Sign in to follow this  
master_q

Star Trek & Physics Weekly

Recommended Posts

ST & Phys Weekly Discussion: Quantum Gravity

 

The new topic for Star Trek & Physics Weekly will be on Quantum Gravity!

 

Quantum Gravity or called “The Quantum Theory of Gravity” is what can be called “the holy grail of modern physics”! I hope that you will enjoy this new topic.

 

Quantum Gravity is trying to unify General Relativity (the “large scale”) and Quantum Mechanics (the “small scale”). Physics still has no real answer or definite answer to the problems of this topic. It is still underdevelopment and there are several different ideas out there to unify the two topics in physics (general relativity & quantum mechanics).

 

So I really hope that you all read it here and even give your input by replying ever now and then.

 

 

Master Q

StarTrek_Master_Q@yahoo.com

Share this post


Link to post
Share on other sites

Star Trek & Physics Weekly

Edition 49: The New Frontier of Unknown

{Please Reply!! - Comments, Extra info, What You Think. . . }

 

For our next topic in Star Trek & Physics Weekly we will be looking at the Quantum Theory of Gravity. We will look into relativity, quantum mechanics, string theory, supergravity, twistor theory, M theory, loop quantum gravity, and so on. I hope you enjoy it

 

What Do You Think? / Q’s?

 

What do you think about the compatibility problems of the large scale and that of the small?

 

Do you have any analogies with the topics talked about here?

 

 

Edition 49

-- The New Frontier of Unknown --

In Star Trek & Physics Weekly we have a new topic because of our completion of logarithms. Like I have stated we will be looking at some modern physics for an application look into relativity and beyond. In this edition we will look at the need for quantum gravity.

 

~~GENERAL RELATIVITY QUICK INTRO~~

General Relativity was developed by Einstein after he developed Special Relativity. Before Relativity we had only Newtonian Physics (also called today as classical physics) and when technology was getting more advance, our observations of the heavens were more in-depth, and so on . . . people saw several counter dictions with Newtonian Physics in the physical world. Things like the orbit of Mars did not behave as defined by Newton (and other scientists). It really was a mystery.

 

Then Albert Einstein came along and changed our understanding of the universe very radically and correctly. It really is amazing what Einstein said. It gives us the understanding of how space & time is constructed and helps us understand the construction of the universe. This is how profound the theory of General Relativity is.

 

General Relativity describes gravity. It defines it! Gravity is a wrapping of the fourth dimensional space-time fabric or continuum. Gravity creates this, so the sun, planets, stars, . . . give off gravity which means it creates wrappings in the continuum. One way to view this in our three dimensional perspective is to think about a sphere in space. So the Earth would be a 1/2 plane sphere when looking at the space time continuum (for the gravity it gives off).

 

Think of one of those charity coin collectors that are in the stores/malls were you drop and coin and it rolls round & round until it falls down the whole. It’s the same idea.

 

~~QUANTUM MECHANICS QUICK INTRO~~

Quantum Mechanics tries to explain the subatomic world. It looks at the motion of this subatomic world. Classical Physics only really described motion of regular things and did not really explain how the quantum world works & behaves. Quantum Mechanics deals with things like an atom’s motion, how different pieces make up an atom, and things to that nature. One main role in the mathematics of Quantum Mechanics is probability. If you worked on the math for trying to figure out where some particle is located you then, give it a ratio (or % of probability) of where it most likely is. Quantum Theory describes matter (or even energy) as both waves & particles. This is most definitely a major factor.

 

But even today we still have lots of questions in this filed. Quantum Mechanics is very confusing and in trying to build up a picture of it or create a model you can’t really show the process (I’m not referring to a single moment in time) and this creates difficulties . . .

 

~~COMPATIBILITY PROBLEMS~~

A question that you might be asking is “What’s the point in unifying General Relativity with Quantum Theory?” and in fact that is a great question. I say this because both deal in opposite directions. One deals with the larger scale and the other deals with the smaller scale. Large vs. Small

 

But when you think about it the small makes up the large . . . all of those small particles are built on top of each other and when you add all that up you finally get the larger scale. So we can think of terms of the Quantum world building up to the Larger scale. But how can we do this? How can we connect the two and unify them?

 

That is the question! And that question we will try to answer during this topic for ST & Physics Weekly in coming editions.

