Physics thread

OP, HOW did the Universe CREATE such a BEAUTIFUL Gurl like LILIANA!!??!! ^

maybe you missed my point.
if you can't be pigeon holed into some sort of protected group how are you going to get into a respectable grad program though?

I don't have the cynicism you have for affirmative action being the most dominant factor of admissions especially in STEM fields.

Maybe I am naive and in for a bunch of failed applications but maybe not. DO you have a personal anecdote you wish to share?

not really just giving you a hard time. but seriously by the time I was a junior I knew my fate was not to continue with physics past BS.

I knew this because I had applied for summer internships and discovered I had nothing to offer besides a desire to learn and make a living. I was a mediocre student with a mediocre mind. I couldn't compete with the actual geniuses who were some of my student peers. beyond that I would have needed to be a woman, black or international student to garner interest.
keep in mind this was 15 years ago so I can't imagine it is not worse now.

I went on to get an industry specific engineering degree. I make good dough and spend my free time shitposting and getting drunk.

seriously I don't want to discourage you. you seem like a cool guy and your answers to the actual physics questions asked here show you to be pretty smart. I would advise you to take the red pill and get seriously cynical about shit like that though…it's us vs. them. they won't hesitate to check your privilege for you. be prepared to fight back.

well there is the reason you had trouble getting into grad school. Not that there is anything wrong with being a mediocre student of physics, I certainly wouldn't act like being good at academics is the be all and end all of life. Yet it is obvious from what you said that you never had the drive to do physics above BS level which is perfectly acceptable.

I don't think it's fair to say you had a mediocre mind. How does someone with a mediocre mind end up making good dough and having enough time to shitpost and get drunk and generally have fun? You seem to be comfortable with your life which is better than most people. Part of the reason I make these threads is to get more people inspired by physics because I find it so interesting and want to show that indeed our most complicated theories can be explained to the average barmaid (or Holla Forumstard in this case).

If you ever decide you want to continue doing physics in your own time and need help, you know where to ask :)

Also I am fairly sure if Trump gets in most of the diversity shit is going to be gone pretty quickly. The attitude and spirit of America has changed so much for the better in the last year I have felt.

how hard is it to make a vacuum tight seal? Is it enough to just put a rubber washer around the doorframe to make it airtight, like in submarine?

likely. but by mediocre I am comparing myself only to the exceptionally bright people studying with me. I did graduate with a 3.33 bs physics/math minor. I breezed through my engineering ms…of course I was more mature and had my shit together by grad school.

dude trump is our only hope but there is no way he is going to have any kind of lasting impact on academia. universities are liberal cess pools and he can't change that. I hope you're are right about a change though. I feel it too but it may be too late. there are still ~50% of the population out there who will vote for the cunt or the jew.

keep up the good work with STEMming up the btards!!

The only thing that matters in making an air tight seal is whether there are gaps larger than air molecules present. Not sure how hard in practice but theoretically its very easy to do just as you say. Rubber is non porous to air (which basically means gaps between polymer chains are smaller than air molecules) and so if bonded well to a surface I guess there would be no gaps for air to go through.

One thing to note is that in a submarine you don't need to make an air tight seal, only a tight water seal against water coming in from outside (in fact I think most submarines aren't completely water tight as they just require water to be pumped out faster than it comes in) and oxygen can be replaced by hydrolysis.

Something else to note although im not completely sure about it: all water contains oxygen and nitrogen dissolved into solution. Is the partial pressure of the air inside a submarine equal to the partial pressure of the dissolved air outside? Sure there is a much smaller concentration outside but it is under a lot more pressure at the bottom of the sea. It could be the gases are in pressure equilibrium and hence you could have a totally air porous submarine and still survive, although I somewhat doubt this.

Not him, the students. The dialogue has shifted on campus there has been an awakening… have you felt it? :^)

Not what I'm seeing. I think you are having Holla Forums depression. I suggest you stay away for a couple days and see if you feel better.

I heard gravity bends space time. Does the hairy ball theorem still apply around black holes and shit like that? In strange cases could one have a monopolar magnet with a net magnetic charge of zero and an E field that is tangent at every point to a ball and so would still satisfy Gauss's law?

whats the deal with vacuum anyway? Its an isolator, but u can boil water in it in the waters own temperature and then it just freezes, but the human body merely suffocates. Wouldnt then such a rubber seal become frozen and brittle and break easily?

On the last point, lets make that more quantified. Assuming equal temperatures inside and outside the porous submarine so that the only differences are the pressures and concentrations

dF = pdV+mdN Helmholtz free energy with equal temperatures.

now the pressure inside the sub = p1, outside = p2. Similarly the concentration of air inside N/V = n1 and outside = n2

hence dN = ndV. We thus write the free energy as

dF = (p/n + m)dN

if dF/dN in the two systems are equal, we can have a porous submarine. Thus require

p1/n1 + m_gas = p2/n2 +m_solution

where m_ gas is the chemical potential of an ideal gas (= 0 i do believe) and m_solution is basically the energy released when forming a solution from air.

