Questions tagged [laws-of-physics]

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13
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7answers
3k views

How does the whole universe agree on the laws of physics? [duplicate]

How is it possible that the every particle in the universe agrees on the laws of physics? What enforces those laws? Might the laws change slightly across the universe in the same way the cosmic ...
5
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1answer
82 views

What would it mean if symmetries are not fundamental at all?

In this paper 1 written by Joseph Polchinski, he seems to indicate that all symmetries of nature may not be fundamental: From more theoretical points of view, string theory appears to allow no exact ...
27
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5answers
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General relativity (and other theories) when proven wrong

So, I have been watching some science videos regarding Einstein's theory on general relativity and until today the predictions based on his equations have been proven to stand. My question would be, ...
0
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0answers
17 views

Church–Turing–Deutsch principle

In what sense from the  Church–Turing–Deutsch follows that it is possible to simulate with one physical system all the other physical systems? I know that we can build logic circuits with a Toffoli ...
4
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2answers
80 views

Could the basic fundamental laws of physics change between universes in cosmological inflationary models?

According to cosmological inflationary models, different universes governed by different effective/low-energy laws of physics could exist, but the most fundamental laws of nature would remain the same....
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2answers
46 views

When an object is on an inclined plane the perpendicular gravitational component is equal to the normal force. How can you conclude this?

When an object is on an inclined plane the force of gravity acts downwards on the object and the normal force is perpendicular to the surface of the inclined plane. When we normally solve these ...
0
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2answers
23 views

Forces acting on two blocks of different masses and their relations (Newton's Laws)

Could someone please help me with this question about Newton's laws and free body diagram? "A block of mass M = 8.00 kg is located on a horizontal surface without friction. A second block of mass ...
0
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1answer
22 views

Binnig's fractal evolution applied to multiple universes?

Gerd Binnig, Nobel laureate in physics in 1986, proposed in his article "The fractal structure of evolution" 1 that everything in the universe, including its laws, had changed and became ...
3
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4answers
264 views

Why does a physical theory need to be testable? [closed]

We are generally not interested in physical theories that cannot be tested with the scientific method. This would seemingly apply even if the theory has other advantages, e.g. simpler, more general, ...
0
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3answers
88 views

Doesn't the Ideal Gas Law contradict the First Law of Thermodynamics

Let's say that an ideal gas does work on a piston, thus increasing the volume of the gas in its insulated cylinder. The pressure of the gas is assumed to be constant; therefore, by the ideal gas law, $...
0
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2answers
34 views

Force exerted by hand

Kindly give me the explanation of this numerical which says A ball of mass $0.2$ kg is thrown vertically upwards by applying a force by hand. If the hand moves $0.2$ m while applying the force and the ...
1
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0answers
88 views

Why are so many physical laws expressed in terms of *integer* powers of some quantities? [duplicate]

Why are so many fundamental physical laws expressed in terms of integer powers of some quantities? I'd expect this to be a very, very unlikely occorrance, since the Nature doesn't know that "we ...
0
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0answers
25 views

Unification of Forces

I was reading that unification of Forces is the most important task in the entirety of Physics. My question is why do the forces have to Unified. Why can't they be different forces what makes us think ...
3
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0answers
76 views

Why are most physical laws dependent on small powers?

The equation with the highest exponent I could find was the coefficient of energy loss of light scattered in an optical fiber: $$ {\displaystyle \alpha _{\text{scat}}={\frac {8\pi ^{3}}{3\lambda ^{4}}}...
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0answers
32 views

Are the laws of physics eternal? [duplicate]

It is scientifically assumed that objects on a planet or heavy bodies fall towards it, when not supported by some ground; irrespective of time. Over a million years this does not change. Its the same ...
1
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0answers
29 views

Consistency in the laws of physics [duplicate]

When I read about past events in the universe (i.e. big bang, formation of the sun and planets, etc) future events (i.e. sun becoming a red giant) and distant objects (black holes, nebulas, galaxies, ...
1
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0answers
49 views

Why are squares, square-roots, and second-order differentials, common in natural laws, but not cubes, cube-roots, and higher order effects? [duplicate]