 

 

Master Q

Share this post


Link to post
Share on other sites

Star Trek & Physics Weekly

Edition 50: Quantum Gravity Logic & Superposition

{Please Reply!! - Comments, Extra info, What You Think. . . }

~Quantum Gravity “The Holy Grail of Modern Physics”

 

What Do You Think? / Q’s?

 

What do you think about the compatibility problems of the large scale and that of the small?

 

Do you think the uncertainty principal needs to be replace because there has to be something to describe all variables?

Or do you think that the uncertainty principal can’t be replaced because of unknown variables?

 

What do you think of Intuitionist Logic and the mathematics from Topos Theory?

 

Do you have any analogies to superposition that could be helpful?

 

Edition 50

-- Quantum Gravity Logic & Superposition --

Star Trek & Physics Weekly will continue to look Quantum Gravity. In this edition we will talk about topos theory, superposition, and so on.

 

~~ INTUITIONIST LOGIC~~

Let’s say that I’m doing an experiment on something and try to watch the subatomic particle. Then of course I record the data that I get, but you have to ask yourself “Am I causing that particle to behave different or am I interfering with it in some way?”. This is a very important factor in doing an experiment. We want accurate data!

 

Classical Logic: this kind of logic says that something will be true or false, black or white, . . . with this we only look at what the observer is seeing and his state of mind and that’s it.

 

But this kind of logic does not fit or really work.

 

For example in the past we were only able to see x amount of the universe. Now we see more because time has passed and light (+ other things) have reached us. In the future we will even see more . . . We can see 14 billion light years out (I’m referring to light reaching us and things to that nature) and a billion years from now we will be able to see 15 billion and so on.

All of this depends on observe & there time frame.

 

How about the latest fashion? In the past we considered x to be fashionable, but not we consider y to be fashionable. Classical logic does not care about the observer if its the view point, time, . ..

 

Intuitionist Logic:

 

So now we can say that a statement if true or false depends on the relationship between the observer and our subject

 

Now what’s the point of this logic?

In cosmology, quantum gravity, . . . we need know that it is observer dependent! First of which our actions affect our outlook on the universe and that one observer to another may see something different. (Kind of like frame of references in special & general relativity)

 

Topos Theory: the mathematics of Intuitionist Logic

 

~~QUANTUM THEORY~~

Superposition Principle . . .

After spending some time on some science boards I see tons of misconceptions on what it is. Some people take it very radically or not radically enough and then there are the ones that understand it. I do admit that it’s not the easiest thing to understand, but stay with me!

 

Well first off I need to get into the term states. If I am sleeping, them I am in a sleeping state. If I am running, then I’m running. The state of something is the configuration of a particle at a specific moment of time. It is as simple as that!

 

For example lets say that our system is H2O in a glass of water that I’m drinking through a straw. The state could be the position, speed, and direction of each molecules of H2O.

 

Trouble Ahead

Uncertainty Principal: we can only measure the location or the direction + speed of a particle and that’s it, but we can give certain accepts of it a ratio from probability.

So we don’t have a complete picture of the state after all.

 

{So I can know the exact location or the exact motion}

 

Building Up to Superposition . . .

Now we know that we have a limited picture of the subatomic world. We can say that the state of a system may be x or y because of the uncertainty principal. Or we can say that x and y describe the system because it has both qualities. (Or even because of probability / the uncertainty principal)

Share this post


Link to post
Share on other sites

The compatibility problems become apparent most because of the uncertainty principle. The problem I have seen most when I was in Modern Physics class was that there is often a value or function left off when translating the General relativity (which has time as a constant tangible function), to the Quantum theory(which has time not as a constant, but as yet another changing value). Gravity has a particular value in the General, 9.8 meters per second squared. Yet this isn't always the case in the Quantum, because you must take into account superposition and translation of the two different points of view(stationary and the accelerating field). --To be honest, I had gotten stuck a few times in that course myself (However because of severe illness, I was forced to withdraw from Modern Physics . . .so I still need to take the course for my major)

 

Now for a comment- I am so very glad that you have these threads, it'd sure keep me ready for school. As for my post I may have it wrong, but figured I would try my hand at commenting. It has been almost a year since I last was taking a Physics course (I was taking Classical Mechanics and Modern Physics, but like I said...I got ill and had to withdraw, I spent more time at home than at the lectures...)

