• Tlaloc_Temporal@lemmy.ca
    link
    fedilink
    English
    arrow-up
    2
    ·
    20 days ago

    Sure, I agree with most of that. Dwarf planets not being planets feels intentionally confusing though, and the definition is basically Major/Minor planet anyway. A planet having hydrostatic equilibrium is such an elegant and applicable limit, yet the current definition specifically counts only bodies that clear orbits (how is poorly defined) around this star. It’s a bad definition in several ways, and many astronomers have already complained about this. Many use planet anyway, particularly planetary scientists.

    It’s all about how useful the word is, and putting the limit at our star and a vague idea being the biggest thing in one general area feels more like it’s gatekeeping the word “planet” rather than facilitating understanding or discriminating something useful. Planets can change class simply by drifting closer or farther away from the sun, or even be temporarily demoted by a rogue planet.

    most would agree that the best definition would be the one that has the biggest consensus amongst biologists, and maybe more precisely microbiologists.

    This is precisely the part I disagree with. Consensus isn’t truth, and better definitions are likely possible. Not that consensus even exists here, the specific definition of life is controversial and several definitions are used in different areas. Homeostatic reproducers, replicators, entropy pumps, chemical system that evolve; it’s almost as bad as double-slit interpretations.

    And most such definitions you’d find would include “self-replication” as a necessary trait.

    Replication? Sure. Self-replication? That’s either an incredibly arbitrary limit seeminly designed to specifically exclude viruses, or isn’t applicable to anything except perhaps the entire tree of life as a whole. Where is the line of “self” drawn? As a human, you can’t replicate yourself, you need other organisms to collect energy for you and to make some proteins for you, and a sexual partner. Tapeworms need their hosts to digest food for them; cuckoos need other birds to feed and raise their chicks; E.coli needs other organisms to feed them and maintain a suitable environment; clonally transmissible dogs need another dog for all nutrients, and protection; and viruses need cells to provide the replication hardware. Some viruses even have some of the genes necessary for DNA copying and protein synthesis, and can be infected by smaller viruses themselves.