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Temporal Uniformity


Daedalus
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O.K. well understood. But NEVER make honest statements about your lack of knowledge. It is intellectual suicide in this Forum. No need to lie, just don't say anything. That is my humble advice.

 

I am quite happy to admit my lack of expertise in many (all?) areas. I am often corrected by those more knowledgeable than me, an I am grateful for it.

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Yes, time is measured with motion. However, it may be more accurate to say that all clocks measure distance traveled. The distinction being that distance is a characteristic of all dimensions and thus no fourth dimension is needed to explain it.

 

That's even more wrong than what Daedalus had claimed.

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Hey swansont, would you please be more specific as to what is wrong with my statement and maybe include a reference or two? Call me weird all you like, but I rather enjoy figuring out how I got something wrong.


After reading further through the posts on this topic, I apologize for my sound bite. I claim inexperience with the forum leading me to respond to only the first page of posts.

 

I still haven't read all of this topic's posts, so this may have already been covered, but I have questions.

How do you explain reflection? How does a photon oscillate within itself?

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Hey swansont, would you please be more specific as to what is wrong with my statement and maybe include a reference or two? Call me weird all you like, but I rather enjoy figuring out how I got something wrong.

One can move in +1m in X axis in f.e. 1 second, or 2 seconds, or 1 hour,

or +1m Y axis in 1 second, or 2 seconds,

or +1m Z axis in 1 second, or 2 seconds,

(or any other distance d, less than c, in time less than t=d/c)

 

Then how can you say "and thus no fourth dimension is needed to explain it.".. ?

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Okay Sensei,

Clocks are designed for consistency. Any oscillating motion includes changing accelerations and/or velocities. The same consistency can be achieved by measuring the distance traveled by an object moving at a constant velocity. Yet consistency is not a requirement for our perception of time. Consistency is only necessary for repeatable measurements that more or less correspond with our perception of time. We perceive changes. Without perceived changes, our feeling of time passing goes away. I would take this so far as to say that without changes, we go away.

I think that daedalus' theory is pretty cool, and wrong. This is mostly because it leaves some things unexplained. Thus, my previous questions.

If this explanation is as weak for you as it appears to me, I will try again when I am more awake.

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How about radioactivity?

 

[math]m(t)=\frac{m_0}{2^\frac{t}{t_{1/2}}}[/math]

 

m0 - initial mass of radioactive isotope f.e.[math]^{14}_6C[/math] https://en.wikipedia.org/wiki/Carbon-14

t1/2 - half-life for [math]^{14}_6C[/math] is 5730 years.

 

so after 5730 years we find that [math]m =\frac{1}{2}m_0[/math]

 

There is no motion involved in this calc.

 

We find animal body, carbon ore, ancient artifact, we know how much of Carbon-14 it should have, and measure what is actually mass of this isotope, and finding out how much of time was needed to decay isotope to have such effect. Reverse of above equation. Instead of measuring mass m at time t, measure time t from known m0 and m and t1/2..

 

Radioactive dating article:

https://en.wikipedia.org/wiki/Radiometric_dating

Edited by Sensei
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How about radioactivity?

 

[math]m(t)=\frac{m_0}{2^\frac{t}{t_{1/2}}}[/math]

 

m0 - initial mass of radioactive isotope f.e.[math]^{14}_6C[/math] https://en.wikipedia.org/wiki/Carbon-14

t1/2 - half-life for [math]^{14}_6C[/math] is 5730 years.

 

so after 5730 years we find that [math]m =\frac{1}{2}m_0[/math]

 

There is no motion involved in this calc.

 

We find animal body, carbon ore, ancient artifact, we know how much of Carbon-14 it should have, and measure what is actually mass of this isotope, and finding out how much of time was needed to decay isotope to have such effect. Reverse of above equation. Instead of measuring mass m at time t, measure time t from known m0 and m and t1/2..

 

Radioactive dating article:

https://en.wikipedia.org/wiki/Radiometric_dating

I might not be able to discuss the QM nature of radioactive decay, but we do know that the decay components move away from the decaying particle where such motion is a consequence of the act of decaying. However, the fact that I can use measurements of distance traversed by some mechanism instead of units of time to formulate the equation for decay is what I am discussing.