Share this post


Link to post
Share on other sites
The compatibility problems become apparent most because of the uncertainty principle. The problem I have seen most when I was in Modern Physics class was that there is often a value or function left off when translating the General relativity (which has time as a constant tangible function), to the Quantum theory(which has time not as a constant, but as yet another changing value). Gravity has a particular value in the General, 9.8 meters per second squared. Yet this isn't always the case in the Quantum, because you must take into account superposition and translation of the two different points of view(stationary and the accelerating field). --To be honest, I had gotten stuck a few times in that course myself (However because of severe illness, I was forced to withdraw from Modern Physics . . .so I still need to take the course for my major)

 

Now for a comment- I am so very glad that you have these threads, it'd sure keep me ready for school. As for my post I may have it wrong, but figured I would try my hand at commenting. It has been almost a year since I last was taking a Physics course (I was taking Classical Mechanics and Modern Physics, but like I said...I got ill and had to withdraw, I spent more time at home than at the lectures...)

That’s definitely one thing that ‘bolds’ the problem between this incapability or as it appears to be, but the fact is that we are talking about different interactions that are working together in a bigger picture or can be viewed as building up to general relativity (“the big scale”). (As you know)

 

 

The next coming editions are going to be more interesting. Mainly when we get into black holes and acceleration (where we would be expanding on the general relativity equivalence principal) . . . . . . So I think they we be worth wild for everyone to read, but right now we still have to work up to that.

 

 

(Just curious) Yillara_Soong in your Modern Physics course that was on Quantum Gravity (and probably other topics) did you have to deal with Topos Theory or anything to that nature?

 

 

Master Q

StarTrek_Master_Q@yahoo.com

Share this post


Link to post
Share on other sites

Star Trek & Physics Weekly

Edition 51: Causality & Space Time Cone

{Please Reply!! - Comments, Extra info, What You Think. . . }

~Quantum Gravity “The Holy Grail of Modern Physics”

 

What Do You Think? / Q’s?

 

What do you think about the compatibility problems of the large scale and that of the small?

 

Do you have any ideas on how we could enhance the Space Time Cone Model?

 

What do you think about causality and how it fits in a timeline?

 

 

Edition 51

-- Causality & Space Time Cone --

Star Trek & Physics Weekly will continue to look at Quantum Gravity. In this edition we will talk about causality and the space time cone

 

~~CAUSALITY~~

Causality: cause & effect

I turned left and as a result said hello to the person at that location

I turned right and as a result said hello to the person at that location

A to B {A as the cause B as the effect}

 

Relational Universe: properties are described by terms of relationships between the events

 

If A happens, then B will happen

If A does not happen, then B will not happen

 

If A, then B

 

If A is a contributing cause to B, then more then A was needed to cause B

 

~~SPACE TIME CONE~~

Now lets apply causality to a space time cone

 

Q: What is one way we can define a location through 4D perception?

A: Through a space time cone

 

This is a double-napped cone or two cones on top of each other where the poitns meet (just like with conic sections, but that’s another story)

 

The interception of the two cones gives us the object A at present time

The bottom cone gives us the past

The top cone gives us the future

 

We know that nothing can go faster then light and because of that we have limits to the space time cone (if it’s the past, present, or future). Now knowing that we can build up to and say that an event that happened light years away at the same time could not affect our event in our space time cone and we can also conclude that all light rays that will reach in time will help describe the structure of it (as in the possible casual relations).

 

Causal Structure Of The Universe: the building up of casual relations

 

In General Relativity we here a lot about the casual structure of the universe. Like the fact that gravity warps space and time.

 

~~ATTRACTIONS FROM GRAVITY & THE SPACE TIME CONE~~

Lets say that the particle A and its space time cone is orbiting the Earth. Because it is orbiting the Earth due to Earth’s gravity that cone is tilted towards that of the Earth!

 

The next edition we are finaly going to get into some applications of Quantum Gravity with Black Holes!!

Share this post


Link to post
Share on other sites
(Just curious) Yillara_Soong in your Modern Physics course that was on Quantum Gravity (and probably other topics) did you have to deal with Topos Theory or anything to that nature?