You mean the no hairs theorem? That is specifically for black hole and says that the only properties a black hole has are mass, angular momnetum, and charge from which all other properties may be calculated and depend on only these three quantities (i.e there are no hairs that distinguish two black holes when these 3 properties are fulfilled).

This makes no sense. If a monopole exists it must have a magnetic charge thats the definition.

Vacuum is just absence of stuff. Boiling is whent he average energy of molecules of a substance is enough to escape into the surrounding. In space with zero pressure this is much easier to do because if it escapes it never returns to the substance.

Yes the rubber will freeze but since vacuum is an insulator the only way heat is transmittedin any meanignful way is through radiation. At some point the rubber will radiate all its heat energy and cool down below the glass transition point and become brittle I do believe.

...

Lol!

Gauss's law for magnetism is 0 = ∮ B · dA. The obvious solution is that there is no B field. But another solution is for the B field to be tangent everywhere to a toroid such as in a dipole. There are also more complicated solutions. However, there is no solution for a ball where the B field is tangent to the ball everywhere because of the hairy ball theorem (not the no-hair theorem.) But if space is bent enough could you bend a toroid into a ball or something like that?

What do you think of the presence of pseudo-intellectuals who bring up physics in conversations of a philosophical nature?

I few examples that come to mind: 1) Most of the movie Waking Life 2) When I was in a philosophy of religion course my senior year of uni we had to read The Tao of Physics 3) Some hippie talking about the double slit theory when he otherwise knows nothing about higher level physics

double slit experiment not double slit theory. I'm tired af fam

What quantum mechanics were involved in the creation of the first self-replicating protein strings/rings, and also how they evolved into DNA and eventually life.

That is a very interesting theorem, easy to "prove" just by thinking about it.

That is not what the hairy ball theorem says. It says there are no non-vanishing tangent vector fields on a sphere. You can always confine motion of a charged particle in a dipole field to a sphere and what it sees is just a tangent field to the surface it lies on. I assume this is what you meant. Sorry for being pedantic.

The simple answer is therefore no. The singularity (the hole of the toroid) will always remain when you map to a sphere. There will never exist a smooth mapping from one to the other.

One way of looking at it is considering the curvatures of the two manifolds. Mapping from one manifold space to another requires the same signature of curvature. Spheres have +ve as at any point on orthogonal directions the curvature is in the same direction. Locally on the outside of the torus the curvature is also +ve but on the inside it is -ve so there will never exist a smooth mapping.

I can't explain it much better than this tbh. I am no mathematician and haven't done much topology outside of GR.

I meant to say

This is the cartographer's problem: trying to smoothly map the entire earth onto a flat piece of paper. It's impossible to include the poles which is exactly the same problem here.

I believe there are some interesting ramifications on philosophy due to quantum mechanics. The main one is the definition of realism. This is the that objects have certain properties when not observed which QM contradicts. Otherwise in terms of free will stuff its kinda stupid. It's on par with saying "statistically all the air in this room could be localized to one corner and we all suffocate".

No idea here. Maybe quantum tunneling meant proteins were able to bond even thought they didn;t have the required activation energy?

That is so FAR from being an "explanation" that I question whether you understand it at all.

Here's my answer; there is a quantum of distance. There is a quantum of time. Their ratio is c.

actually there is only a quantum of time because there is a quantum of distance (which is related to the Plank energy) and the speed of light is constant so we say the time it takes light to travel the smallest distance is the smallest time step.

There is no reason why the speed of light has to be constant that we know of, except that experiments show that it is. Maxwell's equations provided the first hint because they are invariant under Lorentz transform which basically means they preserve the speed of light in vacuum.

The hairy ball theorem says that there is always a cowlick in a continuous vector field over a ball. Such a cow lick would therefore result in a field vector not tangent to the gaussian surface and therefore a net flux and charge.

I don't understand about what you mean by confining motion of a particle to a sphere in a dipole field. Necessarily that is a dipole field (a field with toroidal symmetry) and what I was trying to get away from.

You're explanation of why one can't bend a toroid into a ball makes sense though.

Nevermind I think our miscommunication is that you can have a B field that is tangent to a ball everywhere (at the tops and bottoms make it zero) but you can't have a constant B field that is tangent to a ball everywhere.

If you confine motion to a sphere, you reduce the dimension of the problem hence need to look at projection of the dipole toroid field onto the sphere. As far as the particle is concerned, the field is always tangent to the surface of the sphere cause we are looking at a projection.

It's a really minor point. Just that in projecting down to a lower dimension you have a map that works everywhere and is thus continuous but vanishes at the poles giving a cowlick.

You probably already know it and we are just talking about the same thing with different words. Don't worry about it.

precisely :)

I'm convinced that there are quantum conditions necessary for the creation of life in addition to classical conditions… specifically to explain how spontaneous self-organization doesn't violate entropy laws. But I am just a layperson, so not knowledgeable enough in Physics to know what they are.

kekd

Entropy laws are not violated because enough heat is released to the surroundings when the molecules self organise. There is nothing fishy going on.

wew lads

Do you think gravitational and electric dipoles exist?

