[juner]

You're right. I let an 11% overstatement get into my post that I could have avoided by spending more time explaining where 8.7 m/s² came from to someone who appears not to even grasp the concept of acceleration. I opted for concept over precision. I do apologize that my choice doesn't suit your likes, but, hey, that's why I read and respond to replies to my posts--to learn. Now, if you could please take the time to explain to Thork why you think that he is woefully wrong, I would bet many would be appreciative. I know I would. Thanks in advance.

I enjoyed how when PP showed how incredibly wrong you were, your only defense was to whine and make excuses.

It is okay to be wrong.  Maybe try learning some humility.

[Gulliver]

You're right. I let an 11% overstatement get into my post that I could have avoided by spending more time explaining where 8.7 m/s² came from to someone who appears not to even grasp the concept of acceleration. I opted for concept over precision. I do apologize that my choice doesn't suit your likes, but, hey, that's why I read and respond to replies to my posts--to learn. Now, if you could please take the time to explain to Thork why you think that he is woefully wrong, I would bet many would be appreciative. I know I would. Thanks in advance.

I enjoyed how when PP showed how incredibly wrong you were, your only defense was to whine and make excuses.

It is okay to be wrong.  Maybe try learning some humility.

Just out of curiosity... do you ever use this alt to provide content, or can we all just put it on the "ignore list"? Thanks.

[juner]

You're right. I let an 11% overstatement get into my post that I could have avoided by spending more time explaining where 8.7 m/s² came from to someone who appears not to even grasp the concept of acceleration. I opted for concept over precision. I do apologize that my choice doesn't suit your likes, but, hey, that's why I read and respond to replies to my posts--to learn. Now, if you could please take the time to explain to Thork why you think that he is woefully wrong, I would bet many would be appreciative. I know I would. Thanks in advance.

I enjoyed how when PP showed how incredibly wrong you were, your only defense was to whine and make excuses.

It is okay to be wrong.  Maybe try learning some humility.

Just out of curiosity... do you ever use this alt to provide content, or can we all just put it on the "ignore list"? Thanks.

I created this alt and made it an administrator so I could purposefully upset you.

I am sorry if the only content I provide is hurting the feelings of angry noobs.  I see you didn't take note of my comment about learning some humility.  Please, continue on being butt hurt.

[Pete Svarrior]

You're right. I let an 12% overstatement get into my post that I could have avoided by spending more time explaining where 8.7 m/s² came from to someone who appears not to even grasp the concept of acceleration. I opted for concept over precision.

In this particular case, you were responding to inquisitive, not Thork. While I have personal disagreements with inquisitive, I do know that he's an RE'er, and I doubt he would have denied that the ISS has an acceleration; so no, you weren't explaining this to someone who doesn't grasp the concept - you were answering a question to someone who was probably appreciative of the concept, and you were answering it incorrectly.

Seriously, sometimes it's easier to just say "okay, I made a mistake" and move on. Everyone makes mistakes sometimes - it only reflects negatively on you when you do everything in your power to deny the mistake (and make further mistakes in doing so).

As for why Thork is wrong - I think others have done a pretty good job at explaining it. Under the round Earth model, it would be impossible for the ISS to stay in orbit if it wasn't accelerating - it would necessarily have to either float away from the Earth or crash right into it. In fact, this would be largely true for a flat Earth as well (although the specifics of the acceleration may vary).

[Gulliver]

I enjoyed how when PP showed how incredibly wrong you were, your only defense was to whine and make excuses.

It is okay to be wrong.  Maybe try learning some humility.

Just out of curiosity... do you ever use this alt to provide content, or can we all just put it on the "ignore list"? Thanks.

I created this alt and made it an administrator so I could purposefully upset you.

I am sorry if the only content I provide is hurting the feelings of angry noobs.  I see you didn't take note of my comment about learning some humility.  Please, continue on being butt hurt.

Thank you. That's what we needed to know. I'll be sure to encourage noobs to read this post and ignore this and any other alts we detect.