 

I still have my textbooks, and I could check..but because of getting ill, I had to withdraw from the class (and school as well) before we reached interesting topics such as this. :wow: I will stop by from time to time and read up on all of your Star Trek & Physics Weekly(they are great) and I may even comment again, as well! B) This section will definately go a long way in keeping me up to date in the world of Physics! :wow:

Share this post


Link to post
Share on other sites
(Just curious) Yillara_Soong in your Modern Physics course that was on Quantum Gravity (and probably other topics) did you have to deal with Topos Theory or anything to that nature?

 

I still have my textbooks, and I could check..but because of getting ill, I had to withdraw from the class (and school as well) before we reached interesting topics such as this. :wow: I will stop by from time to time and read up on all of your Star Trek & Physics Weekly(they are great) and I may even comment again, as well! :wow: This section will definately go a long way in keeping me up to date in the world of Physics! B)

Well I’ll try to keep your mind (and everyone’s) fresh in this topic! It will be getting a bit more interesting in coming editions. (Or at least hopefully)

 

 

Master Q

StarTrek_Master_Q@yahoo.com

Share this post


Link to post
Share on other sites

Star Trek & Physics Weekly

Edition 52: Karl Schwarzschild’s Black Hole Connections

{Please Reply!! - Comments, Extra info, What You ThinK. . . }

~Quantum Gravity “The Holy Grail of Modern Physics”

 

What Do You Think? / Q’s?

 

What do you think about the compatibility problems of the large scale and that of the small?

 

What do you think of the fact that a black hole acts (to a certain sense) like a magnification glass? Do you think that it might help in looking close up at the structure of space and time and not just the casual structure?

 

Do you have any interesting facts about black holes?

 

 

Edition 52

-- Karl Schwarzschild’s Black Hole Connections --

Star Trek & Physics Weekly will continue to look Quantum Gravity. In this edition we will talk about black holes and connect something that is on the larger scale to that of quantum mechanics in our first steeps in understanding Quantum Gravity

 

~~DESCRIBING A BLACK HOLE~~

A black hole has a paramount gravitational field. It’s so strong that nothing can escape (well something does come out of it, but that’s another story). This includes electromagnetic radiation and light. When light enters it does not come out. It stopped the only constant in the universe. That’s why when you look at one you only see black. So when light enters a black hole’s extreme curvature it does not come out.

 

Horizon: Area or boundary where nothing can escape (making it appear dark & anything that enters it will become invisible to the outside world)

The horizon is filled with light rays that became trapped inside! These light rays keep trying to get away, but they can’t.

 

Singularity: point of infinite density and curvature of space time (in the center of a black hole)

 

Hidden Region: It is basically an area that we can’t or someone else can’t see because a black hole blocks a specific region away from us.

As you can see a black hole can hide things from us in the universe.

 

 

~~APPLYING THE SPACE TIME CONE~~

If a particle ends up in the horizon, then its space time cone will be tilted all the way to the black hole. If a particle does not enter the horizon and just goes by close to it, then it will again be tilted a lot. As you can see this is pretty logical. (And remember that the top is the future, the interception is the present, and the bottom is the past)

 

~~TIME & A BLACK HOLE~~

Let’s say some how we threw a clock near a black hole. First it is moving closer and closer to the black hole and at the same time, time is going slower and slower. Next it enters the horizon and it stops!

 

Now lets look at an analogy to help us understand light frequencies. Let’s say that clock was ticking . . . tick tock tick tock . . .

 

First we have nice high frequencies . . . . tick tock tick tock . . .

Then it seems to get lower . . . . tick . . tock . . . tick . . . . tock . . .

Then it stops . . . .

 

**Quantum Mechanics:

Frequency of light is proportional to its energy!!

 

Its energy is getting less and less as it approaches that black hole. (Kind of like its strain is getting more and more making it have less and less energy)

 

More Connections:

Now that we know this we can say that light that went close by a black hole lost energy and so lost its height in frequency.

 

**Quantum Mechanics:

Wavelength of light is inversely proportional to its frequency!!

 

So now we can say that because its frequency is less and its wavelength is more.

 

~~MORE CONNECTIONS~~

So let’s connect some more dots. Because wavelengths will be stretched all around a black hole tells us that an area that has a black hole will have large and usual wavelengths!

 

We can also see a very important rule quantum mechanics is playing on the large playing filed! Quantum Gravity!

