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Joined 2 years ago
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Cake day: June 23rd, 2024

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  • If you have a meter on the wall that says “height”, height exists outside the meter too. Height is a property of every point in the room. For any point, you can follow a horizontal line to the corresponding point on the meter, read the number, and that’s the height at that spot. Also, every point on a horizontal plane will have the same height: all points on the kitchen counter will have a height of about 83 cm, every point on the ceiling a height of about 230 cm. The meter is basically an axis and you’re using it to measure how high various points throughout the room are.

    Then people realized you can do it in 2 or 3 dimensions and represent data.






  • In graphs, how high and how far right a point is describe its properties. Like the phase diagram of water: the further right you are, the higher the temperature, the further up you are, the higher the pressure. At each point, water would be in a certain state, which is plotted on the graph as colored areas.

    Wikimedia: Phase_diagram_of_water_simplified.svg

    Axes are markings that only help measure how hot and pressurized a certain point is. You are probably at around 100 kPa (atmospheric pressure) and 295 K (room temperature) so you experience liquid water. Even though the vertical axis is labeled “Pressure”, that does not mean pressure only exists on that line; same for the temperature axis. These meet at absolute zero in near-vacuum. Even though you pr But you might prefer axes at 0 °C (the left vertical red line) and 1 atm (the horizontal red line).



  • If you’re at the intersection of time and space, it means you are anywhere in spacetime: you exist, will exist, or have existed at some place in the universe. Yes, the “intersection of time and space” is all of spacetime, much like the “intersection of latitude and longitude” is the entire surface of the Earth because that’s the set of points for which both latitude and longitude are defined.

    We can put the 4 axes of spacetime (𝑥-, 𝑦-, 𝑧-displacement* and time) anywhere we want to define a point 0 (𝑥=0 m, 𝑦=0 m, 𝑧=0 m, t=0 s) where they meet (and that’s symbolic too, graphs where axes don’t cross at 0 are common and often useful but sometimes purposefully misleading). This is probably what you meant. Astronomers might put it into the infinitesimal universe at the time of Big Bang (and align the space axes to the cosmic microwave background as time passes). Islam scholars might put it on 622-06-16 CE at Kaaba in Mecca. As far as GPS satellites are concerned, the zero point is 1980-01-06 00:00:00 UTC at the center of the WGS-84 ellipsoid (and the space axes are locked to the rotating Earth as time passes).

    * Diagrams of spacetime are limited to 1 or 2 space axes because they exist as representations of the 4D concept in space (2D (𝑥𝑦), aka plane, or 3D (𝑥𝑦𝑧)) only.


  • Nope.

    The question is as nonsensical as “what if you’re on the intersection of latitude and longitude?”, as if longitude only existed on the equator and latitude on the Prime Meridian. All points on Earth have longitude and latitude, and are the intersections of their respective local meridian and local circle of latitude (aka “parallel”). Not necessarily the Prime Meridian and the equator, that’s only for “point zero” of Earth. These lines are often in the center of maps and can be thought of as “axes” but axes only mark values, they aren’t the quantities the values represent.

    If you’re at the intersection of time and space, it means you are anywhere in spacetime: you exist, will exist, or have existed at some place in the universe.




  • denary

    Yes, that’s technically the correct 10th term in the Latin-based unary-binary-ternary-… sequence but nobody calls it that… I wondered what your mother tongue is but I couldn’t find a language in which the preferred name for “decimal system” would use den- rather than dec-, dek-, des- or a completely different word. Not to mention you avoided senidenary for obvious reasons…