The celebrated apple tree, the fall of one of the apples ...

The celebrated apple tree, the fall of one of the apples of which said to have turned the attention of Newton to the subject of gravity, was destroyed by the wind about twenty years ago; but it has been preserved in the form of a chair. The house itself has been protected with religious care. It was repaired in 1798, and a tablet of white marble put up in the room where our author as born, with the following inscription:-

"Sir Isaac Newton, son of John Newton, Lord of the Manor of Woolsthorpe, was born in his room, on the 25th of December, 1642."

Nature and Nature's Laws were hid in night,

God said, "Let Newton be," and all was light.

Gravitational Field vs. Spacetime Curvature: Discrepancies in GR's Lensing Model

Soumendra Nath Thakur

ORCiD: 0000-0003-1871-7803 

09-11-2024

General relativity (GR) posits that massive celestial bodies—such as galaxies or galaxy clusters—warp spacetime, causing gravitational lensing, where light’s path appears bent. In regions between massive objects, spacetime remains flat, but when a massive body is present, it curvatures spacetime, bending light as it passes.

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The photon’s path can be described in three phases:

Initial Straight-Line Trajectory: The photon starts along a straight path from the source, traveling at speed c. As it moves away from the gravitational well of the source, a slight redshift occurs, indicating a small increase in wavelength (Δλ > 0).

Interaction with External Massive Body: As the photon approaches an external massive body, it undergoes a temporary blueshift (Δλ < 0) while moving toward the body. Once the photon passes the body and begins to move away, it experiences a redshift (Δλ > 0), returning to its original wavelength. This reversible shift reflects the energy gained and lost by the photon in response to the external gravitational field. The photon’s inherent energy drives its straight-line path, but the external field temporarily adds energy, altering its trajectory in an arc-like fashion. After completing this interaction, the photon resumes its original straight path, with no net change in wavelength (Δλ = 0).

Return to Original Trajectory: After passing the gravitational influence of the external body, the photon’s trajectory returns to its original straight-line path, maintaining its inherent energy and wavelength. The photon’s wavelength remains unchanged beyond the initial shift caused by the source’s gravitational well.

However, GR asserts that light bends along the curvature of spacetime itself, where the gravitational field mirrors this curvature. In contrast, observational experiments suggest that light bending is primarily due to the curvature of the gravitational field itself, rather than spacetime. This discrepancy challenges GR's interpretation and suggests the need for a re-evaluation of theoretical models.

This study critically analyses the discrepancies between GR’s predictions and experimental observations. The findings suggest that while GR visualizes the gravitational field as mirroring spacetime curvature, this model does not fully capture the complexities of actual light-gravity interactions observed in experiments. Therefore, a re-examination of gravitational lensing and the underlying mechanisms of light propagation is necessary.

Conclusion:

GR posits that gravitational lensing occurs due to spacetime curvature, but experimental data suggest that the bending of light is primarily driven by the curvature of the gravitational field. This misalignment calls into question the validity of GR in explaining light’s interaction with gravity, suggesting that the relationship between light, gravity, and spacetime may require further exploration and modification. The study advocates for alternative models that could more accurately explain the observed phenomena, paving the way for future research into the mechanics of gravitational lensing.

#GravitationalLensing

Clarifying the Photon’s Trajectory and Energy Exchange in Gravitational Fields: A Response to Mr. André Michaud

The Discussion Link Here

09-11-2024

Soumendra Nath Thakur

Discussion Topic: Is Spacetime Curvature the True Cause of Gravitational Lensing?

Dear Mr. André Michaud,

Thank you for your thoughtful reply. Your mention of a "little inconsistency" in my description seems to stem from a different interpretation of the photon's trajectory during its interaction with an external gravitational field. To clarify, there are three main considerations in the photon’s path:

Consideration 1: The Photon’s Initial Straight-Line Trajectory

The photon begins its journey from the source along a straight-line trajectory with velocity c. Here, an initial redshift occurs as the photon loses a slight amount of energy due to gravitational interaction with the source’s gravitational well, resulting in a corresponding increase in wavelength (Δλ>0). This change follows the relationship E = hf = hc/λ, where the energy E and frequency f are inherent to the photon and directly proportional to the wavelength.

