u/GeneralJannis

Hi all I find it very impressive that Ancient Greek scholars could calculate the size of the Earth with eerie accuracy - using shadows and angles :-)

I was working on an explainer for Fusion,
And it is really amazing if we think about it how a very small mass difference in the weight of 4 protons compared to 1 Helium is what gives us energy, stars, and life in the Universe!

What do you think?

Hi all , if you take a look at the night sky , and images from space you typically can see White/Yellow , Blue and Red Stars … But why don’t we see any Green stars?

It turns out that stars emit continious spectrum of light that depends on the temperature of the star. High temperature gives Blue, medium T White/Yellow and low temperatures give red. The way our eyes interpret such light , will basically never be able to perceive any star as green- there is no temperature of a star that would work for our eyes/brain.

I have made a short explainer video if you are interested in the comments .

Hi all I was working on an explainer for how Nuclear Power plants work, and I was looking at the math for energy density of fission of U235 compared to say coal. It’s mind boggling how much more energy is released in fission. However spent fuel rods are replaced typically whilst having 90% or more of the U235 left in them - so not super high utilization of the total potential.

Also it seems that the thermal efficiency of Nuclear plants are a bit lower than other types of plants operating at higher steam pressures and temperatures.

What are your thoughts?

This has always fascinated me:-) Pythagoras and the Pythagoreans were trying to explain harmonies and everything in the world guided by math and only Rational numbers - Integers and Fractions of Integers.

The grave irony is that even in the simplest geometrisk shapes such as a simple square and a simple circle hide within them the mathematical abomination (for Pythagoras) of Irrational numbers such as Sqrt2 and Pi!

Sometimes Nature is cruel :-)

I still find it very interesting that water and steam is in the heart of most energy systems like thermal power plants .

Water has high heat capacity, can be heated and cooled at constant temperatures (boiling and condensating) so is ideal for heat machines.

And how a steam table can be used to understand what happens in a big Power plant :-)

Also electrolysis will use water , and for future possibilities in Fusion water will be the source of hydrogen.

Go Water :-)

I’ve been working on a short explainer about world energy use, and one thing that stood out to me is how huge the scale of the energy transition challenge still is, and how linked energy use is to World Population and GDP growth!

Fossil fuels still provide roughly 3/4 of global energy, and total energy use has grown dramatically over the last 25 years, by more than 50%! That’s part of why the transition is so difficult: modern quality of life, food production, and industrial systems all depend heavily on abundant energy.

If useful, I can also share the short video version in the comments.