13 July:How does the sun work?: Cool things I learnt today

marmitelover2000

Okay, so this next one is super obvious for physics experts. However, I am a mere mortal so initially I was confused.

I was always taught, for there to be fire, you need 3 things: oxygen, fuel and heat

In the vacuum of space there is no oxygen! How can the fiery sun survive?

I'm gonna try and break the answer down so its less confusing- physics experts don't come for me 😝

1.The sun is basically a ball of gas ( a bit like my father after eating sprouts ) The "fire" comes from nuclear fusion.

How I explained it to my Grandma is:

2. Nuclear fusion is just hot, electric gas caused by the center of an atom (nucleus ) fuses with another one to make lots and lots of energy.

She asked a good question, why does it look like fire? here is my answer, it may not be at all correct but it makes sense.

A Glowstick when snapped emits light. Its a chemical reaction so proves that you don't need combustion ( burning) for light.

Neon signs also emit light, they are essentially electrified gasses. Apparently having a full outer shell makes them nobel ( the bar is so low these days)

3. So imagine Hot electrified gasses which is essentially the sun. It's not fire but plasma (Hot, electrified gas !).

Interestingly due to nuclear fusion, the sun has the potential to create it's own oxygen. But that's a story for another day.

Jimm_Scope

I did some physics at A level and university and this is really good!

Technically, plasma is another state of matter entirely but calling it "hot electrified gas" works well as a simple explanation.

It is incredibly interesting. I will also say that not all stars look "like fire". Each can have their own frequency of light. Some look yellow, some more blue, some incredibly red.

The sun is actually more white than any other colour, but we draw it as yellow because it turns that colour during sunrise/sunset when we are most likely to notice the sun. This is because the light has to pass through more atmosphere, only the longer wavelengths of light can do this without being deflected. The longest visible light wavelengths are yellow, orange and red.

The wavelength that the sun puts out the most light is actually a green colour, but it is not dominant at all, which is why it mostly just looks white except at sunsets.

marmitelover2000

https://forum.scope.org.uk/discussion/comment/888211#Comment_888211

Wooooow thats sooo cool 🤩

thanks for the extra info. It's cool to get some expert input

Jimm_Scope

I wouldn't call myself an expert 😂 I studied physics and astrophysics but I never finished my degree in astrophysics. I just really enjoy space and physics.

Cantilip

Woohoo, @Jimm_Scope that's fab. I have a strictly amateur interest in space-itime. It was something I was going to pick up on when I retired but I got ill instead. I did start a couple of Coursera courses. One was geology and the other was something like Exploring Einstein. Dropped out mostly because I simply didn't have the energy It's really hard to concentrate when you just want to be asleep! it was interesting though. I might sign up for other things just to get acccess to the course materials and download them and read them in my own snail-pace time.