Ask a Physicist anything.

So I'm a physicist. I am finishing off a Masters in general physics and am currently applying to PHDs. Hence I know lots of science. If any of you have questions (which is why most people come to this forum) I will try to answer them and explain them. I should clarify, I am a round earth believer so I believe main stream physics. If any parts of main stream science confuse you / to you there seem to be holes in theory I will try to explain the confusing jargon / explain what modern science's answer to that hole in theory is.

What causes gravity?

why do salmon swim out of the ocean into little creeks to breed?

if they started out as freshwater fish, why didn't they stay there?

if they adapted osmotically to salt water as adults, why not breed in salt water as well?

What caused the UA?

Why is ice slippery?

What causes gravity?

The proper way to explain gravity is using general relativity and space-time jargon that without alot of maths, just confuses people and has to be taken for granted. So instead I am going to try a quantum approach.

You accept that two north or two south magnetic poles will repel each other and a north and south will attract? Like and like repels and like and unlike attract. This is an example of the electromagnetic force. The "electro" bit is because magnetism is caused by moving charges and charge is traditionaly measured in electrons. Therefore it is easy to understand that because of the same force two "like" charged objects (positive and positive for example) will repel and two "unlike" charged objects (positive and negative for example) will attract.

Now in school you are taught magnets work because of magnetic fields, and charged objects attract/repel because of electric fields. But this isn't strictly true, its alot complicated. To explain it, imagine a positively charged particle A and a negative charged particle B a set distance apart. In order for one particle to react to the others existence, information has to pass between the two. I mean how else can they react to the others charge if there isn't some sort of information transfer between them to let each other know? Common sense. What actually happens is that A and B are both constantly emitting virtual exchange particles (this is the same as the field theory you know and love but I just replaced field with virtual particle) and these exchange particles travel out in all directions. When an exchange particle from A reaches B then energy is transferred, and vice versa. This facilitates the needed information swap so that A and B know to attract to each other. Obviously as you move further away from A or B the amount of virtual exchange particles per unit space decrease, so the strength of the force decreases over distance.

Now I explained how charged particles / magnets / electromagnetic force works. Gravitational force works in an identical matter between massive particles as opposed to charged particles.

Do you get it? I glossed over information = energy equivalence and the term "virtual particles" sounds like they are things made up in theory but they are experimentally proven but the explanation would require an independent post. I can post it if you would like.

that doesn't answer my question about the fish, though.

Quote from: Roundy the Truthinessist on January 19, 2013, 05:59:27 PM

What causes gravity?

The proper way to explain gravity is using general relativity and space-time jargon that without alot of maths, just confuses people and has to be taken for granted. So instead I am going to try a quantum approach.

You accept that two north or two south magnetic poles will repel each other and a north and south will attract? Like and like repels and like and unlike attract. This is an example of the electromagnetic force. The "electro" bit is because magnetism is caused by moving charges and charge is traditionaly measured in electrons. Therefore it is easy to understand that because of the same force two "like" charged objects (positive and positive for example) will repel and two "unlike" charged objects (positive and negative for example) will attract.

Now in school you are taught magnets work because of magnetic fields, and charged objects attract/repel because of electric fields. But this isn't strictly true, its alot complicated. To explain it, imagine a positively charged particle A and a negative charged particle B a set distance apart. In order for one particle to react to the others existence, information has to pass between the two. I mean how else can they react to the others charge if there isn't some sort of information transfer between them to let each other know? Common sense. What actually happens is that A and B are both constantly emitting virtual exchange particles (this is the same as the field theory you know and love but I just replaced field with virtual particle) and these exchange particles travel out in all directions. When an exchange particle from A reaches B then energy is transferred, and vice versa. This facilitates the needed information swap so that A and B know to attract to each other. Obviously as you move further away from A or B the amount of virtual exchange particles per unit space decrease, so the strength of the force decreases over distance.

Now I explained how charged particles / magnets / electromagnetic force works. Gravitational force works in an identical matter between massive particles as opposed to charged particles.

Do you get it? I glossed over information = energy equivalence and the term "virtual particles" sounds like they are things made up in theory but they are experimentally proven but the explanation would require an independent post. I can post it if you would like.

So Einstein was wrong when he said that gravity happens as a result of mass curving spacetime? 

What caused the UA?

I don't believe in the Universal Acceleration force, I state in the OP that I am a round earther. In fact I experimentally proven myself that the gravitational constant 9.82, changes appreciably with altitude.
http://en.wikipedia.org/wiki/Kater's_pendulum

why do salmon swim out of the ocean into little creeks to breed?

if they started out as freshwater fish, why didn't they stay there?

if they adapted osmotically to salt water as adults, why not breed in salt water as well?

Ha ha. Yes okay I said anything. Though my post clearly implied that I meant physics questions.

Why is ice slippery?

Its 2:30am so I will get to that question in the morning. However I should point out my aim is to explain the bits of science that made you doubt a round earth.

Quote from: Lorddave on January 19, 2013, 06:22:33 PM

Why is ice slippery?

