This is of course true from the reference frame of earth as you stipulated. I can only assume that you have had a major misunderstanding of relativity and are pleased that you have cleared it up in your mind. So congradulations!
No confusion on my part. You seem to be the one confused, thinking the beach ball's velocity is increasing at the rate of 9.81 m/s^2 while it is on the beach. So you are telling me that if the velocity on the beach is 0 m/s, that after 1 second the ball has a velocity of 9.81 m/s towards the center of the earth, and after two seconds the ball has a velocity of 19.62 m/s towards the center of the earth? So tell me, then, how much time elapses before the ball actually reaches the center of the Earth?? You are a very confused individual..
Not so, but you don't realize. Before you have relativity you made certain assumptions. (Do not forget, we can not talk yet about relativity.) And I've shown you that yours assumptions are wrong.
When did I talk about a beach ball? I certainly do not think that a ball sitting on the ground has a velocity relative to the ground. You really come up with some interesting stuff.Please Register or Log in to view the hidden image!
Did I? (Oh - shhhhhh) You have? What assumptions? Are we allowed to talk about them?Please Register or Log in to view the hidden image!
You said: The reality is, an object such as a beach ball at the earth's surface (the beach) is not accelerating. What makes you think that the ball's velocity is increasing at the rate of 9.81 m/s^2 while on the beach? At the surface of the earth, while the ball is at the surface of the earth the velocity towards the center of the earth is 0 m/s, and since I can sit there and watch the ball for two and a half hours, and the ball doesn't get any closer to the center of the earth, then I can correctly say that the ball did not accelerate, which means its velocity did not change in 2 1/2 hours, its velocity is still 0 m/s, and therefore it's acceleration is 0 m/s^2! You want to say the beach ball is accelerating at the rate of 9.81 m/s^2 at the surface of the earth??? Prove it!!! Please Register or Log in to view the hidden image!
Oooooo, you have such deep and mysterious knowledge of the universe. Mere mortals cannot hope to comprehend the depths to which you understand high school algebra. We are not worthy. Please Register or Log in to view the hidden image!
Why don't we let you prove it. Follow these steps. 1. Jump into the air. 2. If you post again I will assume that you are not in outerspace and you have proved it. Like I said these Newtonian physics are just, so, like you know, wicked hard to understand.... it's mind boogling dude. Please Register or Log in to view the hidden image!Please Register or Log in to view the hidden image!
You said the acceleration at the surface of the earth is 9.81 m/s^2. Well, I'm at the surface of the earth, and I am NOT accelerating towards or away from the center of the earth. My distance from the center of the earth is remaining unchanging. Therefore I have a 0 m/s velocity towards the center of the earth, and the rate at which my velocity towards the center of the earth is increasing or decreasing is 0 m/s^2. So you say when I am laying on the beach my acceleration is 9.81 m/s^2, and I say my acceleration is 0 m/s^2. The distance between me and the center of the earth remains unchanged, so you are wrong and I am correct. You see how that works? Are you living in your imaginary world again where you like to pretend beach balls on the beach are accelerating at the rate of 9.81 m/s^2, when really the rate of change of velocity is 0 m/s^2? You really need to start living in reality and stop pretending. Please Register or Log in to view the hidden image!
This is very basic stuff here. I am not going to try and teach you elementary physics. Suffice to say that accleration can be calculated by the change in velocity or it can be calculated by the dividing the force of an object by the mass of the object. In the case of gravity you can derive the acceleration by measuring the change in the velocity of a falling object or by weighing an object and dividing the weight (force) by the mass. Either way you are calculating the acceleration due to gravity. The fact that this is something that you think is imaginary is really not surprising. I recomend that you do not test your theory by jumping off a bridge.Please Register or Log in to view the hidden image! You really need to take an introductory course in physics, especially since you have shown (in your mind) that you are smarter than Einstein, and the millions of people that have actually studied physics.
How do you recommend I jump off a bridge at the surface of the earth? Are saying I need to get above the surface of the earth, and free fall until I reach the surface of the earth?? Now you are changing your story. Before you said I would be accelerating at 9.81 m/s^2 AT the surface of the earth, not while I'm above the surface free falling towards the surface. You really are confused, aren't you??
Sarcasm noted. But, origin, by whose curriculum standards is this "high school algebra"? I think you have overestimated Emil's contributions to this thread. It looks like literally elementary school arithmetic, circa age 11, to me. By the standards, I thought were in place, I thought this was high school algebra: Likewise, high school algebraic geometry: If Emil was working on the subject of Physics, Emil would be meaningfully addressing the claims and arguments here:
Damn, you can seem to understand anything at all. I said, "I DO NOT recommend that you jump off a bridge"! Again I personnaly do not recommend that, but you are free to do what you want. No, I do not believe that is an accurate statement. No, I am not confused in the slightest. I gave you 2 ways to calculate acceleration, a change in velocity and F=ma. Did you not read the post or did you not understand the post? You can choose to have your own definitions of generally accepted terms but it is a bit presumptous to assume that academia will adopt your terminology. Especially since you appear to be completely ignorant of any physics advances since Galileo...
You said you don't recommend I jump off a bridge to test my theory. Do you think my theory is that when I do jump off a bridge above the surface of the earth that while in free fall I wouldn't be accelerating? I never said or implied that. You said I would be accelerating at 9.81 m/s^2 at the surface of the earth. I am on the surface of the earth, and I am not accelerating, so please provide some evidence that my velocity is increasing or decreasing at the rate of 9.81 m/s^2 in order to back up your wild imagination with some type of fact. Why would you recommend that, that would be silly, because that would require me to be above the surface of the earth, not AT the surface of the earth, of which you made statements about. While we're on the subject, do you acknowledge that if I were to be free falling towards the earth, that my acceleration rate would be increasing the closer I got to the earth? How do you reconcile that fact in your equations of acceleration while falling towards the earth? It is not just a particular acceleration rate, because if you are accelerating, you are getting closer to the earth while falling towards the earth, and the distance is decreasing, increasing the acceleration rate while accelerating. How do you account for that? Well a change in velocity towards the center of the earth is not happening while I'm standing on the beach, so that rules that out. Now you mention f=ma. Isn't that a net force? In order to have acceleration, there must be a net force, correct? I use the standard definition of acceleration, which is the rate of change of velocity. Is that not an acceptable definition of acceleration in your physics world?
I think what Motor Daddy is overlooking completely, probably because he hasn't studied physics at high school, is that you can be accelerating in time. Although you have a speed of 0 m/s at the surface of the earth, you experience a force. To explain the force, you say gravity is accelerating your mass towards the centre of the earth. Since the universe is 4-dimensional, you can accelerate in one dimension; that leaves three in which you aren't accelerating. On the surface of the earth the three remaining dimensions are spatial; you accelerate in the time dimension. This is the 'force' of gravity with acceleration g = F/m.
