1481

Philosophy, Religion & Society / Re: Apparently The Revolution Has Begun

« on: June 13, 2014, 03:39:52 PM »

Of course.  Literally no other problem could arise from everyone in a confined area carrying weapons.

Someone should tell all the gun stores.

Yeah, gun stores never get robbed because everyone knows that the owners and patrons are packing heat!

oh wait that doesn't actually deter criminals nevermind

http://www.aikenstandard.com/article/20140612/AIK0101/140619823
http://www.huffingtonpost.com/2013/11/26/charles-rowan-gun-store-manner_n_4345204.html <- literally decided to rob a gun store with a hammer.  succeeded.  deterrence works, right?!
http://www.wboc.com/story/13897486/4-arrested-in-laurel-gun-shop-robbery
http://www.wtae.com/news/local/coroner-called-to-shooting-at-gun-shop/23715272#!Ysf0E
http://www.wthr.com/story/19562707/two-shot-at-dons-guns

hey remember that episode of it's always sunny when dennis threatens to shoot that guy and then everyone in the gun shop pulls out a gun and stops him?  that was awesome and never actually happens

1482

Flat Earth Community / Re: Newton's Laws of Motion

« on: May 29, 2014, 10:05:24 PM »

Why would you consider the linear motion of an object when it is oh-so-obviously in an orbit (according the the RE model)?

Thork is right. The ISS has constant angular velocity, ergo no acceleration.

Ergo no angular acceleration.  Any curved motion through space is accelerated motion.  In a non-rotating frame, the path of the ISS is curved.  Acceleration must be happening.

Forget it. They can't be that stupid. I think I got trolled for 2 pages. :-(

You haven't been trolled.  You're just not correct that the ISS isn't accelerating.  And you haven't brought to bear a single source that disagrees with my assessment.

Here are more sources that agree with me and say virtually word-for-word what I've been saying to you in this thread:

http://www.gravity.phys.uwm.edu/~doqui/doqui/209-5.pdf

An object revolving in a circle is continuously accelerating even when the speed remains constant.

http://dev.physicslab.org/Document.aspx?doctype=3&filename=CircularMotion_CentripetalAcceleration.xml

An object is said to be moving in uniform circular motion when it maintains a constant speed while traveling in a circle. Remember that since acceleration is a vector quantity comprised of both magnitude and direction, objects can accelerate in any of these three ways:
 
       1. constant direction, changing speed (linear acceleration);
       2. constant speed, changing direction (centripetal acceleration);
       3. change in both speed and direction (angular acceleration).

http://www.physicsclassroom.com/mmedia/circmot/ucm.cfm

An object moving in a circle is accelerating. Accelerating objects are objects which are changing their velocity - either the speed (i.e., magnitude of the velocity vector) or the direction. An object undergoing uniform circular motion is moving with a constant speed. Nonetheless, it is accelerating due to its change in direction. The direction of the acceleration is inwards.

http://www.sparknotes.com/physics/dynamics/uniformcircularmotion/section1.rhtml

Because the direction of a particle moving in a circle changes at a constant rate, it must experience uniform acceleration.

http://web.utk.edu/~cnattras/Physics221Spring2013/modules/m5/uniform_circular_motion.htm

An object moving in a circle of radius r with constant speed v is accelerating.  The direction of its velocity vector is changing all the time, but the magnitude of the velocity vector stays constant.  The acceleration vector cannot have a component in the direction of the velocity vector, since such a component would cause a change in speed.  The acceleration vector must therefore be perpendicular to the velocity vector at any point on the circle.  This acceleration is called radial acceleration or centripetal acceleration, and it points towards the center of the circle.

1483

Flat Earth Community / Re: EnaG Critique

« on: May 29, 2014, 02:02:19 AM »

Rapid does not mean 'accelerate.'  For example: The car traveled at a constant speed of 100mph as it rapidly approached the cliff face.  This sentence is not confusing because I described something as moving rapidly and constantly.

http://www.merriam-webster.com/dictionary/rapid

rap·id adjective \ˈra-pəd\
: happening in a short amount of time : happening quickly
: having a fast rate
: moving quickly

http://www.merriam-webster.com/dictionary/accelerate

ac·cel·er·ate verb \-lə-ˌrāt\
: to move faster : to gain speed
: to cause (something) to happen sooner or more quickly

Your quoted definition does not say that 'rapidly' refers to a constant pace. It says that it refers to something happening quickly in a short amount of time. Ie. accelerate.

