relationship between space and time

[Tren Bull]

I wonder what on the other side of a black hole. There has got to be a lot of shit in there seeing as how it pulls everything in its path in.

BLACK HOLES are the only thing powerful enough to draw in light right?

a black hole is a star that colapsed on itself, and its so massive that even a supernova cant blast it apart

[stunner5000pt]

I wonder what on the other side of a black hole. There has got to be a lot of shit in there seeing as how it pulls everything in its path in.

BLACK HOLES are the only thing powerful enough to draw in light right?

they have big enough mass (but not necessairly big) to cuase the bending of spacetime into a singularity.

[AnabolicAndre]

Right but there are a lot of other elments that factor in to Van der walls force. Like, ok, elements that play a key role in such forces are unstable in stellar atmosphere. I need to brush up on chem and physics.

[AnabolicAndre]

This is all so fascinating

[stunner5000pt]

Right but there are a lot of other elments that factor in to Van der walls force. Like, ok, elements that play a key role in such forces are unstable in stellar atmosphere. I need to brush up on chem and physics.

the intial universe was mostly Hyrodgen and helium

the igher elemtns like C, O, N would not have been formed until stars were formed themselves - thats where the elemnts with higher atomic number come from

[stunner5000pt]

This is all so fascinating

This is boring

[Tren Bull]

you see, they call it a black hole cause its so massive that it creates a huge bending of space and time.

according to general relativity, mass bends space and time similarily to how a weight on an elastic surface would.

well, imagine we have a thin piece of spandex, with an 8 pound shotput chillin on it. thats the situation im trying to describe, cept in the case of a black hole in space, the spandex is space and time, and the black hole would be a 10 billion pound shotput

[Tren Bull]

This is boring

no it isnt. i think its mind blowing

[stunner5000pt]

no it isnt. i think its mind blowing

this is boring because im not learning anything new

i cant wait till school starts... but im not learning any of this yet... its modern physics, statistical mechanics and 3rd year EM is waht im taking

[Tren Bull]

newton's laws dont say anything light (because it has no mass) and gravity

and there isn o Newton's 4th law

there are only 3 Newtonian laws and they have nothing to do with gravitation directly - they do not state the relationship between mass, force and distance.

just cause your teacher said light has no mass does not mean its true. personally i believe light has to have mass.

btw yes there is a 4th law. its the equation that describes the gravitational attraction between 2 masses

[Tren Bull]

this is boring because im not learning anything new

i cant wait till school starts... but im not learning any of this yet... its modern physics, statistical mechanics and 3rd year EM is waht im taking

3rd semester e&m huh?

hell bro, 2nd semester e&m is a graduate level class.

[italianplayboy09]

this is quite interesting

[stunner5000pt]

just cause your teacher said light has no mass does not mean its true. personally i believe light has to have mass.

btw yes there is a 4th law. its the equation that describes the gravitational attraction between 2 masses

i didnt know that was called the 4th law

i just know it is Newton's law of universla gravitation

[stunner5000pt]

3rd semester e&m huh?

hell bro, 2nd semester e&m is a graduate level class.

what dou mean 2nd semester e&m??

[Tren Bull]

i didnt know that was called the 4th law

i just know it is Newton's law of universla gravitation

i think it depends on what source you get it from. but in my classes, it was refered to as the 4th law

[Tren Bull]

what dou mean 2nd semester e&m??

its e&m physics, but its the second semester, which has much more complicated problems and examples

[stunner5000pt]

its e&m physics, but its the second semester, which has much more complicated problems and examples

do you mean intro to gauss law and ampere's law??

so laying the groundwork for maxwell's equations? or beyond this

[l2elapse]

i love stuff like this. quantum physics intrigues me. you should see the "what the bleep do we know" movies if you haven't already

this movie was created for the RSE, also known as the Ramtha School of Enlightenment. That movie is a bunch of crap

[Polska]

this movie was created for the RSE, also known as the Ramtha School of Enlightenment. That movie is a bunch of crap

Some of the stuff I didn't like, like that stupid psychic broad. But otherwise I found it really thought provoking; made me want to research the subject matter for personal enlightenment

[Kärnfysikern]

No way would you reach the end of the universe as soon as you went the speed of light. Look at how many light years a lot of stars are away. The light you see at this moment took years at the speed of light to get here.

You have to think in different frames of references. To a person traveling the speed of light he would observe himself traveling infinitly fast. But for you and me sitting here watching him we would just observe him going at 300 000km/h.

Photons that have been traveling for billions of years in our frame of reference has gotten here without any time passing at all from the photons frame of reference.

