Evolution Definition and 735 Threads

The hamiltonian ´for a free falling body is $$H = \dfrac{p^2}{2m} + mgy$$ and since we are using cartesian coordinates that do not depend on time and the potential only depends on the position, we know that ##H=E##. For this hamiltonian, using the Hamilton's equations and initial conditions...

I made an effort to find an answer to this question on the Internet, but I was unsuccessful. I did learn that there are some researchers who report that there are many living non-human animals with a hymen, but also that this may be controversial. In particular...

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 what we have got today through a process which mixes some concepts from darwinian evolution and fractal...

Why people believe that life become by accident if math say that it is almost imposible ? it is matahmaticly-statistic almost imposible that even simple protein become just by accident! mathematitions calculate that probability to becom simple protein by accident is only 1 : 10 to the 171...

This is for an alternate Earth that I've been building and rebuilding for years. Sometime between the Paleocene and Eocene epochs, there was a mysterious, sudden, dramatic rise in global temperature. This moment in time was known as the "Paleocene-Eocene Thermal Maximum", shortened into...

Hi all, When I first learned about cladistics, it seemed like an elegant and objective way of classifying life - forget about subjective physical similarities, classify purely based on scientifically testable ancestry, and have all taxa be monophyletic clades, so everything in one taxon is more...

Hi everyone! I am studying spectral methods to solve PDEs having in mind to solve a heat equation in 2D, but now i am struggling with the time evolution with boundary conditions even in 1D. For example, $$ u_t=k u_{xx}, $$ $$ u(t,-1)=\alpha, $$ $$ u(t,1)=\beta, $$ $$ u(0,x)=f(x), $$ $$...

There are several facts one wonders why evolution evolved some traits that look disadvantageous. The typical example that comes to mind is the appendix that has no function in our digestive system, and it can easily become infected. But several other aspects can be cited. Wisdom teeth in humans...

How did you find PF?: Searching a way to share own thoughts I was wondering if we could gather all the laws of the universe and try to link anything to everything. I'm thinking of the possibility of finding links between quantum physics and the theory of evolution. It reminds me of the...

I don't really have any idea how to approach this, but the answer says that it is the compounds which are more basic than ammonia liberate it.

I'm not sure about my proof. So please check my step. I used log as a natural log(ln). Specially, I'm not sure about "d/dt=dρ/dt d/dρ=i/ħ [ρ, H] d/dρ" in the second line. and matrix can differentiate the other matrix? (d/dρ (dρ lnρ))

[url="https://www.physicsforums.com/insights/the-evolution-of-the-universe-cosmic-web-and-connections/"]Continue reading...

Summary:: Specifically, how Earth and life on it would have evolved if our planet was twice as massive but with the same composition of building elements? Could humans or sentient, upright walking creatures appear in the evolutionary scale in a twice as strong gravitational field? How that...

So I am writing a campaign for dungeons and dragons, and I have just started putting together a part of the setting in which a kingdom was shrunk about 2000 years prior, and stored in a small container. The upshot of this (by my own authority as the author) is that time travels about 10 times as...

Summary: A supply of negentropy into a system is necessary to create states of higher order and complexity. Since the origin and evolution of life involves the creation of ever more complex molecular arrangements of atoms, life could not start without a sufficient supply of negentropy. So when...

https://www.nature.com/articles/d41586-019-03061-x?utm_source=pocket-newtab

Dear PF, As an excercise I am to find out how the expectation value of the spin operator evolves over time. There was a hint, stating that it is enough to show that $$ e^{i \frac{\phi ( \hat{n} \cdot \sigma )}{2}} \sigma_i e^{- i \frac{\phi ( \hat{n} \cdot \sigma )}{2}} = [R_{ \hat{n} }]_{ij}...

With the Liouville's theorem $$\frac{{d\rho }}{{dt}} = \frac{{\partial \rho }}{{\partial t}} + \sum\limits_{a = 1}^{3N} {(\frac{{\partial \rho }}{{\partial {p_a}}}\frac{{d{p_a}}}{{dt}} + \frac{{\partial \rho }}{{\partial {q_a}}}\frac{{d{q_a}}}{{dt}})} = 0$$ when we calculate the time evolution...

