05 May 2024

Is it possible for an object to travel through space without being affected by gravity if it moves at or exceeds the speed of light?

Soumendra Nath Thakur
05-05-2024

Yes, an object can travel through space without being influenced by an external gravitational field.

As per Hubble's law, the expansion of the universe causes distant galaxies to move away from us at speeds exceeding that of light.*

Gravity typically dominates over vast distances, although there are circumstances where antigravity might be stronger than gravity. Systems bound by gravity, such as galaxies or galactic clusters, can only exist within their respective spheres of gravitational influence.#

However, the object must be located in intergalactic space, beyond the zero-gravity sphere of the nearest galaxy.

Moreover, the object must possess its own gravitational field, as described by classical field theory.*# This implies that the gravitational field of object M at a point r in space can be calculated by determining the force F exerted by M on a small test mass m located at r, and then dividing by m. Ensuring that m is significantly smaller than M ensures that the presence of m has a negligible effect on the behaviour of M.

References: 

*Wikipedia contributors. Faster-than-light. Wikipedia. #A. D. Chernin et al. 2010, 2012a. *#Wikipedia contributors. Classical field theory. Wikipedia.

04 May 2024

How is more than one channel received on the same frequency on satellites?

The process of receiving more than one channel on the same frequency on satellites involves several steps. Firstly, carrier frequency, which is the frequency of a carrier wave used for signal transmission, is modulated. Modulation can be done in various ways, such as frequency modulation (FM), amplitude modulation (AM), or phase modulation (PM). In satellite TV transmission, frequency modulation is commonly used.

Digital frequency modulation is predominant in satellite TV transmissions, where the carrier's frequency is varied based on binary data. Frequency-division multiplexing (FDM) is employed to combine multiple signals onto a single channel by assigning each signal a different frequency.

At the receiving end, demodulation is carried out to recover the transmitted data. Signals are received through a satellite dish and a low-noise block (LNB) down converter. The desired television program is then decoded for viewing.

FDM involves a demultiplexing process, where signals are modulated and transmitted over separate bands, then combined and transmitted over the channel. At the receiving end, the combined signal is demultiplexed to extract individual signals. Double-sideband suppressed-carrier transmission (DSB-SC) is used, where frequencies produced by amplitude modulation (AM) are symmetrically spaced above and below the carrier frequency, ideally suppressed, to reduce complexity in demodulation.

03 May 2024

Entropy Dynamics: Universal Big Bang Singularity vs. Local Black Hole Singularity.

Soumendra Nath Thakur¹⁺ Deep Bhattacharjee²

03-05-2024

Abstract:

This study examines the entropy dynamics between the Universal Big Bang Singularity and the Local Black Hole Singularity, shedding light on fundamental cosmic phenomena. Entropy, order, and disorder are analysed in the context of these two singularities, showcasing the intricate interplay between cosmic evolution and thermodynamic principles.

Keywords: entropy, singularity, Big Bang, black hole, order, disorder,

Soumendra Nath Thakur
ORCID iD: 0000-0003-1871-7803
Tagore’s Electronic Lab, West Bengal, India
Email: postmasterenator@gmail.com,
postmasterenator@telitnetwork.in

Declarations:

Funding: No specific funding was received for this work,
Potential competing interests: No potential competing interests to declare. 


Introduction:

Entropy, a fundamental concept in thermodynamics, plays a crucial role in shaping the evolution of cosmic phenomena. In this study, we delve into the entropy dynamics between two pivotal singularities: the Universal Big Bang Singularity and the Local Black Hole Singularity. These singularities represent extreme conditions in the universe, where the laws of physics are pushed to their limits. By comparing the entropic views of these singularities, we aim to gain deeper insights into the fundamental nature of entropy and its implications for cosmic evolution. The Universal Big Bang Singularity marks the inception of the universe, while the Local Black Hole Singularity represents the endpoint of stellar collapse. Through this comparison, we seek to elucidate the complex relationship between order and disorder in cosmic systems and explore how entropy drives the evolution of the universe from its earliest moments to its farthest reaches.

Method:

Data Collection:

Gather relevant theoretical frameworks and empirical data regarding the Universal Big Bang Singularity and the Local Black Hole Singularity from established cosmological models, observational astronomy, and theoretical physics literature.

Conceptual Analysis:

Conduct a comprehensive review of the concepts of entropy, order, and disorder in the context of thermodynamics and cosmology.

Analyse the theoretical underpinnings of the Universal Big Bang Singularity and the Local Black Hole Singularity, focusing on their entropic characteristics and implications.

Comparative Study:

Compare and contrast the entropic views of the Universal Big Bang Singularity and the Local Black Hole Singularity, highlighting their differences and similarities in terms of entropy dynamics, order, and disorder.

Investigate how the evolution of the universe from the highly ordered state of the Big Bang Singularity to the potential ordered regions near the Black Hole Singularity challenges conventional notions of entropy and cosmic evolution.

Synthesis and Interpretation:

Synthesize the findings from the comparative analysis to develop a cohesive understanding of entropy dynamics in the context of cosmic singularities.