Natural laws often feature squares and square roots, and second-order differential equations. Cubic laws, cube-roots, and third-order differentials are fairly rare. (Some counter-examples: square-...
1
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2answers
53 views

A Newton's third law confusion

Suppose you have a bird inside of a glass cage with some amount of gas inside it. We now place this cage on a weighing scale and observe its readings in different situations. Case (1): when the bird ...
1
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2answers
63 views

Explain how scaling of the inverse square law breaks down at a stars surface

If the radiation pressure at distance $d>R$ from the center of an isotropic black body star is found to be $$P_{rad}=\large{\frac{4\sigma T^4}{3c}}\left[1-\left(1-\frac{R^2}{d^2}\right)^{\frac{3}{2}...
5
votes
1answer
182 views

Laws of Physics [closed]

Here is a thought. Let us assume the there is an infinite uni-directional line of balls. And it is being jumbled up again and again, randomly. (say by 'God'!) I in my limited experience/capacity can ...
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2answers
89 views

Is there any different model for universe which can create life?

I am an undergraduate student. I am not good at physics at all, but I interested to understand the physics. We know, our universe has four forces (there can be more than four) and some laws. And laws, ...
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0answers
52 views

Are there any physics equations that involve exponents >= 5? [duplicate]

This might be a strange physics question, but I am curious about it. Are there any physics equations that involve exponents $\geq$ 5? There are plenty of equations with square exponents. Inverse ...
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3answers
380 views

Is Newton's third law a consequence of first and second law?

Refer to the diagram shown above Question Assume a system of two objects ($1$ and $2$) which are applying force on one another ($F_{12}$ and $F_{21}$), which can be zero, (read $F_{12}$ as force on ...
1
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3answers
132 views

Why transcendental terms in the laws of nature are dimensionless?

Through my years in nuclear engineering, it has always been the case that in physical relations, the arguments of transcendental functions, e.g., the exponential in the law of radioactive decay, $N=...
1
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3answers
138 views

The first postulate in special relativity

In Einstein's special relativity, there are two postulates: 1. the laws of physics are invariant in all inertial frames of references; and 2. the speed of light in a vacuum is the same for all ...
1
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1answer
58 views

What did Stephen Hawking mean with “not demanded by logic or physical principle”?

In his book, "The Grand Design", physicist Stephen Hawking said: "It appears that the fundamental numbers, and even the form, of the apparent laws of nature are not demanded by logic or physical ...
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2answers
119 views

What are laws in physics? [duplicate]

Many times a precise definition of something in physics is not available but yet there exist some rough definitions that guide us through. I need the same rough (if not precise) definition of physical ...
5
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3answers
260 views

Are there any physics formulas with high/large exponents? [closed]

Most physical laws seem to only have low integer exponents for their variables - in my experience I've never seen a physical law containing variables raised to a power greater than 3 or occasionally 4....
8
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1answer
223 views

How do we know the laws of physics remain the same in different dimensions?

Section on Wikipedia dealing with the possibility of different dimensions. When reading this section it feels like there's a giant elephant in the room that is not addressed. For example, here's a ...
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3answers
72 views

What is the necessity to universalise a law? [closed]

What are the necessary conditions or observations that are required for universalisation of a law? I am not good at English so by universalise I mean to claim something to be universal. So how can ...
3
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2answers
122 views

Are these Stephen Hawking's statements legitimate? [closed]

I am reading 'Brief Answers to the Big Questions' by Stephen Hawking and it seems to me that some of his statements are just hypotheses, but they are written in such a way that they 'sound' like they ...
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1answer
34 views

A circuit out of a ring in amper law paradox [closed]

Assuming that there is three line of circuit and our amper ring is surrounded just two circuit . According to amper law the magnitude of B is just related to the circuits in the ring . But here the ...
1
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3answers
583 views

Why we don't use Ampere's law to find the magnetic field due to a wire of finite length at its perpendicular bisector?