 

Accelerate does not mean 'to happen quickly in a short amount of time.'  Read the definitions of those two words.  Notice that they have different meanings. 

In physics, acceleration is a change in velocity.  'Rapidly' does not mean 'a change in velocity.'  If Rowbotham wanted to say that the horse is accelerating away from the rider, then he should have used that word instead of rapidly, because 'rapidly' does not mean 'to accelerate.'  Equivocate all you like.  Those two words are not synonyms.

1484

Flat Earth Community / Re: Newton's Laws of Motion

« on: May 26, 2014, 07:01:33 PM »

How about you take a reading comprehension test.

Setting the gravity force from the universal law of gravity equal to the required centripetal force yields the description of the orbit.

I missed this yesterday, and I can't pass it up.  This sentence agrees with me.  It says that the description of an orbit comes from setting the force of gravity equal to the required centripetal force.  Equal to.  No opposed to.  As we just learned (from your own source), centripetal force is applied toward the center of curvature.

Every single statement from this source that you provided is in direct opposition to your argument, and in exact alignment with mine.

Just look at the maths you provided.



This describes exactly what I've been saying to you.  The very first term is "F_gravity = F_centripetal".  It's a force equation.  Nothing in these maths is showing a canceling out of the force of gravity.  It describes an accelerating object.  By definition.

Please tell me more about my reading comprehension.

1485

Flat Earth Community / Re: Newton's Laws of Motion

« on: May 26, 2014, 01:08:10 AM »

Just admit that you're wrong.  Your own source says directly and explicitly that you are wrong.  "Any motion in a curved path represents accelerated motion, and requires a force directed toward the center of curvature of the path."  The ISS follows a curved path.  All of the credible evidence in this thread, including your own sources, explicitly concur with what I've been saying since my first post in this thread.

source: http://www.reformation.org/geostationary-satellites.html

That diagram is showing centrifugal force, which isn't a real force and doesn't keep satellites in orbit.  It also manages to get that wrong.  Centrifugal force cannot explain the orbit of the ISS in a rotating reference frame.  It's just a mathematical tool to describe objects in a non-inertial reference frame as if they were in an inertial reference frame.

http://en.wikipedia.org/wiki/Centrifugal_force_(rotating_reference_frame)

Analysis of motion within rotating frames can be greatly simplified by the use of the fictitious forces. By starting with an inertial frame, where Newton's laws of motion hold, and keeping track of how the time derivatives of a position vector change when transforming to a rotating reference frame, the various fictitious forces and their forms can be identified. Rotating frames and fictitious forces can often reduce the description of motion in two dimensions to a simpler description in one dimension (corresponding to a co-rotating frame). In this approach, circular motion in an inertial frame, which only requires the presence of a centripetal force, becomes the balance between the real centripetal force and the frame-determined centrifugal force in the rotating frame where the object appears stationary.

It's also different from centripetal force, which is what you were talking about originally.  Dunno why we're talking about centrifugal forces now.

Oh, and your source talking about centrifugal force is both incorrect and incredible:

http://www.reformation.org/page2.html
http://www.reformation.org/stationary-earth.html
http://www.reformation.org/antichrist.html
http://www.reformation.org/lincoln-conspiracy-solved-at-last.html

Weren't you just criticizing another user for offering sources that weren't scientifically credible?  Do you think this religious website counts as credible or reliable?

e: I'm getting my inertial/non-inertial/rotating reference frames mixed up in my head, so I'm not sure I'm getting those relations right in relation to centrifugal force.  The point is that it's a fictitious force that doesn't actually describe how a satellite stays in orbit.

