Possibility of star formation around black holes

[Motor Daddy]

Either play or watch tennis. Note the difference in trajectories. A ball hit with topspin (every ball you see a pro hit), travels faster and lands before a flat ball hit with the same force. Yet a ball hit with backspin will travel further. With backspin it is also possible for the ball to be hit a little higher, land and spin back toward its starting point. It happens in golf too when a wedge is used. Some points in tennis have ended with a ball that hits the opponents side and spins back over the net out of the opponents reach.

In order to create a spin on a ball the ball must be hit at a different angle than a ball hit without spin. I mean, a ball hit the same way in the same spot moves the same. Spin is created by hitting the ball at a different point or at a different angle.

 

[origin]

So what you're saying is that it takes 1 second to travel the 5 meters and get to a velocity of 10 m/s. If at that exact t=1 second point you started decelerating to 0 m/s at the acceleration rate of 10 m/s^2, then presumably it would decrease velocity from 10 m/s to 0 m/s in 1 second, hence, it took you 2 seconds to travel 10 meters. Do the same in reverse direction and it takes you the same two seconds. So if at the exact point in time (t=2 seconds) you reach the turnaround point and you return to the start point in an additional 2 seconds, then you've completed a 20 meter round trip journey in 4 seconds. 20 meters in 4 seconds is a speed of 5 m/s, not 10 m/s.

Very good. Do you know there is a difference between instantaneous velocity and average velocity?

Outcome of your scenario:

t = 0 instantaneous v = 0 m/s average v = 0 m/s
t = 1 instantaneous v = 10 m/s average v = 5 m/s
t = 2 instantaneous v = 0 average v = 5 m/s
t = 3 instantaneous v = 10 m/s average v = 5 m/s
t = 4 instantaneous v = 0 average v = 5 m/s

 

[origin]

Either play or watch tennis. Note the difference in trajectories. A ball hit with topspin (every ball you see a pro hit), travels faster and lands before a flat ball hit with the same force. Yet a ball hit with backspin will travel further. With backspin it is also possible for the ball to be hit a little higher, land and spin back toward its starting point. It happens in golf too when a wedge is used. Some points in tennis have ended with a ball that hits the opponents side and spins back over the net out of the opponents reach.

Yes, it is well known how a tennis ball, a golf ball or a baseball move due to spin and air friction.

I still feel comments like these...

Therefore under a coordinate system angular momentum of a photon is created by gravity only. Under equivalence it is an additional momentum and an additional velocity

... do not make sense!

 

[Beaconator]

Yes, it is well known how a tennis ball, a golf ball or a baseball move due to spin and air friction.

Friction is not a fundamental force. Nor does its mention negate the possibility of angular momentum being effected by gravity Wrt direction.

If you were trying to get a photon to hit a "standing" electron at a perfect tangent, would it be easier to calculate gravity and friction, or calculate the momentum of the electron and try a frequency which matches approximately the same area?

 

[Trippy]

So what you're saying is that it takes 1 second to travel the 5 meters and get to a velocity of 10 m/s. If at that exact t=1 second point you started decelerating to 0 m/s at the acceleration rate of 10 m/s^2, then presumably it would decrease velocity from 10 m/s to 0 m/s in 1 second, hence, it took you 2 seconds to travel 10 meters. Do the same in reverse direction and it takes you the same two seconds. So if at the exact point in time (t=2 seconds) you reach the turnaround point and you return to the start point in an additional 2 seconds, then you've completed a 20 meter round trip journey in 4 seconds. 20 meters in 4 seconds is a speed of 5 m/s, not 10 m/s.

Correct, as Origin pointed out, it's the difference between average velocity and instaneous velocity. While the object might have had a peak instaneous velocity of 10m/s its average velocity through the entire journey is 5m/s. Same principle applies when you're driving.

Regarding my earlier example, it's also correct to say that the 'delta vee' was 14m/s in a south westerly direction.

 

[Motor Daddy]

Correct, as Origin pointed out, it's the difference between average velocity and instaneous velocity. While the object might have had a peak instaneous velocity of 10m/s its average velocity through the entire journey is 5m/s. Same principle applies when you're driving.

Regarding my earlier example, it's also correct to say that the 'delta vee' was 14m/s in a south westerly direction.

So you agree that a beach ball at rest on the beach has an acceleration of 0 m/s^2 towards the center of the earth??