Interpret the implications of the observed differences in entropic views between the Universal Big Bang Singularity and the Local Black Hole Singularity for our understanding of the fundamental nature of entropy and its role in shaping the cosmos.

Discussion and Conclusion:

Discuss the broader implications of the study's findings for cosmology, theoretical physics, and our understanding of the universe's evolution.

Draw conclusions regarding the significance of entropy dynamics in driving cosmic evolution and shaping the observed structures and phenomena in the universe.

Identify potential avenues for future research to further explore the entropic dynamics of cosmic singularities and their implications for our understanding of the cosmos.

Mathematical Presentation:

Entropy Formulation:

Entropy S is defined as the measure of disorder or randomness in a system.

For a closed system, entropy can be calculated using the Boltzmann entropy formula:

S = k ln W

Where k is the Boltzmann constant and W is the number of microstates corresponding to a given macro state of the system.

The symbol "ln" stands for the natural logarithm function. The natural logarithm, denoted as "ln", is a mathematical function that calculates the logarithm to the base e, where e is Euler's number, approximately equal to 2.71828. The equation's "ln W" represents the natural logarithm of W, which represents the number of microstates for a given macrostate, aiding in quantifying the system's entropy using the Boltzmann entropy formula.

Universal Big Bang Singularity:

The entropy of the universe at the Big Bang Singularity (Sʙʙ) is initially very low, as the entire universe exists in a highly ordered and compressed state.

As the universe expands, the number of microstates (Wʙʙ) increases exponentially, leading to an increase in entropy over time:

Sʙʙ = k ln Wʙʙ

Local Black Hole Singularity:

The entropy of a black hole at its singularity (Sʙʜ) is maximal due to its extreme disorderliness and infinite density.

Despite the disorder at the singularity, the presence of the ergosphere introduces orderliness in the surrounding region, leading to a reduction in overall entropy (Sʙʜ − Sₑᵣ₉ₒ):

Sʙʜ − Sₑᵣ₉ₒ = k ln Wʙʜ − k ln Wₑᵣ₉ₒ

Where:

• Sʙʜ:  Entropy of the black hole singularity.
• Sₑᵣ₉ₒ: Entropy of the ergosphere surrounding the black hole singularity.
• Wʙʜ: Number of microstates corresponding to the black hole singularity.
• Wₑᵣ₉ₒ: Number of microstates corresponding to the ergosphere surrounding the black hole singularity.
• k:  Boltzmann constant.
• ln:  Natural logarithm function.

Comparative Analysis:

The entropy dynamics of the Universal Big Bang Singularity and the Local Black Hole Singularity showcase contrasting trends:

The Big Bang Singularity exhibits an increase in entropy over time, reflecting the universe's evolution from a highly ordered state towards disorder.

The Black Hole Singularity initially represents a state of maximum entropy, but the presence of ordered regions challenges conventional entropy dynamics.

The mathematical analysis highlights the complexities of entropy dynamics in cosmic singularities and their implications for our understanding of the universe's evolution.

Further research is needed to explore the interplay between order and disorder in extreme cosmic environments and its broader implications for cosmology and theoretical physics.

Discussion:

The comparison of entropy dynamics between the Universal Big Bang Singularity and the Local Black Hole Singularity offers valuable insights into the fundamental nature of entropy and its role in shaping cosmic phenomena. This discussion highlights several key points:

Divergent Entropic Trajectories:

The Universal Big Bang Singularity and the Local Black Hole Singularity exhibit divergent entropic trajectories. The Big Bang Singularity marks the inception of the universe, characterized by a low entropy state that gradually increases over time as the universe expands and evolves. In contrast, the Black Hole Singularity represents a state of maximum entropy, where matter is compressed to infinite density, leading to the breakdown of conventional physics.

Entropy and Cosmic Evolution:

The increase in entropy from the Big Bang Singularity to the present epoch reflects the universe's evolution from a highly ordered state to a more disordered state. This progression aligns with the second law of thermodynamics, which states that entropy tends to increase over time in isolated systems. The observed structures and phenomena in the universe, such as galaxies, stars, and planets, emerge as a result of this evolving entropy landscape.

Order and Disorder near Black Holes:

The presence of ordered regions, such as the ergosphere, near the Local Black Hole Singularity challenges conventional notions of entropy. Despite the extreme disorder at the singularity itself, gravitational forces impose a degree of order on the surrounding matter and energy. This interplay between order and disorder within gravitational systems highlights the complexity of entropy dynamics in extreme cosmic environments.

Implications for Cosmology and Theoretical Physics:

The study of entropy dynamics in cosmic singularities has broader implications for cosmology and theoretical physics. By understanding how entropy shapes the evolution of the universe from its earliest moments to its farthest reaches, we can gain deeper insights into the fundamental laws governing the cosmos. This knowledge can inform our understanding of phenomena such as dark matter, dark energy, and the nature of spacetime itself.

