Leaderboard

! Moderator Note No, you're racist because you espouse racist beliefs, the expression of which on this forum (besides being wrong) is also against the rules. Consider yourself banned.

Can one become tolerant to one's own neurotransmitters? I know this can happen with a drug like dexedrine. Dexedrine increases the supply of dopamine in the synaptic gap, and based on my own experience, one can develop a dopamine tolerance at these sites. But what if you were in an environment in which you were being constantly stimulated by things which resulted in dopamine releases in the brain. For example, what if you were a video game addict. I'm told that the joy of playing video games comes from all the little dopamine releases that the game provides. Would you develop a dopamine tolerance even then?

Here I meant d/p. With the f's it's even worse, I suspect.

essereio has been permanently banned for repeated violations of rule 2.1.

I wouldn’t waste your time, Eise. He’s just here to stir up trouble And now he’s not here at all since he got banned. Carry on...

This thread has nothing to do with your justifications for why you and your friends do not like black people and their loud music, or why Hitler was "ok". Go spread your racist views elsewhere.

Hi, Matthew. Sorry for the misunderstanding. Now I understand much better. The last identities for dH in terms of (V, P, T, S) or dG in terms of (V, P, S, T) are totally right AFAICT. The problem I see is in delta G in terms of (H, T, S) in an intermediate step that I think is the one that leads to contradiction. You write, \[\triangle_{R}G^{0}\left(T\right)=\triangle_{R}H^{0}\left(T\right)-T\triangle_{R}S^{0}\] (this is the one that's wrong, I think) Then you take the delta H^0 at T to delta H^0 at 298K by, \[\triangle_{R}H^{0}\left(T\right)=\triangle_{R}H^{0}\left(298K\right)+\int_{298K}^{T}dT\left(\triangle_{R}c_{p}\right)\] The last step is right, but the mistake, I think, is in the first equation, as, \[\triangle_{R}G^{0}\left(T\right)\neq\triangle_{R}H^{0}\left(T\right)-T\triangle_{R}S^{0}\] When the actual identity should be, \[\triangle_{R}G^{0}\left(T\right)=\triangle_{R}H^{0}\left(T\right)-T\triangle_{R}S^{0}-S^{0}\triangle_{R}T\] The term you're missing in this intermediate step is the one that cancels the discrepancy, if I'm not mistaken. Edit: Thanks for the careful explanation. +1. I hope that helps.

Is it fair to say your argument is basically, "if a black hole's entire existence is within an event's past light cone, then any interior events of the black hole are also within that event's past light cone"? I think the argument is false. The interior events are not in your past light cone. For one thing, a light cone is based on the paths of light from one event to another, and a black hole doesn't have such paths from interior events to exterior. I think what you're doing is using a mathematical definition of a light cone in "Your" flat spacetime. Then with a black hole placed in that past light cone, you're effectively assigning flat spacetime coordinates to events within the black hole, like you might do if the black hole wasn't there at all and the spacetime remained flat. You're effectively giving physically meaningless flat-spacetime coordinates to events in a curved spacetime, which I think is okay, but then you're drawing conclusions about those events based on physics that applies in flat spacetimes, which is not correct. In the curved spacetime, the black hole's interior events are geometrically outside of your past light cone, I think... or, I have no idea. Maybe another way to put it is that black holes tilt light cones, and you're not accounting for that. As an amateur, I think I'm missing the maths and vocab that would make this clear and precise. edit: Thinking more about tilted light cones... Say the event of the BH evaporating is in your past light cone. You can say there's a causal connection between you and it because its future light cone intersects your past light cone. But for an event within the BH's horizon, the event's future light cone is tilted more than 45 degrees such that its future light cone does not intersect your past light cone, and there is no causal connection. I suspect there's more to it than that.