Its 2:30am so I will get to that question in the morning. However I should point out my aim is to explain the bits of science that made you doubt a round earth.

Then you're in the wrong area.  The lower forum is where the non-flat earth discussion occurs.

Clearly Eireannach subscribes to graviton theory, despite the whole of zero evidence for it.

Ha ha. Yes okay I said anything. Though my post clearly implied that I meant physics questions.

hmmm

not intending to be argumentative, but then you don't actually know "lots of science?"

what you meant to say was that there are some things in science of which you have some knowledge, and other things in science of which you are ignorant.

how easy is it for you to tell the difference?

So Einstein was wrong when he said that gravity happens as a result of mass curving spacetime? 

No I explained to you how one body/mass can affect another body/mass. I only explained the communication mechanism. Spacetime curvature is an instigator while virtual particles are a mediator. So I suppose I answered "How does gravity work" as opposed to "Ehat causes gravity" but I find the most common issue people have is understanding why one object would be attracted to another by invisble forces.

If you still want to know the specific "Why there is a gravity" then you will have to settle for spacetime curvature or enroll in a 4-dimensional tensor mathematics course.

Then you're in the wrong area.  The lower forum is where the non-flat earth discussion occurs.

Point taken, I am new to the site. Will explain tomorrow.

Clearly Eireannach subscribes to graviton theory, despite the whole of zero evidence for it.

First of all, you cannot have a theory with zero evidence, that is a hypothesis. Second, there is hard proof for virtual particles and exchange particles between forces. You would be correct however in stating that the graviton has not been discovered yet. But there is also proof of gravitational attraction between bodies on Earth on the horizontal plane. This cannot be explained by upward acceleration. Plus, katers pendulum.

Will continue in morning.

Here's a question: if Dark Matter is supposed to make up so much of the universe and have such a mahoosive effect on galaxies, why does it appear to be impossible to detect? Surely the same property that reveals its influence on galaxies (its enormous gravity) could be used to detect it around us? And why does the dark matter theory take precedence in the scientific community over the variable strength gravity theory?
Also, why are physicists so useless at explaining the Uncertainty Principle to laymen?

Uncertainty Principle, you can't see how fast something is and where it is at the same time with the same level of accuracy. What do you not understand about that?

Uncertainty Principle, you can't see how fast something is and where it is at the same time with the same level of accuracy. What do you not understand about that?

I didn't ask what it was, I asked why physicists are so bad at explaining it to laymen. You're not even a physicist. I know perfectly well what it is. You think you're so smart, Rushy, let's see you explain it rather than just state it, shall we?

I didn't ask what it was, I asked why physicists are so bad at explaining it to laymen. You're not even a physicist. I know perfectly well what it is. You think you're so smart, Rushy, let's see you explain it rather than just state it, shall we?

I wouldn't know, as I am not a physicist. Not knowing something does not make someone intelligent or unintelligent. The term for that is known as being ignorant. Aside from that, it appears to me you got rather defensive that I tried stating something simply to you. I assure you if I hurt your feelings, I didn't do it on purpose.

Good morning, Physicist.

I wonder how many planets orbeting the star BD +5deg 1668.
And what  explains the anomalous spin of protons?

Quote from: Roundy the Truthinessist on January 19, 2013, 06:32:48 PM

So Einstein was wrong when he said that gravity happens as a result of mass curving spacetime? 

No I explained to you how one body/mass can affect another body/mass. I only explained the communication mechanism. Spacetime curvature is an instigator while virtual particles are a mediator. So I suppose I answered "How does gravity work" as opposed to "Ehat causes gravity" but I find the most common issue people have is understanding why one object would be attracted to another by invisble forces.

If you still want to know the specific "Why there is a gravity" then you will have to settle for spacetime curvature or enroll in a 4-dimensional tensor mathematics course.

Isn't there a couple of issues though that we are glossing over?  Roundy knows the answers to the questions that he is asking.  The gravitron is as of now just a hypothetical particle that corresponds to the gravitational force.  This however contradicts Einstien's theory that gravity is not a force, that it is the bending of spacetime.  This is why time, something without even hypothetical particles, could be effected by it.  But I obviously don't have to explain to you that relativity and quantum mechanics are not unified, and currently don't even play well together.

Now of course I could be wrong.  I have not taken a Quantum mechanics course, and I have never taken a math based Physics course.  However If you spend a large amount of time in Astro courses like I do, then you pick up the general issues regarding the two competeing theories.

Science currently does not have a great explanation for gravity, some even hypthesize that M theory would allow for gravity to be a force that is leaking in from the 11th dimension, also known as a parrallel universe.  This would explain why it is such a comparitvly weak force.

Really Roundy is just waiting for you to admit that like all scientists you don't really understand what is going on, and that you have no evidence for the puller particle that you described, except to say that the other forces have particles that correspond to them.  And even if there is a puller particle, it is at this point incompatible with the idea that gravity is not a force, but rather the curvature of spacetime. 

Now Like I said earlier, I could be butchering all of this.  But If i am, please explain what I am getting wrong, I love to learn more.

