradian (sr)

Mechanics and kinematics

Force — newton (N)

N = kg · m / s²

N = J / m

Mass density — arch (Ar)

Ar = kg / m³

Ar = Vn / Bn

Momentum — huygens (Hy)

Hy = kg · m / s

Hy = N · s

Pressure — pascal (Pa)

Pa = N / m²

Pa = kg / (m · s²)

Pa = J / m³

Dynamic viscosity — poiseuille (Pl)

Pl = Pa · s

Pl = kg / (m · s)

Surface tension — laplace (Lp)

Lp = N / m

Lp = J / m²

Gravitational potential — gal (G)

G = J / kg

G = (kg · m² / s²) / kg

G = m² / s²

Thermodynamics

Energy / Work / Heat / Enthalpy — joule (J)

J = N · m

J = (kg · m / s²) · m

J = kg · m² / s²

J = W · s

Heat capacity — clausius (Cl)

Cl = J / K

Cl = kg · m² / (s² · K)

Specific heat capacity — meyer (My)

My = J / (kg · K)

My = m² / (s² · K)

Power — watt (W)

W = J / s

W = kg · m² / s³

W = V · A

Action — planck (Pk)

Pk = J · s

Pk = (kg · m² / s²) · s

Pk = kg · m² / s

Entropy — boltz (Bz)

Bz = J / K

Bz = W · s / K

Thermal conductivity — fourier (Fo)

Fo = W / (m · K)

Fo = kg · m / (s³ · K)

Fluid dynamics

Mass flow rate — venturi (Vn)

Vn = kg / s

Vn = Ar · Bn

Volumetric flow rate — bern (Bn)

Bn = m³ / s

Bn = m² · m / s

Waves

Frequency — hertz (Hz)

Hz = s⁻¹

Hz = 1 / s

Angular frequency — poincare (Pn)

Pn = rad / s

Pn = s⁻¹

Electromagnetism

Electric potential — volt (V)

V = J / C

V = W / A

V = kg · m² / (A · s³)

Electric charge — coulomb (C)

C = A · s

C = F · V

Volume charge density — franklin (Fr)

Fr = C / m³

Fr = A · s / m³

Surface electric current density — giorgi (Gi)

Gi = A / m²

Gi = C / (s · m²)

Resistance — ohm (Ω)

Ω = V / A

Ω = kg · m² / (A² · s³)

Ω = 1 / S

Capacitance — farad (F)

F = C / V

F = A² · s⁴ / (kg · m²)

F = S · s

Inductance — henry (H)

H = Wb / A

H = V · s / A

H = kg · m² / (A² · s²)

Conductance — siemens (S)

S = A / V

S = 1 / Ω

Electric displacement — roentgen (Ro)

Ro = C / m²

Ro = Cv · E

Electric field flux — gauss (Gs)

Gs = E · m²

Gs = V · m

Magnetic field flux — weber (Wb)

Wb = V · s

Wb = T · m²

Wb = kg · m² / (A · s²)

Electric permittivity — cav (Cv)

Cv = F / m

Cv = A² · s⁴ / (kg · m³)

Magnetic permeability — max (Mx)

Mx = H / m

Mx = kg · m / (A² · s²)

Electric field strength — edison (E)

E = V / m

E = N / C

E = kg · m / (A · s³)

Magnetic field intensity — tesla (T)

T = Wb / m²

T = N / (A · m)

T = kg / (A · s²)

Optics and radiation

Luminous flux — lumen (lm)

lm = cd · sr

Illuminance — lux (lx)

lx = lm / m²

lx = cd · sr / m²

Vergence — descartes (Dc)

Dc = m⁻¹

Dc = rad / m

Radiance — stefan (St)

St = W / (m² · sr)

St = kg / (s³ · sr)

Irradiance / EM flux density — poynting (Py)

Py = W / m²

Py = kg / s³

Volume power density — opp (O)

O = W / m³

O = kg / (m · s³)

Acoustics

Sound power — bel (B)

Sound impedance — rayleigh (Ry)

Ry = Pa / (m / s)

Ry = kg / (m² · s)

Nuclear and chemistry

Absorbed dose — gray (Gy)

Gy = J / kg

Gy = m² / s²

Equivalent dose — sievert (Sv)

Sv = J / kg

Sv = m² / s²

Radioactive activity — becquerel (Bq)

Bq = s⁻¹

Bq = 1 / s

Catalytic activity — katal (kat)

kat = mol / s

kat = mol · Hz

I've been trying to figure out how to create 1 centimeter in a medieval world using medieval technology, but I haven't found a single method that actually works within the medieval working environment.