 

We know from the uncertainty principal that the quantum world is in a ‘quantum dance’ as it fluctuates. This might (we will look into this in a future edition) also apply to the geometry of the space time in a micro sense. And because a black hole is kind of like a magnification glass (with wavelengths) it might in the future let us see parts of the structure of space time.

 

 

Master Q

Share this post


Link to post
Share on other sites

Star Trek & Physics Weekly

Edition 53: Quantum Gravity & Acceleration

{Please Reply - Comments, Extra info, What You Think. . . }

~Quantum Gravity “The Holy Grail of Modern Physics”

 

What Do You Think? / Q’s?

 

What do you think about the compatibility problems of the large scale and that of the small?

 

What do you think about the fact that when accelerating you will see lots of particles and the fact that your temperature in a void will = that of your acceleration?

What do you think about the Quantum Fluctuations going up in this?

 

 

Edition 53

-- Quantum Gravity & Acceleration --

Star Trek & Physics Weekly will continue to look at Quantum Gravity. In this edition we will talk about the equivalence principle, Unrul’s law, Bekenstein’s law, . . .

 

 

~~GOOD OLD GENERAL RELATIVITY~~

We are in Earth’s orbit and our Starfleet shuttle craft is falling down (free fall) to Earth and is out of control and the gravity generators don’t work. While we are going down I physically jump up to fix something as a result I am not going to touch the ground until we crash.

---*During free fall when you jump up the “floor” is also in free fall and you will appear to be floating **Why? Because you jumped up and now are falling at a constant acceleration as the shuttle is.

 

Now let’s say that this time - we are in our Starfleet shuttle craft and again the gravity generators don’t work. We go at impulse (with out going into subspace or anything to that nature). At impulse we go up at 9.8 m/s^2 and then suddenly my feet hit the ground (The shuttle is going up and we are just floating in the middle until that ground hits my feet)! In fact we are accelerating at the same acceleration that we would be falling on Earth. If there was no window in the shuttle you could not physically tell the difference between that acceleration of that shuttle and that of gravity. They are equivalent! This is called The Equivalence Principle

 

~~OTHER EFFECTS? YES, . . .~~

Unruh’s Law

This is a very interesting thing

 

Let’s say we are again in the middle of no where and when we look out the window we see nothing but a void. When we start to accelerate our sensors detect lots of particles. Let’s say that there is another shuttle craft and that one is not accelerating. There sensors don’t really detect anything despite the fact that we do!!!

 

I don’t know about you, but that is pretty neat!

 

Now we (in the accelerating craft) look at the thermometer and the group that are not accelerating look at there thermometer. The group that is not accelerating says its 0 (because the temperature measures the energy in random motion). When we look it is a # that is proportional to our acceleration!

 

Heat is in fact energy and by using that logic we can figure that the temperature is = to that of the acceleration and so on (in a case like this one). And that our engines that are pushing us through space create energy & heat, but heat is not only regular energy, but energy in random motion.

 

~~APPLYING QUANTUM MECHANICS~~

Uncertainty Principal tells us that a particle can’t be sitting still.

It doesn’t matter even if we are talking about a particle that has no energy. There still will be some random motion in that particle.

 

Zero Point Motion: a particle with no energy will still have random motion

 

Quantum Fluctuations: the randomness

 

Connecting . . .

 

What actually happened on our trip when the temperature raised was that quantum fluctuations went up!

 

~~EINSTEIN-PODOLSKY-ROSEN EXPERIMENT~~

This experiment helps show the randomness of the subatomic world. If we create 2 photons & split them in opposite directions, then even though they are separate they contribute to each other (in there movements, . . ). In fact all photons that are around (even if they are far away) will affect those photons. Because we can’t measure or observe all the photons in the area it creates randomness in our 2 photons (or it makes it appear random / chaotic). When we try to measure what they are doing we can’t really. All we really can detect in this case is heat.

 

~~MORE CONNECTIONS~~

Bekenstein’s Law

Lets go back to our ship that was accelerating

First of all one thing that I can say is that because we are accelerating some photons that are far away will never reach us until we stop accelerating. We can call this a “hidden region” to us. Are rapid randomness we see in our ship is masked because of our hidden region and so we can’t really collect exact data.

