/sci/ - Science & Math

Both revolve around each other. Welcome to physics 101.
But remember to never say this in public or you become a victim of the "atheist" censorship.

linear motion is relative

angular (circular) motion is not

/thread

>>4490985

>>4490989
true. prove me wrong faggot

circular motion requires acceleration

They both revolve around each other, gravity works this way.

However, the center of mass, and thus center of the rotational system is far, far, far nearer to the Sun. In the Sun's diameter, in fact. So the sun is at the center of our system, and takes priority in mention.

>>4490989

>>4490972
No they both orbit a common centre of mass which is very close to the centre of the sun due to the huge mass of the sun relative to the Earth. Also

>you become a victim of the "atheist" censorship.

The hell are you talking about?

>>4490997
>>4490999
Do you even know what relative motion is?

considering another planets - it's much more efficient to assume that they are all revolve around the sun.

>>4491001
Choose the reference frame of the earth. In this frame the sun is revolving around the earth. That's babby's first physics, seriously.

>>4491003
well duh

basically relative motion is motion that can only be referenced relative to some other object/frame/what have you

circular motion is not this, it is absolute. even in a sealed chamber i can tell if i'm spinning or not.

>>4491001
There is some kind of censorship going on. Certain scientific facts are not allowed to be said. The ones enforcing that censorship are the same pseudo-intellectual redditors who promote a wrong understanding of "atheism". In fact this "atheism" (not the true atheism, but the pseudo-religious version of it) is detrimental to knowledge and science in general. These persons value pop sci and its analogies that are dumbed down into incorrectness more than actual scientific facts.

It's totally reasonable to say that.

In fact, it's a natural point of view, considering we're standing on Earth. Once you consider the motions of other bodies in the system as well, though, it's more convenient to describe motions relative to the Sun instead.

>>4491006
it's not a inertial frame though. only inertial motion is relative. (requiring something the motion is given relative to)

>>4491011
Okay, I see you don't know what relative motion is. Move on to a thread that fits your level of education.

Rotating frames of reference are not inertial.

>>4491016
>>4491020
The center of rotation is inertial.

>>4491014
>Certain scientific facts are not allowed to be said.

Stop making up bullshit, nobody is 'enforcing' censorship in the way you seem to think.

>>4491018
can't tell if troll or retarded high schooler

>>4491011
...
becouse spinning is acceleration, you can tell that you are accelerating on straight line too.

>>4491024
Not censorship as a law. But instant insult, threats and trolls are a form of censorship as well.

>>4491025
yes, and acceleration is also an absolute, not relative to anything

>>4491027
I don't know. You might tell better what you are. I'd say you are a retarded highschooler. For a troll your statement would be way too uncreative and boring.

>>4491024
>nobody is 'enforcing' censorship
>implying the fact that Europeans are more intelligent than Africans is not suppressed

You can say that the sun goes around the Earth, but this is going to have some consequences on the form of your physics [choosing a rotating coordinate frame results in the appearance of "forces" that are not in the non-rotating frame].

>>4491032
acceleration is an absolute, not relative to anything. deal with it. newton had to.

>>4491039
Your sentence is complete and utter bullshit. You don't even know what you're talking about.

>>4491036
If you're going to be completely reasonable maybe you should find somewhere else to play.

yea, they do rotate around each other, but the center of mass is inside the sun's diameter, so we're usually considered a satellite of the sun rather than the other way around.

>>4491040
this. acceleration is a vector quantity.

>>4491040
http://physics.stackexchange.com/questions/173/is-acceleration-an-absolute-quantity

>>4491018
>the guy has his definition of relative motion
>you: NUH UH
Your argument would be more convincing if you could say why he was wrong and provide your own definition.

>>4491044
>thinks vector means it must be relative

>>4491044
samefag is a samefag quality

>>4491045
>if you're doing classical mechanics in an accelerating frame it's not absolute

>>4491057
yes, and fictitious forces have to be introduced to account for the fact that you've forced something absolute to be relative

Can you retards please shut up?
Acceleration is irrelvant to relative motion.