Dear Joigus, thank you for your reply! First of all, I meant gibbs free energy, not gibbs free enthalpy, that was a mistake that occurred due to translation as I am learning physical chemistry in german and it is called free enthalpy there. Secondly, sub R stands for reaction - for example, G sub R would mean the molar free energy of products minus reactants. When the formula is valid for one side of the equation it must be for the whole equation too. 3rd, the total differential of G should indeed be the formula that I used in the beginning, I'll post the calculation via legendre transform of H down below. Concerning Edit 2/3: The superscript zero should suggest that the reaction happens at standard conditions in terms of standard pressure and equal concentrations of reactants/products. H sub r therefore is the enthalpy of the reaction as a function of temperature (as reactants and products can have different heat capacities, the enthalpy of the reaction can vary with different temperatures). Edit: The formula should be valid for fixed temperatures, however, as the temperature chosen can be anything and the total enthalpy is defined by standard conditions at 298K, we have to integrate from 298 to T

https://www.forbes.com/sites/startswithabang/2020/06/17/is-it-dark-matter-mystery-signal-goes-bump-in-worlds-most-sensitive-detector/ Another article here: https://www.quantamagazine.org/dark-matter-experiment-finds-unexplained-signal-20200617/ And a Twitter thread from one of the physicists involved:

It should be noted that the drug is a steroid, which are used to manage inflammation and are not antivirals.

Nope. I see people who look angry. Are black people allowed to be angry at injustice, or are you suggesting they should blithely accept whatever mistreatment comes their way? Right....so when people of color are "loudmouths" and step out of line, it's OK to gun them down. That must be the Nazi sympathizer in you talking, Stats please? I guess that platitude is intended to justify fascism? Fascism is an obsolete ideology, like Communism. The world is moving on.

I said it would take a while to answer but first a word of gentle friendly advice. This must be a very small part of your first year curriculum. I have never heard of Chemical Engineers requiring such detail. So don't be diverted from the main thrust of your subject, there is so much introduced in the first year, from fluid mechanics to science of materials to advanced mathematics to thermodynamics to transport phenomena...... Remember that this is only about atoms. So think about how few times a CE will deal with pure atoms as opposed to the great many times he will deal with molecules? So to proceed with atoms. I will try to clear up a few things you may know or may only partly know on the way. Firstly the Hamiltonian in a system (H) relates the total energy of a system to some controlling parameter. In the case of wave mechanics the Schrodinger equation this is the wave function. We say that the Hamiltonian operates on the wave fucntion to ouput the total energy. [math]H\left( \psi \right) = {E_\psi }[/math] Now this can be broken down to measurable quantities such as momentum, charge, mass etc For a single electron atom Ie a hydrogen-like atom this becomes [math]H = - \frac{{{\hbar ^2}}}{{2\mu }}{\nabla ^2} - Z\frac{{{e^2}}}{r}[/math] Where Z is the atomic number that is the number of protons in the nucleus. So the energy depends upon the number of protons in the nucleus. Further this equation has been solved analytically. Some notes here are in order. A hydrogen-like atom has one outer electron over a core of fully paired, if any, electrons so includes lithium, sodium, potassium etc. This electron will inhabit an S orbital, generally of higher energy than any orbital in the core. More of this later. Your diagram refers to S orbitals only, and further more is proportional to the square of slutions of the Schrodinger equation. Since it is a squared term it is non negative ie positve or zero. Plots of the wavefunctions themselves show positive and negative regions. The various humps in the square (probability plot can be seen forming in these plots) Further the S orbital is the only one that is not zero at the origin (I have only show p but this is also true of d and f orbitals). The second point is as already made; the actual energy value depends upon Z. So the actual energies of 'the same' orbital in the atom of one element will be different from those in the atoms of other hydrogen-like atoms. Note carefully on this chart Such variation of levels becomes even more complicated when we consider atoms with two or more outer electrons Looking back at the Hamiltonian this is because we need to add more terms due to the interaction of the other (Z-1) electrons. [math]H = - \frac{{{\hbar ^2}}}{{2\mu }}{\nabla ^2} - Z\frac{{{e^2}}}{r}[/math] Now the electrostatic energy is increased by the addition of this interaction energy. Unfortunately even this simple addition cannot be solved analytically. This accounts for the majority of the effects and the reason why all the building up , aufbau, Hund, Slater diagram, Mollier etc rules have exceptions. And all this effort is only for less than 0.01% of the substances a CE will be dealing with. For molecules and chemical bonding several more terms involving cross products of the Z numbers for the second and subsequent nuclei in the molecule are needed. This is why the build up of atomic orbitals, which was greatly studied in the first half of the 20th century, faded in the second half, when the subsidiary Science of Computational Chemistry was born. https://en.wikipedia.org/wiki/Computational_chemistry How are we doing?