(In order to ask my question, I need to explain a little bit. But I don't have a background in biology, so I may make some mistakes along the way. corrections are welcome.) Recently I've been thinking a lot about evolution. Its really fascinating. The random exploration of the life "phase...

Watching Dr. Susskind show how to find the time evolution of the average of an observable K, he writes: I can not for the life of me figure out he derived it, and he also did something which I found terribly annoying throughout which is set hbar to 1, so after steps you lose where the hbar...

In this paper ##J=\frac{\partial f_1(X_1)}{\partial X_1}\frac{\partial f_2(X_2)}{\partial X_2}\frac{\partial f_3(X_3)}{\partial X_3}## where ##f_2(X_2),f_1(X_1),f_3(X_3)## evolves with time. Now using this ##\dot J=\frac{d}{dt}(\frac{\partial f_1(X_1)}{\partial X_1}\frac{\partial...

1. If we descended from an unknown common ancestor that was a step up from chimpanzees and bonobo's, then by biological definition, shouldn't chimpanzees and bonobos be much more wise and more intelligent than humans as they are the ones who came first through evolution before our unknown common...

Some organisms still have magnetoreceptors, what would be the evolutionary benefits of these receptors?

Is it possible that evolution happens in quantum jumps as no intermediate lifeforms were ever found? Analogous to an electron jumping from lower energy level to higher energy level without intermediary states.

In QM, states evolve in time by action of the Time Evolution Unitary Operator, U(t,t0). Without the action of this operator, states do not move forward in time. Yet even stationary states, like an eigenstate of energy, still contain a time variable – they oscillate in time at a fixed...

This paper was recently published in the Monthly Notices of the Royal Astronomical Society. Batygin 2018, Schrödinger Evolution of Self-Gravitating Disks I am posting this in here, but I am actually more interested in the implications of looking at this the other way around: namely, from a...

In a discussion between Sam Harris and Brian Greene, at this point, Brian stated that even if we return the brain and all the environment to its previous state, we "WON'T MAKE THE SAME NOISES"; I know that for example, indeterminacy in determining the precise time of decay of an atom (and the...

For this problem at t=0 Ψ(x,0)=Ψ1-Ψ3 Where Ψ1 and Ψ3are the normalised eigenstates corresponding to energy level 1 and 3 of the infinite square well potential. Now for it's time evolution it will be Ψ1exp(-iE1t/ħ)- Ψ3exp(-iE3t/ħ) And taking the time given in the question the time part of the...

Homework Statement Homework Equations For this question my ans. is coming option (3) since the time part of the wave comes out to be same for both the energy states which is (-1)^(-1/8) and (-1)^(-9/8) respectively (using exp(-iEt/ħ)). But the correct option is given option (4). Am I right...

I am interesting in list of readings of the following basic course. It is offered by UCSB: https://www.materials.ucsb.edu/academics/courses 100C - Fundamentals of Structural Evolution (3) An introduction to the thermodynamic and kinetic principles governing structural evolution in materials...

Hi, i just read that a lot of genetic mutations are neutral and do not have much of an effect on the organism or the population. But sometimes, when the environment suddenly changes these neutral mutations can become advantageous and can aid the organism in surviving or in reproduction ect.. I...

Link: https://www.techtimes.com/articles/228798/20180530/massive-genetic-study-reveals-90-percent-of-earth-s-animals-appeared-at-the-same-time.htm Question: Does this article support Evolution or Disprove it? I've seen Pastors Link: https://www.youtube.com/watch?v=5dkwg4fKElw using this article...

Hi . For a system such as an infinite well or a harmonic oscillator if the energy is measured and it returns a value , say E1 corresponding to the ket | 1 > then this evolves according to exp( -iE1t/ħ) | 1 >. So this means that for any time >0 a measurement of the system will always give the...

Was there any need or utility or aim, for which Cantor created his theory? Did Cantor's theory clear any of the problems which existed before? (Though my user name is Cantor, I don't know lot about him or his theory :biggrin:) Reddit...