 

Acceleration is proportional to the hidden region

 

 

Master Q

Share this post


Link to post
Share on other sites

Star Trek & Physics Weekly

Edition 54: More Quantum Gravity Black Hole Connections

{Please Reply - Comments, Extra info, What You Think . . }

~Quantum Gravity “The Holy Grail of Modern Physics”

 

Want to know what ST’s starships should see when flying by a Black Hole?

Answer: In This Week’s Edition of ST & Physics Weekly!

 

What Do You Think? / Q’s?

 

Do you think ST has been true when representing the effects of a Black Hole to a starship?

 

What do you think happens in the black hole evaporation process (when it is nearly completed)?

What do you think Quantum Gravity will predict in the future about this?

 

Do you have any interesting facts about black holes?

 

 

Edition 54

-- More Quantum Gravity Black Hole Connections --

Star Trek & Physics Weekly will continue to look at Quantum Gravity.

 

~~ENTROPY~~

Entropy: is the measure of ‘disorder’ of a system where the amount of information about the motion of atoms making up the system it self can’t be found by the state of that system

 

From the last edition we learned a bit about Unruh’s & Bekenstein’s laws. Were we talked about some other interesting things that will happen if you are accelerating in space in a void . . .

 

{Note: Planck Length = 1.6 x 10^-35 m}

 

Lets think and look at a black hole like it is a computer monitor. Where each Planck area has only one pixel that is “on” or “off” (just like in binary!) and that each pixel has a bit of information (entropy). Because we are talking about such a small size there would be billions and billions of pixels making a black hole have ‘lots of information’.

 

~~THERMODYNAMICS~~

Thermodynamics is another branch in the grand tree of physics. It deals with the microscopic world of matter and energy.

 

Second Law of Thermodynamics: entropy can only be created (not destroyed)

 

Hawking suggested that because items fall into a black hole and that they will not be able to come out, then the area of the black hole’s horizon will never lose any area. Just like in the second law of thermodynamics the entropy is not going to get destroyed. But is this a complete picture?

 

~~PROBLEMS?~~

If nothing comes out of a black hole, then it must have a temperature of 0. As has been stated before temperature measures energy in random motion and because it appears that there is none then it would have a temperature of 0

 

More Problems?

 

With entropy there is heat because missing information tells us how much heat. But if a black hole has some entropy, then it would be violating the laws of thermodynamics.

 

Later on Hawking figured out that if a black hole did have heat that it would not violate the laws of thermodynamics! If I am in my Starfleet starship I would see that the temperature would be finite.

 

He figured out that the temperature of a black hole is inversely proportional to the mass! But we do have a constant term k. Which makes the actual temperature of a black hole not that large (so don’t expect it to be your next vacation to Arizona). So the smaller the black hole the hotter it is and the larger the black hole the colder it is.

 

~~HAWKING RADIATION~~

Well most of you probably know of Hawking Radiation by now, but if you take into some new things like what I said previously some more interesting things happen. (I’m just giving a general look at it) In a black hole there are electron-positron particles (think of positive & negative. . .) The particle’s energy increases because of the gravitational field from the black hole (e=mc^2 tells us that energy & mass can be transformed). One part of that particle gains substance (remember e=mc^2) and the other half gets taken by the black hole. That particle that gained that substance is now large enough to become a full blooded particle. Because it gained energy & mass it then shoots off into space (as the other half got sucked in).

 

From this it also takes away more and more mass away from the black hole because a black hole in space has no other source of energy to prevent it from losing mass

 

Because the black hole is loosing mass - its temperature is going up!

 

Black Hole Evaporation: when a black hole ‘evaporates’ its mass completely

 

Unknown Question

 

Heat is going up and up as it is loosing more and more mass, but it is not yet really known what will happen when a black hole ever reaches a point where the horizon is only a Planck length. That is a question that is yet to be answered in quantum gravity, but of course there are hypotheses / conjectures to what will happen and we will talk about some of them in the future.

Share this post


Link to post
Share on other sites

Star Trek & Physics Weekly

Edition 55: “Space” & Quantum Gravity

{Please Reply!! - Comments, Extra info, What You Think . . }

~Quantum Gravity “The Holy Grail of Modern Physics”

 

What Do You Think? / Q’s?

 

Do you really think that there is a limit in space it self like mater?

 

Do you have any interesting conjectures on the atomic structure of space?