I know that finite length doesn't have symmetry and thus its hard to apply maths here but take the case of magnetic field of a wire of finite length at a distance r from axis of the wire exactly at ...
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0answers
23 views

Arranging objects by mass [closed]

I have n objects with different masses . Say mass of n1=m1, n2=m2 .... so on. I want to use concept of centrality in physics to arrange these objects in a field (computer simulation ) . Where object ...
0
votes
1answer
86 views

Are there other theories (apart from string theory) that combined with inflation, would produce universes with different laws?

In chaotic inflation, space would stop expanding in some points, creating hubble volumes that could experience different spontaneous symmetry breaking, which would result in different properties, such ...
1
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1answer
51 views

Question reg. reasoning of deterministic reversible cyclical laws - The Theoretical Minimum

I recently started reading "The Theoretical Minimum: What you need to know to start doing Physics". In the first chapter, the authors define the "Minus-First law", and state that reversible ".. laws ...
1
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4answers
535 views

Difference between Postulate versus Law

In quantum mechanics, we have many different postulates. In classic mechanics, we have different laws. As far as I know, physics's laws are temporarily correct until an anomaly. But what is the ...
1
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0answers
46 views

What physical laws differs in non inertial frame

For me physical laws should be observers independent, what should be depend on the observers are measurements. But one of the postulates of Special relativity is that all laws of physics should be ...
-1
votes
2answers
88 views

Examples of theories that assume the existence of an “External Reality”?

In this paper written by physicist Max Tegmark (https://arxiv.org/pdf/0704.0646.pdf) it talks about "External Reality Hypothesis". Specifically, he says: Although many physicists subscribe to the ...
0
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0answers
51 views

Is Universal Law of Gravitation a 'law'? [duplicate]

My textbook mentions that the universal law of gravitation cannot be proved. If so, then why is it called a 'law' and not a 'hypothesis'?
2
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2answers
259 views

Does the principle of explosion mean we can prove objects must “fall up” because QM is inconsistent with GR?

(Not sure if this is more appropriate to the Maths.SE) The Principle of Explosion is a law of classical logic which says that if we accept inconsistency, then everything becomes possible. I am ...
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1answer
57 views

Would any continuous model of the universe have/be based on hypercomputational laws?

I've read that when Turing-Church thesis is applied to the universe and physics, one of the three interpretations that we can use and is defended by some important physicists is that: "The universe ...
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3answers
276 views

Is physics the same everywhere in the universe? What if it isn't? [closed]

So, my friend the other day brought up an interesting topic: Does physics need to be the same everywhere? He asked, how do we know the universe doesn't, say, simplify itself, far away from us? For ...
16
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3answers
2k views

Is the second law of thermodynamics a “no-go” theorem?

As defined here, there are several no-go theorems in theoretical physics. These theorems are statements of impossibility. The second law of thermodynamics may be stated in several ways, some of which ...
2
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4answers
235 views

Thermodynamics second law variational statement query

In thermodynamics as I understand entropy is a state function. A state function is a property whose value does not depend on the path taken to reach that specific value. In contrast, functions that ...
3
votes
1answer
53 views

Theories, Corollaries, and Models

I apologize if this question seems overly basic. I was wondering how to recognize what a theory is really saying, as opposed to the explanation/corollaries that are drawn from it. As an example, take ...
1
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1answer
125 views

Faraday's Law and the Law of Inertia

Faraday's Law can be stated qualitatively as : Any loop (of wire) opposes/resists the change of magnetic flux through it. The Law of Inertia states that any physical object resists its change in ...
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2answers
80 views

Issue regarding Newton's second law

Newton's second law says that : The rate of change of momentum of a body is directly proportional to the applied force and takes place in the direction in which the force acts. Mathematically it says,...
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3answers
299 views

What are the most fundamental laws of Newtonian Physics? [closed]

By fundamental, I mean, those laws which if assumed could be used to prove all other laws and provide the essence of the complete picture. I am a high school student, while learning physics I came ...
1
vote
1answer
567 views

If two different theories describe experimental observations equally well, can one be said to be more valid than the other? [closed]

Assuming both use accepted rules of logic, which of the two theories would be accepted and on what basis, for example: simplicity etc.