A satellite navigation or satnav system is a system that uses satellites to provide autonomous geo-spatial positioning. Several satellites continuously transmit signals containing their positions and the time when the signal was sent. Receiver units listen to the signals and use the information to calculate their positions.
Flat-Earthers assume that if GPS satellites are used to determine positions, then they should be able to pinpoint the position of a receiver. They are wrong. GPS satellites only transmit signals but never receive signals from the receivers. It is impossible for the satellites to determine the position of a receiver.
Continue reading “How GPS and Other Satellite Navigation System Work”
In the context of spaceflight, a satellite is an object that has been intentionally placed into orbit. A few of these satellites are balloon satellites. They are satellites that are inflated with gas after they have been put into orbit. There are also other human-made objects which are also called satellites, only placed in a much lower altitude, and with a very different operating method. These are actually regular high altitude balloon, but providing services traditionally provided by orbiting satellites.
Flat-Earthers deny the existence of satellites, and after they discovered the existence of balloon satellites, they started to use the fact as “proof” that orbiting satellites do not exist. It is the fallacy of hasty generalization. Using the same “logic” they are using, we can use the existence of trucks to “prove” buses don’t exist.
Continue reading “Balloon Satellites”
Fiber-optic communication is a method of transmitting data by sending pulses of light through an optical fiber. These days, the majority of data communication involves a fiber-optic connection. However, other methods of transmitting data exist, including satellites.
Flat-Earthers use the prominence of fiber-optic communication as “proof” of the nonexistence of satellites. Such a line of thinking is a fallacy of hasty generalization. Using the same “logic,” we can “prove” trains don’t exist just by showing the existence of cars.
Continue reading “Fiber-Optic vs Satellite Communication”
Troposcatter is a signal propagation method using the scattering phenomenon in the upper troposphere. As the signal pass through the upper troposphere, some of the energy is scattered back toward Earth, allowing the receiver station at the correct location to pick up the signal.
White Alice is a decommissioned troposcatter network in North America. Some flat-Earthers invented the “explanation” that the various satellite-based services we enjoy today are using White Alice. They are wrong. White Alice and other troposcatter networks cannot possibly replace all the services provided by satellites.
Continue reading “White Alice and the Troposcatter Propagation”
The amount of Earth’s surface we can see at once from a location in space depends on our distance to the Earth. The closer the observer, the smaller the amount of visible Earth’s surface. Conversely, the farther the observer, the larger the amount of Earth’s surface visible to them. But no matter how far the observer, they would not be able to see the entire hemisphere.
Flat-Earthers discovered that there are the differences in the sizes of continents in the different images of the Earth, and used the fact as ‘evidence’ of misconduct. They are wrong. Such differences in continent sizes are present because the images show the Earth from different distances and different field of view.
Continue reading “The Varying Continent Sizes in Different Images of Earth from Space”
A satellite in a high enough orbit can remain operational for a very long time because in space there is practically no air resistance. This is a situation that never occurs in our everyday life. A car requires a constant consumption of fuel to keep running, but a satellite can remain in motion without consuming any fuel because there’s practically no force stopping it.
Flat-Earthers claim that satellites cannot stay up there for such a very long time because ‘we never refuel any satellites.’ They are wrong. In space, there is practically no drag, and satellites only need to consume fuel to adjust their speed periodically.
Continue reading “Orbital Station-Keeping”
Flat-Earthers reject the existence of satellites. They are wrong. To prove the existence satellites, we can attempt to take pictures of the ISS when an ISS transit happens, or the ISS passes in front of the Sun or the Moon.
Continue reading “Observing the ISS from ISS Transits”
It is not hard to spot satellites. Satellites can easily be seen under the following conditions:
- They are easier to see the larger and the closer they are.
- The darker the sky, the easier to see them.
- Satellites are visible only when they are lit by the sunlight.
Because of these conditions, satellites are usually seen a few hours after sunset or a few hours before sunrise.
Flat-Earthers claim that satellites can never be seen, and the fact is evidence that “satellites don’t exist”. They are wrong. Satellites can easily be seen under the right conditions.
Continue reading “Satellite Watching”
Jupiter possesses four large moons: Io, Europa, Ganymede, and Callisto. These are called the Galilean Moons. They are easy to observe and the first objects found to orbit a planet other than the Earth.
Flat-Earthers are often seen demanding proof that an object can orbit another object. All they have to do is to use a telescope to observe Jupiter and its Galilean moons.
Continue reading “Galilean Moons: The First Objects Observed to Orbit Another Object”
If Earth’s gravity pulls everything towards the Earth, then how can satellites stay up there and are not falling towards the Earth?
The answer is that satellites orbit the Earth. They have the correct velocity with respect to Earth’s position and gravitational pull.
