Questions tagged [phase-transition]

A phase transition is a change in the nature of a phase or in the number of phases of a system as a result of a change in the external conditions. Examples: melting/freezing, vaporization/condensation, ferromagnetic transition, superconducting transition.

Filter by
Sorted by
Tagged with
53
votes
3answers
25k views

Why is boiling water loud, then quiet? [duplicate]

Water in my electric kettle makes the most noise sixty to ninety seconds before the water comes to a full boil. I have been fooled many times by the noisy kettle, only to discover that the water was ...
3
votes
2answers
182 views

For the recently reported production (January 2017) of metallic hydrogen in the laboratory - what is the evidence exactly?

My google news page has burst forth the news that metallic hydrogen has been produced in a laboratory using a diamond anvil cell. Only one service mentions (at this particular moment) that it has been ...
71
votes
3answers
57k views

First and second order phase transitions

Recently I've been puzzling over the definitions of first and second order phase transitions. The Wikipedia article starts by explaining that Ehrenfest's original definition was that a first-order ...
18
votes
2answers
3k views

What is the Kosterlitz -Thouless transition?

I couldn't find any simple texts explaining the Kosterlitz-Thouless transition. More specifically can someone explain the role of vortices in the transition. edit: links explaining the transition in ...
30
votes
3answers
16k views

Why is there more steam after a pot of water *stops* boiling?

I have a pot of vigorously boiling water on a gas stove. There's some steam, but not alot. When I turn off the gas, the boiling immediately subsides, and a huge waft of steam comes out. This is ...
87
votes
9answers
23k views

Why does matter exist in 3 states (liquids, solid, gas)?

Why does matter on the earth exist in three states? Why cannot all matter exist in only one state (i.e. solid/liquid/gas)?
10
votes
3answers
13k views

Is there a phase transition between a gas and plasma?

Does a phase transition occur as a gas is heated to create a plasma? If so, is this a first or second order phase transition? Also, does the presence of a phase transition depend on the pressure or ...
7
votes
1answer
13k views

What is heat and how does it affect an atom?

What happens in an atom when it gets heated or cooled and turns into gas, liquid or solid? I just want to know how does heat affect an atom.
13
votes
2answers
535 views

Are there published predictions that hydrogen could remain metallic at ambient pressure?

Below the question For the recently reported production (January 2017) of metallic hydrogen in the laboratory - what is the evidence exactly? there is a comment that directed me to the BBC News ...
9
votes
4answers
2k views

What happens if you try to freeze water in an water tight container

If I have a container that is full of water and I attempt to freeze the water by freezing the container, what would happen if the container is strong enough to prevent the water expansion? Could the ...
6
votes
1answer
343 views

Question about Ginzburg-Landau Theory

I was reading CH3 of Reichl's "A Modern Course in Statistical Physics" on Ginzburg-Landau theory and don't really understand a couple of points he makes. He writes: I don't understand why the first ...
5
votes
2answers
197 views

Why can't the density difference between the liquid and solid be an appropriate order parameter for liquid-to-solid transition?

The order parameter $\mathcal{O}$ in the case of a liquid-gas transition is the density difference $\mathcal{O}=\rho_{liq}-\rho_{gas}$. But in the case of a liquid-to-solid transition, the order ...
5
votes
2answers
2k views

Solidification by the application of heat

When you add heat to a liquid (or a fluid), can it be solidified? If not, why in the world does an egg's stuffs become solid (or at least no more a liquid) when you 'boil' it in water?
38
votes
2answers
16k views

What happens when you put water under intense pressure?

Pretend you have an indestructible tube that cannot leak, inside which is water. Imagine that in each side of the tube, you have very powerful pistons What would happen if you compress the water ...
19
votes
3answers
4k views

Why would different metals glow red at different temperatures?

According to everything I've been taught about incandescence and black-body radiation, and some quick Googling to confirm I'm not crazy, just about everything, regardless of composition, should start ...
11
votes
1answer
835 views

Why does Landau theory not fail when dealing with a first order phase transition?

Here is a problem where I can do the calculation, but I am not understanding the philosophy behind it. It is about Landau theory: The Landau theory of phase transitions is based on the idea that the ...
9
votes
2answers
881 views

Could spontaneous symmetry breaking happen again in our universe?

