/sci/ - Science & Math

>>6366786
in depth research on absorption refrigeration, specifically the ammonia, water, hydrogen cycle used in RV refrigerators. studied the fluid dynamics of the gas / vapor pathways. found work on substituting helium for the hydrogen to increase flow rates. whole project was to increase COP and investigate lower thermal limits of operational efficiency. All towards using it with solar generated hot water as the source of heat.

Current project isEE related... the effect of interaction amplification in a slow wave induced by an axial moving charge. a little known effect with applications in many high energy fields.

>>6367024
>studied the fluid dynamics of the gas / vapor pathways. found work on substituting helium for the hydrogen to increase flow rates
Experimental or computational?

>Tfw only interesting thread here
>Tfw no one responds
If only I were smart enough.

One of my senior theses in geology was about trying to determine the number of metamorphic events in an iron orebody. I used petrography and EDS from an SEM.
I want to get into stable isotope geochemistry.

>>6366786
Mostly working with plasmas now, base research at the moment. Been working with a professor in our department studying behaviors connected to electrostatic ion cyclotron waves in plasmas.

Did a series of experiments last Summer to study how introducing neutral gasses into the plasma damps out the harmonics. Our results generally agreed with the theoretical growth rates (higher harmonics expected to damp out faster) apart from a few oddities. We're hoping to do some followups later this Spring and publish.

Also did some work seeing whether it was possible to produce stable ionized CO2 through electron attachment. Results were inconclusive, may revisit later if we get a chance to swap out our positive ion source.

Currently working on experiments dealing with shear-driven instabilities.

After that not sure what we'll move onto next or what I'll do from there. Graduated in December so I'm putting my free time towards helping my prof work through some of his To-Do List. Waiting to hear back from grad schools, mostly applied to programs with strong plasma/fluids programs - most programs seem pretty focused on fusion, space plasmas, propulsion, etc. Got an offer from Dartmouth last week - they've got a great space plasma program - waiting to hear back from the others.


Can post some copies of posters and stuff if you don't mind me censoring names/logos and the like. Also happy to offer advice on getting involved in research as an undergrad.

>>6366786
Haven't been involved in any projects yet but I'm looking at solid state. Figure I should wait until I've at least finished quantum mech before approaching any professors about research work

>>6366786
Two projects currently:

First is on increasing antenna array directivity using post processing - microwave hardware and/or dsp.

Second is entirely applied math - optimization of radar waveforms, and related phase recovery algorithms.

>>6367111
mostly experimental in regards the refrigeration, the EE project is mostly researching papers at the moment

>>6367205
>electrostatic ion cyclotron waves

I dig Bremmstrahlung but ? a "cyclotron wave" ?
please expound

>>6367916
is it possible to measure the polarization(s) of the returning radar "echo"?

anomalous Z-gamma couplings production at 8 TeV energies

Morning /sci/


>>6367911
Solid state's a lot of fun from what I've heard. I have a friend who's working with a group on trying to grow more efficient organophotovoltaics (OPVs).

No reason to put off talking to professors about research though - check out what they're working on and if you find projects that sound interesting go talk to those faculty members. Most of the stuff you'll start off doing as an undergrad doesn't require a serious understanding of the physics to do (taking data, analyzing results, setting up experiments or simulations, etc) and your professor and fellow researchers will typically make an effort to catch you up on some of the material or recommend texts that will help you.


>>6367929
In a magnetically confined plasma, high relative drift between ions and electrons can create an instability in the plasma. The dispersion relation for the instability incorporates the normal cyclotron resonance frequency.
<span class="math">\omega^2~=~{\omega}_{c}^2~+~{k}_{\perp}{c}_{s}^2~+~...[/spoiler]

A biased Langmuir probe can excite and detect these instabilities which can be used to, among other things, identify composition of a plasma.