Oh look more physicists saying exactly what I'm been saying to you this whole time: http://math.ucr.edu/home/baez/physics/General/Centrifugal/centri.html

After this fine start, von Braun then proceeds to muddy the water.  He says that as the bullet is shot at ever faster speeds, "its trajectory will be less deflected because the centrifugal force is increased by its higher speed, and more effectively counteracts the Earth's gravitational pull."  At this point physicists baulk.  Centrifugal force?  What has that got to do with satellite motion?
[...]
In an inertial frame, if there really were two equal-but-opposite forces on the satellite as von Braun drew them, then the total force on it would be zero.  So it wouldn't accelerate; it would move in a straight line with constant speed.  Since the orbiting satellite doesn't move in a straight line, neither von Braun's picture nor his explanation can be right.
[...]
In reality, nothing holds the Moon up.  As Newton's inertial frame analysis predicts, the Moon is completely under gravity's thrall; in other words, it falls, because in such a frame there's only one force on the Moon: gravity.  Gravity accelerates it.  That doesn't mean its speed must necessarily change, or that it must get closer to Earth (although actually both of these things do occur slightly during the month, but that's not an important point).  If Newton's F=ma is solved for the general case of falling under gravity, the motions that result are lines, circles, ellipses, parabolae, and hyperbolae.  In one of those great correspondences between Nature and pure mathematics, these are precisely the curves that result if we take a cone and slice it in any direction.

Even if the Moon's orbit were circular, its direction of travel would still be changing, which is one kind of acceleration.  (Remember that acceleration is a change in velocity, meaning that acceleration can change an object's speed, or it can change merely the direction of motion, or both.)

It's practically a word-for-word summary of my arguments.  Do you have anything other than some random religious website to support your argument?

1486

Flat Earth Community / Re: Newton's Laws of Motion

« on: May 26, 2014, 12:09:26 AM »

centripetal force

DING DING DING DING DING WE HAVE A WINNER!!!!  Welcome to the point I've been making this whole time.  But you seem to think centripetal force opposes gravity?  Gravity is the centripetal force.  You'd know that if you read the links your image came from instead of just being like 'yo dude check out these maths cool huh they totally prove my point for some reason.'

http://hyperphysics.phy-astr.gsu.edu/hbase/orbv.html#co

Gravity supplies the necessary centripetal force to hold a satellite in orbit about the earth.

http://hyperphysics.phy-astr.gsu.edu/hbase/cf.html#cf

Any motion in a curved path represents accelerated motion, and requires a force directed toward the center of curvature of the path.

But please, keep asserting your asinine misconceptions with absolute confidence.

1487

Flat Earth Community / Re: Newton's Laws of Motion

« on: May 25, 2014, 11:34:05 PM »

I can't be any more specific.

You could start by using the correct words to describe the correct things.

I'm sat in my chair. I'm not accelerating anywhere. t=0 is the same as t=15 seconds.
There is a force of acceleration exerted on me, But I'M NOT ACCELERATING.

You experience no acceleration in the direction of the Earth's surface because you are resting on a chair.  The force of the chair opposes equally the force of gravity.  The ISS is not resting on a chair.  There is no force opposing the force of gravity for the ISS.  Again, if there were, then the ISS could not be in orbit.  I don't think you actually read my posts.  I've explained this like five times now.  You're just like PP.  You just read a couple of sentences and skip over responding to the substance of what anyone says.  Just hit reply and start typing something.  And you think for some reason that it's a mark of intelligence.  You're fucking weird.

There isn't a legitimately licensed pilot on the planet who could possibly have this kind of trouble applying and speaking intelligently about Newton's laws.  Get out with that nonsense.  What a joke. 

e: you also don't seem to get what an inertial frame of reference is, which would also be super troubling if you were actually a licensed pilot.  You are not accelerating toward the surface of the Earth when seated (or accelerating at all in your local, rotating inertial frame.  Everything around you is moving at the same rate under the same forces).  But, you are being accelerated in a non-rotating inertial frame (say, from the point of view of someone looking at the whole Earth from a stationary position in space).  Your velocity vector changes as you rotate around the globe on the Earth's surface.  Just as with the ISS, if it didn't, then you would travel at a constant speed and direction and fly off the surface as it fell away below you.

Any change in the direction or magnitude of a velocity vector is called acceleration.  By definition.  That's what the word means.