Consideration 2: Arc Path and Energy Exchange During Gravitational Bypassing

As the photon approaches and passes an external massive body, it undergoes a temporary arc-shaped deviation in its trajectory due to the external gravitational influence. This interaction involves two phases:

First Half-Arc: A blueshift occurs, corresponding to a wavelength decrease (Δλ<0) as the photon gains energy due to gravitational influence while approaching the massive body.

Second Half-Arc: As the photon moves away, a redshift (Δλ>0) occurs, returning the photon’s wavelength to its original state as it completes the arc and leaves the gravitational field. This reversible shift is due to energy exchange within the field, summarized by E + Eg = E + 0, where Eg represents the energy gained and then lost by the photon within the gravitational arc path.

Consideration 3: Return to Original Straight-Line Trajectory

After exiting the gravitational field, the photon resumes its original straight-line path. At this point, it retains its inherent energy, with any additional energy or momentum imparted by the gravitational field removed. Its wavelength also remains as it was upon entry into the gravitational encounter, indicating no net change in wavelength (Δλ=0) beyond that caused by its initial emission.

Conclusion

Your perception of a "net deflection" and an uncompensated redshift does not account for the full cycle of energy exchange during the photon's passage through the gravitational field. The photon’s wavelength shifts symmetrically—first through blueshift, then redshift—without resulting in a net loss of inherent energy. Consequently, upon exiting the gravitational field, it continues along its original trajectory, undisturbed in frequency and energy.

This balanced interaction negates the need for "expended work" or a net trajectory deflection, aligning with the complete arc-path considerations outlined above. I hope this clarification resolves the apparent inconsistency and aligns our perspectives on the photon’s behaviour in gravitational interactions.

Best Regards,

Soumendra Nath Thakur

#GravitationalLensing

Dear Mr. André Michaud

Thank you for your thoughtful reply. I appreciate the opportunity to clarify my perspective further.

1. First, I reckon that there may have been a slight misinterpretation of my earlier statement: “Your perception of a 'net deflection' and an uncompensated redshift does not account for the full cycle of energy exchange during the photon's passage through the gravitational field.”

The intention behind this statement was to emphasize the photon’s symmetrical energy shifts during its interaction with external gravitational field. Specifically, the photon’s wavelength undergoes a blueshift as it approaches the massive body, followed by a redshift as it moves away. This complete cycle results in no net change in energy or trajectory once the photon exits the external gravitational field. This was also highlighted in the conclusion: “The photon’s wavelength shifts symmetrically—first through blueshift, then redshift—without resulting in a net loss of inherent energy. Consequently, upon exiting the gravitational field, it continues along its original trajectory, undisturbed in frequency and energy.”

2. Regarding the table you provided, titled “Experimental Results on the Deflection of Light”, I must point out that it references deflection observed on Earth due to direct sunlight rather than deflection in an external gravitational field. This does not directly support the discussion concerning the photon's trajectory when interacting with an external gravitational field, such as the one caused by a massive celestial body.

To further clarify my stance on this topic, I would like to offer the following elaboration, which aligns with the core of our discussion:

General Relativity (GR) suggests that massive objects, such as galaxies or galaxy clusters, curve spacetime, causing light to bend as it passes through this curved spacetime. However, this curvature is not uniform throughout space, and regions between massive objects remain flat. When a massive body is present, it bends spacetime, leading to gravitational lensing.

The photon’s path can be divided into three phases:

Initial Straight-Line Trajectory: The photon begins its journey from the source along a straight path, traveling at speed c. As the photon moves away from the source’s gravitational well, it undergoes a slight redshift, resulting in a small increase in wavelength (Δλ>0).

Interaction with External Massive Body: As the photon approaches the external massive body, it temporarily experiences a blueshift (Δλ<0) while moving toward the body. Upon passing the body, the photon begins to move away and experiences a redshift (Δλ>0), returning to its original wavelength. This reversible shift is due to the energy gained and subsequently lost by the photon as it moves through the gravitational field. The photon’s inherent energy drives its straight-line path, but the gravitational field temporarily alters its trajectory in an arc-like fashion. Once the photon completes this interaction, it resumes its original straight path, with no net change in wavelength (Δλ=0).

Return to Original Trajectory: After passing the gravitational influence of the external body, the photon returns to its original straight-line trajectory, retaining its inherent energy and wavelength.

