Comments by "H. de Jong" (@h.dejong2531) on "Investigating Space Trolls u0026 Flat Earth Nuts" video.

  1. Flat-Earthers are either trolls, or people who have difficulty discerning the value of information they're given (i.e. can't distinguish between truth and lies). The second category unfortunately tends to cling to the lies while dismissing all of the evidence of the truth. This spills over from areas that don't directly influence daily lives to areas that do. Covid is a prime example. The people who didn't take solid-science-based information seriously ended up clogging our hospitals and morgues.
    6
  2. The ancient Greeks found out Earth is not flat. NASA is not in a position to lie about this.
    3
  3. I can see satellites pass overhead even with the naked eye.
    3
  4. Look at the sky tonight. You can see "ideas" passing overhead. You can measure their altitude, and find they're above 200 km. Look at the horizon at sea. The sun sets, disappearing behind the horizon. If Earth were flat, it'd stay in sight, because there would be no horizon. Simple experiments, anyone can do these. And they prove that Earth is not flat.
    3
  5.  @freefreepalestine360  Farts can be used to propel you in space, yes.
    2
  6. We have a dozen different ways to establish the shape of the Earth. All of those agree with each other: Earth is a sphere. These methods are available to everybody: there are no "gatekeepers to the truth", anyone can use simple tools to measure the shape of our planet. A few examples: 1. Earth's curvature can be measured directly, using simple tools. Every surveyor in the world sees Earth's curvature on a daily basis. With cheap binoculars and a ruler you can do this too. https://www.youtube.com/watch?v=wYz_Hs35YrQ 2. Eratosthenes was able to measure Earth's circumference in 250 BC, coming within 10% of the actual value. He did this by measuring the length of shadows in two places at the same time. The ancient Greeks all knew Earth was not flat. 3. Anyone can take photos at high altitude and see the curvature of the horizon. https://youtu.be/jSx7ZzPOtVw
    2
  7. They aren't. There are people who claim ISS footage is faked, but all of their examples turn out to be simple video glitches (transmission gets interrupted briefly, which means incomplete data is received and the video decoder fills in the blanks. This video has more information on how that works: https://www.youtube.com/watch?v=3M01m3UUgoM
    2
  8. No, ships don't 'disappear because we can only see so far'. When I observe a ship disappearing over the horizon, this happens at the same distance whether the ship is large or small. When I'm at the sea shore and I watch a ship disappear, I can climb a nearby tower to bring it back into view. But at sea level, no amount of zooming in will bring the ship back into view.
    2
  9. For small buildings, curvature is not taken into account. For a house 10 meters wide, the curvature is 0.8 mm, and housing is not made that accurately. For large constructions, like bridges that are several km long, curvature IS taken into account. For large suspension bridges, the two towers are both perpendicular to the local surface, but they are not parallel because of the curvature of the surface between them.
    2
  10. Earth's curvature is 8 cm per km. Our eyes are not sensitive enough to distinguish between a straight line and such a subtle curve. We can easily measure this curvature though.
    1
  11. False. Rockets have explored the entire solar system. 10,000 satellites have been launched successfully and orbit our planet, at more than enough altitude to see Earth's curvature. In addition, we have many methods to see and measure Earth's curvature that don't rely on observations from high altitude. We can measure Earth's curvature directly in a geodetic survey. We can photograph Earth's curvature even at sea level: https://youtu.be/fbyWC9cqEGo. 2500 years ago, the Greeks realized our planet cannot be flat.
    1
  12.  @freefreepalestine360  False. Rockets work fine in a vacuum. A rocket doesn't need anything external to push against: it pushes against its own exhaust gases.
    1
  13.  @TB-xx8vj  Gravity is not a concept. It is an actual physical phenomenon. Its effect in nature is visible everywhere: objects fall to the ground. Planets orbit the sun, and moons orbit planets. Everywhere we look, gravity influences everything.
    1
  14.  @TB-xx8vj  The 'black swan' observation proves that atmospheric refraction exists and is variable. At other times, most or all of that oil platform is hidden by the horizon, as predicted by the sphere model. This is impossible on a flat Earth, therefore Earth is not flat. We can measure Earth's curvature directly. We have indirect measurements (elevations of the stars at different latitudes) that are impossible on a flat Earth, but perfectly explained by the sphere model. We have direct observations of Earth from enough distance that its curvature is visible. During a lunar eclipse, we can see Earth's shadow projected on the moon. This shadow is always a circle segment, no matter which part of Earth is facing the moon. This is only possible if Earth is a sphere. You see, we have multiple independent lines of evidence that all show Earth is a sphere. You, on the other hand don't have a single piece of evidence that shows Earth is flat.
    1
  15.  @TB-xx8vj  The ground is not flat, it just looks that way to the naked eye at sea level. When you look out over the sea or e.g. a salt flat, the horizon is about 6 km long. Over that distance, it curves by only 50 cm. Our eyes cannot distinguish between a straight line and one that is curved by that amount. With simple tools, we can make this curvature visible: https://youtu.be/fbyWC9cqEGo
    1
  16. Every time we measure the surface of our planet, we find curvature. Every time we launch a satellite, we fly to altitudes much greater than where the "firmament" is supposed to be, and we find no obstructions. We have sent spacecraft to Pluto and found no obstructions.
    1