[ramans93]

I need SIMPLE, understandable explanations, and if there are good examples, those will do too.
I really need someone to explain all these and also provide examples if you have any.

1)What are reference frames ?

2)Why can simultaneous events for one observer not be simultaneous for another?

3)What is the significance of the Mickelson-Morley Experiment?

4)What is the Relativity Principle?

5) What is meant by the constancy of the speed of light?

6) What is time dilation?

7) What is length contraction?

8) What is mass increase?

9) Why can't objects exceed the speed of light?

10) How cany you solve Energy, Mass, and Speed of Light problems?

Thank you

[HelpinHere]

1: Your terminology may be different, but I believe you are referring to "pictures" or frames of an object moving. Like a flip book, or the still frames of a movie.

2: Because, light/sound takes time to travel.
IE: One person could see a ball bounce, and hear a gunshot at the same time, but someone farther away will observe them at different times.

4: Do you mean principle of relativity? If so, then it's that the laws of physics must be the same for all observers, regardless of whether they are accelerated in relation to each other.

5: The speed of light is ALWAYS 299,792,458 m/s, in a vacuum. I think that's what you're referring to, at least.

9: Because, theoretically, to go faster than light would be to go faster than time itself. (REALLY basic way to put it)

10: Use equations, such as for light, for mass, and and/or for energy.

I could Google the others, but I'm sure other users know about those off the top of their heads! ;)

[Unknown008]

7: I guess you are referring to the contraction of substance on cooling. Substances usually contract on cooling, that is get a smaller volume, or shrink. In the case of a solid, you'll find that the length will decrease.

8: Mass usually is said to be always constant. But if you look at Einstein's equation, E=mc^2, you'll see that you can increase mass by giving energy to a substance. Of course, you will require huge amounts of energy to increase the mass of an object by a pound, since the energy you provide will be divided by the square of the speed of light. That's also why, in nuclear physics, a small mass gives off a huge amount of energy.

10: If you're referring to a question involving all of energy, mass and the speed of light, then Einstein's formula is the link of all the three. That is

E is the energy, m the mass and c the speed of light.

[galactus]

3)What is the significance of the Mickelson-Morley Experiment?

In a nutshell, the idea was that waves need a medium to travel through, so physicists at the time made the completely reasonable assumption that there was a medium that filled all of space, called the luminiferous ether.

It was thought that this ether provided the medium necessary for the propagation of electromagnetic waves.

The Mickelson-Morley experiment was designed to detect the motion of the earth woth respect to the ether---but found nothing. This is one of the most famous "null" results in the history of experimental physics.

Then Einstein came along and once again used mostly theoretical arguments to derive special relativity.

The bottom line is that Physics is a science that stands on theory and experiment. Not on either alone.

[HelpinHere]

Hmm... between all responses, the only one not covered is #6: "What is time dilation?"

I have some knowledge on that one, but can't explain it simply...

Hope someone can, it's the only one left!

[ebaines]

Unfortunately there is some misinformation in a few of the previous posts. Let me try a few:

5. The important concept regarding the constancy of the speed of light (c) is that it is constant FOR ALL OBSERVERS, regardless of their relative motion to each other. Think about it - this doesn't apply to any other thing that moves. Example - if you're on a train going 60 MPH and throw a ball forward at 40 MPH, to you it's going 40 MPH but to an observer on the ground that ball is going 100 MPH. The two velocities add - this is the concept of relativity as it apples in the every day world - and I believe is what 4 is asking about. But if you're on a hypothetical train going 1/2 the speed of light (1/2 c) and shoot a laser gun forward, you will perieve the laser photons leaving you at speed c, but amazingly to the observer on the ground photons are also going at c. So for light, the velocities do NOT add, but rather c is constant for all observers.

6. Time dilation is the only way to explain 5. If two observers see the same photon as going at c regardless of their relative velocities, this can only occur if each observer percieves the other's clock as running slow.

7. Similarly, each observer perceives that the other's physical size has shrunk in the direction of relative travel. This is another consequence of 5. In the example of the train - the observer on the ground watching the train approach at 1/2 c will perceive that the train to be shorter in length than the person on the train believes it to be; and conversely the person on the train will perceive that the person on the ground is very thin.

8 & 9. The mass of a particle increases and approaches infinity as its speed approaches c. This is why anything with mass can never quite reach c - because the energy required to accelerate it approaches infinity as its speed approaches c, so it can't be done.

Hope this helps.