Showing posts with label astronomy. Show all posts
Showing posts with label astronomy. Show all posts

Tuesday, August 2, 2011

The Fundamentals, Part 1: Gravity

With all the talk happening on PiPT about fictitious motion, antimatter transformations, and overly-complicated analyses of the tides, it’s about time that we went back and explored the bare necessities of the Universe, those few things it absolutely needs to be what it is today. These absolutes are called the fundamental interactions of nature: 
  • Gravity
  • Electromagnetism
  • Strong Force
  • Weak Force
They're the four things that keep everything in one piece; without them, nothing, not even atoms, would exist. 
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1. Gravity
Good ol' gravity. It's the force that most of us are probably most familiar with, though it's the weakest of the four by far. Its effects have been known for about as long as humans have been on this Earth, yet it took a long time for someone to truly see it as its own entity. Aristotle was one of the first; he described gravity as the movement of objects to their 'natural place'. Earth went the lowest, water floated on that, air floated on that. Pretty straightforward. 

Wednesday, July 27, 2011

I Can't Believe They're Not Forces!

If you’ve ever taken a Physics course, you may have learned about Newton’s 3 Laws of Motion. In case it’s been a while:
  1. An object in motion stays in motion
  2. The force of an object is equal to the mass multiplied by the acceleration (F=ma)
  3. For every action, there is an equal but opposite reaction.
These are the rules upon which Classical Physics was founded. They are taught in grade school like they are the end-all and be-all of motion in our Universe, and one can certainly do amazing things with them. However, think about this interesting mind experiment: you slide a puck on a frictional rotating table.
That’s it. That’s the mind experiment. You can picture that, right? Because Newton’s Laws can’t.

...pause for dramatic effect...