 

Measuring Time with Motion

 

Why is it important to define and understand how we take measurements? How can we even begin to answer questions about time if we don't even understand the underlying nature inherent to time itself? It all comes back to the statement that In order to measure any physical phenomena, we are forced to use an attribute inherent to the phenomena itself. When we examine how we measure time, we find that we always use motion to take the measurement. A sun dial works because the Earth rotates, grandfather clocks works due to the swing of their pendulum, spring watches use a spring to turn gears, digital watches use electricity to cause crystals to oscillate, light clocks reflects photons between two plates, and atomic clocks measure quantum mechanical properties derived from the motion of the energy contained within atoms (I will address atomic clocks later in this post). The mechanism that measures time in all of these devices does so by some form of energy changing position through space.

 

If we can agree that we use motion as defined by energy changing position through space to measure time, then motion must be inherent to time. If motion is inherent to time, then time is purely spatial and is governed by distance, which makes sense because the only thing that exists in the universe is energy and space. Because it is mathematically impossible for energy to traverse distances through space with an infinite speed, the passage of time must occur. So, our experience of the passage of time is a mathematical consequence of motion being restricted to finite speeds and nothing more. This is no different than how objects seem smaller at greater distances. Such things are mathematical consequences of distance. Therefore, in temporal uniformity, time is defined as a mathematical consequence of energy changing position through space with finite speeds.

 

However, we measure motion as a change in space over a change in time. How can time be a consequence of motion if our definition for motion is based on units of distance and time? This contradiction can be resolved by analyzing how we use motion to measure motion. Because energy has to change position through space for change in the environment to occur, when we use a clock to measure the rate of change of a physical property, we are actually using the motion of the mechanism in the clock to measure the motion of the energy causing the physical property to change. In essence, we are using motion to measure motion no different than how we use distance to measure distance.

 

Besides, a change in position [math]\Delta\,x[/math] does not require measurements of time. The change in position is purely a spatial property which relates back to measuring distances. We introduced the concept of measuring time because energy can change position at different rates. However, we don't need measurements of time to measure these different rates at which energy can change position through space. All we need are measurements of the distance traversed for some unit of motion compared to the distance traversed by some form of energy. If this is true, then we should be able to remove the time variable [math]t[/math] from every equation in physics, and replace it with a measurement of distance. We can demonstrate this concept using a light clock.

 

attachicon.gifLightClock.png

Figure 2 - The light clock to the left is at rest and the clock to the right is moving relative to the observer's coordinate system.

 

The light clock to the left is stationary in the coordinate system or frame of reference (FoR) of the observer, and the clock to the right is in motion relative to the observer's FoR. For now, let's examine the light clock to the left that is stationary. There are only two ways to use the clock. We can either count the number of times photons have traversed the distance between the two reflective plates and define that measurement as a unit of time, or we can measure the distance the photons traversed between the plates. Both measurements are equally valid and allows us to quantify motion and order events.

 

[math]t = d_c[/math]

 

where [math]t[/math] equals a unit of time and [math]d_c[/math] is the distance traversed by the clock mechanism. Therefore, a unit of time is nothing more than a normalization of a unit of distance. If we choose to use measurements of distance, then we can define speed as the change in distance traversed by energy divided by the change in distance traversed by the clock mechanism.

 

[math]\text{speed} = \frac{\Delta\,d_e}{\Delta\,t} \ \ \text{or} \ \ \frac{\Delta\,d_e}{\Delta\,d_c}[/math]

 

where [math]\Delta\,d_e[/math] is the change in distance traversed by energy when the change in distance traversed by the clock mechanism equals [math]\Delta\,d_c[/math]. If the speed is constant, we could multiply the total distance our clock mechanism has traversed by our newly defined speed, and we can derive the distance the energy traversed through space without having to use units of time.

 

[math]d = \frac{\Delta\,d_e}{\Delta\,d_c} \times d_c[/math]

 

where [math]d[/math] is the calculated distance. Again, this is no different than measuring distance with a ruler. We are simply quantifying the distance traversed by energy in multiples of the unit distance traversed by the clock mechanism. So instead of measuring motion in units of distance per units of time, we are comparing distance to distance, which adheres to the rule that we have to use the phenomena itself to take measurements. The standard equation for motion using only measurements of distance is defined no differently than when we use values of time. So, we can completely rewrite every equation in physics that uses measurements of time to use measurements of distance instead.

 

[math]d = \frac{1}{2} \left(\frac{\Delta\,d_e}{\Delta\,t^2}\right) t^2+\left(\frac{\Delta\,d_e}{\Delta\,t}\right) t + d_0[/math]

 

[math]d = \frac{1}{2} \left(\frac{\Delta\,d_e}{\Delta\,d_c^2}\right) d_c^2+\left(\frac{\Delta\,d_e}{\Delta\,d_c}\right) d_c + d_0[/math]

 

As a result, measurements of time are the only units in physics that can be replaced by units of distance. Such a contradiction is a violation of dimensional analysis, which provides further evidence that when we use time to measure rates of change in physical properties, we are actually using motion to measure the motion of energy changing position. Again, let's recap.