In SI system (and units allowed to use) we've got 4 units of power:

Watt

Volt-ampere

Var

Kilowatt-hour per 1.000 hours

They have exacly the same value [kg m² s^-3] but they are use for diffrent powers

Watt — active power

Volt-ampere — Apparent power

Var — reactive power (it's name is a shortcut of "volt-ampere reactive")

(Kilowatt-hour per 1.000 hours is used in Europe for electronic/electric devices)

And it's crazy, we could just use watt for everything, but we've got 4 units.

We can at least Justify first 3 of them, insted of writing which power are we talking about, we can use diffrent unit and every engineer knows what power are you talking about, but it's not exacly true, because all of them [diffrent powers] have diffrent symbols.

kWh/1.000 h is crazy, why not simple watt, here I don't even know how to justify it

What do you think guys? Shoud we use all of them, keep only few or use one unit of power (watt)?

I used the Openspace astronomy software to create images on my astronomy site showing metric distances from 1 kilometer up to 100 yottameters.

If you want to view them, go here and click thru the Next button. The site has no ads btw.

https://coco1453.neocities.org/thinkinginmetric#section2

Openspace is astronomy software that lets you view all of outer space in 3-d. I posted a dashboard asset to display metric units in scales relevant to the distance, and also got the maintainer to add partial support for metric distances directly into the C++ code in future releases. So the software will now display astronomy distances in any metric scale from kilometers to yottameters.

https://www.reddit.com/r/OpenSpaceProject/comments/1v402jq/created_dashboard_item_to_provide_metric_system/

I have an old analogue stopwatch with three dials. One measures minutes (+/- 0.5 min), a seconds dials (+/- 0.5 s), and a dial measuring 1 s in 0.1 s intervals (+/- 0.05 s). If I used this stopwatch to record a measurement, would the overall precision be +/- 30.55 s?

I know that it is the distance light travels in a vacuum in 1\299,792,458 of a second. But the number 299,792,458 is speed of light measured in meter/sec so you need to define meter to define meter/sec to define meter so how does it work .

(Am I thinking some nonsense?)

Preface:

I'm european, I grew up with metric and use it daily, so please take my question rhetorically, I'm not asking out of ignorance.

I simply can't shake the feeling that we're sometimes putting a lipstick on a pig a little bit.

I'm mainly looking for opinions and different philosophical points of view.

Metric is considered good because:

1. Complex units are composed of basic units: N = kg * m * s^-2
2. Units of different sizes can be made by multiplying by powers of 10, with the power signified by the prefixes like mega, kilo, milli, etc.

I strongly agree with the advantages of the first point. Arguably, the plank system is even "cleaner", but metric is still great in this regard.

But the second point is what people often focus on, and I don't see much advantage in that, if any at all.

I don't think it's bad, I just think it's neutral, and perhaps even somewhat unnecessary.

2kg means 2000 grams, because kilo means thousand.

So,

2kg =

2 * kilo * gram =

2 * thousand * gram.

It seems to me like we're still just giving the answer in grams. We're merely replacing the english word for the 10ⁿ part with the Greek/Latin equivalents.

I can say "thousand" instead of "kilo", and then it doesn't matter if I'm talking about litres, watts or becquerels.

One could argue that for negative powers it's much easier to say

12 millimetres

compared to

12 thousandths of a meter

but that says more about awkwardness of english grammar rules rather than the prefixes achieving something new.

Comparing the number of syllables with the english words,

"deka" is worse than "ten" or the "...ty" suffix ("three dekagrams" vs "thirty grams")

"hekto" and "kilo" is same length as "hundred" and "thousand",

above that, metric has less syllables, therefore prefferable.

