Questions tagged [laws-of-physics]
DO NOT USE THIS TAG just because the question deals with a law of physics!
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Could the laws of physics have existed before the universe? [closed]
Alexander Vilenkin writes that perhaps the laws of physics could have existed even before the universe emerged from nothing.
How could the laws of physics exist without the existence of the universe ...
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How to understand the laws of physics correctly? [closed]
Are the laws of physics something that exists separately from the universe or is it a description of the physical properties of the universe and objects in it?
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Why are there two pressures acting on a body in opposite direction during free fall on earth?
This is how my sir explained this to me:
There are more than billions of atoms present in the earth's atmosphere. All those atoms have their force acting downwards.
When he explained this diagram to ...
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Are the different fields in multi-field inflation described by different Lagrangians?
The most simple models of cosmological inflation consider only one scalar field. However, there are more complex models (like hybrid inflation or multi-field inflation) which consider more than one ...
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Could some kind of vacuum decay modify the most fundamental laws of physics?
A false vacuum is a hypothetical vacuum that is not actively decaying, but somewhat yet not entirely stable ("metastable"). It may last for a very long time in that state, and might ...
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Do the laws of physics describe the properties of the universe? [closed]
What do the laws of physics describe? Do they describe the properties of the universe? Or does the properties of the universe described by physical theories, and laws describe how those theories work?
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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 ...
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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 ...
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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: ...
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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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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 ...
user274098
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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 ...
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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 ...
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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, ...
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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, $...
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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 ...
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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 ...
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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:
$$
{\displaystyle \alpha _{\text{scat}}={\frac {8\pi ^{3}}{3\lambda ^{4}}}...
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Consistency in the laws of physics [duplicate]
When I read about past events in the universe (i.e. big bang, formation of the sun and planets, etc) future events (i.e. sun becoming a red giant) and distant objects (black holes, nebulas, galaxies, ...
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Why are squares, square-roots, and second-order differentials, common in natural laws, but not cubes, cube-roots, and higher order effects? [duplicate]
Natural laws often feature squares and square roots, and second-order differential equations. Cubic laws, cube-roots, and third-order differentials are fairly rare.
(Some counter-examples: square-...
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A Newton's third law confusion
Suppose you have a bird inside of a glass cage with some amount of gas inside it.
We now place this cage on a weighing scale and observe its readings in different situations.
Case (1): when the bird ...
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Explain how scaling of the inverse square law breaks down at a stars surface
If the radiation pressure at distance $d>R$ from the center of an isotropic black body star is found to be $$P_{rad}=\large{\frac{4\sigma T^4}{3c}}\left[1-\left(1-\frac{R^2}{d^2}\right)^{\frac{3}{2}...
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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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Is there any different model for universe which can create life?
We know, our universe has four forces (there can be more than four) and some laws. And laws, forces, and particles consequently give the universe the ability to produce living things. Can we create ...
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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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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 ...
user249968
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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=...
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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 ...
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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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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 ...
user238497
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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....
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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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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 ...
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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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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 ...
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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 ...
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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 ...
user232526
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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 ...
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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 ...
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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 ...
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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 ...
user231633
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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'?
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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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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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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 ...
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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 ...
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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 ...
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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 ...
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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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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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