From this month until practically August are the best months to see the Milky Way. Although his observation time varies depending on the month (May to 3:00 a.m. to 6:00 a.m. June, July and August 10PM to 4:00 a.m. and from August to October from 7PM to 10PM Come ve- not in the northern hemisphere) we can and we are obliged to observe this phenomenon at least once in my life.
Actually, what you see is not what we see in the image but will see a line with a high density of stars as our eyes, despite being quite evolved, they are not a great machine to distinguish shapes and colors.
To get view images as the top need “make presentations” for quite some time (minutes, 20 minutes) with a camera and a motorized tripod because, remember, the celestial orb rotates as the Earth rotates on its axis.
But what is the Milky Way?. Well, it’s just our galaxy, the galaxy in which the solar system is. In fact we are in one of the arms on the outside edge of the galaxy.
What you see in the sky is the elliptical center and, with a little algebra, the passage from 3D to 2D (can not remember what it was called when a space of higher dimension as proyectabas on a space of lower dimension) as us, we see it in a plane.
In fact, what most stands out in the sky is its center and clouds of gases. Are the elements that because they reflect the brightness of the stars are more visible and give it its typical configuration.
That is, do not see it as a spiral since we are in one of the branches and on the angular momentum, the whole system is in the same plane.
Because all this at great distances, up to the light, it is a very curious thing called temporal relativity.
The phenomenon tells us that, in the sky, we see as an event has happened after another, that is, the order in which we see the events that happen is not linear.
For this let us imagine two stars, one 8 light years and over 4 light years from us.
Now think 2 events, one that happens at a given time (the star that is 8 light years) and another happens 2 years (land) after the star that is 4 light years.
While the former, which has happened before, travels to our observer, the second, which also travels to our observer, arrived before because the distance it has to travel is much lower.
So after 4 years, the first event remaining 4 years (this halfway) while the second event, has only traveled 6 light years (4 + 2 years between events) so that even not have knowledge of he. That is, two simultaneous events can reach us at different times and order can be modified.
But an event that is because of another, can not arrive before. That is, if the star A happen two events at a time (1 and 2), and event 2, cause a reaction or other event (3) in the star B, to us (distances) we got the event 1 before the event 3. then causality is temporarily dependent, let’s happening one after another. No we can get the result of something before it occurs.
What does this mean?. Well, there is a spatial paradox in which if we had a ship traveling at light speed and leave the Earth to Mars could never get before they left Earth, never see the ship on Mars before they left Earth .
This, it seems silly is a big controversy if you have a vehicle that travel faster than light (remember that events, travel at the speed of light to gravitational waves) could have our ship before receiving the information that has left Earth to travel faster than the speed of information.
And if you travel faster than light we can say that information travels back in time and would have a curious paradox.