Geocentric and Earth’s Layers in answer to questions from Heather and Keira

Dear Heather and Keira,

I never know when a post or comment from a student or class might prompt an extended comment. Something written makes me recall some information I have read or seen over the years and before long I find a comment growing longer or I want to include photos, videos, audio or links.

In the "How did the Earth begin?", the challenge was one I thought I could meet. Being keen on science and many other things, I had been following theories on the origin of the Earth and the universe. Once I have an idea for a post, I research my facts to try to make certain my thoughts are on the right track then start writing the post. I knew "How did the Earth begin?" would be a longer post because there is much to consider.

Geocentric is a term used to describe the belief the Earth is the centre of the universe and all planets, stars including our sun, and the moon orbit us. From research, I have found many people still believe in geocentrism today. For some, it may be a religious decision, others a firm belief they believe science can support, and for others it's more a matter of not knowing any other way.

We do live on the crust of the Earth. It's the solid part that is our land and the bottom of oceans and seas. Compared to the rest of our planet, it is very thin but I wouldn't have it any other way. If you cut an apple in half, you can see the thin skin (like the Earth's crust) covering the rest of the apple down to its core.

Schools and students have permission to use this graphic for non-commercial, educational purposes.

The inner core is thought to be very hot but solid iron hotter than the surface of the sun. It's pressure keeping it solid. The outer core is still mostly iron but it is liquid and flows around the inner core. Remember, the Earth turns on its axis and this causes the spin and also gives us night and day. Think of stirring a drink. You can see the liquid moving around as you stir.

It's this movement of the outer core that gives our planet a magnetic field and protects us from much of the sun's dangerous radiation. Mars doesn't have this activity so has a weak field. Even if there was air to breath on Mars, we would probably still need special clothing to protect us.

The mantle is semi-liquid and is basically moving hot rock (magma).

Schools and students have permission to use this graphic for non-commercial, educational purposes.

The mantle movement is known as convection. We can see this effect in boiling water. Below is a video clip I prepared for you. To see the movement of the water, some rice grains were dropped into the water. You can see them move to the side being heated, rise with the heated water then sink back down as the water cools a little. The same thing happens in the mantle. The hot rock (magma) sinks down as it cools a little, is heated near the outer core and rises again. There are many of these convection currents in the mantle not just one big one.

Schools and students have permission to use this video clip for non-commercial, educational purposes.

Sometimes this movement of the magma brings magma to the surface and it flows out as lava. I was on Hawaii (The Big Island) a number of years ago and took a helicopter ride over the Kilaeua and along the coast. Look in the photo below and you see see the lava pouring out into the sea. Kilaeua has had a very active period.

The photo is a scan of an old 35mm slide so the quality isn't the best.

Schools and students have permission to use this graphic for non-commercial, educational purposes.

Location: Kilaeua, Hawaii, U.S.A.

Curiosity is a great gift. It's something still driving me to explore new ideas and things. I can see you both have curiosity. I wonder what great discoveries and learning is ahead for you? 🙂

10 thoughts on “Geocentric and Earth’s Layers in answer to questions from Heather and Keira

  1. James P.

    In typical scientific arrogance/ignorance this article asserts: “Geocentrism is a term used to describe the belief the Earth is the centre of the universe and all planets, stars including our sun, and the moon orbit us. From research, I have found some people still believe in geocentrism today. For some, it may be a religious decision and for others it’s more a matter of not knowing any better.”

    On the contrary, geocentrism has never actually been disproven nor has heliocentrism ever actually been proven. See http://www.geocentrism.com if you don’t mind putting on your thinking cap and looking at things anew and getting out of that mindset/worldview that most of us were raised with. It’s nice to know there are still some folks out there who put their quest for real scientific truth ahead of their job security or other self-determined comfort level requisites.

    Get ready for the major scientific breakthrough movie coming this summer which will turn the Copernican Principle which holds that Earth holds no special place in the universe on its head. See http://www.theprinciplemovie.com.

    Reply
    1. rossmannell

      Post author

      As with many things in our world, there can be disagreement.

      At no time did I say I believed in Copernicus’ heliocentric view of the universe. Placing the sun at the centre of the universe is as absurd to me as placing the Earth at the centre of the universe. I do hold our system, the Solar System, is heliocentric. This has been seen to be so when the motion of the planets, particularly those beyond Earth’s orbit, is considered.

      To explain what appears to be the slowing and reversal of the motion of Jupiter as it orbited around the Earth, Ptolemy suggested it orbited Earth while moving in circles. This may have gone some way to explaining its motion but was ignorant of our current knowledge of the gravitational effect such an eccentric orbit would have on the other planets or the then unknown asteroid belt. The geocentric model falls short.

      Our planet is one of a number orbiting our sun in what we call the Solar System. Our system is one of perhaps a billion star systems in our galaxy and our galaxy is one of possibly billions of galaxies in the universe. Where is the centre of the universe? I can’t say but I hold it is neither centred on the Earth nor our Sun.

      As far as job security is concerned, I am a retired teacher and earn nothing for the blogging I do. I seek scientific truth and that leads me to disagree with your view. I have approved your comment more as an example to others the geocentric view is still held by some as I have stated. If people agree with you, your links are there for them to visit. This blog is not where I am interested in arguing the belief or not in the Ptolemaic geocentric view or the Copernicus heliocentric view of the universe. Science has revealed much more about the universe than was known in the times of Ptolemy or Copernicus.
      * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
      I have modified the comment, “From research, I have found some people still believe in geocentrism today. For some, it may be a religious decision and for others it’s more a matter of not knowing any better.” I see the view is much more widespread than I originally thought.

      It now reads, “From research, I have found many people still believe in geocentrism today. For some, it may be a religious decision, others a firm belief they believe science can support, and for others it’s more a matter of not knowing any other way.”

      The links you have given, and the explanations I have read, I found unconvincing based on science and in further discussion with an astronomer. Your second comment had appeared in my spam folder because it carried a link to a site where the information had to be purchased. I don’t allow such links on this blog. I did read the Q&A section.

      Reply
    2. rossmannell

      Post author

      It has now been 4 years and no such film has been released despite me waiting. Had it done as claimed, by now the “major scientific breakthrough” would have been world news yet nothing has come of it. Could it be they failed to make any breakthrough that scientists would see as science? Meanwhile, the planets orbit the sun and the sun is just one star amongst potential billions in our galaxy. NASA and other space agencies calculate based on the solarcentric. If they were to prove Earth as the centre of our solar system, surely then all of the successful space flights and probes to other planets must have been a hoax.

      Reply

Leave a Reply

Your email address will not be published.