Most of the experiments we've done so far have dealt with current-driven behavior but we're working on an experiment now to study the effects of the theorized shear-driven contribution to the waves. We've got a series of about 20 probes ranging from disc probes a centimeter across to cylindrical probes a few dozen microns thick. The shear theory suggests that as we get to collection areas smaller than the ion gyroradius we should see the current driven contribution damp out, and then the shear-driven contribution should strongly reemerge as we get down to the scale of the electron gyroradius. As far as I know, no one has attempted to excite EIC waves with probes as small as some of these.

>>6368047
Whoops, mucked up the latex
<span class="math">{\omega}^2~=~{\omega}_{c}^2~+~{k}_{\perp} {c}_{s}^2~+~[/spoiler]...

Currently researching the effects of electrostatic forces in microgravity accretion. We're hoping to contribute to planetary formation theory and the dynamics of particle/moon systems in saturn's rings, but even if we fail I'll still come out of it with a free ride floating around on a parabolic flight.

>>6367205
What are some good texts to start studying plasmas?

>>6368060
ah... the vomit comet... have fun!

seriously tho... interesting line of research, but be careful there are some serious haters and what you are doing sounds close to the demonized EU stuff.

>>6368047
>identify composition of a plasma.
is the frequency spectra specific to ion species?

>>6368092
Thanks man! I'm pretty psyched for it; roller coasters are my thing, so I won't be blowing chunks everywhere (unlike my co-workers lel). What do you mean by haters and demonized EU stuff? I haven't heard of this.

Just finished up my first big paper in December. Described and characterized a new halophilic protozoan. The way it fit in the heterolobosea phylogeny we decided it would be best to propose a new family and group its closest relatives in there with it. Cleans it up a bit.
First authored the shit outta that. Not bad for a first publication.
Now if only I could find the funds to support me while I do a PhD.

>>6368100
>first authored the shit outta that
Noice, I would think that boosts your chances of getting funding by a ton.

>>6368095
EU = electric universe aka electric cosmology

look into it if you haven't already. It questions some of the basic assumptions in cosmology. I did not realize how many of those assumptions were based upon "no electrical conductivity in space". The research you are talking about is very much pointed towards answering some of the "dark matter" questions. "is gravity the only major player"

>>6368116
Ah, we'll be staying away from cosmological applications here so I think we're safe. This paper is more about the early stages of a system of dust (like a nebula or protoplanetary disk) and the optimal relative particle velocities to allow for accretion. Gravity isn't a major player here until large masses have already stuck together, so electrostatic (and lorentz to a lesser degree) are the earlier driving forces in the process we're looking at.

>>6368076
I'm currently neck deep in "Introduction to Plasma Physics and Controlled Fusion" by Chen, which is the best text I've come across so far. I've also heard good things about "Introduction to Plasma Physics" by Gurnett, which I've got on order actually. You should also look at picking up a nice introductory text on fluid dynamics ("Fundamental Mechanics of Fluids" by Currie is a good one). Nearly all the equations and phenomena you run into in plasma physics are similar to those in normal fluid dynamics, just with the added complexity of electromagnetic effects.


>>6368092
Have fun, but be careful - I've heard it's very easy to get injured on those flights without proper precautions. A researcher in our department was doing an experiment on one of those flights a few years back and they hadn't thought to put foam covers on any of the sharp corners of the instrument and he ended up taking a hit just above the eye.


>>6368093
Yes, different ions have different EIC spectra, and we can even identify multi-species plasmas using EIC waves since the spectra simply superimpose on one another.

Unfortunately this doesn't always work out so nicely. During one of our recent experiments we wanted to see if it was possible to produce semi-stable negatively ionized CO2 using a process called electron attachment (it's exactly what it sounds like). We saw a noticeable dropoff in the electron density, which seemed to confirm we were producing the negative ions, but we had failed to take into consideration that Cesium, which we use to produce our plasma, has almost exactly three times the mass of CO2 - so all of the peaks in the spectra from CO2 wouldn't have been visible anyways.

If we have time this Spring we'll switch over to Potassium and give it another go.


>>6368100
First author! Congrats!