>>4491049
He lacks understanding of the basics. I'm not gonna make up for what his teacher failed to teach him. It's like when you're talking to someone about higher math and he tells you he doesn't know what multiplication is.

>>4491060
Anon probably thinks fictitious forces are real.

>>4491060
Aren't all "forces" fictitious? We just use the simplest ones.

>>4491067
Fictitious forces are real. In whatever reference frame they occur you can measure a change of momentum, i.e. a force.

>>4491065
other guy is right though, though he isn't being very rigorous, so you look kind of silly being all "oh i can't explain he won't understand"

>>4490961
Both are equally correct, but in the battle of the ancients they didn't consider relativity.

>>4491069
in newtonian mechanics, no

>>4491072
you sound like mach, and he was kind of eccentric on this stuff. fictitious forces don't result from any physical interaction, they result from the frame of reference being non-inertial

>>4491076
He is not right. Not at all.

>>4491088
how so, let me guess, we're too stupid to understand

>>4491092
He is missing the point. We are talking about relative motion here and relative motion is always well-defined.

>>4491095
anon has given a definition. what is yours?

>>4491095
http://hyperphysics.phy-astr.gsu.edu/hbase/relmot.html

>in a straight line at constant speed.

ie, not orbiting

>>4491103
He hasn't given a definition at all. All he posted was some babble about acceleration. Irrelevant. Relative motion is the motion of an object relative to another object that we assume to be at rest in his reference frame. Being inertial can be a property of this reference frame but is not required.

>>4491109
That's the version for 10 year olds. Have you ever attended a physics course at university?

>>4491110
>is not required
>acceleration is irrelevant

it sure is required to specify if your origin is accelerating. it changes everything.

>>4491110

>>4491114
no. i'm a maths graduate, though we did mechanics and SR

i fear this is becoming a semantic argument, the last refuge of the told

>>4491120
It makes it necessary to introduce fictitious forces. That's all it does. It definitely does not change the definition of relative motion.

Oh you faggots. All this babble about relative frames of reference is inane. Can you specify an example of two reference frames that are NOT relative please?

>>4491124
now you're just being a silly crybaby who is clutching at straws

>>4491125
>hurr durr I post /b/ image macros

>>4491127
Then you focused to much on your math and didn't learn some important concepts of physics.

>>4491129
I relatively support this motion. Do this, troll, or shut the fuck up.

>>4491132
Do you have more to offer than ad hominems? Maybe a bit of science instead? I posted physical definitions. There's nothing to disagree anymore.

>>4491110
This isn't quite correct. The object you "assume to be at rest" can be shown not to be at rest in non-inertial frames of reference.

Inertial frames are privileged, and drawing motion relative to a non-inertial frame is somewhat artificial. Useful sometimes, but different.

>>4491152
Inertial frames are usually prefered. Indeed. But that doesn't contradict my definition, which remains correct.

>>4491140
not that guy, but weren't you posting a load of ad hominem's earlier?

>>4491155
I have a problem with the "assumed to be at rest" part.

>>4491157
No, I didn't. It's sometimes hard to distinguish anon's posts from anon's posts.

>>4491158
Why?

maths guy here

so physics fags, amirite or amirite?

>>4491160
Because assuming something to be true which can be shown - within the frame, not relative to anything else - to be false, is not good science.

Acceleration is absolute in Newtonian mechanics, not relative. You can bend the math to make it relative, but this is an artifice.

>Motion is relative, so why is it not equally correct to say the sun revolves around the earth as to say the earth revolves around the sun?

It is, it's just more complex to formulate things the other way around. Physicists like elegance.

>>4491158
I don't see what is wrong with it. If I assume that an object is at rest and build my coordinate system appropriately, I should still be able to get a fully functioning physics out of it.

