General Forum

General Forum

  1. Standard memberChessPraxis
    Cowboy From Hell
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    20 Aug '14 20:27
    Originally posted by Great Big Stees
    How 'bout we all head for the Northern most part of Mother Earth and just start jumping. We may be able to flatten her.
    There is no earth "Terra firma" at the North Pole. There is a huge hole which leads to an inner Earth warmed by an internal Sun. That's where the Lizardmen live.
    Thought you knew
  2. Joined
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    20 Aug '14 20:52
    Originally posted by ChessPraxis
    There is no earth "Terra firma" at the North Pole. There is a huge hole which leads to an inner Earth warmed by an internal Sun. That's where the Lizardmen live.
    Thought you knew
    I did actually, it just slipped my mind...musta been that demon weed.
  3. SubscriberPonderable
    chemist
    Linkenheim
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    25 Aug '14 13:52
    Originally posted by sonhouse
    Dam round planet! I am at work and have to wait 3 frigging hours to get hold of the left coast. If we lived on a flat Earth we would all have the same time zone. Anything we can do about that?
    Why would we be on the same time zone on a flat earth?

    The sun will rotate around the earth I presume and then you have the same east-west problem like before...

    But the wagon of Sol would be a real nice vehicle to wonder about 🙂
  4. Standard memberHandyAndy
    Read a book!
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    25 Aug '14 15:07
    Originally posted by Ponderable
    The sun will rotate around the earth I presume and then you have the same east-west problem like before...
    According to Copernicus and some other smart people, the sun doesn't travel around the earth.
    The "east-west problem" exists because the earth rotates on its axis and revolves around the sun.
    Whether or not a flat earth would rotate or revolve or move at all is open to conjecture.
  5. SubscriberPonderable
    chemist
    Linkenheim
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    25 Aug '14 15:40
    Originally posted by HandyAndy
    According to Copernicus and some other smart people, the sun doesn't travel around the earth.
    The "east-west problem" exists because the earth rotates on its axis and revolves around the sun.
    Whether or not a flat earth would rotate or revolve or move at all is open to conjecture.
    A rotating flat earth would be really great, think of the different velocities experienced at different locations...
  6. Joined
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    25 Aug '14 16:31
    Originally posted by Ponderable
    A rotating flat earth would be really great, think of the different velocities experienced at different locations...
    Actually the rotational speeds are the same on a rotating flat plane and a rotating sphere with the same axis and diameter. A point one meter from the North Pole rotates around the pole once every 24 hours for a total distance of 2 pi meters per day, and a point at the equator goes about 13,000 pi meters per day. This would be the same if the earth were a rotating disc.

    I think.
  7. SubscriberPonderable
    chemist
    Linkenheim
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    25 Aug '14 17:03
    Originally posted by JS357
    Actually the rotational speeds are the same on a rotating flat plane and a rotating sphere with the same axis and diameter. A point one meter from the North Pole rotates around the pole once every 24 hours for a total distance of 2 pi meters per day, and a point at the equator goes about 13,000 pi meters per day. This would be the same if the earth were a rotating disc.

    I think.
    You are right, but I was thining about a disc rotating on a diamter instead a centric axis.
  8. Subscribersonhouse
    Fast and Curious
    slatington, pa, usa
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    25 Aug '14 17:31
    Originally posted by Ponderable
    You are right, but I was thining about a disc rotating on a diamter instead a centric axis.
    It would make an interesting experiment to make a small version to launch into space, say a disc 100 meters across and 1 meter thick then put into orbit say a million klicks from Earth but in the same orbit. Let it rotate in various ways, see what it would be like on Earth if the disk was 12,000 km across and some significant thickness.

    I guess a planet like that could not exist since the gravity of it would force it back into more or less spherical shape.

    So how fast would a 12,000 Km disk have to spin to keep gravity at bay and still maintain the disk shape? Would it be slow enough to be habitable?