It is generally believed that $10^{-35}$ seconds after the Big Bang, the symmetry of a GUT was broken and after $10^{-12}$ seconds the electroweak force was broken: \begin{equation} \mathrm{SU(2)} \...
9
votes
2answers
16k views

What is the definition of correlation length for the Ising model?

The correlation length $\xi$ is related to critical temperature $T_c$ as $$ \xi\sim|T-T_{c}|{}^{-\nu}, $$ where $\nu$ is the critical exponent. Is this the formal definition of correlation length? ...
12
votes
1answer
1k views

What leads to the existence of critical temperature?

We know that $T_c$ is the temperature above which no amount of pressure could force a gas to liquefy. But why is this? Somehow I don't buy the point that the gas molecules exert too much pressure ...
9
votes
1answer
466 views

Why does a Heisenberg magnet break the O(3) symmetry instead of SU(2)?

As stated in the title, why does a Heisenberg magnet break the $O(3)$ symmetry while degrees of freedom of the underlying spins are $SU(2)$?
7
votes
2answers
1k views

Connection between QFT and statistical physics of phase transitions

I have heard that there is a deep connection between QFT (emphasized by its path-integral formulation) and statistical physics of critical systems and phase transitions. I have only a basic course in ...
13
votes
4answers
491 views

Discontinuities and nondifferentiability in thermodynamics

In physics and engineering sources, calculus-based formalisms - whether differential forms on a manifold, or "differentials" of functions of several variables - are presented as a way of modeling and ...
8
votes
1answer
418 views

What is the relation between the representation the Higgs field transforms under, the types of couplings in the theory and Higgs/Coulomb branches?

When reading about Higgs and Coulomb 'phases' I came across two separate definitions: The first tells us that the Higgs/Coulomb phases are determined by the representation that the Higgs field ...
4
votes
1answer
376 views

Scale invariance at phase transitions

The Wikipedia entry for scale invariance states In statistical mechanics, scale invariance is a feature of phase transitions. The key observation is that near a phase transition or critical ...
18
votes
1answer
52k views

Besides water, which substances are less dense as solids than as liquids? [duplicate]

You can read everywhere about water's extraordinary property of expanding when frozen, thus the reason ice floats on liquid water. What other substances do this? There are claims of mercury, silica, ...
5
votes
2answers
650 views

In the Landau theory of phase transitions, is the order parameter a thermodynamic variable of state?

In the Landau theory of phase transitions, one typically considers a "free energy" $F$ as a function of the temperature $T$ and the "order parameter" $\psi$: $F(T, \psi)$. For the sake of clarity, ...
4
votes
1answer
921 views

Critical temperature and lattice size with the Wolff algorithm for 2d Ising model

When I run my implementation of the Wolff algorithm on the square Ising model at the theoretical critical temperature I get subcritical behaviour. The lattice primarily just oscillates between mostly ...
8
votes
2answers
10k views

Why does Triple point exist?

In thermodynamics, the triple point of a substance is the temperature and pressure at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium. Is the ...
7
votes
2answers
16k views

Why did my liquid soda freeze once I pulled it out of the fridge?

Can someone explain in both layman's terms and also technically why when I pulled my glass filled with liquid soda from the freezer, the liquid soda quickly froze? Doesn't this violate the 2nd law of ...
4
votes
1answer
388 views

What are conditions for the existence of a critical value (for a phase transition)?

Can there only be a critical temperature if there is some natural unit for an observable in the model, i.e. if there is a natural scale for something? Otherwise I don't see how for a system there ...
3
votes
1answer
121 views

How to interpret phase diagrams?

I find quite difficult to interpret phase diagrams in general, for example I see people discuss them along the following lines: Here we see the coexistence line between liquid-solid phases.. a ...
2
votes
1answer
321 views

Are bifurcations in dynamical systems related to phase transitions? [closed]

Bifurcation is a qualitative measure for a dynamical system changing the system parameter. Does the statistical behavior in the system shows phase transition-like characteristics?
14
votes
2answers
2k views

Do all phases of ice look the same visually?

I recently read about different phases of ice on Wikipedia. But I can't find any pictures of the different ice phases. Do they all look alike visually? If you weren't able to measure the pressure and ...
3
votes
2answers
2k views

Why does a substance expands upon freezing? What conditions necessitate this?