>>4491170
You keep repeating yourself. Acceleration being "absolute" is irrelevant to the discussion. An object being at rest in its reference frame is a matter of definition. The reference frame then can be accelerated or not. The consequences of this are beyond what we are fighting over right now. Your concerns are justified, but the definition remains valid.

>>4491179
You do realise that absolute is the opposite of relative?

The discussion was about whether it is as correct to say the sun revolves around the earth as the earth around the sun.

I claim there is an absolute notion of rotation, it's measurable by things like Foucault's pendulum. yet you keep claiming that this motion is relative, not absolute.

>>4491179
relative motion is kind of reserved for inertial frames. i mean that's what special relativity is about.

>>4491191
Acceleration is not the same as motion. We're talking about relative motion, not relative acceleration. Also acceleration is only abosolute between inertial systems. What you think of as relative motion is in fact galilean invariance, a very special case of relative motion.

>>4491199
It is not reserved for inertial systems. Not at all.

>>4490996
This. That's why the moon and earth like wobble around each other.

>>4491205
>relative acceleration
There is no such thing (beyond artificial mathematical constructs)

>We're talking about relative motion, not relative acceleration
No this thread is about rotation, hence acceleration, hence about an absolute.

>Also acceleration is only absolute between inertial systems.
Inertial systems have greater ontological weight than other systems, which I claim are artificial (within a Newtonian universe)

>>4491205
you didn't really answer his points at >>4491191

(sits back and eats popcorn)

>>4491224
>never heard of relative acceleration
>doesn't know the difference between acceleration and motion
>brings up "ontological weight"

facepalm * 9001

Please visit a physics lecture. You are embarrassing yourself.

>>4491233
I did. Please tell me which point I didn't answer.

>>4491236
That's what you say whenever you can't answer.

>>4491238
whether is is as correct to say the sun revolves around the earth as vice versa.

whether rotation is an absolute, and i mean in the universe, not in the math.

>>4491242
Please tell me, if you know the difference between acceleration and motion.

>>4491245
It is correct to say and rotation is not absolute, because it requires to specify the center of rotation. In any other frame it is not even a rotation anymore.

>>4491236
I am a physics, um, batchelor? (licence in French)

>>4491248
of course, acceleration is just one aspect of motion

>>4491252
This is just nonsense. You know if I were in a sealed capsule I could measure my angular momentum, whether I was circling on a point or circling the sun?

I don't think you know what absolute means

>>4491191
So, you bring up a Foucault pendulum and say that its rotation is necessarily evidence of rotation as it results from the fictitious forces in the rotating reference frame. The thing is, from the non-inertial frame, I can equally say that the inertial frame is rotating and that my fictitious forces are real forces [they have measurable effects in my coordinate frame], but the inertial frame is accelerating in such a way to cancel these forces. The acceleration still appears, I have just stuck it somewhere else in a manner that keeps the non-inertial frame at rest.

There is nothing *truly* special about inertial frames. We just prefer to use them as they make the math much simpler by getting rid of various forces and they have the easiest time being transformed into other frames. If we preferred the rotating frame of the Earth, all of our physical predictions would still align with those of an inertial frame, the mathematics would just be a good bit more complicated.

>>4491252
don't be a faggot. there is a fixed center of an orbit, within the sun. all other centers introduce fictitious forces.

i think you're a troll. 6/10

>>4491253
That doesn't give you any authority status. It is still possible that you got a wrong idea.

>>4491256
What do you mean by "aspect"? "Aspect" is not a proper term in physics. Please explain how you think motion and acceleration are related.

>>4491261
You can measure fictitious forces in your frame of reference. That means it's accelerated. How does that contradict my post?

>>4491270
Did you even read my post? None of what you said contradicts my statements. Don't embarrass yourself.