 

[origin]

If you were trying to get a photon to hit a "standing" electron at a perfect tangent,

What is a perfect tangent?

would it be easier to calculate gravity and friction, or calculate the momentum of the electron and try a frequency which matches approximately the same area?

I have no idea what you are trying to get at here.

Have we completely abandon the OP about star formation? Are you just bring up random thoughts or is this going somewhere?

 

[James R]

So you agree that a beach ball at rest on the beach has an acceleration of 0 m/s^2 towards the center of the earth??

No, because the Earth is rotating. The beach ball is moving in a circle as the surface of the beach goes around the centre of the Earth. This change in velocity of the ball means it must be accelerating constantly.

 

[Motor Daddy]

No, because the Earth is rotating. The beach ball is moving in a circle as the surface of the beach goes around the centre of the Earth. This change in velocity of the ball means it must be accelerating constantly.

The ball is at point A and the center of the earth is at point B. There is a distance between point A and point B, and that distance is not changing. The distance between the ball and the center of the earth is not changing, but time is changing at all times! A greater than zero time change and a zero change in distance means a zero velocity towards the center of the earth. At NO TIME does the distance between the ball and the center of the earth change. If the velocity was zero for a time greater than zero, then the acceleration was zero.

Think of gravity like this, James:

You are standing on a rotating planet. You are holding a ball in one position for a period of time. Now you lift the ball. What just happened? I'll tell you what just happened, you forced an acceleration on the ball. What does that mean? It means that the ball had a rotational velocity because the planet was rotating. When you "lifted the ball" you were increasing the distance the ball was away from the axis. When you did that you were increasing the rate at which the ball travels though space, as you increased the distance that the ball was traveling per time because you increased the radius. In terms of cars, the object was traveling at a constant 55 MPH and when you "lifted the ball" you stomped on the gas pedal of your 1970 GTO with a 400 CID Pontiac and had real excitement! The only problem is, when you let off the pedal the force is reduced and the car starts decelerating back towards the "center of the earth."

...and with that in mind, my prediction is that the earth will give birth to another moon at some point in the future. Wanna know what happened in the past?

 

[Trippy]

So you agree that a beach ball at rest on the beach has an acceleration of 0 m/s^2 towards the center of the earth??

Not neccessarily.

The earth rotates once every 24 hours.

An object 'at rest' on the earth's surface rotates with the earth, completing a rotation once every 24 hours.

The earth has an equatorial circumference of 40,075 km. An object at rest on the earths equator must cover this distance every 24 hours as the earth rotates about its axis. This means any object at rest on the earths equator is travelling at approximately 1670 km/hr.

At equinox, at dawn, the direction of that motion is toward the sun, at mid-day the direction of the motion is to the east, at dusk the direction of the motion is away from the sun, and at midnight the direction of the motion is towards the west.

In order to go from travelling at 1670 km/hr sunwards to 1670 km/hr eastwards, following the equator of the earth, we must change our velocity by 2362 km/hr (656 m/s) in the direction of the center of the earth. This results in a net instaneous acceleration of 0.03 m/s/s towards the center of the earth. The acceleration is the same for the other three changes, and is always towards the center of the earth.

Whilst the instaneous acceleration is always 0.03 m/s/s towards the center of the earth, the average acceleration over a full rotation of the earth of an object at rest on its surface is 0m/s/s because over the course of a full rotation the sum of the vectors is zero.

This, incidentaly is why we use terms like Peak Music Power Output (PMPO) and RMS Power when describing things such as power supplies or music systems - because the average power of such systems is zero, as is the average of any sinusoidal function that isn't translated vertically.

 

[Motor Daddy]

Not neccessarily.

How much closer did the ball get to the center of the earth?

 

[Trippy]

How much closer did the ball get to the center of the earth?

It doesn't have to in order to accelerate because:

A change in direction of a body in motion, when applied to an object with mass, requires a force to be applied to the object to change its direction of motion. IE: It needs to be accelerated.

And when considering a ball on the surface of the earth:

The earth rotates once every 24 hours.

An object 'at rest' on the earth's surface rotates with the earth, completing a rotation once every 24 hours.
...
At equinox, at dawn, the direction of that motion is toward the sun, at mid-day the direction of the motion is to the east, at dusk the direction of the motion is away from the sun, and at midnight the direction of the motion is towards the west.

Please at least make an effort to read my replies to you in full and address the points raised rather than cherry-picking and trolling.