>>6367889

This is me. Jesus I hate my subject. It's boring as shit

>>6368136
>I'm currently neck deep in "Introduction to Plasma Physics and Controlled Fusion" by Chen, which is the best text I've come across so far. I've also heard good things about "Introduction to Plasma Physics" by Gurnett, which I've got on order actually. You should also look at picking up a nice introductory text on fluid dynamics ("Fundamental Mechanics of Fluids" by Currie is a good one). Nearly all the equations and phenomena you run into in plasma physics are similar to those in normal fluid dynamics, just with the added complexity of electromagnetic effects.
Thanks for the response. Besides a strong base in EM and fluid mechanics, how important is statistical mechanics to the study of plasmas? It was one of those subjects where I just closed my eyes and hoped it would be over.

>>6367942
yes, the polarization information can be used to further characterize a scene.

>>6368134
>Ah, we'll be staying away from cosmological applications here so I think we're safe.

I understand what you are saying.

when you investigate the "electrostatic" I'm glad to see you recognize the "Lorentz" components as well, they might be more complex than you anticipate. EM field interactions are some tricky, tricky stuffs

And like this anon>>6368136
points out, I'd sure be wearing goggles and a cup during the flight.

>>6368136
Thanks for the heads up, but I'm still going to attempt a backflip because I'm a dumbass like that. NASA has already nixed some of our proposed equipment so they're looking out for us too.
After this project I'm thinking of going into directed energy research, and I stumbled upon the concept of electrolasers. They heat up the medium they pass through to the point that it ionizes along the beam, allowing you to sent electricity along it. The defense applications are obvious, but do you think this has significant energy applications as well? I wonder whether you could harvest more energy than expended by aiming these at thunderheads to guide lightning.

>>6368136
>Yes, different ions have different EIC spectra, and we can even identify multi-species plasmas using EIC waves since the spectra simply superimpose on one another.

thank you for the interesting information.

I have a further question. are these EIC waves longitudinal or transverse? The rate the power falls with the distance is it by direct proportion or in proportion to the square of the distance?
Since you are investigating magnetically confined plasmas is the cavity resonant? and does this have any effects on the EIC energies

>>6368113
>>6368136
Thanks, fellows. My application is out for some glacial microbiology, but my first choice project is out of the question. This is the programs' last year, so they aren't taking applications. Too bad, since the project I had lined up would have brought me to Antarctica for some soil geochem/microbio. Now I'll have to settle with glacier climbing in the Yukon.
Sigh.

>>6368165
>I wonder whether you could harvest more energy than expended by aiming these at thunderheads to guide lightning.

look into TWT and BWO type devices. the interaction of a moving charge along the axis of a "slow wave helical resonator"... basically there is an energy transfer between a "beam" of energy and a (nearly) standing wave that has great properties for exploitation.

>>6368100
congrats anon.
bio isn't my thing but a new species especially an extremeophile is always interesting. I've always been curious about the pathways involved in a protozoan's "sense and response" actions.

This is probably one of the most
interesting threads I have been on.

You're all making me feel confident with my choices of study.
(really hoping they are ok)

>>6368165
here's a thought

>pic related

>>6368165
>but do you think this has significant energy applications as well?

you are barking up Tesla's tree.

The questions you ask are ones I am currently investigating see
>>6362638
>>6366638

two threads I am currently involved in

>>6368204
hnggg if only that weren't against their safety regulations. I really wanted to do the one where you charge a pen by rubbing it and watch the water droplets orbit around it ;_; . This reminds me I need to make some microgravity gifs for the next gif thread. There are some great youtube videos where people on the space station do fun things like this. I'll read up on these >>6368172 when the studies cool off in a couple days. I really need to learn how to get off 4chan.

>>6368202
Whatcha studying anon?

>>6368227
>I really need to learn how to get off 4chan.
best of luck anon I'll be looking forward to vids of your flight

>>6368158
>how important is statistical mechanics to the study of plasmas
Ehhhh... *hand wavy motion*

I'll be honest - I know it supposedly plays a big role in some cases but it really hasn't come up in most of the work I've done up to this point. I think I've had thermal physics come up a handful of times and even then a lot of it was pretty basic stuff. Stat Mech is definitely important but I think most of what you'll need for a lot of research is stuff you'll either already know from introductory physics or is relatively easy to pick up.