Quiet, Orbis, you're totally misrepresenting my intentions. 

So Mr Physicist guy, how do your magic puller particles fit in with Einstein's Theory of Relativity, exactly?

Quote from: Eireannach on January 19, 2013, 06:44:28 PM

Quote from: Roundy the Truthinessist on January 19, 2013, 06:32:48 PM

So Einstein was wrong when he said that gravity happens as a result of mass curving spacetime? 

No I explained to you how one body/mass can affect another body/mass. I only explained the communication mechanism. Spacetime curvature is an instigator while virtual particles are a mediator. So I suppose I answered "How does gravity work" as opposed to "Ehat causes gravity" but I find the most common issue people have is understanding why one object would be attracted to another by invisble forces.

If you still want to know the specific "Why there is a gravity" then you will have to settle for spacetime curvature or enroll in a 4-dimensional tensor mathematics course.

Isn't there a couple of issues though that we are glossing over?  Roundy knows the answers to the questions that he is asking.  The gravitron is as of now just a hypothetical particle that corresponds to the gravitational force.  This however contradicts Einstien's theory that gravity is not a force, that it is the bending of spacetime.  This is why time, something without even hypothetical particles, could be effected by it.  But I obviously don't have to explain to you that relativity and quantum mechanics are not unified, and currently don't even play well together.

Now of course I could be wrong.  I have not taken a Quantum mechanics course, and I have never taken a math based Physics course.  However If you spend a large amount of time in Astro courses like I do, then you pick up the general issues regarding the two competeing theories.

Science currently does not have a great explanation for gravity, some even hypthesize that M theory would allow for gravity to be a force that is leaking in from the 11th dimension, also known as a parrallel universe.  This would explain why it is such a comparitvly weak force.

Really Roundy is just waiting for you to admit that like all scientists you don't really understand what is going on, and that you have no evidence for the puller particle that you described, except to say that the other forces have particles that correspond to them.  And even if there is a puller particle, it is at this point incompatible with the idea that gravity is not a force, but rather the curvature of spacetime. 

Now Like I said earlier, I could be butchering all of this.  But If i am, please explain what I am getting wrong, I love to learn more.

That's more or less it. Just don't mistake not a force with can be treated as an inertial force. Try telling someone who's been in a car crash that inertial forces are not real. Whoever came up with the term 'fictitious force' needs some 're-education' 1984 style.

For what reason doesn't gravity have an opposite? And I don't mean anti-gravity, I mean a force that pushes objects away from objects? D: I don't get it. It seems like it should have an opposite :I

Mathematically you can do - you just need negative mass or rather negative energy density which so far hasn't been found and I don't think anyone is expecting to.

Hmmm... Okay.

For what reason doesn't gravity have an opposite? And I don't mean anti-gravity, I mean a force that pushes objects away from objects? D: I don't get it. It seems like it should have an opposite :I

Are you alluding to Newton's third law of motion? If so, it does have an opposite. That's why you are currently stationary on the ground (I assume) and not in free-fall through the solid Earth. The electromagnetic force of the electrons in your feet repelling the electrons in the floor is counteracting the downward force of gravity (if we assume for a moment that gravity is a force).

Uncertainty Principle, you can't see how fast something is and where it is at the same time with the same level of accuracy. What do you not understand about that?

This is actually more like the Heisenberg uncertainty principle relating just momentum and position, and it's phrased a little bit wrong. It says that momentum and position cannot be measured both with 100% accuracy, as there is a lower limit to the value of the product of the standard deviations (they can still be measured with the same level of accuracy, just not 100%). There is a much broader definition, using any two observables and relating their standard deviations with the commutation and anticommutation relations, again arriving at a lower limit for the product.

is the uncertainty not just the commutator of the two operators?

Quote from: Rushy on January 19, 2013, 06:52:41 PM

Uncertainty Principle, you can't see how fast something is and where it is at the same time with the same level of accuracy. What do you not understand about that?

I didn't ask what it was, I asked why physicists are so bad at explaining it to laymen. You're not even a physicist. I know perfectly well what it is. You think you're so smart, Rushy, let's see you explain it rather than just state it, shall we?

Most physicists, and indeed most scientists, are completely incapable of putting their thoughts down on paper. Also, since they are usually talking about these things with their peers they forget how to talk about them to other people. This is also why it takes training and practice to read a scientific paper. It's less that the subject is so complicated and more that the writer can't write clearly.

that's quite true, you know, and the sciences sometimes encourage it. some fields require papers to be written in the passive voice, for example, which obscures the agent in discussions of previous research and is generally vague. other fields require the exact opposite.

to some extent it's similar to the obscuring vocabulary used by physicians: lesions, erythematous, bowel disimpaction, decerebration, and so on. and sometimes, people with andvanced educations simply grow out of touch with the rest of the world.

Quiet, Orbis, you're totally misrepresenting my intentions. 

So Mr Physicist guy, how do your magic puller particles fit in with Einstein's Theory of Relativity, exactly?

Oh I am sorry.  I will never again do that.  Please forgive me.