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 The Lycaeum Forums » Integrate » Science (Moderator: farmerjack)Topic:
 So im reading elegant universe...

[housearrestee]

and i have some questions...this would work much better if i had the computer in the bathroom when i normally read while i shit...so perhaps ill just write down some of the questions when they come up and then list them here...i know some of you guys know some shit about physics...so for the first question, its just a general one applied to the basic theory of relativity and what not

Being observers lends itself to special relativity, correct? if so, couldnt this be a slippery slope filled with bullshit...i mean yes you can use experiments to "prove" these ideas..but again if we are observers, and as physics proves you get what you expect, whose to say any of this shit is really correct...does being an observer lends itself to an observed outcome that is always wrong? 

be gentle 

[gorfehttimrek]

You have to bring the word "relative" in there somewhere.   

Being an observer, means that what is observed is true in that frame of reference only.  It is relative.  If the other observer, observes you, he will find different facts that are true in his frame of reference only. 

The ah-ha moment here is that ANY observer in ANY frame of reference will always get the same answer for the speed of light.


Maybe that will help?

[housearrestee]

alright i got that kermy....

just finished pooping so...

so if you are traveling at the speed of light...you are diverting all of your speed to spatial movement taking away that speed from movement in time, correct...they give an example that a photon that was created in the big bang is the same age now as it had always been...but when talking about muons...they said that they were able to slow down the speed of it disintegration to about 10 seconds, but yet time still felt like a second to the muon, and 10 seconds only to the observer of the muon...so is it aging, or just aging to outside observers when traveling at the speed of light?  i may have fucked that up a little...im on my way to work and was in a hurry

[Dr. Suess]

Also, wouldn't the "uncertainty principle" come into play? Just the act of observation is said to alter what is being observed so that what is observed is not a true portrayal of what is being observed. Or something like that....

[gorfehttimrek]

Relativity and Quantum Mechanics are oil and water.

uncertainty applies with quantum scale particles.  If you know the speed the location is not discernable, and if the location is pinpointed the speed in unknown.

Divergence in the passage of time never occurs within the same frame of reference.  It is across frame reference.  ie. You see the people on a rocketship traveling near the speed of light moving very slowly.

Travel out of Earths frame of reference(a clock put in orbit) will change the passage of time RELATIVE to the Earths frame.  The clock does NOT change in the execution of its function except when compared to a different frame of reference.  The clock keeps on keeping time at the exact same rate it was designed to function.  The MATTER out of which the clock is made will change SIZE; growing smaller in the direction of travel the faster it goes.  This can ONLY be detected from a different frame of reference.  Once you step into the clocks frame of reference you will see that it is still exactly as it was designed and has not altered in its functioning even slightly.

Moving down to particles that are small enough to be called 'sub-atomic' puts relativity in a bind.  Other forces come into play that cause strange interactions with the predictions of relativity at these small scales.  This is where uncertainty rules.   


Are you still with me?

[housearrestee]

well i havent gotten to the complete explanation of string theory but doesn't relativity come into the mix with sub atomic particles in that theory...isnt that one of the magnificent abilities of string theory...melding general relativity with quantum mechanics?

[Newfound_wonder]

It's important to know the two postulates of special relativity:

1.)  The laws of physics are the same for all observers in uniform relative to one another.

2.)  The speed light is the same in a vacuum for all observers, regardless of their relative motion of the source of the light.

I'd start with wrapping your mind around these ideas before getting into the more complicated stuff.

[pshmell]

The most important thing, I think, for someone interested in physics to realize, is that they are not a transient observer surrounded by an objective world.

Whatever hypothetical line you may draw between your 'self' and the 'stuff' around you is entirely a abstraction, a construction of your mind.

It's not as if the atoms that make up your skin are somehow 'owned' by you, while the atoms of oxygen, nitrogen, and carbon right next to them are not. 'You' and 'the rest of the world' is a dualist perspective. Really, everything is unified and continuous.
The only tool we have is direct experience

"That we do not feel this to be obvious is the result of centuries of habituation to the idea that oneself is only the envelope of skin and its contents, the inside but not the outside. The extreme folly of this notion becomes clear as soon as you try to imagine an inside with no outside, or an outside with no inside."

[housearrestee]

anyone wanna describe how acceleration and gravity are intertwined?...i think i understand the idea given in the book...but one more good explanation would be awesome...as laymen as possible please

just to let you know this is the about the basis of albey's theory of general relativity or his happy moment

[pshmell]

watch the whole thing: http://www.youtube.com/watch?v=LHPqhTY6dh0

You should definitely pick up The Universe and Dr. Einstein by Lincoln Barnett if you can find it. Most concise and simple explanation of special and general relativity I've EVER seen.

