Why is there a problem with thermodynamic entropy being defined by heat and differences in heat, whereas one can also say that entropy is equivalent to what isn't known about particle momentum (or for instance in a gas, what isn't known about particle velocities)?

To even be able to say there is an entropy,...

What is entropy and what is information?]]>

We can measure the distance of a receding sound source by recording it's frequency, if we know the original wave character, medium etc (Doppler).

What is necessary in both the cases is movement of the object, without which we cannot measure the distance even if we record the emitted light/sound.

I am opening this thread for a discussion to find out if it is possible to ascertain the distances of...

Distance Measurement]]>

How did it get from step two to step three without...Help! I'm trying to better understand the math of special relativity.]]>

I understand (I think) that QM requires a certain randomness and is not just a lack of perfect knowledge as is the case in Classical Physics. Isn't it possible that with more knowledge in the future about how the quantum world works that the predictions of QM today could still be upheld but the underlying math changed in a more deterministic manner?

For instance Classical...

QM randomness...]]>

If you don't know what this thought-experiment entails, a brief description won't help, but here is some history anyway:

It was actually Einstein's idea (not many people are aware of this). Einstein had deep problems with Quantum Mechanics, even though he helped start the field with his non-relativity papers. Quantum Mechanics was championed by Heisenberg, who is...

Problem with Schrodinger's Cat]]>

* All particles in the universe can interact with each other.

* We are systems of particles.

* Observation is interaction.

* We suppose we can

* Physics would be impossible if there were special observers.

?]]>

In the proposed experimental setup, a host spacecraft (right) shines a femtosecond laser pulse onto a retroreflector moving in the tunnel...

Measuring the Gravitational Constant with 1000 times present Precision:]]>

Motion Mountain Free Physics Textbook

Free for download in pdf.

Physics/Math References]]>

1: Approximately linear

2: Somewhat like a parabola

3: Approximately asymptotic to some upper limit.

4: Initially somewhat like a parabola & then approximately asymptotic to some upper limit.

5: Other

2: Somewhat like a parabola

3: Approximately asymptotic to some upper limit.

4: Initially somewhat like a parabola & then approximately asymptotic to some upper limit.

5: Other

The 4th seems most likely to me.

Perhaps other Posters would include more possibilities.

It is likely that some or many others would disagree with my opinion.

My Theory can be seen here https://www.academia.edu/31457696/A_Mathematical_Theory_of_Success]]>

f=(1-v^2/c^2) / ( 1-v^2*sin^2(θ)/c^2 )^1.5

where v is the velocity of the charge relative to the stationary test charge, θ the angle between v and the radius vector between the two and c the speed of light.

For v/c<<1, we can use a Taylor...

Relativistic Coulomb Force]]>

with the same average speed,

the time taken for:

1) London to NY, T1

2) NY to London, T2.

Should it be T1<T2 ?]]>

I've posted this image which I've described as a

"

Trispokedovetile tessellation by Peter Dow, on...

Geometry. Three-spoke dovetailing tile tessellation. "Trispokedovetile"?]]>

When two particles are moving at same velocity, the relative velocity between them is zero and it can be said that the particles are at rest relative to each other. If the motion of a particle is also compared with itself, the particle can be consider at rest with relative to itself.

We know that our universe is expanding. But if we compare the expansion of our universe, with relative to our universe...

Universe is at rest?]]>

If you look diametrically opposite where you are standing on the outside rim of a relativistic merry-go round, you will see the greatest degree of Lorentz length contraction (distance contraction between the ponies or the stars), compared with the ones on the same side of the rim as you are.

First, satisfy yourselves that this is the case, and then tell us, what would be the effect of said contraction on your perception of...

Ehrenfest Special Relativistic Galactic Distortion]]>

Length-contraction-magnetic-force between arbitrary currents]]>

A Chinese LEO (Low Earth Orbit) satellite named Micius after a 5th century Chinese scientist has achieved a new entanglement telecommunication distance record of about 1,500 miles.

A low bit rate channel for the entanglement test was established by means of an onboard beam splitter which targeted a pair of Earth stations separated by 1,500 miles.

Applications for the system include...

Chinese Satellite Achieves Quantum Entanglement Distance Record]]>