Black Holes .

Discussion in 'Astronomy, Exobiology, & Cosmology' started by river, Aug 11, 2019.

Thread Status:
Not open for further replies.
  1. davewhite04 Valued Senior Member

    Messages:
    4,884
    What?
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. DaveC426913 Valued Senior Member

    Messages:
    14,760
    Making a silly statement you know to be false.
     
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. davewhite04 Valued Senior Member

    Messages:
    4,884
    How do you know I think it is false in the moment I thought of it? Are you a troll?
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. davewhite04 Valued Senior Member

    Messages:
    4,884
    The definition of troll on wikipedia discriminates against people making mistakes. Your all trolls you just don't know it.
     
  8. DaveC426913 Valued Senior Member

    Messages:
    14,760
    So, you're admitting that you think the sun is a planet.
     
  9. James R Just this guy, you know? Staff Member

    Messages:
    34,678
    Read our site rules. There's a section that explains it. You can find the rules in a sticky thread in the Site Feedback subforum.

    Are you telling us that you seriously think/thought the sun was a planet? Define "planet" for me, please.
     
  10. davewhite04 Valued Senior Member

    Messages:
    4,884
    No.
     
  11. davewhite04 Valued Senior Member

    Messages:
    4,884
    Did you read my post?
     
  12. RainbowSingularity Valued Senior Member

    Messages:
    5,232
    third hole to my planet ...

    ode to the black hole sun
    you are my schwarzschild radius

    pure essence ...

    Please Register or Log in to view the hidden image!

     
  13. DaveC426913 Valued Senior Member

    Messages:
    14,760
    Could we get back on topic please?
    If DW4 wants to know bout trolling, and/or whether the sun is a planet, he can start up a new thread on it.
     
  14. RainbowSingularity Valued Senior Member

    Messages:
    5,232

    Please Register or Log in to view the hidden image!

     
  15. Write4U Valued Senior Member

    Messages:
    14,932
    Not by our common definition of a planet. But it is a conceptually limiting definition.
    The sun does in fact follow an orbit, one of the requirement to qualify as a planet (of the Milky Way.)
    https://www.universetoday.com/18028/sun-orbit/
    https://en.wikipedia.org/wiki/Definition_of_planet
     
    Last edited: Aug 25, 2019
  16. RainbowSingularity Valued Senior Member

    Messages:
    5,232
    The sun is a moon of the milky-way galaxy orbiting a super massive black hole ?

    question

    2 black holes orbiting each other...
    which one is mooning the other ?

    pull your Event horizon up
    i can see your schwarzschild radius

    Please Register or Log in to view the hidden image!

     
    Write4U likes this.
  17. DaveC426913 Valued Senior Member

    Messages:
    14,760
    It is not conceptually limiting; it is conceptually clarifying.

    You cannot possibly be serious about this logic.

    A firetruck has wheels.
    An office chair also has wheels.
    Therefore, it is conceptually limiting to make a distinction between two things that both have wheels.
     
  18. Write4U Valued Senior Member

    Messages:
    14,932
    No, but clarifying that only firetrucks have wheels is limiting, you see. It leaves out a bunch of rolling stock that also uses wheels.

    p.s. note I used the phrase "conceptually limiting" in reference to the only reference that planets are orbiting objects. Fact is that within the confines of the universe, "everything" is orbiting something else, from sub-atomic particles to galaxies.

    I see that as conceptually expanding the concept of "being in orbit" around something else.
     
    Last edited: Aug 25, 2019
  19. DaveC426913 Valued Senior Member

    Messages:
    14,760
    Nobody said that only firetrucks have wheels.

    You are confusing supersets and subsets, and are generating only confusion and ambiguity.

    This is a ridiculous, argumentative digression, spun off from a troll post.
     
  20. Write4U Valued Senior Member

    Messages:
    14,932
    In effect yes, you did say that only planets orbit stars. Attaching orbital motion of planets around stars is limiting, IMO. Everything revolves around other things, its a basic universal phenomenon that explains gravity
    Yes, I know. We look at things differently.
     
  21. RainbowSingularity Valued Senior Member

    Messages:
    5,232
    The Sun calls out, "hey Pluto don't bother, your not in my orbit"
    "im not liking the lack of specificity in your relativism" says micro black hole
     
  22. Janus58 Valued Senior Member

    Messages:
    2,155
    Not in the sense that the SMBH gravitational dominates or even is really significant when it comes to that orbit. Except for those few stars really close in to the SMBH, the main source of gravity determining stellar orbits is the combined mass of all the stars, etc closer to the center of the galaxy than the orbit. Remove the SMBH at the center of our galaxy and you would be hard pressed to notice any difference in the Sun's path through the Milky Way.
    Using the official definition of planet:
    • orbits the sun
    • has sufficient mass to be round, or nearly round
    • is not a satellite (moon) of another object
    • has removed debris and small objects from the area around its orbit.
    We could expand "orbits the Sun" to " orbits a star" to cover extra-solar planets, but even if we expand this to SMBHs, it would take the loosest definition of "orbit"* to say the Sun orbits Sagittarius A.
    It fits condition 2 as it is massive enough to be round.
    Condition three is a bit iffy. While the Sun doesn't orbit any other singular object( it is not within any single objects Hill sphere), it does orbit the combined mass of all the objects closer to the center of the Milky Way than it is.
    Then there is condition four. If you trace out the Sun's Milky way orbit, it turns out that there are a huge number of stars that share similar orbits. In fact, right now there are numerous other objects within just a few light years of the Earth, which when compared to the Earth 27,000 light year distance from the center of its galaxy counts as the "area around its orbit". If we compare this to the average distance between asteroids as a ratio to the average orbital distance of the asteroid belt, for the same ratio, the average distance between stars in the Sun's neighborhood would need to be 67 light years. So in these terms, the local stellar neighborhood is more "crowded" than the asteroid belt is, and the "crowding" in the asteroid belt is what eliminates Ceres ( which meets every other qualification for planet), from being a planet proper.

    *And contrary to what others might think, narrowing the definition for a term is not "conceptually limiting", It simply allows us to be more precise in the use of the term or label. It just means that when we use that term we are referring to this particular type of object. It does not exclude the existence of objects that don't fit into that particular definition, only that we are not referring to them when we use it.

    "Loosely Goosey" "definitions" that means different things to different people are pretty useless.
     
    Write4U likes this.
  23. Write4U Valued Senior Member

    Messages:
    14,932
    Thank you Janus58 for that excellent explanation of the definitive differences in terms.

    I tend to categorize things by common denominators, rather than by what sets them apart.
    This does get me in trouble once in awhile.....

    Please Register or Log in to view the hidden image!

     
Thread Status:
Not open for further replies.

Share This Page