I like metric because it’s structured around an abstract amount. Even something like Celsius is pretty abstract, because the freezing and boiling point of water changes depending on the atmospheric pressure. The measure of a second? Why is a second, 1 second long? Why is it 1/60th of 1/60th of 1/24th of a day?
There’s other stuff based on seconds too, like Hertz, which is literally “cycles per second”
I like to think about how abstract these things are, because if we were to ever try to communicate with a truly alien race, we couldn’t really use numbers, because their base numbering system would be different than ours, their symbols for numbers would be different, their entire understanding of math and how to calculate stuff could be wildly different, possibly because they understand things we do not. We couldn’t even say to them to communicate on a specific frequency of EM, because that frequency is based on Hertz, which is based on seconds, which is based on ??? IDFK (neither would they).
We base everything we know on the world around us, and that’s entirely unique to earth. We make so many assumptions about how things are because we’ve only ever experienced life on this planet.
The only thing that kind of makes sense is how many days of the year there are, because it’s based on solid science about our solar system. It’s still unique to earth, but at least it makes sense on a larger scale. Everything else? Who the hell knows. Why is a meter as long as it is? Who defined this? Why? What abstract Earth-based thing was this based on that other societies of individuals would have no point of reference to relate to?
It’s wild we’ve made it this far, to be honest.
Anyways, I kind of got sidetracked… I guess all I’m really trying to say is that metric makes more sense than whatever the USA is doing. Even if it’s just as abstract in its conception.
I’d assume that if we are ever communicating with aliens and trying to figure out each other’s way of expressing numbers and doing math, dimensionless constants like pi, Euler’s number (e), the fine structure constant, etc. will be important first steps. As you say, our units of measure are purely human inventions. But the ratio of a circle’s circumference to its diameter is the same no matter what units you use to make the measurement.
…which is based on seconds, which is based on ??? IDFK (neither would they)
“The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical
value of the caesium frequency, ΔνCs, the unperturbed ground-state hyperfine
transition frequency of the caesium 133 atom, to be 9 192 631 770 when expressed in the
unit Hz, which is equal to s−1.”
https://www.bipm.org/en/si-base-units/second
I don’t think that was the idea when the second was created.
The solar rotation cycle is naturally divided into 365 rotations of Earth (give or take), each daily rotation was divided into 24 segments called hours, each hour was further divided into 60 units called minutes, and each minute was then further divided into 60 units which we call seconds.
In the modern era, we have refined how we measure a second by a very stable natural phenomenon, the emissions of cesium (which we also refer to as an “atomic” clock). But we got there first by dividing one of Earth’s rotations by 86400. It just so happens that 9 192 631 770 oscillations from cesium also equals 1/86400th of one rotation of Earth.
Additionally, neither a “second” nor even “one rotation of Earth” would have any meaning to someone who has never been to earth before.
It doesn’t matter how these units were originally defined. They have all been redefined as science progressed. As long as you relate the arbitrary unit to a constant it can be translated.
Except an alien species wouldn’t know what cesium is… We would need to represent it to them as it’s molecular makeup, which is the only absolute representation of it, and would they know what a proton/neutron/electron are? Would they have a deeper understanding of the physics, and thereby have a different understanding of what we consider to be quantum particles?
We only generalize protons, elections and neutrons because we don’t really know what those things are made up of. Maybe they do, so when we show them our representation of it, would it be too rudimentary for them to comprehend what we mean?
There’s still a lot we don’t know. And these are the kinds of questions that tickle my brain.
their base numbering system would be different than ours, their symbols for numbers would be different, their entire understanding of math and how to calculate stuff could be wildly different
The neat thing about math is it’s built upon universal truths that exist independently of how you describe them. 1+1=2 regardless of how you represent those numbers. Even among humans we have plenty of different ways of describing numbers.
Also, the best thing about science is that physics works the way it does regardless of how you describe it. An atom of hydrogen will always have the same spectral peaks, regardless of what units you describe those peaks in.
It’s these kinds of things we consider when trying to communicate with aliens. Take a look at:
These messages will probably never be received, even if there is intelligent life out there. But if something intelligent does find these messages, they will probably determine they are artificial, and hopefully manage to decode some of it.
See, this is all fascinating for me. I love this stuff.
It’s also a good exercise in recognizing the assumptions we make every day. I’m trying to get to a point where I can articulate my thoughts and I don’t have to struggle through the curse of knowledge.
I think one useful comparison would be to convert their measurement of the speed of light to our measurement and vice versa. They will use different units of distance and time, but the values themselves will be proportional unless they live in a black hole.
That could work for velocities, but any measure of distance is based on our notion of time, like “light year” (the distance light can travel in one rotation of the Earth around the sun), which is relative.
Even an AU is the distance from Earth to our sun.
To be fair, we don’t really have another point of reference with which to measure stuff.
A good way to portray distance could be a blip the length of time it would take light to travel that far. Like an RF signal that lasts as long as it would take for light up travel from one edge of an object to the other edge of the object.