>It was one of those subjects where I just closed my eyes and hoped it would be over.
Oh believe me, we've all been there.


>>6368169
Longitudinal relative to the magnetic field lines
I'm embarrassed to say but I'm drawing a blank off the top of my head
No as far as I'm aware cavity resonance isn't a factor.

>>6368252
thank you anon for your replies.

I wonder if cavity resonance isn't a factor? I would be very interested to hear any info about standing waves in this EIC radiation.

I am also very interested in the information that the frequency spectra are species specific much as the emission spectra are for normal spectral analysis.

Graduate student, soon-to-be-postdoc. Photovoltaics, mainly growth and characterization of semiconductor interafaces. Fuck, it's dead-end. No long term employment except for NREL or academia. Industrial jobs: most of them are improve yield. Boring. Not as many R&D type jobs.

>>6368328
see >>6368047 mentions OPVs

and I would suggest the combinations of photovoltaic elements along with piezoelectric elements are two areas that show some growth besides just "tweaking" the parameters

>>6368421

I work in inorganics.

OPVs are not economical (cost over lifetime is relevant metric, not cost/W), but there's like 1 research group at every uni doing them. One company (Konarka, I think) tried commercializing them and failed miserably, and Gratezel switched to perovskite, IIRC (and it turns out the whole nanoporous "Graetzel" stuff that made him famous isn't necessary because the excited state lifetime is good enough in those semiconductors).

Anyway, funding system is so fucked up (groupthink gets funding), and now all the graduate students used as cheap labor doing OPV research have no realistic job opportunities (unless they did polymer growth/catalysis).

Organic transistors for displays got replaced by metal oxides.

Organics for non-volatile memory got replaced by CBRAM/ReRAM.

Organic electronics is really only good for OLEDs.

For every other application something else does what organics electronics does better and cheaper.

Then again, most of the inorganic photovoltaic research isn't that viable, either. Lots of stuff sucks, but it makes a pretty picture and science news sites eat it up. People get credit for things they didn't pioneer/aren't actually experts in just because they throw buzzwords together (see John Rogers and his epitaxial liftoff stuff. It's been done to death, but make it "nano" and all of a sudden there's a ton of hype around it)

>>6368421

Eh, by combination photovoltiac/piezoelectric, you mean "bandgap engineering" by inducing strain (think that's been done before, but not 100% sure, probably done with lasers since it's easier to see shifts in emission).

Or systems stuff?

>>6368455
I'm not sure if engineering the bandgap is what they were doing... I mentioned it because of a recent patent I had read about somewhere. Seemed there was a synergistic action or something

>>6367911

Def. do research, it's the #1 thing grad schools look for, if you're looking in that direction, and will let you know if you like it or not.

There's lots of variation in leadership/mentoring styles, among advisors. Graduate experience is way too varied. Some people get forced to work on shit projects, some people have too much freedom to the point that they don't get anything done, some people end up trying to fix an instrument for four years.

>>6368459
>some people end up trying to fix an instrument for four years.
that student truly learned the meaning of "multi-disciplinary"

>>6366786
First year physics undergrad. I'm pretty sure what interests me the most is QFT, second option would be elementary particles maybe and the third is organic chemistry. Any PhD/BSes on one those to tell what it's like? Also is it true that theorists unlike experimentalists don't have to do their lecture minimum or whatever it's called, teaching undergrads?
Anyone ever thought about contenting all sci&maths knowledge in a memory palace, like to put everything in there so you'll be the most competent man in your surroundings?

>>6368459

the grad school I'm aiming for looks for a 3.2 gpa.

>>6368512
Pro-tip: What grad schools say they're looking for and what they actually look at on your applications is rarely the same thing.

Schools will say they have GPA and GRE cutoffs, and true some large schools will filter out applications that don't meet the minimum requirements... but small and mid-size schools usually don't.

Excellent letters of rec, a strong personal statement, and good research experience mean a helluva lot more to schools looking at prospective grad students than a 4.0 and a high GRE score.

