Planet Earth is round. Primitive man did not know this because he could not see the planet in it’s entirety, nor did he know of a way to calculate the planet’s size.
We know this *now* because we’ve explored the planet and we’ve traveled to space, gaining a complete view of the planet from a distance. We have learned math and can calculate the planet’s diameter with extreme precision. Hundreds of years ago, sailors noticed that a ship’s mast would come into view first; then more of the ship, as it sailed towards the viewpoint on land. Conversely, when the ship sailed away, the body of the ship would sink over the horizon until just the mast was visible, then even that would disappear over the horizon. The natural horizon for an average sized person is approximately 3 miles. On Earth, you can start traveling in a straight line in any one direction and approximately 25,000 miles later, you’d come back around to your starting point. (Granted there are a lot of obstacles in the way.) But even today, some people claim that the Earth is flat because they say you can’t see the arc of the planet. Obviously, if you get back far enough, the shape of the planet is quite plainly NOT flat.
Earth is just one planet in the Milky Way galaxy. Scientists estimate there to be 100 billion planets in our solar system. How many of them can support life? Surely there has to be more than just one (Earth), right? The Drake Equation says that there should be a small percentage of planets that can support life. Yet we seem to be alone.
Other scientists, using the Hubble telescope, estimate there to be 100 billion galaxies in the entire universe. Trying to grasp the enormity of this is truly mind boggling.
Most people think that the universe simply goes on and on, for an infinity. Einstein’s theory of general relativity explains how space-time can be “bent” around a massive object that has a magnetic field (gravity).
But what if the universe is also round, just like a planet? What if space & time curve in a spherical arc, connecting one side to the other? If it is continuous in every direction, just like our planet, traveling in one direction would (eventually) bring you back around to your beginning point. How would you even measure that arc on such a grand scale? Stephen Hawkings described curved space in his description of “Imaginary Time“.
Scientists estimate the age of our planet to be 4.5 billion years old and they estimate the Milky Way galaxy to be 13.5 billion years old. It’s a safe assumption that some parts of the galaxy are older than other parts. The level of technology will vary with age, knowledge, and exploration.
As technology improves, newer technology is invented/discovered at an exponentially increasing rate; meaning the smarter we get, the faster we get smarter. Just look back at the previous 100 years and look how far technology has come in that time. Every advance in technology gives us a larger leap forward in overall knowledge and ability to learn.
So what if “advanced life forms” from another part of the galaxy have just a 1% head start on technology over what we (humans) have? That would mean their technology is 45 MILLION years ahead of ours. Maybe they do have the technology necessary to travel through space.
And maybe, they have finally learned to get along with other inhabitants of the galaxy.