Question 1: How is acceleration caused if
not by an unbalanced force?
Ethan: I just came from another physics
site that discussed Newton's laws. They said his 1st law states
that an
object's acceleration is due to an unbalanced force. Are you saying
here that there is no such thing as an unbalanced force? How do
you think an object can possibly accelerate if it is not
being pushed in some direction by an unbalanced force? I'll go with Newton
on this one. W. J. Lincoln
City, OR, USA
Question 2: Why does gravity behave so
forcefully at times?
Hi Ethan: I am enjoying your
articles. Keep them coming. My question is about gravity. Most
times it seems easy to handle. But at other times, the force of gravity
can be brutal. Like when I was younger and fell from a ladder and hit my
head on a sidewalk. I'll never forget how violent that blow felt to my
head. I didn't black out, but it was some time before I felt okay.
Why does gravity behave so forcefully at times like this and not at
others? R.S. Austin, TX, USA
Question 3: Would a
non-rotating Earth still bulge?
Good morning Sir: I was
wondering if the earth's rotation were halted and instead all other objects in
the universe rotated the other way around earth's axis at the rate of one rotation every 24
hours, do you know if the earth would continue to maintain the bulge
around its equator? rhanson
Question_4: Does A.C.E. disprove the a/R
force of matter?
Hello: Have you visited the A.C.E.
spacecraft web site at http://sd-www.jhuapl.edu/ACE/ACE_FactSheet.html
? This spacecraft is in a halo orbit of the Lagrange L1 point where it
generally stays in line between the earth and the sun throughout the year. The fact
sheet lists the spacecraft's position as follows.
"ACE will orbit the L1 libration point which is a point of Earth-Sun gravitational equilibrium about 1.5 million km from Earth and 148.5 million km from the Sun."
Notice how the gravitational forces are in equilibrium, meaning the spacecraft is attracted to the sun by a gravitational force that is equal to the gravitational force the spacecraft is attracted in the opposite direction to the earth. My question is that if this event is occurring as you predict, with the ACE spacecraft accelerating in the sun's direction as it orbits the sun, then are you not predicting that your acceleration/Reaction force is reacting on the spacecraft's matter in the earth's direction? If so, I wonder if your a/R force is not an extra, unnecessary outward force, which if it did exist, would upset the balanced state of the spacecraft's current gravitational equilibrium which is the obvious reason the spacecraft is able to maintain its position at the L1 point throughout the year?
Please explain,
Ralph
Question 5:
Is centrifugal force real?
Ethan: I think centrifugal forces are real.
Do you agree? If so, then why are we being told by the experts that they
are false or
imaginary?
E.R., Mexico City, Mexico.
Question 5:
Addendum
Additional thoughts on the confusion surrounding accelerating
frames of reference.
Question 6: What is kinetic energy's role during
braking?
Ethan: If you are correct in saying that
kinetic energy is imaginary, then how do you explain the heat being
generated by the application of a moving car's brakes? Is
not the car's stored kinetic energy being converted into heat energy as the
car's speed is being reduced? mkleist, Bonn, Germany
Question 7: What is curved space?
Ethan: Please explain curved space.
Brett W., Boston, Massachusetts, USA
Question 8:
What causes Earth's dual high tides?
Hello Ethan:
I have read that the greater high
tide on the moon side of the earth is caused by attraction of the water
toward the moon while the lesser high tide on the opposite side of earth
is caused by that water lagging behind in earth's
acceleration around the center of mass it shares with the Moon. I
think this comes from Newton's theories. Do you think this is the
correct cause of these high tides? Walter E., Vancouver
BC, Canada.
Question 9:
Will you help me fill in the blanks?
Hello Ethan,
Please help me fill in the blanks
1. a body at rest tends to --------- at rest
2. a body in motion tends to -------- in motion
3. For every action there is an ---------and------------ re-action
Thank you, E.B., Weston, Ontario, Canada
Question 10: The direction of the
pendulum's overall force is... ?
The Pendulum Event
The following survey question was asked of the Physics
students of several colleges. The results of the survey caused the
survey's author great concern since the students, more often than not, failed to
give the expected answer. An article on the results by the survey's author
was printed in a well-known Physics magazine. The magazine received
several letters challenging the validity of the expected answer. The
author defended his position with apparent success. Since I still
disagreed with the expected answer, I decided to submit an analysis to the
magazine. My analysis included a drawing of the event. Overall my
submission was the opposite of brief. The magazine's editor politely
explained that he could not print my analysis of the pendulum event due to the
lack of space.