Homework Statement I posted a picture of the question https://imgur.com/a/8byywYL Homework Equations P = $$(<\psi_{n}|\psi_{o}>)^2$$ The Attempt at a Solution I am guessing that I compute(denote by ##\psi_{o}## the ground state of the old well and by ##\psi_{n}## the ground state of the new...

What do you think we are going to evolve into or adapt to in the far future or mutations arise that will cause some kind of change in our features and maybe even intelligence, strength, physical attributes. Also do you think it will be the entire human race that will evolve in the same way or do...

Hello all.. This is my first question here, i am looking forward to learning new things ! As far as my understanding goes, evolution happens through small incremental changes to populations over time. Mainly due to genetic mutations.. However, instead of small incremental changes, has...

In his book "the black hole war" Susskind writes that in quantum mechanics information cannot be lost because it is unitary. As collapse is not unitary does he say that collapse never occurs?

Hi, I'm not a biologist and I'm not studying biology. But I'm curious so I read and watch some popular papers or videos. I have a question but first of all, I would like to conclude what I think is true: a) The evolution is a process of adapting of living to live in some environment. b) The...

Is anyone here familiar with the Brittanica.com article on evolution? I was just about to read it but had a quick look at the article history to see if it was by a scientist or just one of the Brittanica editors. It is by a scientist but one who's won the Templeton Prize and written a books...

https://www.cell.com/trends/ecology-evolution/fulltext/S0169-5347(18)30117-4The authors do not seem to use the term bushy to describe the non-linear evolution of Homo sapiens, but other authors have used it. They use 'African multiregionalism' instead. And also they exclude panmyxia (free for...

I assume that before the Big Bang, there was no Higgs Field, since there was no universe for it to fill. I assume that at the moment of the Big Bang, it began to seep into every corner of the expanding universe and was carried by inflation, that is, moving faster than the speed of light by the...

I'm reading through a couple of books (Lahiri & Pal's "A First Book of Quantum Field Theory" and Greiner & Reinhardt's "Field Quantization" and have come to the derivation of the evolution operator which leads to the S-matrix. In both books, the derivation starts with the Schrodinger equation in...

An important step in the evolution of plants, animals, and other complex, multicellular forms of life was eukaryogenesis, the evolution of eukaryotes. Eukaryotes are one of the three major classifications of life (alongside single-celled bacteria and archaea) and are characterized by cellular...

Homework Statement Question attached here: I am just stuck on the first bit. I have done the second bit and that is fine. This is a quantum field theory course question but from what I can see this is a question solely based on QM knowledge, which I've probably forgot some of. Homework...

Hello, I’m an undergraduate physics student. Recently, I recognize that I am interested in evolution and I want to study life’s origin. When I preferred physics, because I want to learn how nature works. Now, I am not only interested in how nature works, also I’m passionate for neuroscience and...

Homework Statement The unitary time evolution of the density operator is given by $$\rho(t)=\textrm{exp}(-\frac{i}{\hbar}Ht)\,\rho_0 \,\textrm{exp}(\frac{i}{\hbar}Ht)$$ General definition of entropy is $$S=-k_B\,Tr\,\{\rho(t) ln \rho(t)\}$$ Proof: $$\frac{dS}{dt}=0$$ Homework Equations I am not...

The reason I'm writing this is because I would like to share my thoughts about this interesting thing I was thinking about. So we all know how animals and all other living organisms share a common microbial ancestor that dates back billions of years. Well, I just find it fascinating how when...

Suppose I have a 1-D harmonic oscilator with angular velocity ##\omega## and eigenstates ##|j>## and let the state at ##t=0## be given by ##|\Psi(0)>##. We write ##\Psi(t) = \hat{U}(t)\Psi(0)##. Write ##\hat{U}(t)## as sum over energy eigenstates. I've previously shown that ##\hat{H} = \sum_j...

Now first of all biology is not my strong subject but I am interested in it nevertheless, if my questions come off as arrogant or ignorant then pardon and please explain as I am curious.Last night before going to sleep I suddenly stumbled upon a question, the question goes somewhat like this...