  • There are only two measurements a clock can make; a measure of the number of times the clock mechanism has completed a cycle, or the distance the clock mechanism traversed throughout the cycle.
  • What we experience as the passage of time is the mathematical result of energy being restricted to finite speeds. Since it is mathematically impossible for energy to traverse space with an infinite speed, the passage of time must occur.
  • For any equation in physics, we can replace the time variable [math]t[/math] using measurements of distance.
  • Units of time become normalizations for units of distance and are interchangeable.
Although we can demonstrate that we use motion to measure time, there exists a different view regarding time that is based on change. That it is change that drives the mechanism of time. So, let's now discuss how change is propagated throughout space.

 

See, we can easily replace measurements of time with measurements of distance. This is a very important piece of evidence. Time as measured by mechanical clocks can only do so by using some mechanism that changes position through space. There's simply no denying that with regards to classical physics that change cannot occur without matter and energy changing position through space. Otherwise, everything would be static.

 

The real question is, as put forth by swansont, does this hold true for QM? Swansont simply says my statements aren't true within the QM world, and he really won't eloborate as to why. He says he can lead the horse to water, but that simply isn't true. When I asked why my statements were wrong, the reply given was:

 

Your claim, your burden of proof. It's not my job to teach you QM, nor is math without experimental support sufficient to show anything; your math so far has been describing classical physics.

 

http://en.wikipedia.org/wiki/Hydrogen_atom#Wavefunction

Where is the motion?

 

So, OptimisticCynics... don't hold your breath. He'll tell us QM doesn't work that way, and the horse is left thirsty for water.

 

Hey swansont, would you please be more specific as to what is wrong with my statement and maybe include a reference or two?

 

I would like to know why a generalization that given matter and energy the only thing it can do with respect to space is to change position is wrong with regards to QM. Classicaly, change in a system within space can only do so by stuff changing position through it. However, swansont has not elaborated as to why this is untrue with respect to QM. The problem I have with his point of "It's not [his] job to teach [us] QM" is that it's not really helpful in progressing the discussion. Why even reply to a discussion if you really aren't going to provide any input besides saying it's wrong?

 

I am very good at math, and that would be similiar to me posting in the Calculus forum about how someone got integration wrong:

 

OP: "Check out this new way I'm integrating the area"

 

Daedalus: "What you are doing is wrong."

 

OP: "Why?"

 

Daedalus: "Integration doesn't work that way."

 

OP: "Can you explain what is wrong?"

 

Daedalus: "It's not my job to teach you Calculus."

 

OP: " Then why even reply if you won't explain your statments?"

 

Perhaps, swansont is used to dealing with people who won't accept the answers he gives them. Perhaps, the answer is way over our heads, but that doesn't mean I wouldn't investigate. I might even be able to utilize some of that knowledge to come to the same conclusions as the good doctor himself. After all, I do hold swansont in high regards even if he won't teach us QM ^_^

 

I will continue to learn and study QM and cosmology until I can better debate my claims or retract them.

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I might not be able to discuss the QM nature of radioactive decay, but we do know that the decay components move away from the decaying particle where such motion is a consequence of the act of decaying.

This movement of daughter isotopes and products is final stage.

 

This is decay energy,

easily calculated as I am showing in article from my signature.

 

However, the fact that I can use measurements of distance traversed by some mechanism instead of units of time to formulate the equation for decay is what I am discussing.

Because you are not familiar with it.

 

Say we have Uranium-238,

with m0 = 238 g/6.022141*10^23 = 3.95208282e-22 g

It's decaying to Thorium-234,

and Helium-4.

If you subtract rest-mass of U-238 from rest-mass of Th-234 and rest-mass of He-4,

you will have missing-mass, in u units,

multiply it by 931.494061 MeV

and you will have decay energy in MeV units.

 

m0 = 238.051 u

m1 = 234.044 u

m2 = 4.0026 u

m0-m1-m2=238.051 u-234.044 u- 4.0026 u=0.0044 u

0.0044 u * 931.494061 MeV/u = ~4.1 MeV

(actual value is Uranium-238 -> Thorium-234 + alpha + 4.26992 MeV)

 

Basically rest-mass m0 of isotope prior decay, is equal to relativistic-mass of daughter isotope plus relativistic-mass of alpha particle (for composite Boson as is U-238).