    You probably know about the Ringworld Sci fi series, that is basically a ribbon at some distance from the sun going 360 degrees all around the sun but what about a habitable disk the size of Earth? Could it exist in reality given our laws of physics as we know them?
  9. SubscriberPonderable
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    25 Aug '14 17:42
    Originally posted by sonhouse
    It would make an interesting experiment to make a small version to launch into space, say a disc 100 meters across and 1 meter thick then put into orbit say a million klicks from Earth but in the same orbit. Let it rotate in various ways, see what it would be like on Earth if the disk was 12,000 km across and some significant thickness.

    I guess a planet ...[text shortened]... ble disk the size of Earth? Could it exist in reality given our laws of physics as we know them?
    Yes Ringworld is feasible, though it is questionable about the big ring caryying the areas to make the night plus the questin how thick it would have to be to maintain atmosphere...

    Dyson has proposed what is called a Dysonsphere as a space habitat
  10. Joined
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    25 Aug '14 18:40
    Originally posted by Ponderable
    Yes Ringworld is feasible, though it is questionable about the big ring caryying the areas to make the night plus the questin how thick it would have to be to maintain atmosphere...

    Dyson has proposed what is called a Dysonsphere as a space habitat
    Is he the guy that invented the Dyson vacuum cleaners?
  11. Joined
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    25 Aug '14 18:40
    Originally posted by sonhouse
    It would make an interesting experiment to make a small version to launch into space, say a disc 100 meters across and 1 meter thick then put into orbit say a million klicks from Earth but in the same orbit. Let it rotate in various ways, see what it would be like on Earth if the disk was 12,000 km across and some significant thickness.

    I guess a planet ...[text shortened]... ble disk the size of Earth? Could it exist in reality given our laws of physics as we know them?
    I am more familiar with Terry Pratchett's discworld.

    I remember the concept of a space station that was a torus with people living in the hollow ring. The station rotated around its axis like a bicycle wheel, and the rotational rate was designed to provide a centrifugal force of one earth G. I believe this was depicted in Kubrick's 2001 a space odyssey. I wonder what the rotational rate would need to be for a given diameter.

    Somebody's figured it out:
    "In the 1950s, Wernher von Braun and Willy Ley, writing in Colliers Magazine, updated the idea, in part as a way to stage spacecraft headed for Mars. They envisioned a rotating wheel with a diameter of 76 meters (250 feet). The 3-deck wheel would revolve at 3 RPM to provide artificial one-third gravity. It was envisaged as having a crew of 80."

    http://en.wikipedia.org/wiki/Rotating_wheel_space_station
  12. Standard memberHandyAndy
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    25 Aug '14 18:59
    Originally posted by JS357
    Actually the rotational speeds are the same on a rotating flat plane and a rotating sphere with the same axis and diameter. A point one meter from the North Pole rotates around the pole once every 24 hours for a total distance of 2 pi meters per day, and a point at the equator goes about 13,000 pi meters per day. This would be the same if the earth were a rotating disc.

    I think.
    Speed (distance divided by time) isn't the same as velocity. During a 24-hour period, the point at
    the equator travels a much greater distance than the point near the pole. Velocity, on the other
    hand, is a vector quantity that measures the rate at which an object changes its position.
  13. Joined
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    25 Aug '14 20:28
    Originally posted by HandyAndy
    Speed (distance divided by time) isn't the same as velocity. During a 24-hour period, the point at
    the equator travels a much greater distance than the point near the pole. Velocity, on the other
    hand, is a vector quantity that measures the rate at which an object changes its position.
    I just changed position but forgot to record the velocity. Let me do it again. I'll get back to ya.
  14. Joined
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    25 Aug '14 20:29
    OK I was successful this time. It was 4.
  15. Joined
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    25 Aug '14 21:05
    Originally posted by HandyAndy
    Speed (distance divided by time) isn't the same as velocity. During a 24-hour period, the point at
    the equator travels a much greater distance than the point near the pole. Velocity, on the other
    hand, is a vector quantity that measures the rate at which an object changes its position.
    I know. That's why I said speed. The way I learned it, velocity includes both magnitude and direction. I didn't want to get into discussion of the rate of directional change of points on a rotating sphere vs points on a rotating disc.
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