>>4491265
>>4491265
This is the mathematical trickery I was referring too. I believe the actual universe corresponds closest to the most elegant, simplest formulation. This is the ontological weight you mocked.

>>4491279
>I believe the actual universe corresponds closest to the most elegant, simplest formulation.

why do you believe that

>>4491275
I claimed no authority, someone asked if I had ever been in a lecture, or something.

You seem to contradict yourself. You concede that some frames are privileged, but also that it is not correct to give one as a correct description and the other as less correct. This is I suppose a defensible philosophical position, but an eccentric one (no pun intended).

Also it seems perhaps two three times you have said "you are embarrassing yourself". I think this is what people say when they have a weak position.

>>4491297
Because i am not a nihilist.

>>4491301
I think you're worse, you're religious. Accepting of belief and superstition.

>>4491310
I am an atheist. Please don't confuse metaphysics and religion, it is, how you say, embarrassing for yourself.

>>4491298
I did not say that some frames are "privileged". All I said was that most people prefer to work with inertial frames (because of their mathematically easier to handle properties like galilean invariance).

As for the embarrassment phrase: Those people obviously didn't read my post properly. I suggested to them to this prior to posting unrelated statements. In no way my position is weak. So far no one has provided a counter-arguments and I think it's quite pointless to search for them. My "point" is nothing but the definition of relative motion, which every physicist should recognize.

>>4491319
But you cannot see the counter arguments. I think we should call this "willful stupidity".

>>4491324
Which counter-arguments? Whatever has been posted ITT, has been refuted by me. Once again: There is no point in arguing over a definiton. Either you accept it or you don't. Physicists do accept my definition.

>>4491328
I have repeated myself so many times now. You fail to see again and again. And you keep resorting to weasel words and just saying we embarrass ourselves. Perhaps you read posts but do not understand them, or place in them your own understanding, and so see nothing.

>>4491341
Your post contains no arguments. Please try again.

>>4491328
the other guys provided two cites that contradicted you. you provided none. i'm going to bed now

>>4491347
And neither does yours. You see this is the psychology you possess. Your arguments are golden and irrefutable, everyone else says nothing. Are you autistic?

>>4491350
None of these contradicted me. Please read my posts again, you obviously didn't understand them.

>>4491358
>autistic

i think we got it.

they should wear a badge like the jews so we don't have to waste our time

>>4491358
I don't see your point now. Are you discussing/trolling for the only purpose of discussion itself? This is not a debate about opinions.

>>4491366
Yeah right, calling someone "autistic" on /sci/ means that accepted the poster to be correct, but you want to continue your trolling. Please go on.

>>4491367
>>4491367
I am saying your reasoning skills are impaired. You fail to see your own errors and manage to erroneously disregard good arguments against your position. With these kind of psychological problems you are bound to think you are correct regardless, and so arguing with you about physics becomes pointless.

>>4491379
My reasoning skills are fully functional and so far I am successful with respect to physics. I did not simply disregard any "counter-arguments", I fully explained why they were wrong. You can keep attacking my person. That won't undermine the correctness of what I posted.

>>4491372
thanks.

calling people autistic on /sci/ usually means you've detected characteristics that may be typical of autistic people.

>>4491385
>grandiose self regard
you only thought you did those things, but you are wrong in this

they don't rotate around each other, our sun and everything in orbit around it revolve around the center of mass of the solar system... the sun is <99% of the mass of the solar system so that point is still well inside the volume of the sun

in response to ops question, what clued people in to the earth revolving around the sun was the orbits of the other planets, the only way our solar system and the orbits of the planets make any logical sense with newtonian ideas about gravity is if the earth and planets revolve around the sun

>>4491388
Not really. /sci/ doesn't know what autism is. Anything you don't like is automatically labeled as "autistic". But please go on. As long as you have fun while "trolling".

>>4491385
no one believes you mate

any fool knows if they spin on the spot they get dizzy, but if i stand still on a spinning floor they don't

>>4491391
You keep denying, but you fail to back up what you posted. What did I not refute ITT?