[gorfehttimrek]

anyone wanna describe how acceleration and gravity are intertwined?...i think i understand the idea given in the book...but one more good explanation would be awesome...as laymen as possible please

just to let you know this is the about the basis of albey's theory of general relativity or his happy moment

You are in a box.  You have access to all the instruments and tools of science.  Discern, whether the box is sitting on the surface of a planet with 1G of gravity, or is accelerating with a speed 9.8 meters per second per second through empty space.

No instrument can tell us this because there is no difference of action to be found between the two of them.  The effect on the time and space of our surroundings is the same.  We are ineffect experiencing acceleration by being in a gravitational field. 

Simple as it can be made by me,
Kermit

[Newfound_wonder]

Kermie said it best.  I was gonna say that objects exert a gravitational force on other nearby objects, which in turn accelerates them toward the object. The gravitational force is described by F_g= G (m₁m₂/r²), where G is the gravitational constant, m is the mass of each body (m₁ would be the earth and m₂ would be you), and r is the distance between the center of mass of each object.

Plug F_g into Newton's second law F=ma to find the acceleration of an object due to the gravitational force, F/m=a.  The m cancels out and you're left with A_g= G (m/r2).  This is where the 9.8m/s² comes from.

[housearrestee]

thanks kermie and newfound...those combined responses were perfect...kermie made it clear cut and you back it up with some mathematics....excellent

i cant wait to see how this is all put together  

edit...ill have to check out that video later on pshmell

[pshmell]

imagine this in reverse. same thing, like kermie said.

[prolixity]

You are in a box.  You have access to all the instruments and tools of science.  Discern, whether the box is sitting on the surface of a planet with 1G of gravity, or is accelerating with a speed 9.8 meters per second per second through empty space.

Solution:  cut a hole in the box and look outside.

[pshmell]

Solution:  cut a hole in the box and look outside.

If you're somewhere in the Universe, then sure.
But imagine you are in a vacuum. Then, your box could be made of glass and you still wouldn't be able to discern.

[prolixity]

If you're somewhere in the Universe, then sure.
But imagine you are in a vacuum. Then, your box could be made of glass and you still wouldn't be able to discern.

Yeah, the question was how does one determine if he is in a gravity field on a planet or undergoing the same acceleration in space.

So if I am in a vacuum, I guess we've answered that question, unless we're suspending me in a dark room, etc.  But then a trite answer wouldn't work, so let's not change the rules of the game mid-way through.     

[gorfehttimrek]

Hiya ix (pbuh).

Uhmmmm, why are you reading long haired books? 

Shouldn't you and the new bride be making like energizer bunnies and practicing up for the tricycle motor making competition? 


Congrats on your step up the life ladder.  It's called getting a better half...

She will do this to you.   

You must do this for her.     and   

Then everything will be balanced and the wheel of life may continue to turn.  We are depending on you to keep reality real for all of us.  NO pressure.

Now get back in there, and Practice, practice, practice.  Must make the best tricycle motor!   

[housearrestee]

watch the whole thing: http://www.youtube.com/watch?v=LHPqhTY6dh0

You should definitely pick up The Universe and Dr. Einstein by Lincoln Barnett if you can find it. Most concise and simple explanation of special and general relativity I've EVER seen.

just watched the video...thanks pshmell...so let me ask this...in the video an apple is falling towards the earth...because earth is creating a curvature in space...so if that is the case the apple would fall to the bottom side of earth as it slopes down to the bottom part of where space is curved?

also is there any videos out there that show how the entire solar system looks based on the curvature of space...is it like a series of small and large dips...and how orbits work according to this curvature...wouldnt all smaller objects dip towards larger ones and be destroyed like the apple?

edit...temporarily exchanged "the elegant universe" for "a brief history of time"..."history" i think reads better...im currently learning about light cones and how we pretty much live in the past...universe speaking...actually the way i look at it...we are always incapable of seeing actually present moments sense light must bounce of  things first and then we see that reflection...always behind, no?

[prolixity]

just watched the video...thanks pshmell...so let me ask this...in the video an apple is falling towards the earth...because earth is creating a curvature in space...so if that is the case the apple would fall to the bottom side of earth as it slopes down to the bottom part of where space is curved?

Using this representation, the center of mass of the Earth is the deepest point of curvature.  This point is approximately the "center of the Earth"

[gorfehttimrek]

Trouble comes from the representation of this three dimensional gravity well, being visually represented by the two dimensional rubber sheet with cone shaped dents where "mass" is present.  The distortions caused by mass are not this shape in reality...

Picture a box with threads going from inside face to opposite inside face.  Let's assign a density of "one thread" for every sq in of surface. 

A cube with ten sq inch sides.   10 threads going from each would give us 30 threads.   and would create a matrix of sorts.  there would be 10x10x10 intersections inside this matrix we have created inside this cube.    Let this visual ideal represent the gravitational "slope" of empty space away from the presence of any masses.  Someplace like the open areas between galaxies.

