From what I can tell from wikipedia, in astronomy luminosity is
"the amount of electromagnetic energy a body radiates per unit of time."
From this I gather that that during the dark age the matter in the universe was not emitting an electromagnetic energy. Since the energy must have already existed then it must not have been radiating. I'm still a little unsure exactly what that means.
Looking further into it I cam across this answer:
"most of the photons in the universe are interacting with electrons and protons in the photon–baryon fluid. The universe is opaque or "foggy" as a result. There is light but not light we could observe through telescopes."
Which I instantly recognized as something we where taught in class the day this question came up. Having now spent a little extra time with it I feel like I'm beginning to actually understand what went on.
Showing posts with label light. Show all posts
Showing posts with label light. Show all posts
Monday, March 4, 2013
Friday, March 1, 2013
What The Hell is a Magnet and What Makes Things Bright?
These two questions stuck in my mind after I left class the other day.
The first question occurred to me while I was thinking about electromagnetism. We'd just learned that most things aren't really effected by the electromagnetic force because the positive and negative forces inside them balance each other out and leave them electrically neutral. If this is so then how are magnets made? Obviously something is done to them to upset the balance but what? Do magnets occur naturally? If so where and how? Finally how do magnets work on metal that is still electrically neutral? Do they change the charge of the metal?
The second question came to me when I was thinking about the "Dark Age". If there was light in the universe by this point (assumably the same light that's in the universe now) then how come things where not visible. What is it beyond just light that make something illuminated? I've always assumed it was reflecting off things, if this is so then how solid does something have to to reflect light? What other qualities does it need?
The first question occurred to me while I was thinking about electromagnetism. We'd just learned that most things aren't really effected by the electromagnetic force because the positive and negative forces inside them balance each other out and leave them electrically neutral. If this is so then how are magnets made? Obviously something is done to them to upset the balance but what? Do magnets occur naturally? If so where and how? Finally how do magnets work on metal that is still electrically neutral? Do they change the charge of the metal?
The second question came to me when I was thinking about the "Dark Age". If there was light in the universe by this point (assumably the same light that's in the universe now) then how come things where not visible. What is it beyond just light that make something illuminated? I've always assumed it was reflecting off things, if this is so then how solid does something have to to reflect light? What other qualities does it need?
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