 

. . .

 

Edition 55

-- “Space” & Quantum Gravity --

Star Trek & Physics Weekly will continue to look at Quantum Gravity. In this edition we will start to look at the geometry of space

 

~~MATTER~~

In matter there is a limit in dividing something up into smaller and smaller pieces. Let’s say I took a box cut it in half and then cut it in half again and again and again and again . . . . . . . . Would there be a point were I can’t cut any more?

 

In mathematics the answer would be that you can continue for ever dividing something by 2, but in physics would there be a limit? Matter does have a limit on how small we could divide something. But again - what about space it self? That is a good question

 

~~SPACE~~

In fact we are going to look into and talk about this in this edition and in coming editions. Where we will come to the fact that even space has a limit!! But of course it is much smaller then matter’s atom

 

Space in fact is not “smooth” it is bumpy (as some people might call it or refer to it)

 

But before I jump into space lets go back to matter for a second because it has parallels to our discussion. At first most physicists did not believe in atoms, but later they started to even (with out some direct evidence). The reason physicists started to believe that atoms existed is because of thermodynamics. In this case it’s specifically called statistical mechanics. When physicists still didn’t like the idea of atoms a paradox arose.

 

The laws of thermodynamics are not absolute. There is always a chance that a specific # of atoms will not behave like what is normally expected.

 

And guess who helped prove to physicists that they exist?

ALBERT EINSTEIN

Hey, he did more then relativity! He was also a leader in quantum mechanics! He said from statistical mechanics that the laws of thermodynamics allow it to be violated once in a while. After his findings from connecting the dots between statistical mechanics & thermodynamics to the atom he then started to figure out what light was. People like Einstein gave the birth to Quantum Mechanics!

 

But before we go look into “space” lets talk a bit more about black holes

 

~~MORE BLACK HOLE TALK~~

From the last editions were we talked about black holes we know that they have an entropy and temperature (which also fits and obeys thermodynamics). Let’s say there is a black hole in space and an atom is then sucked in. So if we connect the dots from the last editions we know that the entropy of the region outside the black hole goes down because the entropy measures the information in the region and because there is a smaller # of atoms then there is less to know about it. So the entropy of the black hole increases. And from this fact we know the black hole’s horizon expands a bit. We can also have the opposite thing happen where a black hole’s horizon decreases and so the entropy will decrease. This must make the entropy outside the black hole increase (because the black hole is losing entropy & the outside gains it). Both balance one and another out!

 

~~“SPACE”~~

Entropy really deals with the geometry of space and time.

For example entropy in a black hole is proportional to the area of the black hole’s event horizon. Information can be converted into ‘geometry’.

 

So is there an atomic structure of the geometry of space and time?

 

That’s what quantum gravity is trying to figure out!!

 

In some future editions we will talk about string theory & loop quantum gravity where both say that ther is an atomic structure of space and time. We know that space must have an atomic structure. All the things that we have been talking about relate quantum mechanics (the atomic world) and general relativity. This shows us that there are many connections between the two and that they must connect in some way.

 

That’s what quantum gravity is about!

Share this post


Link to post
Share on other sites

I have not had the time to type out a new edition yet, but I’ll try to have one ready in a few days.

 

So until then . . . .

 

 

Master Q

StarTrek_Master_Q@yahoo.com

Share this post


Link to post
Share on other sites

Star Trek & Physics Weekly

Edition 56: Loop Quantum Gravity & QCD

{Please Reply - Comments, Extra info, Questions, What You Think . . }

~Quantum Gravity “The Holy Grail of Modern Physics”

 

What Do You Think? / Q’s?

 

Which of the three ideas to string theory do you think is most plausible?

 

What do you think about the fact that space has an atomic structure?

 

Do you have any interesting facts about superconductors?

Please Share Them!

 

 

Edition 56

-- Loop Quantum Gravity & QCD --

Star Trek & Physics Weekly will continue to look at Quantum Gravity. In this edition we will talk about the basics on Loop Quantum Gravity, Superconductivity, and String Theory!