>>4491398
How is that related to my statements? I never claimed the opposite.

>>4491395
So you are autistic?

And my spotting it kind of contradicts your assertion about /sci/ not recognising it.

More of your weird correctness double-think.

>>4491401
see>>4491252

>>4491403
Let's see. According to you everyone who is correct and defeats his correct point against trolls is autistic? I think that's not how doctors make the diagnosis.

>>4491412
Which frames did you specify in your posts? I don't see them.

>>4491412
A person standing on a rotating floor rotates with the floor. The person is not rotating relative to the floor, which is why they don't get dizzy.

>>4491413
I didn't say any of that. Though you haven't denied it yet.

I bet you are one of those aspie autodidacts.

>>4491423
Do you have fun right now? I hope so. What a pity, if you wasted your time.

>>4491422
this is just wrong and retarded. if the floor span and you span you would get dizzy as the fluid in your inner ear was forced outward by fictitious forces

but i meant someone who is still while the floor rotates does not get dizzy, even though they are spinning relative to the floor

>>4491433
The earth rotates. Do you get dizzy from standing on the earth?

>>4491426
deny it or gtfo

>>4491436
too slowly. one rotation every 24 hours is not enough

wait, i can't believe you claim to know any physics if i have to explain this to you

>>4491437
Deny what?

>>4491433
>>4491433
>if the floor span and you span you would get dizzy as the fluid in your inner ear was forced outward by fictitious forces
directly contradicts what you said here
>any fool knows if they spin on the spot they get dizzy, but if i stand still on a spinning floor they don't

maybe you should get your argument striaght first

>>4491443
do keep up

deny that you have an ASD

>>4491436
wat?

nigger, don't make me say it

>>4491441
Do you have any idea how fast an object on the surface of the earth is moving? "One rotation in 24 hours" is not even a velocity. Do you have any idea how fast the earth is moving within our galaxy?

>>4491450
Why is my "denial" important to you?

>>4491448
that does not contradict anything. you are just dumb

situation 1, i spin, floor stays still
situation 2, floor spins, i don't
situation 3, i spin with the floor

my first post alluded to 1 and 2. the second one to 3
1 and 3 mess with your inner ear, 2 doesn't

ARE YOU JUST DUMB

and we'll say eyes closed so eyesight/inner ear disparity isn't at issue, just inner ear centrifuge effect

hey do you believe a centrifuge would work if we kept it still and spun the laboratory around?

>>4491448
i think you misread him

>>4491455
confirmed

>>4491453
So you actually don't know the difference between linear and angular velocity. It all makes sense now

>>4491471
You were the one who confused them. Nice try.

>>4491453
that is an angular velocity, which is what makes people dizzy. linear velocity has no effect on the inner ear, as it's not acceleration

also, confirmed retard

>>4491466
>my first post alluded to 1 and 2.

Not unless you're completely retarded it didn't.

>situation 2, floor spins, i don't

Only happens when you're not standing on the floor, which
>but if i stand still on a spinning floor
contradicts.

Please come back when you have a modicum of reading comprehension for YOUR OWN POSTS.

>>4491477
wat?

you asked how fast the earth is moving.

can't tell if trolling or stupid

The guy who posted the definition of relative motion here. I see the thread has now fully become a troll fest. I'm out. Don't expect any actual physics from this thread anymore.

/sci/ - condescending pseudo-intellectuals

The theory of relativity in the early 20th century taught that motion is relative and that different frames of reference are valid, including non-inertial reference frames. In the modern era, some of the modern geocentrists use a modified Tychonic system with elliptical orbits.

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

>>4491514
Get out. We don't want actual science in here. We want to troll, to insult and to throw shit around.

>>4491524

this is just wikipedia

>>4491536
Okay, he nearly got me. It sounded like he understood what he was talking about. That would have been unacceptable.