The definition you quoted, "The black hole region, B, of such a spacetime is defined to be the points of M not contained in the causal past of future null infinity." If there was a black hole then there were such points, which means there must be an event horizon. There's no contradiction there. Can you give an example of an event from inside the theoretical MBH's horizon that causes an effect outside, such that it has some recorded effect "in the lab the next morning"? If so, then you're on to something. If not, you're making extraordinary claims without evidence. It's events that are in past light cones, not spatial regions. Assuming you know that, you mean something like that all the events at that location in a given Euclidean coordinate system, but with earlier times, are in our event's past light cone. However, the events within the past black hole's event horizon are not part of that Euclidean coordinate system, I think. If you were claiming that black hole event horizons can't exist in a Euclidean spacetime, I think you'd be right.

In particular (pardon the pun but not bolding for that reason), I would say any body experiencing CMBR anisotropy would experience drag forces (Without looking it up I'm guessing to the square of the speed wrt to CMBR isotropy but please correct me if I'm off the mark) Deep space, what constitutes greater drag, CMBR photons or other particles assuming average (deep space) distribution? Except you lose mass emitting the light (conservation of momentum and all)

Light has momentum and would produce thrust. The reason it’s not viable is that the photon momentum is E/c, so the thrust produced is P/c (P is power) So you need 300 MW to produce 1 N of thrust. The only real advantage it has is that there is no reaction mass needed.

! Moderator Note You appear to have discovered the concept of "proper time" (and proper distance). I see no reason for this to stay open in Speculations as you are just stating the obvious.

You're killing me Smalls.

GR's treatment of gravity already accounts for stellar motions and accretion discs without requiring event horizons. It's entirely possible that black holes exist, but then it's also possible that the center of galaxies are full of unicorns and lemon ice cream. If GR has "a number of failings with regard to BHs" then you have no model whatsoever to predict them.

Did you watch the whole video? He wasn't a martyr period. You're derailing the point of the video. She's neutral and not picking sides. You're pulling an ad hominem on her. I dislike BLM also because it's self-evident that it's a hate group. I've lived in a multicultural community as a minority white male while receiving an unfair amount of insulting remarks from racist black people while minding my own business and at other times witnessed humble black people feeling frustrated with the rude and loud attitudes of other black people. BLM is a hate group because racism is driven by us verses them mentality. Hitler wanted good for people. It's just that his actions were incorrect towards taking out the trash(religion). Was he a good leader? No. Was he a bad leader? Who cares. He was ok. Nothing remarkable or revolutionary.

Do you see the hate and victim mentality? No prejudice. Simply an aversion to obnoxious loudmouths regardless of skin color who expect their bad behavior rewarded. This includes my younger white brother who I can tell to shut up without being accused of being racist. Police brutality will stop when people stop being loudmouths and breaking the law. Like I said... people want their bad behavior rewarded. Malton, Ontario, Canada. This is a place where police is required to keep the peace. They tried removing the police station after renovating the whole place with new stores and streets but crime rate including killings went up. Without great power comes great irresponsibility.

https://en.wikipedia.org/wiki/Two_wrongs_make_a_right You're twisting everything without seeing the bigger picture of why a few or maybe a good portion of black people turn off a lot of other people. It's not just white people who are extremely annoyed by the rap/hip pop garbage personas. Loud music, loud voices, insults to innocent people, drugs, gun shootings and the list goes on. You get what you give. https://www.quora.com/Why-do-some-people-hate-rap-music Injustice? Verbal abuse on a consistent basis is a lot worse than physical abuse. Black people are much less likely to be taken seriously because of the rude behavior/rap persona of a few. I feel sorry for a good portion of young blacks who get brainwashed by the rap/hip hop music and then go on towards causing psychological issues towards society. A few bad apples spoils the bunch. Hopefully understanding how we feel will help you see that a lot of people have an aversion towards those who stress them out.