 

~~GETTING STARTED IN QG~~

QG = Quantum Gravity

In edition 55 we figured out that there must be an atomic structure of space & time. When physicists first figured this out they started to work on something called Loop QG! As you know we are dealing with subatomic scales and how this subatomic world builds up to that of the larger (Quantum Mechanics building up to General Relativity). Matter as you know is made up of atoms. Loop QG says that space it self is made up of a different kind of atom that caries an extremely small amount of volume. Space in an overall perspective (I’m not referring to space as the heavens) is volume. Of course we also know that this universe is also constructed with time. Time is another dimension!

 

What does this say?

Just think about this for a second and I think anyone can conclude that understanding that space has an atomic structure opens the doors to understanding the actual construction of the geometry of space-time. This in it self is amazing and has amazing results.

 

Let us say that we wanted to figure out the surface area of a box on one of its faces. When we figure this out mathematically using geometry (Euclidean Geometry) we can find out a value. In general terms mathematically speaking we could figure out the area of anything giving us an infinite amount of possibilities, but now because of Loop QG we know that there is a limit in this amount. This gives us a finite amount of possibilities.

 

Space is not continuous

 

~~BUILDING UP TO LOOP QG~~

This whole idea of Loop QG actually came about from the physics of superconductors.

 

Superconductivity: when something conducts electricity without any kind of resistance

 

Some metals when you put them at a temperature close to absolute zero (critical temperature) the metal it self goes through a change in phase. This phase is a change that is pretty profound. The actual atoms that make up this piece start to fundamentally change. The electrons that are in the atoms actually get “liberated” and lets electrons go through it with out any kind of resistance.

 

If you took some kind of magnet and placed it near a superconductor, then the magnetic flux of the filed lines breaks up compared to taking a magnet and placing it close to a regular object.

 

Now if we move on to quantum mechanics one of the interesting things is that there seems to be quarks that make up (or are inside) protons and neutrons. We can today free an electron from an atom, but we can’t free a quark. The major thing in understanding if we can or can not is by understanding if a force in an atom is behaving like an electric filled in holding the electrons around the nucleus and if this force holds it together where the quark can’t come out (or can in some way). After several years physicists have figured out that there is some kind of force, but that this force does not act like the electrical force or magnetism force.

 

~~QCD~~

QCD: Quantum Chromodynamics

The force that holds everything together in a system with quarks are actually three types of charges! These are called colours. In the regular electric force when the distance between two things gets greater and greater the force between them gets less and less. In colours (remember this is a force dealing with quarks!) it is just the opposite. When two quarks get a greater and greater distance between them the force gets larger and larger.

 

Example)

Let’s say that I have a string and two quarks, one at both ends. Now we try to pull this string, but when we pull this string we need more and more energy. This says that we can’t really pull two quarks apart. From this one can think that the forces that hold together a quark might be kind of like a superconductor’s reaction to a magnetic flux.

 

From this notation (or idea): empty space might be like a colour-electric superconductor

 

But if this is true and from the fact that we know the quantum world acts pretty random then that would have to carry over to space also . . . ?

And that’s a question you must face. We know that quantum mechanics can have lots of oscillating random fields and as a result that would have to carry over to QG. So vacuum fluctuations act like atoms in metal during superconductivity and that carries over to the larger scale (general relativity making are full connection to QG).

 

Another take on this superconductivity view is called String Theory

 

~~STRING THEORY~~

If you have read several of my posts in the science & technology board on StarTrek.com or on the official string theory site, then you might have heard me talk about String Theory before. String Theory takes the idea of two quarks and that analogy of the string between them and looks at the “string” directly and so it is called “String Theory”!

 

It does not think of this the two quarks as force lines of a filed, but looks the “strings” directly.

 

There are three ideas on the string theory:

1. That the filed lines are only approximations to the actual “string”

or

2. The filed lines are the actual “strings”

or the combination of the first idea and String Theory

3. Hypothesis of Duality:

The string idea and the field are two different ways to look at the same thing

 

Because there is a lot to on Loop QG and String Theory I will continue this to another edition that I will post in a few days . . . .

 

My Thoughts:

I of course as anyone has there own ideas and things that I support. I do believe in the third choice - the hypothesis of duality. I believe the hypothesis of duality connects several unknowns that have been in physics for years. The question that has haunted physicists for years and still to this date is the simple question “How can light exist as both a particle and a wave?” . . . . the hypothesis of duality would explain that these two things are two ways to look at the same thing . . .

 

 

Master Q

StarTrek_Master_Q@yahoo.com

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this