User blog:Cerne/Oi...

There is a good reason why this entry is so early. I looked over the entry I posted last night and I did not like it very much. There were a number of things I could have explained better, like the part where I got into describing the compromise between more volcanic activity due to a more dynamic core and more rigid plate movement due to a thicker crust.

Basically, if you lower the density in the core, you get a less dynamic core which produces less volcanoes and slower rotation. Centralizing the core (also called "differentiation") to increase density makes the crust thicker, which is what I wanted, but it means less tectonic activity because there is more rock to move and less thermal energy to move it. Planets that are very dense essentially have the best of both worlds (no pun intended) because even after they make core differentiation more centralized, they are still very dynamic and can still muster enough thermal energy to produce a lot of volcanism even while having a thicker crust. So by decreasing my planet's density, I have also decreased my chances of having both a reasonably thick crust and a reasonable amount of volcanism. and therefore I have increased my need to compromise one for the other. I should explain here that the thick crust idea wasn't merely something I wanted for aesthetic purposes. A (terrestrial) planet needs a crust that is thick enough to keep too much heat from the convection in the mantle from escaping into the atmosphere and out into space. If too much heat is lost over too little time, the planet simply "burns out" more quickly and then nothing can live on it anymore. So I want and need a thick crust for my planet. In my particular case, I want an unusually thick crust because I want to imitate the tectonic activity on Venus, but no one gets everything they want and I may have to feign this ideal for the sake of something more plausible, which will be more satisfying for me in the long run.

Lately, I have also received more advice in the thread I started on the ZBB regarding my inquiry into planet density and the scenario offered for a planet with very high density in its core does not sound appealing. The planet becomes a cratered ball of metal with no tectonic activity and a bunch of water puddles in the place of oceans. The actual post I received from Tropylium can explain it better than I can: Volcanoes and volcanic gases. So I will definately want an upper limit for my planet's density, and unfortunately this might need to be lower than Earth's limit is. I already typed in my last entry that I was going to look into tweaking the density, so I will see how far I get with that. Hopefully I will get something appreciably high without winding up with another Mercury.

Speaking of Mercury, one of the paragraphs I typed in last night's entry has an error in it and I feel I should point it out before (or if) someone ends up taking my word for it. Here is the paragraph:

"I think what most affected my vision for the planet was finding out that planets very high in metal don't tend to have a very thin atmosphere. A good analogy would probably be the planet Mercury, which happens to have a lot more Iron and Nickel in it than I had previously thought. So my planet may not have the over-abundance of rare metals that I had been hoping for."

What I meant to type here was that highly metallic planets DO tend to have thin atmospheres. I probably would have caught this if I had spent more time re-reading the entry preview before posting it, but I had spent so much time on the entry already that I just posted it before re-reading the preview. I should make more of an effort to do this...maybe copying and pasting the text of a particularly long entry and reading it more carefully before posting it. At least I am remembering to point out mistakes in previous entries. You probably caught the "volano" typo in the first or second paragraph, though. This was obviously supposed to be "volcano," but I am still going to stick to my non-editing policy for blog entries so the typo stays. This can be a learning experience for me and an example of poor entry previewing for other readers. Sort of a "what not to do" kind of thing.

There was something else I wanted to type in this entry but I don't have time to type about it right now so I am going to end the entry here. I may type it in another entry later, though. Maybe in a follow-up to how my density-tweaking is coming along. Until then, thanks for reading.