Why does a substance expands upon freezing? What conditions necessitate this? For example, how does the slope of sublimation or fusion curve in a P-T diagram affect this?
1
vote
3answers
978 views

Why does evaporation cause cooling?

I am aware that the evaporation process causes cooling in the remaining liquid, but why? If anyone can give me the maths and or equations to prove / show this I would be most appreciative.
116
votes
2answers
11k views

Why does ice cream get harder when colder?

What would seem to be a silly question actually does have some depth to it. I was trying to scoop out some of my favorite soft name-brand ice cream when I noticed it was frozen solid, rather than its ...
38
votes
4answers
2k views

What's the rigorous definition of phase and phase transition?

I always feel unsure about the definitions of phase and phase transition. First, let's discuss in Laudau's paradigm. For example, some people say that phase is classified by symmetry. Some people say ...
69
votes
7answers
19k views

When I boil a kettle, what stops all the water from turning (exploding!) in to steam in one go once it reaches 100°C?

While making a cup of tea in the office kitchen, a colleague asked me this question and neither of us could answer with any certainty. We're guessing it has something to do with the pressure of the ...
18
votes
3answers
4k views

Symmetry Breaking And Phase transition

Is every phase transition associated with a symmetry breaking? If yes, what is the symmetry that a gaseous phase have but the liquid phase does not? What is the extra symmetry that normal $\bf He$ has ...
9
votes
2answers
479 views

What happens for the spins around the phase transition

Suppose we now consider a lattice of spin, say Ising model, and the phase transition at the critical temperature $T_c$. There are few scaling laws describe the regime around the critical temperature ...
8
votes
5answers
1k views

How to understand singularities in physics?

The question is probably two-folded and I will try not to make it too vague, but nonetheless the question remains general. First fold: In most physical laws, that we have analytic mathematical ...
80
votes
6answers
20k views

Why does water stop boiling immediately after turning off the heat?

When I am heating water on a gas stove, it begins to boil after some time and bubbles of air can be seen escaping out. However, as soon as I increase the amount of heat in the stove, the rate of ...
31
votes
5answers
4k views

Why does a critical point exist? [duplicate]

I still cannot fully comprehend the essence of a critical point on phase diagrams. It is usually said in textbooks that the difference between liquid and gaseous state of a substance is quantitative ...
13
votes
3answers
749 views

Are the first order phase transitions always associated with a latent heat?

Is the first order ferromagnetic transition below the critical temperature associated with latent heat? For example, the transition of ferromagnetic configuration with all its spins aligned up to a ...
5
votes
1answer
624 views

Why doesn't topological phase transition break any symmetry? Hidden symmetry?

This question may be superficial. However why all people saying this without a proof? Just like the "hidden variables" assumption in quantum mechanics, can one disproof that there is no hidden ...
13
votes
3answers
5k views

How to freeze the Niagara waterfalls?

Here is a picture of the usual vigorous Niagara Falls (in the winter). Here is the picture of Niagara Falls frozen in 1933 (in the very cold winter). Here is the picture of Niagara Falls frozen in ...
11
votes
0answers
188 views

What did electroweak symmetry breaking actually look like?

Approximately one picosecond after the Big Bang, the universe cooled down enough to pass through the electroweak phase transition. At this point the Higgs mechanism kicked in, the weak force became ...
21
votes
4answers
907 views

Why does water ($\mathrm{H_2O}$) only have two distinct fluid phases?

Water (and other substances) can exist in many distinct solid phases (with different crystallic micro-structure), but only in two fluid phases - liquid and gaseous, in which the molecules are oriented ...
5
votes
1answer
735 views

How does the notion of topological order relate to the Landau-Ginzburg theory of phase transitions?

As per Landau-Ginzburg (LG) theory, we write down a theory (Hamiltonian) with all possible interactions/operators (in terms of some order parameter) that respects certain symmetries. The ground state (...
4
votes
1answer
3k views

Why do spin correlation functions in Ising Models decay exponentially below the critical temperature?

I'm trying to form a better understanding of the 2D Ising Model, in particular the behaviour of the correlation functions between spins of distance $r$. I've found a number of explanatory texts that ...