Continue reading “How Satellites Can Orbit and Stay Up There”
If a satellite has the orbit of 35786 km above Earth’s surface, the satellite will be in motion at the same speed as the Earth’s rotational rate. As a result, the satellite will appear practically motionless when observed from the surface. Many communication satellites reside in this orbit, and a satellite dish receiving signals from the satellite does not have to track the satellite.
Flat-Earthers often take the fact that satellites are in motion and most satellite dishes have a fixed direction as ‘proof’ the dishes cannot be pointing to satellites. They are wrong.
Continue reading “Geostationary Satellites”
Iridium is a satellite constellation consisting of 66 satellites. It provides satellite phone services over the entire Earth surface. The first generation satellites have three door-sized reflective antennas. Because of their reflectivity, Iridium satellites will occasionally reflect sunlight to Earth’s surface. The Iridium flare will look like a bright flash over a few seconds.
Most flat-Earthers deny the existence of satellites. Iridium flares provide an easy opportunity to confirm the existence of satellites, at least until the end of 2018, when they are replaced by newer non-reflecting satellites.
Continue reading “Iridium Flare”
“If satellites exist, then why would mobile phone operators bother to install transceivers everywhere?” flat-Earthers asked this a lot.
The logic is that if using a satellite can get you a vast coverage area, then spending a lot of money and effort to install towers everywhere does not make any sense. Usually, they would follow-up and conclude that “satellites don’t exist.”
They are wrong. Satellites do exist, and there are good reasons why mobile phone communication utilizes cellular architecture.
Continue reading “Cellular Network vs. Satellite Communications”
The GPS system is one-way. The satellites broadcast signals. GPS devices receive and process the signals to determine their location.
Flat-Earthers often point out the fact we were unable to locate the ill-fated MH370 as ‘evidence’ GPS doesn’t work and therefore doesn’t exist. They are wrong. GPS satellites never receive any signal from GPS devices, and it is not possible for them to locate MH370.
Continue reading “The MH370 Disaster and the Inability of the GPS System to Locate It”
“Why don’t we see satellites in photos taken from the ISS?” (or from space in general). That’s a recurring question within the flat-Earth community, usually asked without expecting an answer, assuming that an answer is impossible, and that it is a glaring oversight when the powers that be purposefully made the picture using CGI.
But no, the pictures are real. And satellites are not visible because they are too far spaced apart from each other.
Continue reading “Why Don’t We See Satellites in Photos Taken From The ISS?”
Rockets follow a curved trajectory when going into space because their objective is not only to reach space, but also to enter Earth orbit. In Earth orbit, rockets have enough speed to counter Earth’s gravity and do not require a lot of energy to stay up there. To enter Earth orbit, a rocket needs to attain a high enough horizontal speed.
Flat-Earthers claim the curved trajectory of any rocket launch tells us no rocket has ever reached space. They are wrong. The curved trajectory is a way for rockets to enter Earth orbit.
Continue reading “Curved Rocket Trajectory”
The thermosphere is a layer of the Earth’s atmosphere from about 95 km to 600 km. It is named ‘thermosphere’ because its temperature increases with altitude. The temperature in the thermosphere can reach 2500°C. However, air density in the thermosphere is very low to the point that heat conduction practically does not occur. Objects in the thermosphere will feel cold.
Flat-Earthers discovered that the temperature in the thermosphere could reach 2500°C. They are happy to ignore the other information which usually accompanies it: the air density up there is also far lower.
Continue reading “Space Flight and the Temperature in the Thermosphere”
Google Maps and similar apps use satellite navigation —like the GPS— to determine the location of the device. The apps also utilize cellular data or other data connection to obtain map and route data, which are not part of the GPS or satellite navigation system.
Some flat-Earthers noticed that Google Maps does not fully function when the cellular signal is not available. They concluded that GPS signals are transmitted by cell towers, not satellites. In reality, Google Maps is not GPS. The app uses GPS —and other satnav systems— to determine user location. The maps and route data in the apps are not part of the GPS.
Continue reading “Google Maps, GPS and Cellular Signal Reception”
A human eye can only visually perceive the curvature of the Earth if we are at a considerable altitude from the surface, which is still beyond the reach of most humans today. A commercial jet airliner is the highest position realistically attainable by most humans today. At such altitude, we can only perceive very slight curvature, and only in an ideal condition.
The basis of flat-Earthers’ belief is that the horizon appears flat. They would say if we cannot see the curvature, then there’s no curvature, and thus, the Earth is flat. They are wrong. Most of us these days cannot travel high enough to see the curve. The best we can do these days is going on board a commercial jet airliner, which can only go about 11-15 km up, only a fraction of the radius of the Earth.
Continue reading “So, Where’s the Curvature?”