You're right. I let an 12% overstatement get into my post that I could have avoided by spending more time explaining where 8.7 m/s² came from to someone who appears not to even grasp the concept of acceleration. I opted for concept over precision.

In this particular case, you were responding to inquisitive, not Thork. While I have personal disagreements with inquisitive, I do know that he's an RE'er, and I doubt he would have denied that the ISS has an acceleration; so no, you weren't explaining this to someone who doesn't grasp the concept - you were answering a question to someone who was probably appreciative of the concept, and you were answering it incorrectly.

Seriously, sometimes it's easier to just say "okay, I made a mistake" and move on. Everyone makes mistakes sometimes - it only reflects negatively on you when you do everything in your power to deny the mistake (and make further mistakes in doing so).

As for why Thork is wrong - I think others have done a pretty good job at explaining it. Under the round Earth model, it would be impossible for the ISS to stay in orbit if it wasn't accelerating - it would necessarily have to either float away from the Earth or crash right into it. In fact, this would be largely true for a flat Earth as well (although the specifics of the acceleration may vary).

Thank you for explaining this again to Thork (and his alt, spoon). I'm sure he'll try to learn from your post. I assume your comment about dealing with mistakes applies first and foremost to the worst mistake (Thork's) in the thread. As far as my mistake is concerned, I've admitted to it and explained why I choose to make it.

I disagree that every time that I quote someone that I'm replying to only the author of the quote. Surely you expect others to read your posts, right?

Finally, I'd appreciate if in your signature you correctly quote me. I, as any grade school student should do, specified the direction of the vector involved, here: toward the center of the Earth. Thanks again.

[juner]

Thank you. That's what we needed to know. I'll be sure to encourage noobs to read this post and ignore this and any other alts we detects.

I am glad you can admit you are nothing more than an angry noob.  Someone shows you where you are wrong, and the best you have is accusing people of being alts.  It is kind of sad, really.  Anyway, best of luck in your other endeavors, as you were thoroughly dismantled here.  Another victory for FE!

[Pete Svarrior]

I assume your comment about dealing with mistakes applies first and foremost to the worst mistake (Thork's) in the thread.

No, it doesn't. Thork hasn't made a mistake, he's simply fundamentally wrong about things. You, on the other hand, I suspect were fully aware of Newton's law of universal gravitation, but merely forgot to apply it in this situation, having assumed that 400km wouldn't be enough to make a significant difference. It's a much less serious issue, except for the fact that your continuous dodging and denying of it makes it more serious - there is a difference between making a mistake (and owning up once pointed out), being completely wrong (Thork's case), and being intellectually dishonest (what you've escalated your own case to). Own up, admit a mistake, move on. Simple.

Finally, I'd appreciate if in your signature you correctly quote me. I, as any grade school student should do, specified the direction of the vector involved, here: toward the center of the Earth. Thanks again.

Unfortunately, sigs have limited lengths, and I made sure to include the direction as part of the context. Of course, since the question was about the value (magnitude) of the acceleration, it is inappropriate and needless to specify the direction - magnitudes themselves do not have directions. I'd be happy to include this in my sig to make you look even worse, but, as I said, we limit sigs at 300 characters.

Thank you. That's what we needed to know. I'll be sure to encourage noobs to read this post and ignore this and any other alts we detect.

You may want to acknowledge 2 things:

• Jokes exist, and sometimes people make them. (This is something I recall you failing at on numerous occasions, and it really doesn't help your arguments)
• While there are many people who could easily be accused of being one another's alts, junkers and my identities are transparent enough for this to be highly unlikely.

Ultimately, if you suspect that someone is using alts for sockpuppetting, you should report it in S&C. While having alts is not disallowed here, using them in attempt to benefit oneself in a conversation is.

[Gulliver]

Thork hasn't made a mistake, he's simply fundamentally wrong about things. You, on the other hand, I suspect were fully aware of Newton's law of universal gravitation, but merely forgot to apply it in this situation, having assumed that 400km wouldn't be enough to make a significant difference. It's a much less serious issue, except for the fact that your continuous dodging and denying of it makes it more serious - there is a difference between making a mistake (and owning up once pointed out), being completely wrong (Thork's case), and being intellectually dishonest (what you've escalated your own case to). Own up, admit a mistake, move on. Simple.

