Day 4. How To Make A Galaxy

Imagine if our universe was a book and on important days, someone opened the book and wrote about it. ‘Day’ 4 would have been such a day.

Essentially a galaxy is a whole lot of stars clumped together, but in terms of distance, “clumped together” hardly gives an accurate impression of the size of a galaxy.

Take our own galaxy The Milky Way as an example. Our Sun is just one of somewhere between 200,000 million and 400,000 million similar stars but to get from one side of the galaxy to the other, well you’d need to pack a big lunch.
Technically, it’s possible to build a craft that could travel close to the speed of light. It would have to be very large to accommodate enough fuel to burn constantly for several years, but eventually it could reach speeds approaching 186,000 miles per second. At this speed you could get to the middle of our galaxy (once you decide where exactly that is) in about 20,000 or maybe 30,000 years. Given that the distance between galaxies is many times more than the width of a galaxy, there’s probably not much chance of visiting another galaxy anytime soon. Continue reading Day 4. How To Make A Galaxy

Day 5 – The Milky Way

Imagine if our world had a diary and on the interesting days, someone pulled out a big book and wrote about it.

the bookDay 5.
It’s somehow comforting to think we have neighbours, perhaps lots of them, in our ‘city’ in the Universe, where there are between 200 and 400 million suns much like ours in town.

After an unimaginable time span of 1,800 million years since the ‘Big Bang’ stars in this area ignite forming the Milky Way, our home galaxy.

A discrepancy of 200 million stars is a tad less than accurate, but you can’t just count them.
The main problem is that our solar system is a fair way out of town, on one of the big avenues (the Orion–Cygnus arm) and there are three others just as big. (Actually we are not right on the avenue, more like a side street off one of the main avenues.)
Continue reading Day 5 – The Milky Way