The Bigget Context
It is not necessary to know, in order to understand global warming that there was an instnat when time and space began.
11.75 billion years ago our of nothing there appeared the big bang, or as I call it..
A Spiral Galaxy Like the Milky Way
The picture above is of a spiral galaxy closely resembling our galaxy. We, of course, cannot take a picture of the Milky Way because we are in the middle of it. So we take what we have learned about the Milky Way and labeled the important parts.
I have read that the earth is insignificant. It resides in an outer arm of a somewhat small spiral galaxy and there is nothing about it to make it significant.
Significance due to size and location means nothing unless we discover other inhabined planets with life comparable to homo sapiens and who have accomplished more than we. Or haved survived longer.
There are about 1022 stars in each galaxy. (This 10 with the superscript number saves us from writing 22 zeros. So it is a big number or four billion billion stars.)
You may have heard of a project called SETTI which stands for "search for extra terrestrial intelligence." We have been listening for 40 years and have not heard from anyone else.