I already have some stuff I've written for a FAQ, and as soon as I find the file, I'll post it here. In the mean time, I'm looking for questions and information that you guys would like included.

I'm going to change the normal rules for just this one thread. Normally I don't care if things veer off topic for awhile. This time, however, any off topic posts may/will be deleted. Also, questions asked in subsequent posts will be deleted as they are answered, and edited into this post. This is to keep subject matter straight and grouped properly.

__________________
You don't have to think I'm right, as long as you think.

some of these may be too controversial to go in a FAQ but...

• Is time travel to the past possible?
• Can my friend really see and talk to actual spirits & not just figments of his imagination?
• Is my friend's uncle's stepdaughter's best friend's softball coach's brother's foster mom really a psychic?
• Do I have telepathy?
• Is my "perpetual motion machine" actually a perpetual motion machine?
• Are the folks over in Paranoid Delusions really that fucking crazy?

I could write a load on relativity and quantum stuff if you like.

That would be excellent. Thank you.

__________________
You don't have to think I'm right, as long as you think.

Here are some of the questions I thought of so far. Feel free to suggest others.

• What is relativity?
• What is E=mc² all about?
• What happens if I turn on my car headlights whilst travelling at the speed of light?
• Can I travel at the speed of light anyway?
• Is time travel to the future/past possible?
• What is time anyway?
• Does a photon have mass?
• How does gravity work?
• What are black holes and why are they so mysterious?
• What is quantum theory?
• What’s a photon?
• Is stuff made of particles or waves?
• What’s actually going on in the double-slit experiment?
• What is a wave-function?
• Does quantum theory say a particle can be in two places at once?
• What does quantum theory actually say about reality?
• What’s going on in the uncertainty principle?
• What is “zero-point energy”?
• Is quantum theory incompatible with macroscopic physics, especially gravity?

What? I offered to help. Please forgive me.

When is light a wave and when is it a particle?
If it is both, how can it be both?

Ok, I have a more general question. I am in my first year of physics in high school, and find the class too easy and boring. The subject does interest me however, so I am looking for some outside sources to learn physics from. So what resources do you know of so that someone with an average high school education can learn some of the more complex theories of our universe that aren't covered in my classes? Anything that involves deeper thinking than punching numbers into a calculator would be apreciated.

PS- I've read Steven Hawking's "Universe in a Nutshell" and am in the middle of Brian Greene's "Elegant Universe" if that gives you any indication of my current knowledge. Thanks in advance.

If you like math and want something pretty challenging, I would recommend The Road to Reality by Roger Penrose. The first half of the book explains much of the math used in modern physics and the second half goes into great detail of most of the theories in modern physics with a strong emphasis on the math from the first half. You'll probably have to read over the math sections several times to fully understand it, but if you're interested in the mathematical basis for modern physics, its well worth it.

One can go extremely indepth with this thought, however i will outline the basic idea.

It's not literally "both" at any instantaneous moment. However, light has certain wave-like behaviors and certain particle-like behaviors.

Light can be thought of as a collection of particles. These particles are called photons. In a beam of light, there are many many photons. Each photon has energy.

Just think about taking a bunch of pebbles and throwing them. You can think of light the same way; just a bunch of particles moving in a direction. In both examples, the individual photons and pebbles have energy. However, what makes light "wave-like" opposed to the pebbles is how you define their energy.

Take the pebbles for example. Their energy is defined as the sum of potential and kinetic energy. So you can say, the energy of an individual pebble = .5mv^2 + mgh, where m = mass of the pebble, v = velocity of the pebble, g = gravity, and h height of the pebble. Since these pebbles are "particles" with mass, they are affected by forces such as gravity. Pay close attention to the terms in the equation, such as mass and velocity, things exclusive to physical particles. A pebble, has a mass, and when it's moving, it has a velocity. These characteristics specific to "particles" determine energy.

however, for an individual photon, the energy = hv, where h is plank's constant, and v = the wavelength of the photon. Plank's constant is somethin like 6.67 & 10^-34 J/m. When you multiply h and v, the m term cancels and you are left with J (energy).

This is how light behaves like a particle and a wave. Light is composed of individual particles, but what determinse its energy are things specific only to waves, such as wavelength.



now, this all led to the wave particle duality, which basically states all things in nature of characteristics of a particle and characteristics of waves. Think about these two equatiosn.

E = mc^2
E = hv

equate them
hv = mc^2

this is saying that all things have mass, and all things have a wavelength. These both are characteristics of a particle and a wave. A particle has mass, and a wave has a wavelength, and this is how things behave as a both a particle and as a wave.