The phenomena aurora burealis, explain?
Difficult to compete with a pasted encyclopedia web page. Anyway... here's my simple words explanation: The sun is constantly emitting radiation called the solar wind, this solar wind is not constant in intensity it changes with the solar activity, the greater the solar activity, the greater or more intense the solar wind. This radiations or solar wind travel in all directions and of course they hit the earth. Earth's magnetic field is the shield that protects life on earth from these direct radiations, most of the solar wind bounces off and around earth and continues through deep space. Some of the solar wind is trapped in the magnetic field where it ionizes and reacts with the atmosphere's elements mainly hidrogen and oxygen but also traces of other elements. The magnetic field as most know run from pole to pole therefore the least concentration of energy is at the ecuator and the highest concentration of energy is at the north and south pole. The excess energy is released as light known as the Aurora Borealis at the North Pole and Aurora Australis at the South Pole. The changes in light are due to the interaction with different elements in the atmosphere. These "Northern Lights" as they are sometimes called are an everyday phenomena but they are most spectacular when the sun has great bursts of activity. If you wish to see the most beautiful Auroras, you can keep watch of the sun activity in many internet sites and on the periods of greatest activity you may see Auroras as far South as Toronto in Canada if you are away from the city itself and have a clear sky.
What could be causing a sudden increase in eye floaters?
Ive recently started getting a lot more 'eye floaters' than I have had before. Ive also had very bloodshot eyes. I am worried they may be due to one of many recent changes in my lifestyle. I'm going to list them and I'd like people who know a bit about them to give what they think is the cause, and justify their choice. A: Ive recently started taking an Ephedera based fat burner. Ive had 4 doses, theyre extremely strong. They increase blood pressure as a side effect for several hours. B: Ive been suffering a bit more eye strain from very long amounts of time using the computer. I have also just watched The Sopranos, all 6 seasons in about 15 days on top of my regular 8ish hours day looking at some form of monitor. C: I went travelling in a place where I was unable to use a clean toilet for nearly a week. I had resorted to 'hovering' while doing my business, which meant putting my head almost between my legs while I bent over the toilet and included nearly feinting because of how much blood rushes to your head when its between your knees while pushing out a long loaf. This did cause my eyes to become bloodshot quite a few times. D: I have been using the sun bed. I forgot my goggles a couple of times and used the shops pair of goggles, which didnt feel right, I am worried the UV may have leaked in, but it didnt necessarily immediately cause issues. E: I have had eczema around my eyes due to anxiety. F: All of the above G: Something else Here is a wiki page on what I mean: http://en.wikipedia.org/wiki/Floater Theyre inside the eye, so I am worried they may be permanent, its tough looking at a monitor without them bothering me.
In the famous 'pale blue dot' photo taken by Voyager 1 why are other planets/stars not obvious?
This question is one of a few questions my (then) 8year old daughter asked me while I was showing her the Ultra Deep field images taken by Hubble and the image which Carl Sagan poetically described as the pale blue dot (home) so many years ago. She asked some questions which stumped me and we attempted to contact NASA to see if we could get an answer, but never received a reply. 1) How did the Voyager take a photo from 4 billion miles away? 2) How do you measure four billion miles in space? 3) How close to the sun was the Voyager if the earth is shown in a sunbeam? 4) How was it determined that the 'pale blue dot' was earth and not a larger planet or star? 5) Why don't we see any other stars, planets, etc. in the photo from that distance?