1488

Flat Earth Community / Re: Newton's Laws of Motion

« on: May 25, 2014, 10:55:02 PM »

I am not disputing that there is a component of acceleration. I'm saying the ISS itself is not accelerating. The forces balance.
Read the bloody thread.

That doesn't make sense.  Please clarify.  The ISS can't be accelerating and not accelerating.

I think the problem is that you're using 'acceleration' and 'angular acceleration' interchangeably.  They don't mean the same thing.  Angular acceleration is a change in angular velocity.  Acceleration is a change in any velocity vector.  Speaking of reading the thread, this entire discussion could have been avoided by you reading my first post in this thread that contains these definitions. 

The ISS has a constant angular velocity (no angular acceleration).  It does not have a constant velocity.  Those are different things.  Its speed is constant.  Its velocity is not.  This is because the ISS is being accelerated by the force of gravity in the direction of the Earth's surface, as per all of the sources I've cited.  This is the very definition of an orbit.  It couldn't stay in orbit without being accelerated toward the surface of the Earth.

The OP was exactly right, and you basically just proved his point with your posts in this thread.  You just don't have any concept that acceleration means a specific thing and has a specific definition.  It doesn't just mean 'going faster.'  And it means something different from angular acceleration.  Just as angular velocity means something different than velocity.  You're just mixing up all these terms and definitions and then acting like everyone else is an idiot for not knowing that you're doing that.

1489

Flat Earth Community / Re: Newton's Laws of Motion

« on: May 25, 2014, 08:59:58 PM »

Or consider the following reductio:

Let's assume that you're correct that the ISS is not accelerating.  That means, by definition, that its velocity vector does not change.  So, if the ISS is above the Earth with some velocity, and if that velocity does not change, then, per Newton's 1st, it will move at a constant speed and direction until some force acts on it.  The trajectory of the ISS would look like this:



It would have to.  If the velocity vector doesn't change, then the path of the ISS will always be a straight line in the direction of its velocity.

Since its path is elliptical and not a straight line, its velocity must change.  Any change in velocity over time is acceleration.

1490

Flat Earth Community / Re: Newton's Laws of Motion

« on: May 25, 2014, 08:42:40 PM »

BUT THE ISS IS NOT ACCELERATING! It has an angular velocity.

These two sentences cannot both be true.

Again, http://en.wikipedia.org/wiki/Angular_velocity

angular velocity is defined as the rate of change of angular displacement

Angular velocity is the rate at which the direction component of a velocity vector changes over time.  Acceleration is the rate at which a velocity vector changes over time.  Angular velocity requires acceleration.

Exactly what we've been trying to tell you from the beginning is that the ISS could not have any angular velocity without a force causing it to accelerate in the direction of the Earth's surface.  Angular velocity is a quantity that describes how much its velocity vector changes over time.

1491

Flat Earth Community / Re: Newton's Laws of Motion

« on: May 25, 2014, 07:56:41 PM »

I am saying that the ISS is not accelerating.

I think you're just confusing speed and velocity.  Speed is a scalar quantity.  It is described only by magnitude.  The speed of the ISS is constant.

Velocity is a vector quantity.  It is always described by magnitude and direction.  The direction component of the ISS' velocity changes as it orbits due to the force of gravity.  This is acceleration.  Any change in an objects' velocity is acceleration.

I am sat in my chair. Under RET that means I have a force of acceleration towards the ground at 9.81 m/s^2.
But I'M NOT ACCELERATING ANYWHERE. At t=0 I am sat in my chair and at t=5 minutes I'm still in the exact same spot. There has been no rate of change at all.  Having a force of acceleration applied to me doesn't mean I am accelerating. The forces are cancelled. I'm stationary. The ISS has its forces cancelled. It travels with a constant angular velocity. Its not accelerating anywhere.

The ISS is not resting on a chair resting on the Earth's surface.  The force of gravity is not cancelled out by anything.  That's what we're trying to tell you.  It's always freely falling toward the Earth because of the force of gravity.  This force is not cancelled out.  It changes the direction of the ISS' velocity vector.  That's acceleration.