I'm not saying don't work to get those grades up or don't study for the subject exams... but don't go reaching for a gun just because you got a B average and a mediocre GRE score

>>6368533

Yeah, this. GPA/GRE means fuck-all (well, probably 90% of applicants will have 800 verbal and like 650+ verbal and >10 writing). I think work ethic and creativity are most important in recs (although creativity can be stifled at a lot of places, especially in some disciplines, e.g. organic chemistry). A lot of people just want "hands in the lab."

>>6368462

The worst part is, the power supply failure that fried all the rest of the parts, and it was still under warranty, and the company kept trying to back out of it.

Also: you should never pay to go to grad school, even if it's just a MSc. Get paid to do a PhD and leave with a masters if you can. Schools hate it when you do that, but it's better than paying.

>>6368543
>The worst part is, the power supply failure that fried all the rest of the parts, and it was still under warranty, and the company kept trying to back out of it.

ah.. an education in modern business practices as well... I hope the student didn't have to pay extra for the added knowledge

>>6368545
They pay you for your gradschool? Why would anyone need a Msc? Like, can you even find a research job without phd?

>>6368533

Many universities avoid letting people with 4.0 GPAs and what not into their grad programs because they are usually not well rounded. Think about all the sort of autistic people who you've met over the years who can get perfect grades, but don't have any people skills or any real personality or interests (other than creepy shit like my little ponies). If you have imperfect grades and have shown that you can get shit done and still have a life where you do interesting shit you'll usually get precedence over people who you think are better than you.

>>6368562
This is bullshit. Even here average idiots rule everything and let in only mediocre men. I hate this planet.
But what is GPA/GRI?

>>6368549

Yeah, stipend is like $30k/year.

Sometimes if you find a job beforehand, your company will pay for you to do an MSc.

Realistically, you could do research after an MSc plus one year of grad school (since you usually have a full year of research by then). The rest is just sticking around for cheap labor.

>>6368562
That's nonsense. They want the best people but that does not mean grades are the most important thing, they do help however.

>>6368116
Nonsense as always from the EU crowd. The research in question is proof enough that astronomy doesn't ignore everything by gravity.

>>6366786
Started research in algebraic topology last year. With a few collaborators, I have a couple of papers waiting to be written up.

>>6368562

Well, depends on the field. Success in grad school is a mixed bag. For some people, it's working hard without much thought. For other's it's coming up with a key insight/actually being brilliant that leads to success.

I doubt people who are into that shit would have good grades. Typically, those type of people think they are smarter than they actually are.

>>6368581
So then why would you go phd? And can you do some kind of transfer do get msc in another country after you're finished with bs in yours? Say, I'm in Belorussia. Obviously, no science for me here. What do I do? inb4:
>implying anyone gives a fuck about third world countries
I know only that I should leave as early as possible

I'm investigating energetic particles emitted from solar flares and detected by in-situ instruments. The project covers propagation effects from the interplanetary magnetic field and collision all effects in the heliospheric plasma. The work and pervious work I've done on the topic draws on many observations such as hard x-rays and radio which are a strong proxy of the particles.

At the moment I'm applying for PhDs, I have a few interviews mostly focused on observation ally driven astronomy.

>>6368612

>in-situ
>solar flares

I'm guessing you're doing plasma generated in some sort of vacuum chamber, since that's the only way this makes any sense.

>>6368621
Emitted from solar flares. A solar flare happens, boom magnetic reconnection, lots of accelerated particles, huge fluxes of electrons. If the magnetic configuration is right some escape upwards away from the Sun. Some of these produce solar radio bursts. If they happen in a well connected region the particles can reach us at 1 AU. Or more correctly a spacecraft.

>>6368592
>Nonsense as always from the EU crowd.

This↑is what I meant by haters.

I am the first to admit that the "EU crowd" has attracted far more than it's fair share of crackpottery. But it does raise some interesting fundamental questions, and you shouldn't throw the baby out with the bathwater. The experiment anon >>6368060 is talking about is important re: planetary accretion. If the electrostatic forces were taken into account in the original formulations of modern cosmology why are we just now asking this very basic question? Why has it taken so long to begin asking these questions?