… It’s a difficult problem to try to solve even as a mental exercise.
All units of measure are abstract.
I like metric because it’s structured around an abstract amount. Even something like Celsius is pretty abstract, because the freezing and boiling point of water changes depending on the atmospheric pressure. The measure of a second? Why is a second, 1 second long? Why is it 1/60th of 1/60th of 1/24th of a day? There’s other stuff based on seconds too, like Hertz, which is literally “cycles per second”
I like to think about how abstract these things are, because if we were to ever try to communicate with a truly alien race, we couldn’t really use numbers, because their base numbering system would be different than ours, their symbols for numbers would be different, their entire understanding of math and how to calculate stuff could be wildly different, possibly because they understand things we do not. We couldn’t even say to them to communicate on a specific frequency of EM, because that frequency is based on Hertz, which is based on seconds, which is based on ??? IDFK (neither would they). We base everything we know on the world around us, and that’s entirely unique to earth. We make so many assumptions about how things are because we’ve only ever experienced life on this planet.
The only thing that kind of makes sense is how many days of the year there are, because it’s based on solid science about our solar system. It’s still unique to earth, but at least it makes sense on a larger scale. Everything else? Who the hell knows. Why is a meter as long as it is? Who defined this? Why? What abstract Earth-based thing was this based on that other societies of individuals would have no point of reference to relate to?
It’s wild we’ve made it this far, to be honest.
Anyways, I kind of got sidetracked… I guess all I’m really trying to say is that metric makes more sense than whatever the USA is doing. Even if it’s just as abstract in its conception.
I’d assume that if we are ever communicating with aliens and trying to figure out each other’s way of expressing numbers and doing math, dimensionless constants like pi, Euler’s number (e), the fine structure constant, etc. will be important first steps. As you say, our units of measure are purely human inventions. But the ratio of a circle’s circumference to its diameter is the same no matter what units you use to make the measurement.
I like you.
These are all good points. Thank you.
“The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical value of the caesium frequency, ΔνCs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s−1.” https://www.bipm.org/en/si-base-units/second
I don’t think that was the idea when the second was created.
The solar rotation cycle is naturally divided into 365 rotations of Earth (give or take), each daily rotation was divided into 24 segments called hours, each hour was further divided into 60 units called minutes, and each minute was then further divided into 60 units which we call seconds.
In the modern era, we have refined how we measure a second by a very stable natural phenomenon, the emissions of cesium (which we also refer to as an “atomic” clock). But we got there first by dividing one of Earth’s rotations by 86400. It just so happens that 9 192 631 770 oscillations from cesium also equals 1/86400th of one rotation of Earth.
Additionally, neither a “second” nor even “one rotation of Earth” would have any meaning to someone who has never been to earth before.
It doesn’t matter how these units were originally defined. They have all been redefined as science progressed. As long as you relate the arbitrary unit to a constant it can be translated.
Except an alien species wouldn’t know what cesium is… We would need to represent it to them as it’s molecular makeup, which is the only absolute representation of it, and would they know what a proton/neutron/electron are? Would they have a deeper understanding of the physics, and thereby have a different understanding of what we consider to be quantum particles?
We only generalize protons, elections and neutrons because we don’t really know what those things are made up of. Maybe they do, so when we show them our representation of it, would it be too rudimentary for them to comprehend what we mean?
There’s still a lot we don’t know. And these are the kinds of questions that tickle my brain.
The neat thing about math is it’s built upon universal truths that exist independently of how you describe them. 1+1=2 regardless of how you represent those numbers. Even among humans we have plenty of different ways of describing numbers.
Also, the best thing about science is that physics works the way it does regardless of how you describe it. An atom of hydrogen will always have the same spectral peaks, regardless of what units you describe those peaks in.
It’s these kinds of things we consider when trying to communicate with aliens. Take a look at:
https://en.wikipedia.org/wiki/Pioneer_plaque
https://en.wikipedia.org/wiki/Voyager_Golden_Record
https://en.wikipedia.org/wiki/Arecibo_message
These messages will probably never be received, even if there is intelligent life out there. But if something intelligent does find these messages, they will probably determine they are artificial, and hopefully manage to decode some of it.
See, this is all fascinating for me. I love this stuff.
It’s also a good exercise in recognizing the assumptions we make every day. I’m trying to get to a point where I can articulate my thoughts and I don’t have to struggle through the curse of knowledge.
I think one useful comparison would be to convert their measurement of the speed of light to our measurement and vice versa. They will use different units of distance and time, but the values themselves will be proportional unless they live in a black hole.
That could work for velocities, but any measure of distance is based on our notion of time, like “light year” (the distance light can travel in one rotation of the Earth around the sun), which is relative.
Even an AU is the distance from Earth to our sun.
To be fair, we don’t really have another point of reference with which to measure stuff.
A good way to portray distance could be a blip the length of time it would take light to travel that far. Like an RF signal that lasts as long as it would take for light up travel from one edge of an object to the other edge of the object.
… It’s a difficult problem to try to solve even as a mental exercise.