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This movement of daughter isotopes and products is final stage.

 

This is decay energy,

easily calculated as I am showing in article from my signature.

 

 

Because you are not familiar with it.

 

Say we have Uranium-238,

with m0 = 238 g/6.022141*10^23 = 3.95208282e-22 g

It's decaying to Thorium-234,

and Helium-4.

If you subtract rest-mass of U-238 from rest-mass of Th-234 and rest-mass of He-4,

you will have missing-mass, in u units,

multiply it by 931.494061 MeV

and you will have decay energy in MeV units.

 

m0 = 238.051 u

m1 = 234.044 u

m2 = 4.0026 u

m0-m1-m2=238.051 u-234.044 u- 4.0026 u=0.0044 u

0.0044 u * 931.494061 MeV/u = ~4.1 MeV

(actual value is Uranium-238 -> Thorium-234 + alpha + 4.26992 MeV)

 

Basically rest-mass m0 of isotope prior decay, is equal to relativistic-mass of daughter isotope plus relativistic-mass of alpha particle (for composite Boson as is U-238).

Oh, I am very familiar with the mathematics. The equations aren't that hard to understand. However, it's the processes working at the QM level that are a lot harder to define and describe. The mathematics of QM isn't structured like that of classical physics. Motion in QM is really not defined. So, I can't explain how the particles and fields would change position through space in an atom to cause decay, but can you? Can you describe how the energy contained within an atom gets transfered about? How it behaves? How it forms decay particles?

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Let me clarify my definition for motion. Swansont says it's ill defined, but that's not true. In temporal uniformity motion has a very general but precise definition that encapsulates all forms of motion. Motion is simply a change in position through space, which is a measurement of distance that describes the rate of motion.

[math]\text{motion} \rightarrow \Delta x[/math]

However, we have to have a way to compare various motion, no different than measuring distances. If a point on a wheel or a photon in a light clock traversed [math]x[/math] units through space, I can compare that measurement of distance to the measurements of distance for objects in space that have moved around me and define a speed for each object relative to my frame of reference or coordinate system. However, we don't call these measurement of distance by what they are. Without regard to atomic clocks, the distance the clock mechanism has traversed within a mechanical clock is normallized to a unit of time that we call seconds. So, we define speed as distance over time instead of the ratio of distance an object moves through space versus the distance the clock mechanism has traversed as occurrs in actuality. The only descrepancy is to how atomic clocks work.

Now, most people define motion as having a trajectory, but this doesn't encapsulate every form of motion. We cannot think of motion as being defined in the classical sense because it's relative to the observer's frame of reference. When you throw a ball through space, you see it move along its trajectory. If you placed yourself in the ball's local frame of reference, then the ball would not be moving. It would be at rest within that coordinate system. So, we simply cannot define motion as having a path. The trajectory describes a path through space, but the ball moved because it changed position relative to the observer. The path it took was a consequence of forces acting upon the ball.

However, we also have motion the occurs because the shape of something is changing position through space. For instance, let's look at a waves.

post-51329-0-21981000-1443663961_thumb.png

If you clicked on the link, you will see three waves colored blue, green, and red. The cool thing about waves, is that some of them always change position through space regardless of the frame or reference you choose. This completely defies the relativity of motion as defined in the classical sense. We are taught that the only thing that can change position through space regardless of one's coordinate system is light. That light will always move through space at the rate of [math]c[/math] regardless of your frame of reference. However, try to define a frame of reference where the red wave appears at rest. You'll find that it is mathematically impossible to do. The blue and green waves have frames of reference where the wave appears to be at rest. Define a frame of reference with the origin at one of the peaks on the blue or green wave, and it will no longer appear to change position through space. The structure of the blue and green waves is not changing position through space. However, the points in space that define the red wave always change position through space regardless of your frame of refrence, and that is motion too. The most general and precise way to define motion with regards to all forms of it is to define motion as a change in position through space.

If motion does exist in QM, it would have to be wave motion. Otherwise, we could choose a frame of reference that would simply negate it, which would completely destroy the model. Regardless of our frame of reference, atoms and particles and fields exist. If we accept that motion is simply the act of something changing position through space, then we can demonstrate motion in QM relating to atomic electron transition.