[Kärnfysikern]

there are problems with the big bang model which dont explain how stars were formed... this is what i was told ... i ahvent taken many astronomy courses.

if the big bang did indeed occur then the universe would have expanded uniformly in all directions. But why uniformly? i dont know. Let's say it did for now.

Now stars have to have localized concentrations of hydrogen and helium to fall into themselves due to gravitational force of their mass and ignite forming a star when the outward (by the energy generated by ignition of H and He) and gravitational pressures balance out.

But if the universe was expanding unifromly ... then how did localized concentrations of H and He come about? I'd liket osee explanations on this... if you can find theories i'd liek to know them.

The explanation according to the big bang theory(remember I havent studied it yet so there might be flaws here) is that for the first breef moment of the universe existance it expanded TREMENDOUSLY fast. I dont have any figures on my head but literaly from the size of a atom to the size of a couple of galaxies in microseconds or something like that. This rapid expansion(called inflation in the bb modell) allowed quantum fluctuations to inflate along with the rest and that is why we have a non homogeneous mass distribution in the universe. As far as I know what caused the inflation is unknown but the modell predicts so many features of our universe so exactly that there is no doubt among cosmologist that it did happen. No observation so far has been able to show it wrong.

[Kärnfysikern]

The universe has an end???

No known one atleast. But what we do know is that our visible universe is only a small part of the bigger universe. The size of the bigger universe is and will always be unknown to us.

[Kärnfysikern]

yea but light also has to have some mass. how else can you explain how light gets sucked into black holes? if it were totally massless, then there would be no gravitational force on it... which is not the case

General relativity allows gravitational interaction with massless objects newtonian mechanics doesnt cut it when it comes to massless particles ect.

But with that said even newtonian mechanics predict a bending of light despite it beeing massless. But only half as much as general relativity predicts. Dont ask me how to calculate newtonian bending of light since I havent taken any classical field theory

[Kärnfysikern]

not exactly. im not sure what causes length contraction and time dilation... but once you start moving near the speed of light relativistic effects become more and more noticable. weve even measured time dilation. relativistic effects always occur no matter what speed you're moving, but at slow speeds, its effects are so small that you can neglect them for practical applications... well for engineering projects here on earth.

The cause is the second postulate of special relativity. That the light speed is constant in all frames of reference. For that to be true distances and time has to expand, shrink and do funny stuff. So there is no other explanation for it realy.

[Kärnfysikern]

just cause your teacher said light has no mass does not mean its true. personally i believe light has to have mass.

btw yes there is a 4th law. its the equation that describes the gravitational attraction between 2 masses

well the thing is if light had a mass we would have measured it. Light just can not have any mass because if it had the predictions we get from both general relativity and quantum mechanics would be wrong.

[Kärnfysikern]

this is boring because im not learning anything new

i cant wait till school starts... but im not learning any of this yet... its modern physics, statistical mechanics and 3rd year EM is waht im taking

statistical mechanics is without a doubt the most fun class I have taken so far. Enjoy it and I sure do hope you had a professor as good as mine was.

I have to reteach myself EM sometime. The class I had was so stressed and cut down that I realy didnt have time to learn anything so I am very weak in the EM department and it pisses me off
The university I have switched over to doesnt seem to offer any electrodynamics class either

[Tren Bull]

do you mean intro to gauss law and ampere's law??

so laying the groundwork for maxwell's equations? or beyond this

haha, you think 2nd semester e&m would be an intro to maxwell's equations?

no, its not an intro class. i mean maybe it would be if you took a watered down, business major e&m class, but the one meant for scientists and engineers is much more in depth than that.

[Tren Bull]

statistical mechanics is without a doubt the most fun class I have taken so far. Enjoy it and I sure do hope you had a professor as good as mine was.

I have to reteach myself EM sometime. The class I had was so stressed and cut down that I realy didnt have time to learn anything so I am very weak in the EM department and it pisses me off
The university I have switched over to doesnt seem to offer any electrodynamics class either

ugghhh, e&m was an UGLY class. i mean i had a great teacher but still... thats a tough subject.

i enjoyed relativity and quantum mechanics much more

[Tren Bull]

The cause is the second postulate of special relativity. That the light speed is constant in all frames of reference. For that to be true distances and time has to expand, shrink and do funny stuff. So there is no other explanation for it realy.

i agree. its kinda like asking what God looks like

[Tren Bull]

General relativity allows gravitational interaction with massless objects newtonian mechanics doesnt cut it when it comes to massless particles ect.

But with that said even newtonian mechanics predict a bending of light despite it beeing massless. But only half as much as general relativity predicts. Dont ask me how to calculate newtonian bending of light since I havent taken any classical field theory

it seems strange to me that something could have momentum, but not mass.