Unfortunately, sigs have limited lengths, and I made sure to include the direction as part of the context. Of course, since the question was about the value (magnitude) of the acceleration, it is inappropriate and needless to specify the direction - magnitudes themselves do not have directions. I'd be happy to include this in my sig to make you look even worse, but, as I said, we limit sigs at 300 characters.

Thank you for that very useful and detailed reply. I learned several important things.

I hope you'll accept some feedback though. I'll try diligently here not to be pedantic or "snarky".

How does Thork claim that the ISS does not accelerate without his making a mistake? Are you saying that if I was merely confused about the importance of a 12% error, I did not make a mistake? Maybe you've confused his mistake of ignorance with my error of judgement.

A vector quantity is clearly defined in mathematics to include both its magnitude and (if the magnitude is non-zero) its direction. No, the value of vector is not just its magnitude. You might find this explanation useful: http://www.physicsclassroom.com/Class/1DKin/U1L1b.cfm , If you will, you should consider your mistake here similar to declaring that the value of a real number is just its absolute value, ignoring its sign.

Please define what you mean by "admitting a mistake". Please contrast it with what I've posted:

You're right. I let an 12% overstatement get into my post that I could have avoided by spending more time explaining where 8.7 m/s² came from to someone who appears not to even grasp the concept of acceleration. I opted for concept over precision. I do apologize that my choice doesn't suit your likes, but, hey, that's why I read and respond to replies to my posts--to learn.

Again, you really should quote directly, not add "context" yourself. I count that you dropped 32 characters. But, hey, it's not like accurate quoting is essential as long as you get the context right.

Approximately: 9.8 m/s² towards the center of the Earth.

Again, I found your post helpful. Thanks.

[DuckDodgers]

It looks like a few of you missed the portion where thork clearly states it has no angular acceleration, stating that the angular velocity is constant. 

[Rama Set]

It looks like a few of you missed the portion where thork clearly states it has no angular acceleration, stating that the angular velocity is constant. 

Thork clearly said:

The ISS doesn't accelerate. Its in low earth orbit at a constant speed of around 17000mph To have a force of acceleration in one direction and an opposing force that cancels that out in the opposite direction does not mean one is accelerating. If I get in my car and accelerate to 150mph before the wind resistance is so great my car stops accelerating doesn't mean I am still accelerating. It means I am now at 150mph and that is that as the forces balanced.
You are confusing angular velocity with angular acceleration.
https://en.wikipedia.org/wiki/Angular_velocity

He said the ISS has no acceleration because it has no Angular acceleration, which is not a true statement.

[Gulliver]

It looks like a few of you missed the portion where thork clearly states it has no angular acceleration, stating that the angular velocity is constant.

Please tell me more. Are you saying that Thork meant to say that I was wrong to say that the ISS accelerates (as an example of an object moving in one direction but accelerating in another) because it has no angular acceleration? Surely you'd expect Thork to know the difference between acceleration and angular acceleration before saying that the ISS does not accelerate, right? On the "old site", I believe he claimed to be a laid-off commercial cargo jet co-pilot. Please help me understand your point. Thanks.

It looks like a few of you missed the portion where thork clearly states it has no angular acceleration, stating that the angular velocity is constant. 

Thanks Rama Set for another great post. You bet me to most of the point.

Thork clearly said:

The ISS doesn't accelerate. Its in low earth orbit at a constant speed of around 17000mph To have a force of acceleration in one direction and an opposing force that cancels that out in the opposite direction does not mean one is accelerating. If I get in my car and accelerate to 150mph before the wind resistance is so great my car stops accelerating doesn't mean I am still accelerating. It means I am now at 150mph and that is that as the forces balanced.
You are confusing angular velocity with angular acceleration.
https://en.wikipedia.org/wiki/Angular_velocity

He said the ISS has no acceleration because it has no Angular acceleration, which is not a true statement.