Atomic electron transition is a change of an electron from one quantum state to another within an atom%5B1%5D or artificial atom.%5B2%5D

It appears discontinuous as the electron "jumps" from one energy level to another in a few nanoseconds or less. It is also known as atomic transition, quantum jump, or quantum leap.
Electron transitions cause the emission or absorption of electromagnetic radiation in the form of quantized units called photons. Their statistics are Poissonian, and the time between jumps is exponentially distributed.%5B3%5D The damping time constant (which ranges from nanoseconds to a few seconds) relates to the natural, pressure, and field broadening of spectral lines. The larger the energy separation of the states between which the electron jumps, the shorter the wavelength of the photon emitted.


Here we have the definition for what it means for an electron to change from one quantum state to another where the quantume state is represented by a state vector in Hilbert space.

In quantum physics, quantum state refers to the state of a quantum system. A quantum state can be either pure or mixed. A pure quantum state is represented by a vector, called a state vector, in a Hilbert space.

For example, when dealing with the energy spectrum of the electron in a hydrogen atom, the relevant state vectors are identified by the principal quantum number, written c26e5e674eddc7dcf4993cda58f1e226.png. For a more complicated case, consider Bohm's formulation of the EPR experiment, where the state vector


4cb3149deea382f08a3a18f5882a00a2.png

involves superposition of joint spin states for two particles. Mathematically, a pure quantum state is represented by a state vector in a Hilbert space over complex numbers, which is a generalization of our more usual three-dimensional space.[1] If this Hilbert space is represented as a function space, then its elements are called wave functions.

 

A Hilbert space is still a complete metric space. Therefore, spatial position is defined.

 

The mathematical concept of a Hilbert space, named after David Hilbert, generalizes the notion of Euclidean space. It extends the methods of vector algebra and calculus from the two-dimensional Euclidean plane and three-dimensional space to spaces with any finite or infinite number of dimensions. A Hilbert space is an abstract vector space possessing the structure of an inner product that allows length and angle to be measured. Furthermore, Hilbert spaces are complete: there are enough limits in the space to allow the techniques of calculus to be used.

Hilbert spaces arise naturally and frequently in mathematics and physics, typically as infinite-dimensional function spaces. The earliest Hilbert spaces were studied from this point of view in the first decade of the 20th century by David Hilbert, Erhard Schmidt, and Frigyes Riesz. They are indispensable tools in the theories of partial differential equations, quantum mechanics, Fourier analysis (which includes applications to signal processing and heat transfer)—and ergodic theory, which forms the mathematical underpinning of thermodynamics. John von Neumann coined the term Hilbert space for the abstract concept that underlies many of these diverse applications. The success of Hilbert space methods ushered in a very fruitful era for functional analysis. Apart from the classical Euclidean spaces, examples of Hilbert spaces include spaces of square-integrable functions, spaces of sequences, Sobolev spaces consisting of generalized functions, and Hardy spaces of holomorphic functions.

...

Definition
A Hilbert space H is a real or complex inner product space that is also a complete metric space with respect to the distance function induced by the inner product.%5B2%5D

 

Atomic orbitals define the shape of the electron cloud by associating the probability of detecting an electron at a point in space.

 

Formal quantum mechanical definition
Atomic orbitals may be defined more precisely in formal quantum mechanical language. Specifically, in quantum mechanics, the state of an atom, i.e., an eigenstate of the atomic Hamiltonian, is approximated by an expansion (see configuration interaction expansion and basis set) into linear combinations of anti-symmetrized products (Slater determinants) of one-electron functions. The spatial components of these one-electron functions are called atomic orbitals. (When one considers also their spin component, one speaks of atomic spin orbitals.) A state is actually a function of the coordinates of all the electrons, so that their motion is correlated, but this is often approximated by this independent-particle model of products of single electron wave functions.%5B7%5D (The London dispersion force, for example, depends on the correlations of the motion of the electrons.)

In atomic physics, the atomic spectral lines correspond to transitions (quantum leaps) between quantum states of an atom. These states are labeled by a set of quantum numbers summarized in the term symbol and usually associated with particular electron configurations, i.e., by occupation schemes of atomic orbitals (for example, 1s2 2s2 2p6 for the ground state of neon—term symbol: 1S0).

This notation means that the corresponding Slater determinants have a clear higher weight in the configuration interaction expansion. The atomic orbital concept is therefore a key concept for visualizing the excitation process associated with a given transition. For example, one can say for a given transition that it corresponds to the excitation of an electron from an occupied orbital to a given unoccupied orbital. Nevertheless, one has to keep in mind that electrons are fermions ruled by the Pauli exclusion principle and cannot be distinguished from the other electrons in the atom. Moreover, it sometimes happens that the configuration interaction expansion converges very slowly and that one cannot speak about simple one-determinant wave function at all. This is the case when electron correlation is large.