I'm pretty sure the spontaneous creation of life out of matter includes "something fishy going on" otherwise we'd be able to reproduce it in a lab or at least on a computer simulation.

They do exist. Binary star systems are effectively gravitational dipoles and you have an electrical dipole in every mobile phone

Its unexplained but there is nothing in it that violates current theories of physics.

I meant dipoles as fundamental particles.

In 30 years when they recreate life in a computer simulation by using quantum mechanics (and prove that life can ONLY arise under quantum conditions) then I hope you remember this conversation.

Does the paradox of the universe's existence bother you?

Do you believe that physical reality is so big that identical copies of you exist somewhere?

Explain, in physics, why if I fuck Hollyleaf too hard, it will hurt.

Why do physicists ignore things like remote viewing? The government spent decades and hundreds of millions on it and there is enough proof that there is something extraordinary occuring.

Making power of mind known to goyim would cause major changes in the world, too much of a shock in present times, remote viewing would only be the begging, other phenomena would be quickly researched by anyone interested.

Ive always thought it was because things like it are such outliers they are too hard to include.

Might actually be something to your tongue in cheek post though. Especially considering the drugs considered most dangerous are stuff like lsd.

Probably because it makes normaly rational people perform suicidal acts that can endanger those around them.

It's shit.

how does gravity work?

Clearly you have never taken it before

because a dipole implies the existence of two opposite charged particles and hence will never be fundamental?

QM doesn't violate thermodynamics.

Huh?

Maybe in parallel universes but since we have no evidence for their existence there are a lot of better things to worry about.

Is this near death experience stuff? No idea. Maybe not reproducible?

Imagine a curved sheet of elastic and dropping a ball on it. Then letting another ball roll around in an orbit. That is our best explanation. The balls are masses and the rubber is spacetime.

Matter tells spacetime how to curve, spacetime tells matter how to move.

We have field theories positing the existance of a graviton that explain a mechanism for how masses actually curve spacetime but it's not confirmed yet cause the LHC is about 10 orders of magnitude too low in energy.

Why is theoretical physics such a fucking joke?

The probability distribution is deterministic. THe actual outcome is not.

You don't have to look at quantum mechanics for this to be true. Classical thermodynamics is statsitical although you are purposely ignoring information about the system there.

OP u still here?
what's ur degree?

Can u explain the concepts of dark matter and dark energy to me?

Theroretical physics, and yeah just woke up.

Effectively if we look at the orbit velocities of galaxies as a function of the radius, further out stars orbit faster than they should if we consider only luminous material in a galaxy as mass. On a larger scale this happens with galaxy clusters. We therefore posit the existence of a new form of non luminous "dark" matter to explain it. The matter discrepancy also popps up elsewhere giving the same expected mass ratio of 10 parts dark matter to every one part of luminous matter.

Dark energy drives the expansion of the universe. It is the non-zero vacuum energy of spacetime (and the reason gravitation dosesnt play nicely with field theory). As the universe expands this dark energy, which is effectively a non zero energy density at every point, increases as there is more space in the universe so acceleratingly drives expansion.

alright

what do ur job propsects look like?

No, not near death stuff.

Its been studied for decades so its most definitely reproducible. Some of the examples are so far beyond chance that there has to be something to it.

For example, someone gets told to remote view jupiter. Noone believes what he reports, then 5 years later its discovered he was right.

Hey OP. What's your opinion on worm holes? I've read about them being created in a lab environment eventually. And what about super massive black holes? Do you think that telescope cluster is going to find something significant about the milky ways black hole?

Physics major heading in to second year… I feel the same. I really have no idea where I am going with it but I figure I can't end up a total failure if I complete the degree, and I feel it is a pretty noble pursuit. Like you I am racist and cynical but my inner-aristocrat tells me to take the path that will lead to higher knowledge rather than the one that will lead to monetary reward.

Did you finish your degree? Am I a retard and should I look in to engineering as soon as possible?
pls respond

Some of the smartest physicists to ever live would disagree with you.

Hey OP, how would you have responded to pic related? Showed up in a completely unrelated thread a few days back.

So we know that God created the universe and gave his only son so that we may all be saved but is there a way physics can prove God's moving hand in the universe?

I think we need to wait for gravitational wave astronomy to get big. This will take about 10 years. Then we will see some really cool shit.

If you are feeling meh about physics and don't enjoy it, don't go into it. The good news is that it is easy to jump into engineering and u will make big bucks. Your call man. I just finished my degree.

What people don't understand about general relativity is that it is the theory where truths are the same in all frames related by a lorentz boost or translation. That is how it is built up. "relativity" is a bad name because the whole point is that truth is the same in all these frames. Nothing relative about it.

We have just confirmed gravity waves directly and every binary system decays according to GR. It is our second best tested theory after quantum field theories.

The main point with the eclipse test is that the sun acts as a lens. The EM field of the sun is not constant around its circumference thus even if the EM field could bend light it wouldn't act as a lens.

up

you must be confused sir the universe was made from akashaand jesus was a hermetic wizard

Wow

yo

We have created many types of life in simulations