You must remember the foundations of science that modern science is built upon. It is a few laws and a great deal of theories. Most of the theories we've used to build modern theories have themselves been updated. This recursive revision has not come full cycle, hence things like Hawking's retraction of the "event horizon" will occur.

I've been investigating some of Tesla's claims. In his time the only mode of propagation of EM waves that was know was the transverse "hertzian" form. So when he claimed that his magnifying transmitter did not emit hertzian waves and the transmitted power did not fall off with the square of the distance but rather in direct proportion to it, he was ridiculed and belittled and his reputation never recovered.

Tesla's death ray was relativistically accelerated mecury ions. With a Gev source you can do some serious damage with one of those babies. Many of the anon's in this thread can appreciate just how such a device might work. In Tesla's day such understandings were non-existant or very, very rare.

>>6368549
>They pay you for your gradschool?
Graduate school in science, math, or engineering isn't like going to law or med school. You don't pay them, they offer to pay you.

Any good research school is guaranteed to give you a full ride for tuition, and a moderate stipend as well - usually in the form of a research or teaching assistant stipend (I've seen as low as $15K and as high as $27K on those) or a fellowship. Most will also provide other incentives like health plans, travel plans, moving stipends, etc.

>>6368647
>boom magnetic reconnection,

here is a perfect example,

please explain to me how "magnetic re-connection" works.

Isn't is simpler to suppose that the solar flare was the endpoint of a current flow? When the flow initiates and ceases are moments of great magnetic field flux which would account for the accelerated particles wouldn't it?

>>6368661
>Graduate school in science, math, or engineering isn't like going to law or med school. You don't pay them, they offer to pay you.

this is because you cannot teach creativity, tenacity and intuition, and these are the qualities required to advance knowledge.

>>6368657
EU was started by crackpots. They didn't ask questions they proposed there own solution with no real theorist all or observational basis. It's just a string of thoughts that shrugs at the sight of a testable hypothesis. I don't object to questions I object to guesses which are announced as theory.

> If the electrostatic forces were taken into account in the original formulations of modern cosmology why are we just now asking this very basic question? Why has it taken so long to begin asking these questions?
This is not cosmology and the fact it is a field of study does not mean it was never considered anywhere in astronomy. That's a total fallacy.
Planetary formation is a hot topic at the moment, the fact it has new frontiers does not indicate ideas were ignored.

>Tesla's death ray was relativistically accelerated mecury ions.
There is no evidence of it ever existing.

>>6368690
I don't know how magnetic reconnection works but that isn't what I study. It is however the standard model of the solar flare. It doesn't matter to my research what the mechanism is.

>Isn't is simpler to suppose that the solar flare was the endpoint of a current flow?
How would this model explain the geometry of hard and soft x-ray flares (footprints, the coronal source) and their evolution? How does it explain the hard x-ray spectrum? How does it explain the observed shocks? How does it explain the connection to CME's and big flare syndrome? What is the energy source? How does it explain particle escape? How does it explain radio bursts and their as association with flares? What about microwave emission?... I could go on and on.

Your guess is not on a level playing field with the leading theory.

>>6368690
>please explain to me how "magnetic re-connection" works.
As I understand it, that's still open to debate

>>6368711
Magnetic reconnection isn't fully understood and there are unexplained questions about whatever dactyl triggers it. The 2D case is simple, 3D is however extremely complex. The acceleration mechanism isn't known but the possibilities are constrained.
It is an active area of research and here are experiments which look into it.

>>6368710
>It doesn't matter to my research what the mechanism is.
thank you for that bit of honesty.

now firstly that's a lot of questions but here goes

>How would this model explain the geometry of hard and soft x-ray flares (footprints, the coronal source) and their evolution?

I'm not sure

>How does it explain the hard x-ray spectrum?
I believe anon >>6367205 work in Electrostatic Ion Cyclotron radiation might shed some light

>How does it explain the observed shocks?
I'm not sure what "shocks" you are referring to, the shockwaves propagating on the "surface of the sun"?