The presence of mass will tend to pull all the intersecting points of this thread matrix into a smaller cubic area at the center of the same cubic volume of space we pictured previously.  The density of the intersecting threads being greater at the center and decreasing in density as you get further from the center of mass.   The "density" of packing together of the intersections being directly relatable to the "intensity" of a gravitational field.   Naturally the area of affect on the intersecting threads, turns out to be a SPHERE.  All the density being equal along the surface boundary of any choosen radius.

That would be the correct three dimensional way of picturing masses distorting effect on the substance of space time as represented by the force of gravity.

It "curves" away from the theoretical ideal of perfectly parallel threads between perfectly parallel planes in a three dimension cube.



Close your eyes and try to picture it all happening everywhere any solid object exists.  Like bubbles; varying gravitational gradients surrounding each object and pressing and distorting from ideal spherical shapes by moving towards each other.  Bubbles; joining and growing, or shrinking and moving apart.  Bubbles that become more perfectly spherical the more isolated from other masses we make them. 

[housearrestee]

Trouble comes from the representation of this three dimensional gravity well, being visually represented by the two dimensional rubber sheet with cone shaped dents where "mass" is present.  The distortions caused by mass are not this shape in reality...

Picture a box with threads going from inside face to opposite inside face.  Let's assign a density of "one thread" for every sq in of surface. 

A cube with ten sq inch sides.   10 threads going from each would give us 30 threads.   and would create a matrix of sorts.  there would be 10x10x10 intersections inside this matrix we have created inside this cube.    Let this visual ideal represent the gravitational "slope" of empty space away from the presence of any masses.  Someplace like the open areas between galaxies.

The presence of mass will tend to pull all the intersecting points of this thread matrix into a smaller cubic area at the center of the same cubic volume of space we pictured previously.  The density of the intersecting threads being greater at the center and decreasing in density as you get further from the center of mass.   The "density" of packing together of the intersections being directly relatable to the "intensity" of a gravitational field.   Naturally the area of affect on the intersecting threads, turns out to be a SPHERE.  All the density being equal along the surface boundary of any choosen radius.

That would be the correct three dimensional way of picturing masses distorting effect on the substance of space time as represented by the force of gravity.

It "curves" away from the theoretical ideal of perfectly parallel threads between perfectly parallel planes in a three dimension cube.



Close your eyes and try to picture it all happening everywhere any solid object exists.  Like bubbles; varying gravitational gradients surrounding each object and pressing and distorting from ideal spherical shapes by moving towards each other.  Bubbles; joining and growing, or shrinking and moving apart.  Bubbles that become more perfectly spherical the more isolated from other masses we make them. 

mind doing a power point of above description kerm    or youtube video would be nice...i feel like this is really important to grasp visually for understanding purposes

[housearrestee]

anyone want to explain string jitters that create negative energies?  Greene doesnt go into much detail about it

[gorfehttimrek]

anyone want to explain string jitters that create negative energies?  Greene doesnt go into much detail about it

Your supposed to 'know' this already from your previous studies...   DUH!

Okay, I'll explain it again.   

He mentions ( Ijust went back and reread a bit of it to get these just right) the plank length and the plank tension.  10 to the power of 39 Tons of pressure squeeze the string down to a length of 10 to the negative 33 centimeters.  This sets the value of the smallest quanta of energy; the plank energy.  The plank energy is enormous.  It's f-ing HUGE.  The output of a Star comes close to the scale we are talking.

This is the SMALLEST unit of energy man.  THE SMALLEST unit exchanged between strings which is multiplied by a variable that is EQUAL to the number of vibrations of the string.

Something has to make those energy levels go down, so that lower energy particles; like protons and electrons and neutrons can be possible. 

The thing about strings is; nothing stops them from vibrating 180 degree out of 'phase' with other strings.
The thing about strings is; two strings = one, and three strings = one, and...etc. 

So negative energy strings can mix with positive energy strings.  Strings of every variety emerge from a seething, frothy sea of strings      Some of them have the exact energy level of a proton.  But how? if they all have a whole number amount of energy quanta?  The answer is jitter.  Some jitter is negative in respect to the vibrations of the string.  Letting there be minute differences in energy levels among the strings.  Jitter arises from the undulating moving structure of space time at the sub-plank scale.

So says the theory,    and it comes fully equiped with a functional 'graviton' whose string energy levels cancel completely to equal zero. 

Hope that helped 

Kermit

[housearrestee]

  Jitter arises from the undulating moving structure of space time at the sub-plank scale.

I thought that string theory doesnt allow for sub planck scale discussion...ill get back on this subject...im kinda of drunk but he does discuss using the strings to probe smaller scales and blah blah blah....there is nothing smaller...but anyways thanks kerm...i need to reread that section and get back to you...i have some more questions on this matter...i need to go to school and be in a classroom for this shit..so i have a hands on teacher that got paid to deal with me...i didnt realize it was multiple strings working off each other to create the lower string energy...btw i love this shit...i havent been this absorbed in a really long time