[DuckDodgers]

Christ on a bike. I know their is an acceleration due to gravity in the RET model. I also know that angular acceleration is a vector quantity and not a scalar. BUT THE ISS IS NOT ACCELERATING! It has an angular velocity. Not an angular acceleration. Why are you being so obtuse?

I rest my case.  No angular acceleration is clearly his statement.

[Gulliver]

Christ on a bike. I know their is an acceleration due to gravity in the RET model. I also know that angular acceleration is a vector quantity and not a scalar. BUT THE ISS IS NOT ACCELERATING! It has an angular velocity. Not an angular acceleration. Why are you being so obtuse?

I rest my case.  No angular acceleration is clearly his statement.

No... He said, "THE ISS IS NOT ACCELERATING". In Science, accelerating is not the same as angular acceleration. Here are links to each defintion:
http://en.wikipedia.org/wiki/Acceleration
http://en.wikipedia.org/wiki/Angular_acceleration

Saying that the ISS is not accelerating because the ISS has a constant angular velocity is like saying you can't be thirsty while swimming in the Pacific Ocean.

Oh, and if I read Thork's misspellings as I think he intended, he argues that the ISS has an acceleration, but isn't accelerating. I think he meant there some other force (centripetal?) providing an opposing acceleration, so the IIS's net acceleration is zero. Go figure.

[DuckDodgers]

You clearly did not read thork's post that I quoted.  He blatantly says "it has an angular velocity.  Not an angular acceleration." Thork is clearly right and you refuse to acknowledge that he is.

[Gulliver]

You clearly did not read thork's post that I quoted.  He blatantly says "it has an angular velocity.  Not an angular acceleration." Thork is clearly right and you refuse to acknowledge that he is.

I never said either of those two sentences were wrong. (Well, actually I did agree earlier with markjo that due to variations in ISS's orbit it does indeed have times with angular acceleration. So, yes, Thork is wrong even on that, but it's not nearly as bad (or on topic) as saying the ISS does not accelerate.)

To repeat: Thork stated that the ISS does not accelerate. He is wrong.

ETA (in a flippant manner): So are you proposing a new Rule of Engagement. Every time Thork posts a true sentence, I must log on within a day and acknowledge that he is right? Did you want to extend that to all FEers' sentences in all threads and every REer acknowledgement of each true sentence? I think you may be protesting too much there, pal.

[Rama Set]

You clearly did not read thork's post that I quoted.  He blatantly says "it has an angular velocity.  Not an angular acceleration." Thork is clearly right and you refuse to acknowledge that he is.

Just to be succinct.  No one is saying that the ISS has angular acceleration.

Thork essentially is saying: "The ISS has no acceleration because it does not have angular accleration."  This is wrong because the ISS has linear acceleration.

[DuckDodgers]

He is saying it have no change in angular velocity, hence no angular acceleration.  He has made no claim regarding it in a linear sense.

[Gulliver]

He is saying it have no change in angular velocity, hence no angular acceleration.  He has made no claim regarding it in a linear sense.

Wrong. He said:

The ISS doesn't accelerate. Its in low earth orbit at a constant speed of around 17000mph To have a force of acceleration in one direction and an opposing force that cancels that out in the opposite direction does not mean one is accelerating. If I get in my car and accelerate to 150mph before the wind resistance is so great my car stops accelerating doesn't mean I am still accelerating. It means I am now at 150mph and that is that as the forces balanced.
You are confusing angular velocity with angular acceleration.
https://en.wikipedia.org/wiki/Angular_velocity

Rama Set just told you this. Please pay attention.

[DuckDodgers]

When speaking of orbit, is a constant speed not a constant angular velocity?  You've really muddied up the whole discussion.

[Rama Set]

When speaking of orbit, is a constant speed not a constant angular velocity?  You've really muddied up the whole discussion.

Garygreen provided many sources to elaborate on this.  Please have a boo below:

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.