>How does it explain the connection to CME's and big flare syndrome?
I would suppose the larger the flare the more energetic? and being more energetic it might actually cause significant mass to reach escape velocity?

>What is the energy source?
now here is the biggie... I have no clue except to say that fusion does create a net excess of ions and this "electric charge" does have to go somewhere.

>How does it explain particle escape?
again with sufficient added energy escape velocity is inevitable.

>How does it explain radio bursts and their as association with flares?
Bremmstrahlung in several flavors

>What about microwave emission?.
see above and >>6367160

I hope you have the "standard" answers to those questions so we can compare. I'm trying to be a positive contributor.

I have a few questions to ask in return.
Don't flares generally follow magnetic field lines?
Why is the corona so much hotter than the surface of the sun?
If you remember that you cannot always see an electrical current in space and ask yourself why does the surface of the sun look so similar to the surface of a "plasma globe" toy in action?


>when I'm wrong I learn something

>>6368711
>As I understand it, that's still open to debate
thank you anon, that is my understanding as well.

the attitude towards exploration of knowledge shown by

>>6368710
>>6368697
>>6368647
>>6368592
>Nonsense as always from the EU crowd.

is what we must all seek to avoid

>>6368767
Sorry, I feel I should specify - EIC waves are not a form of electromagnetic radiaton. Plasma waves are acoustic instabilities that forms in a plasma under certain conditions.

The dispersion relations for these waves emerge out of the introduction of electromagnetic forces to the equations which govern fluid dynamics.

I wish there was a bit more biology research here. I'm starting a project that determines the dynamic range of cortisol and glucose in a species of catfish when subject to stress, snake striking behavior differences with varying prey selection (frog or fish), and helping a buddy with endocrine disruption on developmental stages of tadpole.

My adviser thinks the catfish will be decent for a first publication. Hopefully it will help get into an MS program.

>>6368767
>>6368767
>I'm not sure
Well that's a big problem. The standard model gives us the cusp shape and explains footpoints and their motion....

>I believe anon >>6367205 work in Electrostatic Ion Cyclotron radiation might shed some light
It's almost certainly bremsstrahlung. Again another "I don't know".

>I'm not sure what "shocks" you are referring to, the shockwaves propagating on the "surface of the sun"?
Shocks are observed in flares and from flares in global events like Moreton waves.

>I would suppose the larger the flare the more energetic? and being more energetic it might actually cause significant mass to reach escape velocity?
Escape velocity is easy in a flare, the kinds of velocities you get in a CME are tiny compared particle acceleration in flares. They are distinct phenomena, they do not always occur together.

>now here is the biggie...
A very biggie given that we have a model that has no theoretical basis and no observational explanatory power.

>Bremmstrahlung in several flavors
Unlikely to be bremsstrahlung because the spectrum is not what you would expect. You get emission at the plasma frequency which says it's a plasma oscillation but now you have to drive that somehow.

The standard model has explanations for most of these but your model answers none. So why on earth would you suggest it's an easier explanation.

>>6368767
>Don't flares generally follow magnetic field lines?
I don't know what you mean by that. A flare is a magnetic restructuring that's for sure. The structure of the flare is driven by magnetism.

>Why is the corona so much hotter than the surface of the sun?
Either plasma waves or small flares, possibly both.

>If you remember that you cannot always see an electrical current in space and ask yourself why does the surface of the sun look so similar to the surface of a "plasma globe" toy in action?
Why can't we see the current? We can detect very slow electrons, I do that. We have mountains of data on that, even from outside the plane of the solar system, and they cover all directions. So where is this massive flux? Why do we see solar neutrinos if it's externally powered (don't quote me the solar neutrino problem, it's solved)? Why does helioseismology agree that it's hot on the inside?

>>6368795
I'm not sure I understand. I know about "plasma waves" but if it involves the gyro radii of these ions induced by the magnetic field (cyclotron radiation) how is it "acoustic" in nature? are you saying they have no EM component and are purely mechanical interactions between the coulombic forces between ions ?