However, General Relativity asserts that light bends along the curvature of spacetime itself. In contrast, observational experiments suggest that the bending of light is primarily caused by the curvature of the gravitational field, rather than the curvature of spacetime itself. This discrepancy indicates a potential misalignment between theoretical predictions and experimental observations, calling for a re-evaluation of the models explaining gravitational lensing.

This study critically examines the differences between GR's predictions and experimental results. The findings suggest that the bending of light is more accurately explained by the curvature of the gravitational field rather than the warping of spacetime, as proposed by GR. This raises questions about the sufficiency of GR in explaining light's interaction with gravity and indicates a need for alternative models.

Conclusion:

While GR asserts that gravitational lensing is the result of spacetime curvature, experimental data suggest that the bending of light is primarily due to the curvature of the gravitational field. This misalignment challenges GR’s interpretation and calls for further exploration and refinement of theoretical models. I advocate for alternative approaches that could more accurately explain the observed phenomena and encourage continued research into the mechanisms of gravitational lensing.

Best regards,

Soumendra Nath Thakur

*-*-*-*-* 

Dear Mr. André Michaud,

Thank you for your insights.

This discussion aims to clarify whether spacetime curvature, as posited by General Relativity (GR), is indeed the true cause of gravitational lensing, or if another explanation better aligns with observational data.

GR describes gravitational lensing as resulting from spacetime curvature induced by massive objects, which alters the path of light passing near them. However, interpretative evidence from observational and experimental data suggests that light bending might instead be driven primarily by the gravitational field’s own curvature—essentially, the real, physical gradient of gravitational intensity—rather than an abstract curvature of spacetime. This perspective challenges the idea that spacetime curvature is necessarily the sole or primary cause of lensing.

By contrast, your response suggests that GR’s spacetime model might represent an idealized, geometric interpretation of a more fundamental physical reality rooted in the gravitational field's structure. 

(1) However, your response does not conclude that spacetime curvature is entirely irrelevant to lensing, nor does it definitively assert that the gravitational field alone is responsible.

Moreover, regarding your statement, “The gravitational intensity gradient as a function of the inverse square law of the distances is the real thing, and Einstein's spacetime curvature is its geometric mental representation of it,” I would like to clarify that the inverse square law is indeed a concept rooted in classical mechanics, originally articulated by Newton. It describes how the gravitational force between two masses diminishes with the square of the distance between them, and in this framework, the gravitational force is seen as acting at a distance.

In contrast, Einstein's General Relativity (GR) describes gravity not as a force but as the curvature of spacetime caused by the presence of mass and energy. While the inverse square law applies well in Newtonian mechanics and serves as an approximation in weak-field regimes in GR, the concept of spacetime curvature in GR offers a deeper, more comprehensive explanation of gravitational phenomena, especially in stronger gravitational fields.

(2) In this sense, the inverse square law can be viewed as a classical, Newtonian approximation of the more complex curvature-based understanding of gravity provided by General Relativity. GR’s spacetime curvature, then, provides a more generalized framework that goes beyond the limitations of the inverse square law, especially when considering more extreme conditions such as near black holes or in cosmological contexts.

Therefore, while the inverse square law provides an accurate description in many practical situations, it is one aspect of a broader, classical gravitational theory. 

Einstein’s spacetime curvature, as an idealized geometric representation, serves to explain gravitational interactions in a more generalized manner, complementing the classical understanding rather than replacing it.

Best regards,

Soumendra Nath Thakur 

Interpretational Study on Universal Force and the Big Bang Model:

Soumendra Nath Thakur

ORCiD: 0000-0003-1871-7803 

08-11-2024

Abstract:

This interpretational study revisits the Big Bang model with a focus on the concept of a Universal Force, examining gravity as the primordial and singular fundamental force preceding the Big Bang. The study proposes that the universe began in an extremely energetic and dense state dominated by an infinitely intense gravitational field, from which the four fundamental forces—gravity, electromagnetism, the strong nuclear force, and the weak nuclear force—later emerged. This framework redefines gravity not merely as one of the four forces but as the initial unified field that encompassed all forces in an undivided state.