The ISS doesn't stay in orbit because the force of gravity is cancelled out.  The force of gravity acts on the ISS and causes it to accelerate in the direction of the Earth's surface. 



Look at how the velocity vector is constantly changing direction.

http://en.wikipedia.org/wiki/Orbit#Understanding_orbits

There are a few common ways of understanding orbits:

-As the object moves sideways, it falls toward the central body. However, it moves so quickly that the central body will curve away beneath it.

-A force, such as gravity, pulls the object into a curved path as it attempts to fly off in a straight line.

-As the object moves sideways (tangentially), it falls toward the central body. However, it has enough tangential velocity to miss the orbited object, and will continue falling indefinitely. This understanding is particularly useful for mathematical analysis, because the object's motion can be described as the sum of the three one-dimensional coordinates oscillating around a gravitational center.

Notice that all of these descriptions involve acceleration due to gravity.  Gravity alters the velocity vector.  That's what acceleration is.

1492

Flat Earth Community / Re: Newton's Laws of Motion

« on: May 25, 2014, 06:23:56 PM »

The ISS doesn't accelerate.

http://en.wikipedia.org/wiki/Angular_acceleration

Angular acceleration is the rate of change of angular velocity.

http://en.wikipedia.org/wiki/Angular_velocity

In physics, the angular velocity is defined as the rate of change of angular displacement and is a vector quantity (more precisely, a pseudovector) which specifies the angular speed (rotational speed) of an object and the axis about which the object is rotating.

http://en.wikipedia.org/wiki/Acceleration

Acceleration, in physics, is the rate at which the velocity of an object changes over time.

http://en.wikipedia.org/wiki/Velocity

Velocity is the rate of change of the position of an object, equivalent to a specification of its speed and direction of motion, e.g. 60 km/h to the north[...]Velocity is a vector physical quantity; both magnitude and direction are required to define it. The scalar absolute value (magnitude) of velocity is called "speed"[...]

The ISS has a velocity (magnitude and direction).  It's velocity vector changes due to the force of gravity.  This change caused by the force of gravity is known as acceleration.

More info: https://www.khanacademy.org/science/physics/newton-gravitation/gravity-newtonian/v/acceleration-due-to-gravity-at-the-space-station

Seriously, take one physics class if you want to argue about physics.

1493

Philosophy, Religion & Society / Re: Transgenderism

« on: May 22, 2014, 09:37:20 PM »

sometimes some people who look like one gender think of themselves as a different gender.  the end.

1494

Flat Earth Community / Re: EnaG Critique

« on: May 09, 2014, 02:32:08 PM »

Rapid does not mean 'accelerate.'  For example: The car traveled at a constant speed of 100mph as it rapidly approached the cliff face.  This sentence is not confusing because I described something as moving rapidly and constantly.

http://www.merriam-webster.com/dictionary/rapid

rap·id adjective \ˈra-pəd\
: happening in a short amount of time : happening quickly
: having a fast rate
: moving quickly

http://www.merriam-webster.com/dictionary/accelerate

ac·cel·er·ate verb \-lə-ˌrāt\
: to move faster : to gain speed
: to cause (something) to happen sooner or more quickly

But let's assume for the moment that Rowbotham actually meant 'accelerate' instead of 'rapid.'  He performed an experiment to prove that if one object accelerates away from another, that object will accelerate away from the other.  Wow.  Brilliant.

What does that have to do with a round Earth?

1495

Flat Earth Community / Re: Astronomers found a star colder than ice

« on: May 08, 2014, 05:42:21 AM »

Last I checked Jupiter was not self luminous.

Neither are brown dwarfs.  At least, not in the same way as stars with fusion in their cores.  They're just like Jupiter in this regard, only larger.

http://scienceworld.wolfram.com/astronomy/BrownDwarf.html

A failed star which is not massive enough to ignite thermonuclear fusion in the core. According to stellar models, the maximum mass a brown dwarf can have is ~0.08M☉. Young brown dwarfs which are gravitationally contracting can release substantial amounts of gravitational energy, but older stars radiate from remnant internal heat only. For old brown dwarfs, the luminosity is smaller than smallest luminosity possible for a hydrogen-fusing star,  ~0.0001L☉.

