How will the universe end?

Hey guys it’s me again, and I couldn’t come up with anything to put in this intro so i’ll just leave it like this. Anyway today’s question, well one of them, was inspired by a user known as Elusus, I received this message today via the contact page “Can you write a post on the life time of a star and how the ending of stars would effect the earth, thanks”.

So this got me thinking and as you can see the title of this post is not the same as the question Elusus asked, the reason I have changed it slightly is because I thought that the ending of all stars would be the at the end of the universe. So we’ll first look at the life cycle of a sun, let’s take our sun for an example, our sun is a medium sized star and it ‘works’ by compressing hydrogen into helium in a fusion reaction. Now the sun is very large and has a massive mass, meaning it has a lot of gravity, but the sun does a large balancing act. As the fusion takes place, a lot of energy is expelled and is sent outwards so this, in turn, counter acts the force of gravity making the the sun stable.

However the sun will eventually burn out all of it’s hydrogen, this will be in a few billion years, however it will happen and when it does the sun will start to burn it’s outer layer. It will then do this until it eventually becomes about the size of Earth (much smaller than it’s original size), although it will only be half of it’s original mass, meaning it will be extremely dense. Anyway by this time the Earth will be long gone and so will any chance of life on it, but what about the universe, what will be the last things left?

Very large suns die quickly and explode in violent super nova’s or turn into black holes, I’ve just explained what a medium sized star will do, so what will a smaller star do. It will basically do the exact same as a medium sized star but calmer and slower, these red dwarfs slowly burn out over trillions of years and form white dwarfs. These white dwarfs are the things that will last the longest along with black holes. Then eventually these white dwarfs will turn into black dwarfs and the universe will be a cold, dark, lifeless place, where nothing new will ever happen and never could happen. Although these events are so many billion years away that in our lifetime it really does not matter and it is nothing to worry about.

Thank for reading guys and thanks to Elusus for sending in this request, I hope you all enjoyed this post and if you did be sure to leave a like and follow for more.

Why is the sky blue?

Ever wondered why the sky was blue? If you have, find out here.

Hey guys, I’m back, I didn’t go anywhere, but I though it sounded a bit more dramatic. Anyway today’s question ‘why is the sky blue?’ Now this question is a very classic question that is ask by many young children and is probably not even known by most adults. Now to understand why the sky is blue, we first need to think about the light coming from the sun. Now most of us class the sun as a big ball of fire, and you’d be wrong it is actually a large compression reaction, attempting to make hydrogen into helium. I’m getting a bit off topic, but my point is that the sun doesn’t just produce red or orange light, like fire does, it in fact produces white light.

You may have seen the sun and be thinking “No when I look at the sun it looks orange, you dummy.” Yes you’re right, when you look at it, especially at sun set, it looks orange. But this is the point we will eventually lead onto, when light travels through space it contains all of the colours of ┬áthe spectrum: red, orange, yellow, green, blue, indigo and violet. You may also be thinking “Non of those look white” and the light spectrum is a question for another day.

Now just accept that all of those colours make up white light, but when the white light from the sun reaches our atmosphere, the light is scattered by the particles in the air and the blue part of the white light is what remains for us to see, thus making the sky blue. Then at sunset, the blue light is being dispersed above you and is out of your line of vision and you instead see the red and orange colours.

Thank you guys for reading and I hope you enjoyed, if you liked this post make sure you leave a like and follow for more answers. If you want me to write a post about the light spectrum and how it can be broken up, leave a comment and if you have any questions just message me in the contact page.