In this context, the gravitational singularity is interpreted as a point where neither space nor time existed, and where intense gravitational energy acted as the source of the universe’s initial mass-energy. As the universe expanded and cooled, this intense gravitational field transitioned, separating into the distinct forces observed today. This approach diverges from traditional General Relativity interpretations by asserting that curved spacetime is non-fundamental to the Big Bang model, emphasizing that quantum field and thermodynamic processes, rather than relativistic spacetime, are foundational to early cosmic evolution.

The study explores implications for a Grand Unified Theory (GUT), as this model supports the idea that all forces were unified at high energies within an intensely energetic gravitational field. This interpretation offers an integrative approach to understanding the formation of mass-energy and the separation of forces, bridging particle physics, thermodynamics, and cosmology to provide a consistent account of the universe’s earliest moments.

Keywords:

Universal Force, Big Bang model, gravitational singularity, primordial universe, fundamental forces, mass-energy, thermodynamics, quantum field theory, Grand Unified Theory (GUT), cosmic evolution,

Universal Force:

The Big Bang Theory posits that at the beginning of time, a single force dominated—gravity, which functioned as the sole fundamental force within the primordial universe before the Big Bang event. Only later, as the universe expanded and cooled, did the other fundamental forces separate from this primary force. In this earliest phase, the universe existed in an incredibly dense and energetic state, with gravity uniquely prevailing as the singular force prior to the Big Bang. Here, the concept of a "singularity" specifically denotes a gravitational singularity—a state where neither space nor time existed and where gravitational intensity reached an infinite magnitude.

Within this framework, the four known fundamental forces—gravity, electromagnetism, the strong nuclear force, and the weak nuclear force—originated from a single unified force expressed through an infinitely intense gravitational field. This unified gravitational field provided the foundational force from which distinct forces gradually emerged as the universe continued its expansion and experienced cooling. The gravitational singularity thus marks the universe’s origin point, initiating the cosmic processes that followed.

As post-Big Bang expansion and cooling progressed, the fundamental forces separated from this initial unified field and adopted their distinct roles within the physical universe. The notion that gravity was the first force to manifest aligns with early cosmological models; however, the exact mechanisms of this separation remain an unresolved question at the frontier of cosmology and high-energy physics. The ongoing search for a Grand Unified Theory (GUT) aims to explain this unified state of forces at high energies and in the presence of an intensely energetic gravitational field in the early universe.

Interpretive Summary and Analysis of the Primordial State within the Big Bang Framework:

This interpretation provides nuanced insights into the Big Bang model, especially concerning gravity's pivotal role and the origins of mass-energy and space-time. Consider the following points within contemporary cosmological and theoretical contexts:

Intense Gravitational Force as the Unified Source of Fundamental Forces

This description of the primordial state, where an intense gravitational force unified all fundamental interactions, aligns well with the Big Bang model, which characterizes this state as extremely dense and energetic. In this conceptualization, gravity is not merely one of the four forces but rather represents a high-energy, unified field. Here, the infinite energy of this intense gravitational state acts as the initial source of mass-energy, which, through entropy-driven processes, becomes the universe’s content as expansion and cooling unfold. This view captures a critical thermodynamic process, wherein mass-energy emerges from initial gravitational intensity, emphasizing gravity’s foundational role in the early universe.

Curved Spacetime as Non-Fundamental to the Big Bang

The clarification that curved spacetime is not a fundamental concept in the Big Bang model aligns with current cosmology, which builds on high-energy particle and quantum physics rather than solely on General Relativity. Curved spacetime becomes relevant only after the emergence of space and time; thus, the initial singular state precludes such curvature considerations. This distinction positions gravity as an undivided and powerful force in primordial conditions, rather than as a product of spacetime curvature, aligning with particle physics perspectives on early cosmic history.

Separation of Forces from the Pre-Existing Gravitational Field

Interpreting the Big Bang as a phase where a primordial gravitational field unified all fundamental forces is consistent with the cooling and expansion processes described by the model. As temperatures and densities decreased, this unified gravitational field allowed the distinct forces—gravity, electromagnetism, and the strong and weak nuclear forces—to emerge. Here, the immense energy characterizing the early universe is distinct from the fundamental forces themselves, instead acting as the initial mass-energy, undergoing transformation through thermal entropy to form the universe’s structure. This interpretation aligns with the thermodynamic principles foundational to the Big Bang model, wherein mass-energy is a transformation of the initial gravitational state.

