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31
votes
4answers
13k views

Why can't energy be created or destroyed?

My physics instructor told the class, when lecturing about energy, that it can't be created or destroyed. Why is that? Is there a theory or scientific evidence that proves his statement true or ...
17
votes
11answers
38k views

How do you start learning physics by yourself? [closed]

I think this question has its place here because I am sure some of you are "self-taught experts" and can guide me a little through this process. Considering that : I don't have any physics scholar ...
11
votes
5answers
969 views

units and nature

I am wondering whether the five$^1$ units of the natural unit system really is dictated by nature, or invented to satisfy the limited mind of man? Is the number of linearly independent units a ...
11
votes
7answers
2k views

Is physics rigorous in the mathematical sense?

I am a student studying Mathematics with no prior knowledge of Physics whatsoever except for very simple equations. I would like to ask, due to my experience with Mathematics: Is there a set of ...
2
votes
2answers
1k views

Why does a balloon spiral in air instead of moving in a straight line?

When an air-filled balloon is released without its opening tied up, it moves in a circular path rather than a straight line. Why is that? PS: I don't know what to tag this question as.
1
vote
0answers
374 views

What are the biggest unanswered questions in physics today? [closed]

Are there fundamental big questions in physics that most scientists encounter no matter what they're working on, or are most questions details of smaller subtopics? What are the great unknowns of our ...
15
votes
3answers
829 views

Accidental, unplanned breakthroughs in physics [closed]

There is possibly some idioms or saying like this, ``If you try too hard for something, you will never get it. If you do not aim for something, it may fall on you accidentally, not as you originally ...
7
votes
3answers
2k views

Interesting topics to research in mathematical physics for undergraduates

I'm planning on getting into research in mathematical physics and was wondering about interesting topics I can get into and possibly make some progress on. I'm particularity fond of abstract algebra ...
6
votes
4answers
914 views

What is the physical definition of causality?

Maxwell's equations give a physical relationship between the electric and magnetic fields $\vec E$, $\vec B$ at the same time, which some interpret as changes in one causes changes in the other etc. I ...
5
votes
1answer
1k views

Cooking pasta: why does adding a lid lead to overflow?

When cooking pasta, some organic foam usually forms on the surface of the boiling water and the situation can be kept under control by adjusting the heat (and/or adding some oil). Covering the pot ...
8
votes
3answers
3k views

Please recommend a good book about physics for young child (elementary school aged) [closed]

I'm looking for a book that would be appropriate for an advanced elementary school aged kids (say, 6-11 YO) describing the basics of physics (or sciences in general) in entertaining way. The ...
8
votes
7answers
7k views

Can a scientific theory ever be absolutely proven?

I personally cringe when people talk about scientific theories in the same way we talk about everyday theories. I was under the impression a scientific theory is similar to a mathematical proof; ...
0
votes
1answer
167 views

is there any difference between these Differential $dx^2$ and $(dx)^2$? [closed]

is there any difference between these Differential $dx^2$ and $(dx)^2$!? what is relation between them?
-3
votes
1answer
308 views

Is There a List of Physics Formulas? [closed]

I am looking for a list of simple physics formulas - like $F=ma$. Is there any website/book that is a list of such equations?