Future Research Directions:

Further research is needed to explore the intricacies of entropy dynamics in cosmic singularities and their implications for our understanding of the universe. This could involve developing more sophisticated theoretical models, conducting observational studies of black hole environments, and exploring the role of entropy in the emergence of structure in the universe.

The comparison of entropy dynamics between the Universal Big Bang Singularity and the Local Black Hole Singularity provides a window into the fundamental principles governing the cosmos. By elucidating the complex relationship between entropy, order, and disorder in cosmic phenomena, we can deepen our understanding of the universe's evolution and structure.

Conclusion:

In this study, we have explored the entropy dynamics between the Universal Big Bang Singularity and the Local Black Hole Singularity, shedding light on fundamental aspects of cosmic evolution and thermodynamics. Through a comparative analysis, several key findings have emerged:

Divergent Entropic Trajectories:

The Universal Big Bang Singularity represents the inception of the universe, characterized by a low entropy state that increases over time as the universe expands. In contrast, the Local Black Hole Singularity signifies a state of maximum entropy, where matter is compressed to infinite density.

Entropy and Cosmic Evolution:

The increase in entropy from the Big Bang Singularity to the present epoch reflects the universe's evolution from a highly ordered state to a more disordered state. This progression aligns with the second law of thermodynamics and has led to the formation of galaxies, stars, and other structures.

Order and Disorder near Black Holes:

Despite the extreme disorder at the singularity itself, ordered regions such as the ergosphere can exist near black holes, challenging conventional entropy dynamics. This highlights the intricate interplay between order and disorder in extreme cosmic environments.

Implications for Cosmology and Theoretical Physics:

The study of entropy dynamics in cosmic singularities has profound implications for our understanding of the universe. By elucidating the fundamental principles governing entropy, we can gain deeper insights into phenomena such as dark matter, dark energy, and the nature of spacetime.

Future Research Directions:

Further research is warranted to explore the complexities of entropy dynamics in cosmic singularities and their broader implications. This could involve refining theoretical models, conducting observational studies, and exploring novel approaches to understanding entropy in extreme environments.

The comparison of entropy dynamics between the Universal Big Bang Singularity and the Local Black Hole Singularity provides a rich avenue for exploring the fundamental nature of the cosmos. By unravelling the mysteries of entropy, we can deepen our understanding of cosmic evolution and the underlying principles that govern the universe.

References:

[1] Hawking, S. W., & Ellis, G. F. R. (1973). The Large Scale Structure of Space-Time, Cambridge University Press
[2] Penrose, R. (2004). The Road to Reality: A Complete Guide to the Laws of the Universe. Vintage Books
[3] Thakur, S. N. (2024m). Re-examining time dilation through the lens of entropy, Qeios https://doi.org/10.32388/xbuwvd
[4] Wald, R. M. (1984). General Relativity, University of Chicago Press
[5] Thakur, S. N. (2024u, April 22). Formulating time’s hyperdimensionality across disciplines: https://easychair.org/publications/preprint/dhzB
[6] Carroll, S. M. (2004). Spacetime and Geometry: An Introduction to General Relativity, Addison-Wesley
[7] Bekenstein, J. D. (1973). Black holes and entropy, Physical Review D, 7(8), 2333
[8] Gibbons, G. W., & Hawking, S. W. (1977). Cosmological event horizons, thermodynamics, and particle creation, Physical Review D, 15(10), 2738
[9] Barrow, J. D., & Tipler, F. J. (1988). The Anthropic Cosmological Principle, Oxford University Press.

The phase (ΔΦ) of the wave changes with a given displacement (Δx):

Derivation:

Considering two points on a wave separated by a displacement Δx. 

Let's denote the phase difference between these points as ΔΦ.

Now, we know that the phase difference ΔΦ corresponds to the fraction of the wavelength (λ) represented by the displacement Δx. 

Therefore, we can write: 

ΔΦ = (Fraction of λ/λ) × 2π

Since Fraction of λ = Δx/λ, 

we substitute this expression into the equation: ΔΦ =(Δx/λ) × 2π

Simplifying, we get: ΔΦ = 2π/λ × Δx

Where:

• ΔΦ: The phase difference between two points on a wave, measured in radians. It indicates how much the phase of the wave changes between the two points.

• λ: The wavelength of the wave, representing the distance between two consecutive points in phase (e.g., crests, troughs). It's typically measured in meters.

• Δx: The displacement between the two points on the wave along the direction of propagation, measured in the same units as the wavelength. It represents the distance travelled by the wave.

This is the derived formula for the phase difference ΔΦ in terms of the wavelength (λ) and the displacement Δx along the direction of propagation. It shows how much the phase of the wave changes with a given displacement.

The equation Tdeg = x(1/f)/360 is equivalent to ΔΦ(1/f)/360:

Tdeg = x(1/f)/360 is equivalent to ΔΦ(1/f)/360, indicating that the time period Tdeg in degrees is proportional to both the phase shift ΔΦ and the reciprocal of frequency 1/f, with both quantities scaled by 1/360 to convert to the unit of phase.  


Tdeg = x(1/f)/360 = ΔΦ(1/f)/360, so that x = ΔΦ (Phase shift)