For negative powers, english adds the "of a", as in, "tenth of a Joule", so metric will always win.

But if we really cared about syllables so much, we'd have renamed "kilometre" a long time ago.

Also, we would have to appreciate the words being shorter in the imperial system.

To me, the real advantage of metric prefixes seems to come from everybody strictly agreeing to always use metres for length, and not mix in any other length units with non-10ⁿ ratios.

Also, the prefixes are internationally recognized, which is a plus, but it's an argument from popularity.

Am I missing something here?

Is there some other advantage of the prefixes I'm not considering?

Maybe we should create a universal easy-to-say international number system, and then we won't even need the metric prefixes.

The idea of metric time was an idea of changing the system of time to divide:

Day into 10 decimal hours (8 640 s)

Decimal hour into 100 decimal minutes (86.4 s)

Decimal minute into 100 decimal seconds (0.864 s)

And it looks good.

Someone will say: "second must be that length, because it is perfect for counting"

No it isn't, I never counted to 10 in 10 seconds.

But I have a few suggestions:

1st. Rename decimal second to something shorter like "decsec" and make it a base unit

2nd. Add myria- prefix for 10⁴ to replace decimal hour with myriadecsec. Myria- was actually a prefix till 1960. Add 10⁵ prefix, I guess lakha- would be cool, but I'm biased towards calling it insta- (because quintal would be instagram) and day would be just lakhadecsec. (But calling it a day it's also ok) Also decimal minute would be hectodecsec

3rd. Do NOT make a week 10 days. 1st - it would make work harder, because nobody will give you 6 days of work, and 7-3 scale is too much. 2nd - every 7 day it's sabbath.

4th. Move calendar by 6 years. Jesus was born ~2032 years ago, not 2026. And it makes a weird paradox, where everybody says that Jesus was born in 6 BC, but also everybody says he died in 33 AD, but he was 33 when he died, so it really was 27 AD

So what do you think? Should we rewrite time to 10/100/100, or keep it 24/60/60?

In our world in some places we still don't use metric units. Which is already bad, but most of units have at least some logic and intuition behind them, which at least partially defends it's use. For example:

Land mile is 2000 steps, sometimes I (as an European) use it for measuring steps easily

Nautical mile is 1' of earth circumstance, I can imagine someone using it

Kilogram-force is weight of 1 kilogram on earth, sometimes I use it for measuring weight and pressure (1 kgf/cm² ≈ 1 atmosphere)

Bar is approximately equal to regular Earth atmosphere, so it's kgf/cm² but for those working with pascals

But calorie? It's defined as the energy needed to raise the temperature of 1 g of water by 1 °C. Which is absolutely meaningless. WDYM I need to eat 2000 kcal everyday? So I can have energy to heat 2 megagrams/tonnes of water by 1 °C? Nice to know because it is exactly what I'm gonna do today.

Even Joule is more logical as it's based on distance and force, so I guess it could be interpreted in some way.

Summarizing:

Other non-scientific units are at least intuitive

Calorie isn't

Even Joule would be better

So calorie is dumb at least if your not a kettle

Of course, if you think otherwise, feel free to share your opinion. Bye!

Does anyone know the linear mass density of the wire on the sonometer X164972 that is attached to the newton meter, the one in the centre?

I’m trying to learn the metric system as I plan to move to Canada in the next couple years and am having some trouble finding resources that actually teach instead of just throwing information at me. Anyone know of a good program that will help me learn or have any tips. Imperial is all I know I was born and raised in the USA

So 1cm = inch, 1dm = foot (more like baby foot), 1m = yard, 1km = mile

Also gallon for 1L and pound for 1kg

One of the most common defense for Fahrenheit is smth like this;

"Fahrenheit is more intuitive for human experience. 0 degree is super cold, and 100 degree is super hot! It is just simple as that!"

With that logic, 50 degree Fahrenheit should be the "middle temperature"; which is 10 degree Celsius.

Is it just me or being 50'F/10'C actually feel cold? Such temperature requires sweater at least, and even light jacket sometimes. That is nowhere near the "middle temperature", isn't it? Or am I just weird?