 

[Motor Daddy]

It doesn't have to in order to accelerate because:

We are not talking about force. Acceleration is defined as the rate of change of velocity. The velocity of the ball towards the center of the earth is 0m/s, period. If you claim that it is something other than 0 m/s then tell me what the distance change is in between the ball and the center of the earth in the 24 hour day in which you speak of.

 

[Trippy]

We are not talking about force. Acceleration is defined as the rate of change of velocity.

Velocity is a vector, a change in velocity can result from either a change of the diretion of the motion, or a change in the magnitude of the motion.

The velocity of the ball towards the center of the earth is 0m/s, period.

I haven't said otherwise:

At equinox, at dawn, the direction of that motion is toward the sun, at mid-day the direction of the motion is to the east, at dusk the direction of the motion is away from the sun, and at midnight the direction of the motion is towards the west.

If you claim that it is something other than 0 m/s then tell me what the distance change is in between the ball and the center of the earth in the 24 hour day in which you speak of.

I've already answered that question:

Whilst the instaneous acceleration is always 0.03 m/s/s towards the center of the earth, the average acceleration over a full rotation of the earth of an object at rest on its surface is 0m/s/s because over the course of a full rotation the sum of the vectors is zero.

If the average acceleration toward the center of the earth over the course of a 24 hour day is 0m/s/s, what do you think the distance change is going to be?

 

[Motor Daddy]

If the average acceleration toward the center of the earth over the course of a 24 hour day is 0m/s/s, what do you think the distance change is going to be?

I already told you, the ball is on the beach and the distance never changed between the ball and the center of the earth. The ball had a closing speed between the ball and the center of the earth of 0 m/s. ZERO METERS PER SECOND!

 

[Trippy]

I already told you, the ball is on the beach and the distance never changed between the ball and the center of the earth. The ball had a closing speed between the ball and the center of the earth of 0 m/s. ZERO METERS PER SECOND!

If you're struggling with this introductory stuff, what I'm going to say next is really going to bake your noodle.

Whilst the distance between the ball and the center of the earth remain constant at all times, if we measure the eastward displacement of the ball from the center of the earth, it starts at a maximum in the morning, decreases to zero by mid-day, becomes increasingly negative until dusk, at which point it begins decreasing toward zero again at midnight, and finally returns to its original value.

Even though at all times the distance between the ball and the center of the earth is constant.

To recap:

The average acceleration of the ball toward the center of the earth over a full 24 hour cycle is 0m/s/s
The instaneous acceleration of the ball at all times is 0.03m/s/s
The distance between the ball and the center of the earth is, at all times, 6371 km (the mean radius of the earth
The eastward displacement of the ball from the center of the earth varies between 6371 km and -6371km, and is 0 twice during the 24 hour rotation.

 

[paddoboy]

...and with that in mind, my prediction is that the earth will give birth to another moon at some point in the future. Wanna know what happened in the past?

:roflmao:

That has not ever happened, [without some kind of imputus] nor will it ever happen.
That is pure pseudoscience.

 

[Motor Daddy]

To recap:

The average acceleration of the ball toward the center of the earth over a full 24 hour cycle is 0m/s/s

That's what I said, in 24 hours the ball did not change distance from the center of the earth, so the acceleration for that 24 hour period was zippo. You brought up all the other stuff when all I was asking you was how much the distance changed. The ball did not increase or decrease velocity, it simply stayed at 0 m/s for 24 hours.

Imaginary "gravity" because of some magic trick in the air is not to be believed. FORCE and acceleration are to be measured and be believed! Newton got it wrong, there is no magic crap in matter that makes magic work. It isn't magic, it's FORCE, and it doesn't work the way you think it does, hence the inability to understand gravity for what it really is.

 

[paddoboy]

Imaginary "gravity" because of some magic trick in the air is not to be believed. FORCE and acceleration are to be measured and be believed! Newton got it wrong, there is no magic crap in matter that makes magic work. It isn't magic, it's FORCE, and it doesn't work the way you think it does, hence the inability to understand gravity for what it really is.

Newton's model works...It has worked for more than 300 years...It is used by all of humanity every minute of every day of every year....It is still the prime model used when sending space craft and probes to distant solar system planets, as the more precise Einstein version is not needed.
Them there there are the facts.

 

[Motor Daddy]

Newton's model works...It has worked for more than 300 years...

Magic!