The Survey Question
A swinging pendulum bob is, for a brief instant, directly
below its point of support. Draw an arrow indicating the direction of the
overall force on the bob at this instant.
The Expected Answer
The student draws an upward-directed arrow over the bob in
the direction of its support.
Question 11:
Is not inertia the reason for objects same rate-of-fall?
Greetings Ethan:
Interesting site you have here. After reading the first
article about inertia, I have uncovered a problem. I learned in school
some time ago that different sized objects fall at the same rate for the
following reason: a more massive object has more inertia that needs to be
overcome so its greater weight is no more effective in causing acceleration than
is the lesser weight of a less massive object with its lesser inertia. The
problem is that now that I understand that inertia is not real, I am left unsure
as to the reason why objects fall at the same rate here on earth. Do you
know the answer? J. T., Dallas, Texas, USA.
Question 12:
Do Newton's laws hold true in accelerating frames?
Ethan Skyler:
It seems to me that Newton's Laws are not the whole answer
since they only hold true in frames where acceleration is absent. After
reading through your site, I get the feeling that you think otherwise. If
so, please explain why. J.W., Boston, MA, USA
Question 13:
How wrong is the bowling ball-rubber sheet model?
Mr. Skyler:
I often read of the following demonstration of Albert Einstein's
space-time version of gravitation. A bowling ball, representing the sun is placed on top and in the middle of a horizontally stretched
sheet of rubber. The weight of the bowling ball causes a
circular depression to form. A marble, representing the earth, is set into motion around the stationary bowling ball.
It is then pointed out that the earth marble ends up orbiting the sun bowling
ball as if there exists some imaginary gravity force between them that is pulling the earth marble in the
direction of the sun bowling ball.
I have read of this demonstration to explain Einstein's General Relativity theory perhaps a dozen times. In fact I have read of no other type of demonstration of his theory.
After reading through several articles on Universal Physics, I have a pretty good idea of what you think of Einstein's space-time version of gravitation. What I am really wanting to know is if you see anything wrong with this bowling ball resting on a rubber sheet model.
W.G., Philadelphia, PA, USA
Question 14:
Is centrifugal acceleration real?
Dear Mr. Skyler:
I have read with interest your descriptions of centripetal
force and centripetal acceleration. I agree that
centrifugal force is a real acceleration/Reaction force. I wonder if
centrifugal acceleration is also real. On another site where the Coriolis force
is explained, centrifugal acceleration
is said to be possible since it is apparent to an observer who is riding on the
earth's rotating surface.
They say the object being observed is experiencing centrifugal
acceleration and further that its cause is an apparent force predicted to be present by Newton's law
1. This force they refer to as the Coriolis force. No further
explanation is offered as to the nature of this force nor its cause. Will you look into this and let me know if you think centrifugal
acceleration is real or not?
F.W. (no city or country indicated)
Question 15:
Quarter mile drags + lightened flywheel = improved times. Why?
Mr. Ethan:
I have been thinking about momentum and inertia and the
accepted science around these topics as well as the questions posed by your
articles. Here is something I would like to see explained. Take any road car and
measure its performance over a quarter mile. Remove the spare wheel or otherwise
take 15 lb. out of the car and measure the performance again. It may be faster
but the difference will be insignificant. Now lighten the flywheel by 15 lb. and
measure the car's performance times again. The car is faster and not by the
amount of weight removed from the flywheel it is measurably faster. What is at
work here?
There is another situation with the light and heavy flywheel. In quarter mile drags if the same start manner is used by revving up to the limiter and dropping the clutch with the light and heavy flywheels the car with the heavy flywheel will get off the line faster but will be caught and beaten by the car with the light flywheel. Of course we assume identical cars with the same power to weight ratio. The heavy flywheel is also more likely to burn clutches and break drive train parts coming off the line. This must have something to do with the heavy flywheel at high rpm when the clutch is dropped. If inertia and momentum do not exist, then what is causing the damage?
R.M., Thornhill, South Africa
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