[Kärnfysikern]

ugghhh, e&m was an UGLY class. i mean i had a great teacher but still... thats a tough subject.

i enjoyed relativity and quantum mechanics much more

I think EM is beutifull. What I regrett is that I never had the time to appriciate its full beauty. Maxwells equations are brilliant. But I havent yet fully appriciate how everything in EM and everything regarding optics can be connected back to maxwells equations.

We at my universtiy also went into the EM with very poor vector analysis background, we only had a few hours of vector calulus at the end of our multivariable calculus and our math teacher put no emphasis on it whatsoever. So not only was the classes very stressfull we also had to basicly learn vector calculus as we went on

But our professor was great, he did the best with the limited time he had been given. He realy made me appriciate how beautifull EM is.

[Tren Bull]

I think EM is beutifull. What I regrett is that I never had the time to appriciate its full beauty. Maxwells equations are brilliant. But I havent yet fully appriciate how everything in EM and everything regarding optics can be connected back to maxwells equations.

We at my universtiy also went into the EM with very poor vector analysis background, we only had a few hours of vector calulus at the end of our multivariable calculus and our math teacher put no emphasis on it whatsoever. So not only was the classes very stressfull we also had to basicly learn vector calculus as we went on

But our professor was great, he did the best with the limited time he had been given. He realy made me appriciate how beautifull EM is.

aww man, you had to learn vector operations during e&m? that sucks bro.

its too bad you couldn't take the same teacher i had for e&m. hell, youd probably be able to write your own textbook on the subject after one semester with this guy.

[Kärnfysikern]

i agree. its kinda like asking what God looks like

Yeah. Some things are inherently unexplainable. Like asking why there is 4 forces. Why the gravitational constant is so small, why the speed of light is what it is and so on. Those questions anoy me cause I want to know

it seems strange to me that something could have momentum, but not mass.

I guess you are thinking classicaly But even fields that are defenetly without mass can have momentum(dont ask me how, I havent taken any field theory). Remember though that when it comes down to it momentum is defined in such a way to allow for massless particles to have momentum. Sometimes in physics we just have to sit back and accept the definitions, because aslong as the way we mathematicly define concept leads to results that reflect the real world we know we are on the right track even if the definitions makes no real sense.

What I personaly find wierdest is that the electron has no volume, no radius, no nothing. How the **** can something have a mass but no volume? That screws with my mind.

[Tren Bull]

see for my e&m class, we covered thermodynamics with gasses for the first month, then we went into field therory of e&m... plus we touched on linear circuits.

i really enjoyed the field theory cause it is so mathamatical, but thermo was not very enjoyable for me... sh_t, that damn maxwell-bolton distribution for molecular speeds equation is making my head hurt just thinking about it. haha, i prefer the schrodinger equation, even if its longer and more complex, i at least understand where it came from.

we also had a different teacher for the circuits, which was no good cause she would go WAY too fast, give unorganized notes, and not explain things clearly. but she liked me alot, and shed actually do some of my labs for me

[Kärnfysikern]

aww man, you had to learn vector operations during e&m? that sucks bro.

its too bad you couldn't take the same teacher i had for e&m. hell, youd probably be able to write your own textbook on the subject after one semester with this guy.

Yeah, we physcisists took the multivariable calculus class with the mathematicians and mathematicians doesnt seem to think vector calculus is important. Thats hwy it was placed dead last in the class and given only a few hours, no vector calculus question ever got into the examns either so no focus at all on it. Damn pricks. I wish we had been given a whole class for just vector calculs.

The one thing I hate most is if the maths are in the way in a physics class. I want to focus on learning the physics, not the god damn maths.

I think if the faculty at my old university had put more money into the EM class so that we could maby get 5-6 more lectures it would have been a awsome class. But since we where only 7 people taking the class they cut the fundings alot, same thing happened with alot of our other classes. One of the reasons I have switched university

[Kärnfysikern]

see for my e&m class, we covered thermodynamics with gasses for the first month, then we went into field therory of e&m... plus we touched on linear circuits.

i really enjoyed the field theory cause it is so mathamatical, but thermo was not very enjoyable for me... sh_t, that damn maxwell-bolton distribution for molecular speeds equation is making my head hurt just thinking about it. haha, i prefer the schrodinger equation, even if its longer and more complex, i at least understand where it came from.

we also had a different teacher for the circuits, which was no good cause she would go WAY too fast, give unorganized notes, and not explain things clearly. but she liked me alot, and shed actually do some of my labs for me

Sounds like a wierd mixture . Our EM class was pure EM field theory, everything started and ended with maxwells equations.