Summary

This interpretation emphasizes gravity’s central role as the early universe’s unified field, from which distinct forces emerged over time as expansion and cooling progressed. This approach bridges particle physics, thermodynamics, and cosmology, while reserving spacetime curvature considerations for the post-singularity phase. Scientifically consistent, this perspective offers a cohesive path for exploring the universe’s initial conditions, mass-energy origins, and the distinct roles of gravity and other forces within the Big Bang framework.

#UniversalForce, #BigBangmodel, #gravitationalsingularity, #primordialuniverse, #fundamentalforces, #massenergy, #thermodynamics, #quantumfieldtheory, #GrandUnifiedTheory, #GUT, #cosmicevolution,

Question: If Mars is almost airless and seemingly lifeless, what motivates humans to want to establish a settlement there?

08-11-2024

My Answer:

Pessimistic part:

The motivation to establish a human settlement on Mars extends far beyond mere curiosity or incentive; it is fundamentally tied to the long-term survival of our species. Earth faces numerous existential risks, ranging from the catastrophic potential of a global thermonuclear war, widespread deployment of biological weapons, or a super volcanic eruption, to natural cosmic threats like asteroid impacts and extreme solar flares. Additionally, global climate change, biodiversity loss, resource depletion, and even the unforeseen consequences of advanced technologies—such as runaway artificial intelligence or nanotechnology—pose severe threats to life as we know it. The intelligence and power humanity wields bring both advancement and risk, as history shows that civilizations can sometimes engineer their own demise.

Mars, while not without its own vulnerabilities, provides a viable frontier for a backup civilization, potentially shielding humanity from some Earth-bound threats. However, it is worth noting that even Mars would not be immune to certain universal hazards, such as a nearby supernova, gamma-ray burst, or, hypothetically, an alien invasion. Establishing a presence on Mars is thus not about escaping all threats but about creating a resilient foundation that could endure beyond Earth's specific challenges. The drive to settle Mars reflects humanity's pursuit of security, exploration, and the preservation of life. In this sense, Mars offers a strategic lifeline, making settlement not just a goal, but a necessity in the face of an unpredictable cosmic future.

Runaway artificial intelligence capturing the double-edged potential of advanced AI—where rapid, uncontrollable advancements could have significant implications for humanity. It’s a reminder of both the power and responsibility we have in developing technology, whether on Earth or in future colonies.

Optimistic Part:

Scientific Exploration:

Mars presents a unique and invaluable opportunity to unravel the history of our solar system, potentially revealing critical insights into the origin of life and planetary evolution. By studying Mars' geology, climate, and surface features, scientists could gain essential knowledge not only about the Red Planet's past but also about the broader processes that shaped Earth. Discovering evidence of past or even present life on Mars could profoundly impact our understanding of life's existence beyond Earth and offer clues about our own planet's future trajectory.

Technological Advancement:

The challenge of establishing a self-sustaining colony on Mars would necessitate ground-breaking advancements in space travel, life support systems, resource extraction, and habitat construction. The technologies developed for such a venture could have transformative benefits for life on Earth. For instance, innovations in closed-loop life support could lead to more efficient and sustainable systems in agriculture and water management. Moreover, advancements in space propulsion and energy solutions could drive progress in clean energy technologies and other critical sectors, benefiting society as a whole.

Human Curiosity and the Spirit of Adventure:

The innate human desire to explore the unknown has driven civilization forward for millennia. Mars, as the closest potentially habitable planet, represents the ultimate frontier for exploration—offering an unparalleled opportunity to experience an entirely alien environment. The pursuit of knowledge, the thrill of discovery, and the challenge of overcoming the unknown will continue to inspire future generations. Settling Mars is not only a scientific and technological endeavour, but also a testament to humanity's unyielding spirit of adventure and resilience.

Economic Opportunities:

While still speculative, Mars holds promising economic potential that could transform space industries. The possibility of mining Martian resources—such as water, minerals, and metals—could open new avenues for economic activity, while innovations in space travel could foster the growth of space tourism. As technology advances and Mars becomes more accessible, these opportunities may shift from hypothetical to tangible, laying the foundation for a new space economy that could benefit Earth and future Martian colonies alike.