Fundamentally, an atomic orbital is a one-electron wave function, even though most electrons do not exist in one-electron atoms, and so the one-electron view is an approximation. When thinking about orbitals, we are often given an orbital vision which (even if it is not spelled out) is heavily influenced by this Hartree–Fock approximation, which is one way to reduce the complexities of molecular orbital theory.

 

When an electrons transitions to different orbitals, the distances between like probabilities change as a result of the shape of each orbital. This is still a change in position through space even though it was the probabilities of detecting the electron in space that changed position.

 

post-51329-0-07663300-1443666766.jpg

The shapes of the first five atomic orbitals: 1s, 2s, 2px, 2py, and 2pz. The two colors show the phase or sign of the wave function in each region. These are graphs of ψ(x, y, z) functions which depend on the coordinates of one electron. To see the elongated shape of ψ(x, y, z)2 functions that show probability density more directly, see the graphs of d-orbitals below.

 

From the above image we can infer that different orbitals ecompass different points in space such that an electron that jumps from one orbital to another can actually change position through space. We do not have to define a trajectory to see that it can occupy points in space that were only possible after the jump was made. My conclusion is that atomic orbitals define a region in space where an electron can be detected. The only way a single electron can jump to a different orbital that defines a completely different set of points in space is if the electron itself can change position through space to occupy the different orbital. It doesn't matter if the electron teleported by some discreet distance or if it literally travelled through space. For an electron to occupy an orbit that defines points in space that were previously unobtainable or very low probaility, the electron has to change position through space to occupy the new orbital.

 

By calculating the distance between points located on these orbitals with like probabilities, we can calculate the probabilities for the shortest or longest distances the electron can move during a jump. Given the time it takes to complete the transition, we can define probabilities for the speed at which the transition occurred. If we say the electron instantaneously jumped to the new orbital, it still changed position through space. The speed would be indeterminate but, nonetheless, a change in position through space has occurred and the electron has moved. You can say that such motion is ill-defined, but a change in position through space is all we need to infer motion. If we had a way to make an electron jump between two orbitals at a constant rate, we could take the most likely distance the electron could move during the jump, and create a clock based on QM that uses this distance to measure time no different than mechanical clocks. We can either add up this quantized distance each time a jump is made, or we can count the number of times the jump occurred. One is a measure of distance and the other is a measure of time. Both measurements can be equally used to describe processes in physics.

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I am very good at math, and that would be similiar to me posting in the Calculus forum about how someone got integration wrong:

 

OP: "Check out this new way I'm integrating the area"

 

Daedalus: "What you are doing is wrong."

 

OP: "Why?"

 

Daedalus: "Integration doesn't work that way."

 

OP: "Can you explain what is wrong?"

 

Daedalus: "It's not my job to teach you Calculus."

 

OP: " Then why even reply if you won't explain your statments?"

This isn't a matter of making a small error where the person is otherwise well-versed in the material (like, you forgot to add a "+ C"; indefinite integrals only give an answer to within a constant.) But if the person hadn't learned calculus, that wouldn't make much sense. Do you think you could teach someone calculus — so they could actually DO calculus — in a forum post? Keeping in mind that it's a semester of college? Now multiply that, because the immersion into QM is multiple years (an intro "modern physics" class where you learn some basic concepts, undergrad QM, and graduate QM, which is often more than a year, and then applications of QM if you are doing physics that requires it) So no, I can't explain this to you in such a setting. Suffice to say that pop-sci exposure means you have learned a little about QM, but you really haven't learned any QM. If you can't go through and solve problems and understand their application, you aren't doing science.

 

The thing that digs at me (here and elsewhere, since this isn't my first quantum rodeo) is the insinuation that your unwillingness to invest the time to learn or that it's not possible to gain the requisite expertise by reading a post or pop-sci article or wikipedia summary, somehow is my fault.

Hey swansont, would you please be more specific as to what is wrong with my statement and maybe include a reference or two? Call me weird all you like, but I rather enjoy figuring out how I got something wrong.

After reading further through the posts on this topic, I apologize for my sound bite. I claim inexperience with the forum leading me to respond to only the first page of posts.

 

(If you want to ensure someone's response, the best thing to do is to quote the post, so it's possible for a notification to appear.)

 

In a microwave atomic clock, the transition is a spin-flip, and the electron is a point particle. (I.e. spin isn't physical motion). There is nothing that ties into distance traveled.

