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You seem to think that the ISS is not accelerating towards the earth?No. Have you tried actually reading the thread I linked you to? And I already told you you got your r wrong, but I suppose that didn't come through, so I'll try again:
And just to clarify as it seems that centripetal acceleration is poorly understood. The calculated value of g for the ISS using g = -GM/r^2.Yes, I've already explained this to Gulliver in the appropriate thread (although your r is slightly too low, causing an inflated result, but you're still closer than Gulliver's 9.8m/s2, so all is forgiven). If you have anything to add to that thread, please post it there, not here.
r = radius from the centre of the earth to the ISS. The radius of the earth is about 6,371,000 m and the ISS orbits at about 370,000 m hence r = 6,741,000
M = mass of the earth, approx 5.97219 × 10^24 kg
G = 6.67 x 10^-11
Hence g (Of the ISS) = 8.77ms^2 or Nkg^-1
g = -GM/r^2Yes, some parts of physics are fundamentally different between models. You'd think that would be obvious, given that FET introduces a whole new concept of dark energy accelerating the Universe.
It's really as simple as a single equation. The inverse square law tells us that the gravitational force due to stars are completely negligible. Indeed the objects in the heavens as you describe it, have no impact on the calculated value of g.
It's interesting how you separate FE physics from RE physics. One of the principal rules of physics is that the laws of physics are the same regardless of location, yet on earth there's an exception?
Quite simply, everything with mass experiences a gravitational force.I have in the past asked people to show to me that bananas exert a gravitational force (I even suggested the Cavendish experiment when people started getting confused). Unfortunately, no one even attempted it. It is claimed that all bodies exert a gravitational force, and we quite simply disagree.
I think this can be summarised withAssumptions, assumptions, assumptions.
1. The earth has zero mass and is hence unaffected by gravity (Which would pull the earth into a sphere). With UA providing the acceleration of free fall.
2. The acceleration of free fall is affected by the gravitational force of stars.Almost. I'm not sure why you'd restrict yourself to just the stars. We're talking about the heavens.
How are both trueThey're not.
I'm so confused.sirTheMore is a Victorian industrial revolutionary gentleman (think Isambard Kindom Brunel, but with a moustache) who somehow ended up travelling to the 21st century. He also happens to hate Linux and free/open-source software, and sometimes gets very upset about it.
I'm sorry but the explanation for the UA is dark energy?Correct.
The heavens have a slight and uneven gravitational pull?Indeed.
But sticking with UA, you're saying the "heavens" have a gravitational pull. So you're saying gravity is true.Yes and no. Let's hope you don't jump into any rash conclu-
And therefore a flat earth contradicts everything we could know about gravity. What...sions. Right, you did jump to rash conclusions. Just because gravitation (not to be confused with gravity) is exerted by some bodies does not mean all bodies necessarily have to exert it.
What have I done?
Warmest, best, and brightest,
sirTheMore
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.For the record, I don't buy your "error of judgement" explanation. It's quite clear that you didn't realise the correct answer was 8.7m/s2 and went with standard g because you didn't think about it long enough. I do not suspect that you lacked the knowledge necessary to make the correct conclusion - hence it was a mistake. However, even if it was an error of judgement regarding whether or not an unacceptable error margin is acceptable, that's essentially the definition of a mistake (See: http://www.merriam-webster.com/dictionary/mistake).
to blunder in the choice of <mistook her way in the dark>
[...]
a wrong judgment : misunderstanding
[...]
You might find this explanation useful: http://www.physicsclassroom.com/Class/1DKin/U1L1b.cfm
Scalars are quantities that are fully described by a magnitude (or numerical value) alone.
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.Unfortunately, this is impossible - I cannot fit an accurate quote of both the question and your untruncated answer within the character limit. Omitting the question would completely eliminate the context and make it unreadable to the viewers unless they explicitly followed the link in the quote. Those who have any doubts about the appropriateness of my quote can still click on "Quote from: Gulliver [...]" and read the messages in context. However, since the context was relayed accurately, and the only part of your message that got omitted is irrelevant (and could only make you look worse), this is overall a good deal for you.
To know that some RE'ers don't understand grade school physics look no further than:
[quote author=Gulliver link=topic=1577.msg30543#msg30543 date=1401389390]
[quote author=inquisitive]
What is the value of the acceleration? [i][of the ISS towards the Earth][/i]
[/quote]Approximately: 9.8 m/s[sup]2Cool fine with me I bet Parse wins with hacks every time anywayParsifal and I are usually pretty closely matched, actually
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:
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.
So you consider 8.7m/s2 to be "approximately" 9.8m/s2. In other words, an error margin of 12% is perfectly acceptable to you. Well, I suppose that tells us a lot about your understanding of grade school physics. I shall update my sig to reflect that.I highlighted the word you may have missed.Approximately: 9.8 m/s2 towards the center of the Earth. See: http://en.wikipedia.org/wiki/Standard_gravitySurely it would be considerably less than that, given that the ISS is quite much farther away from the Earth. A brief calculation based on Newton's law of universal gravitation suggests something more akin to 8.7m/s2.
Oh, and just to help you with your physics your forgot to specify the direction of your accelerations.Yes, because that's definitely relevant when one's explicitly calculating magnitudes. Get the fuck out of here.
Hey Thork, pizzaplanet not only agrees with me that the ISS accelerates but provides a non-zero magnitude for it.Yes, Thork is woefully wrong. So are you, having claimed that the ISS is literally on the round Earth's surface (if it's not right now, then the acceleration of 9.8m/s^2 will bring it there very soon, and we should brace for this catastrophic event). It's shameful that you're not willing to acknowledge it. It would have been perfectly fine for you to admit that you mistakenly applied standard gravitation where it obviously shouldn't have been applied, but you lack the honesty to do so. This will be duly noted.
Approximately: 9.8 m/s2 towards the center of the Earth. See: http://en.wikipedia.org/wiki/Standard_gravitySurely it would be considerably less than that, given that the ISS is quite much farther away from the Earth. A brief calculation based on Newton's law of universal gravitation suggests something more akin to 8.7m/s2.
I actually played Battle of Westnorth quite a bit after Parsifail wouldn't shut up about it. It's alright.1v1 me m8
is the worst pile of garbage I have ever played.