Just like Jupiter, brown dwarfs emit infrared radiation.  That's how astronomers find them.  They're very faint, and it's apparently quite difficult to detect them.

http://coolcosmos.ipac.caltech.edu/cosmic_classroom/cosmic_reference/brown_dwarfs.html

Brown dwarfs are very dim and cool compared with stars. The best hope for finding brown dwarfs is in using infrared telescopes, which can detect the heat from these objects even though they are too cool to radiate visible light.

1496

Flat Earth Community / Re: Astronomers found a star colder than ice

« on: May 08, 2014, 01:18:37 AM »

It isn't 'powered' by anything.  The core of a giant ball of gas doesn't have to burn fuel to be hot.  See: gas giants.  This is what I was getting at with the Jupiter example on the first page.  This is all perfectly consistent with how modern science describes all the gas giants. 

Jupiter's core is very hot.  Jupiter's surface is very cold.  Convection is happening in between. 

http://www.universetoday.com/11096/jupiters-winds-come-from-inside/

“Our model suggests convection driven by deep internal heat sources power Jupiter’s surface winds,” said Jonathan Aurnou, UCLA assistant professor of planetary physics. “The model provides a possible answer to why the winds are so stable for centuries. Jupiter’s surface is the tail; the dog is the hot interior of the planet."

http://coolcosmos.ipac.caltech.edu/page/jupiter_saturn

Heat from the interior of Jupiter causes circulation patterns in the atmosphere, with warm gas rising and cooling, before sinking back into the depths of the planet. This process is called convection, and it causes the different colored bands in Jupiter's atmosphere.

1497

Flat Earth Community / Re: Astronomers found a star colder than ice

« on: May 07, 2014, 07:22:27 PM »

A thought experiment just came to mind.  Here's how you can know that convection doesn't lead to thermal equilibrium.

Before you put too much thought into your experiment, first we should all agree as to what constitutes thermal equilibrium.  Does it mean that the temperature throughout the brown dwarf is the same or does it mean that the brown dwarf dissipates as much heat into space as it generates in its core resulting in relatively stable temperature zones?  Personally, I vote for the latter.

I take Tom to be saying that because the core is very hot, and because convection carries heat away from the core toward the surface, that the surface ought to be as hot as the core.

1498

Flat Earth Community / Re: Astronomers found a star colder than ice

« on: May 07, 2014, 06:01:29 PM »

A thought experiment just came to mind.  Here's how you can know that convection doesn't lead to thermal equilibrium.

Suppose that the BD suddenly is in equilibrium: the gas around the core is just as hot as the core.  Heat transfer will cause the star to lose that equilibrium.

Atoms at the surface will cool.  Some of them will be ejected from the star and take their energy with them, cooling the surface.  Many of them will radiate energy, also cooling the surface.  Those atoms will tend to fall toward the core.

Atom at the core will heat up.  Gravity will pull them together, and the increase in pressure will increase the temperature of the core.  Those atoms will tend to move away from the core and cool and they reach the surface.

Convection doesn't cause immediate equilibrium.  Heat transfer takes time.

1499

Flat Earth Community / Re: Astronomers found a star colder than ice

« on: May 07, 2014, 03:30:16 PM »

You forgot the part about the outer layers being recycled into the core.

No, I mentioned that in my first post.  Hot matter leaves the core.  It cools as it expands.  After it cools it falls back down toward the core where it is heated again and process continues.  It's like a big circle.  That's what convection is.  Convection doesn't automatically lead to instant thermal equilibrium. 

Heat transfer takes time.  Stars are huge.  The end.

1500

Flat Earth Community / Re: Astronomers found a star colder than ice

« on: May 06, 2014, 12:13:03 AM »

I'm not super up-to-date on my gas laws, but wouldn't the temperature of the gas necessarily decrease as it gets further from the core?  The gas is spreading out over a larger volume, so that means the pressure would decrease, yes?  Which means a decrease in temperature?  And there's definitely less gravitational force acting on the gas, so less energy = lower temperature?

Am I getting those relationships right?