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The thing that digs at me (here and elsewhere, since this isn't my first quantum rodeo) is the insinuation that your unwillingness to invest the time to learn or that it's not possible to gain the requisite expertise by reading a post or pop-sci article or wikipedia summary, somehow is my fault.

 

I do apologoize Swansont. I didn't mean to insinuate that my ignorance was your fault. I am investing time to learn physics. Granted, it's at a slow pace, but we all have our lives to tend to and how we invest our time is on us; not you. Furthermore, I don't expect you to teach me or anyone else physics here on the forum. It would be very difficult to teach someone calculus here on the forums. However, when I reply to someone's thread, I try to be as insightful and helpful as I can, but that's me. I don't expect you to have any obligation or even find joy in trying to have a conversation about QM with someone who doesn't have all the prerequisites. I was just hoping for the kind of discussion where you might give us some inights, clues, or perhaps a lengthy conversation regarding the finer points of how atomic clocks work and why my statements are wrong.

 

In a microwave atomic clock, the transition is a spin-flip, and the electron is a point particle. (I.e. spin isn't physical motion). There is nothing that ties into distance traveled.

 

I'm currently reading and working the problems in the book, "University Physics", and I plan on getting the Feynman Lectures and a few other books on QM, but I'll start reading about spin-flip. I'm also reading material provided by Mordred. I may not fully understand it until I get a little more background in advanced physics, but I really do want to know how physics explains the universe. Unfortunately, I don't have access to the university here to perform the type of experiments that a professor would normally have the student do, but I'll manage.

Edited by Daedalus
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To give an example of where classical motion fails to describe the spin of a particle.

 

Even though it's convenient to model a particles spin as a rotation this cannot be confused with a classical rotation.

Take an electron for example it being a fermion has a non integar spin of -1\2. Mathematically though this means a 720 degree rotation to return to the same quantum state.

 

see the problem? Normally a spherical object like say a planet returns to its orginal state in 360 degrees.

Visualizing particles as little bullets instead of excitations will lead one astray. Yes they have poinlike characteristics, but at the same time wavelike.

 

To Google how particle spin works Google spin statistics.

"quantum mechanical spin is not described by a vector as in classical angular momentum. It is described by a complex-valued vector with two components called a spinor."

 

https://en.m.wikipedia.org/wiki/Spin-%C2%BD

 

PS glad to see your studying.

Edited by Mordred
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To give an example of where classical motion fails to describe the spin of a particle.

 

Even though it's convenient to model a particles spin as a rotation this cannot be confused with a classical rotation.

Take an electron for example it being a fermion has a non integar spin of -1\2. Mathematically though this means a 720 degree rotation to return to the same quantum state.

 

see the problem? Normally a spherical object like say a planet returns to its orginal state in 360 degrees.

Visualizing particles as little bullets instead of excitations will lead one astray. Yes they have poinlike characteristics, but at the same time wavelike.

 

To Google how particle spin works Google spin statistics.

"quantum mechanical spin is not described by a vector as in classical angular momentum. It is described by a complex-valued vector with two components called a spinor."

 

https://en.m.wikipedia.org/wiki/Spin-%C2%BD

 

PS glad to see your studying.

Is that so complicated?

It means a double rotation. I mean a rotation in X and Y axis, not only on X axis as a planet.

I think.

But anyway classically that would mean that the particule has some sort of structure, like a left & right side for example.

Edited by michel123456
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One of the best examples of spin IMHO is radioactivity.

 

Say we have radioactive isotope with even quantity of protons and neutrons, f.e. Uranium-238 has 92 protons, and 146 neutrons. Both even.

So it's composite boson with spin 0.

 

It's decaying:

U-238 -> Th-234 + He-4 + 4.267 MeV

To Thorium-234, which has also spin 0.

Helium-4 has also spin 0.

 

So decay is immediate.

And decay energy is split immediately to Th-234 and He-4.

Appropriately to their masses to conserve both energy (E=mass of uranium-238 nucleus * c^2) and momentum (initially 0).

 

But if radioactive isotope is fermion, it has fractional nucleus spin.

f.e. Uranium-235 has 92 protons, and 143 neutrons.

Spin 7/2

 

It's decaying:

U-235 -> Th-231 + He-4 + 4.86 MeV

 

Th-231 has 90 protons and 141 neutrons, spin 5/2.

7/2 dismatch 5/2 obviously.

So there is needed gamma photon to be emitted by excited nucleus after decay..

Excited nucleus has more mass, and more total energy, than in ground state.