We had electronics and circuts later and that is the most boring class I have ever taken in my entire life. I HATE it.

I loved thermodynamics and statistical physics though and we had gasses in there. It was challanging but I enjoyed seeing how quantum effects are connected to macroscopic world.

I hate the schrödinger. I mean solving it for a particle in a box is fun. But solving it for the hydrogen atom with all the spherical harmonics and all that crap.THAT makes my head hurt I cant even imagine aproximting a solution for a many body system.

Offcourse the approximations in solid state physics wasnt all that complex. Atleast not the first onces that is solvable by hand. So maby there is hope

[Tren Bull]

Yeah. Some things are inherently unexplainable. Like asking why there is 4 forces. Why the gravitational constant is so small, why the speed of light is what it is and so on. Those questions anoy me cause I want to know



I guess you are thinking classicaly But even fields that are defenetly without mass can have momentum(dont ask me how, I havent taken any field theory). Remember though that when it comes down to it momentum is defined in such a way to allow for massless particles to have momentum. Sometimes in physics we just have to sit back and accept the definitions, because aslong as the way we mathematicly define concept leads to results that reflect the real world we know we are on the right track even if the definitions makes no real sense.

What I personaly find wierdest is that the electron has no volume, no radius, no nothing. How the **** can something have a mass but no volume? That screws with my mind.

yea thats the problem when were dealing with things we cant see, and havnt had any actual hands on experience with.

i suppose its best to just accept it, rather than question it.

im just taking a guess here, but i think that being as everything has wave and particle properties, that its the particle properties that give an electron its mass, even though its wave properties dominate over the particle properties.

but then again, its not like i can pick up and look at an electron

[Tren Bull]

Sounds like a wierd mixture . Our EM class was pure EM field theory, everything started and ended with maxwells equations.

We had electronics and circuts later and that is the most boring class I have ever taken in my entire life. I HATE it.

I loved thermodynamics and statistical physics though and we had gasses in there. It was challanging but I enjoyed seeing how quantum effects are connected to macroscopic world.

I hate the schrödinger. I mean solving it for a particle in a box is fun. But solving it for the hydrogen atom with all the spherical harmonics and all that crap.THAT makes my head hurt I cant even imagine aproximting a solution for a many body system.

Offcourse the approximations in solid state physics wasnt all that complex. Atleast not the first onces that is solvable by hand. So maby there is hope

yea i wish i could retake e&m, but have the entire course focus solely on field theory. like if we had immediately started up with maxwells equations. sh_t, we didn't see all four equations grouped together until the last month of the class.

i agree on the circuits... its boring. plus i had a bad teacher for it. but i get to take a class totally dedicated to circuits either next semester or the one after that...

fun fun

haha, btw i can only imagine what the schrodinger equation would look like for something like a carbon atom... or god forbid something even bigger like uranium... man that would be like 400 pages long!!!

[Tren Bull]

Yeah, we physcisists took the multivariable calculus class with the mathematicians and mathematicians doesnt seem to think vector calculus is important. Thats hwy it was placed dead last in the class and given only a few hours, no vector calculus question ever got into the examns either so no focus at all on it. Damn pricks. I wish we had been given a whole class for just vector calculs.

The one thing I hate most is if the maths are in the way in a physics class. I want to focus on learning the physics, not the god damn maths.

I think if the faculty at my old university had put more money into the EM class so that we could maby get 5-6 more lectures it would have been a awsome class. But since we where only 7 people taking the class they cut the fundings alot, same thing happened with alot of our other classes. One of the reasons I have switched university

haha, you know what ive noticed bro? mathemeticians hate physicists and chemists... and the physicists hate the mathemeticians and the chemists.

all 3 are so similar... well physics is based on math, and chemistry is based on physics... it doesn't make sense to me why the 3 departments hate eachother so much.

btw, for vector calculus, are you referring to linear algebra?

[Kärnfysikern]

haha, you know what ive noticed bro? mathemeticians hate physicists and chemists... and the physicists hate the mathemeticians and the chemists.

all 3 are so similar... well physics is based on math, and chemistry is based on physics... it doesn't make sense to me why the 3 departments hate eachother so much.

btw, for vector calculus, are you referring to linear algebra?

there is some truth to it.
But like feynman said
"Physics is to maths as sex is to masturbation"

I enjoy maths though, but it can get a bit dry and a bit to disconnected from reality for my taste. I think mathematicians often view what physcisist do to maths as bastardisations. Because we dont give a shit about the details hehe, we take what works and screw the rest. I know mathematicians do not at all like how things in physics derivered.

Nah I mean vector analysis. Stokes theorem, gauss theorem, curl, gradient, divergence and all that stuff