So alpha particle is accelerated to smaller velocity, and has smaller kinetic energy, and smaller relativistic mass than like it would be in 1st case with U-238.

Edited by Sensei
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Is that so complicated?

It means a double rotation. I mean a rotation in X and Y axis, not only on X axis as a planet.

I think.

But anyway classically that would mean that the particule has some sort of structure, like a left & right side for example.

No you shouldn't think of particle spin as meaning spinning on its axis.

 

I rarely use YouTube vids to answer questions but in this case it will make it easier.

 

http://m.youtube.com/watch?v=v1_-LsQLwkA

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  • 2 weeks later...

 

(If you want to ensure someone's response, the best thing to do is to quote the post, so it's possible for a notification to appear.)

 

In a microwave atomic clock, the transition is a spin-flip, and the electron is a point particle. (I.e. spin isn't physical motion). There is nothing that ties into distance traveled.

Thanks for the forum use tip.

 

Given the electron as a point particle, I see your valid point. (all puns intended) As a counter argument; from my point of view, something moves within the mechanism of that clock as a result of the spin-flip. Thus, distance is measured.

To show that we are both right, I'll use a pendulum clock for an example. When the pendulum reaches the top of its arc, it has no motion. Then its vector flips and it is in motion again. There is nothing moving at the peak of a pendulum's arc or an electron's spin-flip. The same combination of motion and change without motion could be said to exist in most oscillating systems. Which is being measured can be spun either way -ask any politician-.

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Thanks for the forum use tip.

 

Given the electron as a point particle, I see your valid point. (all puns intended) As a counter argument; from my point of view, something moves within the mechanism of that clock as a result of the spin-flip. Thus, distance is measured.

To show that we are both right, I'll use a pendulum clock for an example. When the pendulum reaches the top of its arc, it has no motion. Then its vector flips and it is in motion again. There is nothing moving at the peak of a pendulum's arc or an electron's spin-flip. The same combination of motion and change without motion could be said to exist in most oscillating systems. Which is being measured can be spun either way -ask any politician-.

 

We're not talking about a pendulum clock, we're talking about quantum mechanics. This is the same issue I've had all along in this thread: the presumption of classical physics when dealing with QM. You can't do it.

 

What distance is measured in an atomic clock?

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We're not talking about a pendulum clock, we're talking about quantum mechanics. This is the same issue I've had all along in this thread: the presumption of classical physics when dealing with QM. You can't do it.

 

What distance is measured in an atomic clock?

 

I am not presuming classical physics when dealing with QM. I am pointing out a factor common to the measurement of oscillating systems. I am using your example of the electron spin-flip and my pendulum example as extremes. To illustrate how, in both systems, there comes a point where something, which is described mathematically as an approach to a limit, becomes an actual change. This flip from "approaching" to "moving away from" is precisely the point where classical physics gives way to quantum mechanics. Where "many" particles reduces to "one" particle.

 

from Wikipedia --Introduction to quantum mechanics"In this sense, the word quantum means the minimum amount of any physical entity involved in an interaction. Certain characteristics of matter can take only discrete values."

 

 

The electronic oscillator measures the microwave wavelength.

 

from Wikipedia --"The actual time-reference of an atomic clock consists of an electronic oscillator operating at microwave frequency. The oscillator is arranged so that its frequency-determining components include an element that can be controlled by a feedback signal. The feedback signal keeps the oscillator tuned in resonance with the frequency of the electronic transition of caesium or rubidium."

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I am not presuming classical physics when dealing with QM. I am pointing out a factor common to the measurement of oscillating systems. I am using your example of the electron spin-flip and my pendulum example as extremes. To illustrate how, in both systems, there comes a point where something, which is described mathematically as an approach to a limit, becomes an actual change. This flip from "approaching" to "moving away from" is precisely the point where classical physics gives way to quantum mechanics. Where "many" particles reduces to "one" particle.

 

from Wikipedia --Introduction to quantum mechanics"In this sense, the word quantum means the minimum amount of any physical entity involved in an interaction. Certain characteristics of matter can take only discrete values."

 

 

The electronic oscillator measures the microwave wavelength.

 

from Wikipedia --"The actual time-reference of an atomic clock consists of an electronic oscillator operating at microwave frequency. The oscillator is arranged so that its frequency-determining components include an element that can be controlled by a feedback signal. The feedback signal keeps the oscillator tuned in resonance with the frequency of the electronic transition of caesium or rubidium."

 

What distance is measured in an atomic clock?

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