Undergrad at liberal arts school, so can only really do research during summer. Last summer I looked at the antidepressant effects of acute ketamine--pretty cool stuff. I'll probably want to stay in depression/or mental illness for the future, but don't think I'll stick with ketamine (I'd be really interested to work with drugs that specifically induce neurogenesis, which is currently an emerging field)

>>6368821
>>Why is the corona so much hotter than the surface of the sun?
>Either plasma waves or small flares, possibly both.

aren't the flares cooler than the corona?
what mechanism would allow the plasma waves to heat the corona?

>Why can't we see the current?
small current densities are not "visible" there is a thing called "non glow mode plasma"

>>6368846
>aren't the flares cooler than the corona?
Why isn't an atomic bomb cooler than the ocean? Because it's a massive energy release, heating is one product.

>what mechanism would allow the plasma waves to heat the corona?
You can transport energy with a number of plasma oscillations, damping means energy is lost to the medium. I'm not an expert.

>small current densities are not "visible" there is a thing called "non glow mode plasma"
But we don't have to see things to detect them which is what I assumed you meant. We have specific instruments out there, right now, looking for electron and ion fluxes.
I don't expect to see them but why aren't we detecting them?

>>6368795
thank you anon I have learned. I had assumed the EIC wave had an EM component. Wow, so a plasma sings with a voice whose frequency(s) depends on the distribution of ion species. what pitch (frequency) does the dioxide monomer of carbon sing with?

Protein-ligand interactions via Molecular Dynamics simulation reporting in.

>>6368842
>Last summer I looked at the antidepressant effects of acute ketamine--pretty cool stuff.

Applied pharmacology experimentation is dangerous anon. When I went through my phase I had a world class pharmacy library I could easily access. The web is close these days as far as in-depth information but the signal to noise ratio is very high and many things are still proprietary (journals) and the information is hard to get even in libraries (restricted access). I was always fascinated by the fact I could hold a beaker of solution A in one hand and a beaker of solution B in the other and the instant I mixed them I committed a felony. Explosions, fires & weird chemical reactions I understand... but the law... sometimes just doesn't make a whole lot of sense. I was always inspired by the accounts of Albert Hoffman's bicycle ride home from the Sandoz labs that day he discovered that derivative of lysergic acid.

I'm still waiting for an answer to my question:
>>6368881

>>6368821
>Why do we see solar neutrinos if it's externally powered (don't quote me the solar neutrino problem, it's solved)?

I agree that the sun is not "electrically" powered. But I do think that there is more going on here than meets the eye so to speak.
That fusion is going on there cannot be much doubt. That the interior of the sun is hotter than it's surface is evident. But a good theory for why the corona is so much hotter than the surface or the interior is still lacking.

as anon>>6368881 said
> I don't expect to see them but why aren't we detecting them?

might be answered by are we perfectly certain we are looking with the correct methods?

>>6368942
>might be answered by are we perfectly certain we are looking with the correct methods?
You tell me, it's you who proposed this model with no motivation theory or observational basis.
You're looking for electron and ion fluxes, any current would need be these. Why wouldn't this detect these currents?

>>6368955
>Why wouldn't this detect these currents?
I'm not sure what "this" is, what methods are currently being used?
and what is
>electron and ion fluxes
I've heard of magnetic flux, I use flux when I solder/braze/weld, I've had the flux and seen things in flux but I didn't realize electrons and ions had fluxes.

I enjoy chatting with you anon, I've learned over the years that you do not truly understand an idea until you can properly defend it.

I think you were trying to say that looking for electron flows? they would indeed cause ion density changes and magnetic flux changes, but in the neighborhood of the sun these might be lost in the "background noise" and in the emptiness of intergalactic space unless the cross sectional area of the electron flow was very small it might have no visible effects except at the endpoints where it would be narrowed down and made visible by it's interactions with magnetic fields or regions of high ion density.

>>6369010
>I'm not sure what "this" is, what methods are currently being used?
A number of particle detectors Faraday cups, solid state detectors, electrostatic analysers... They detect particles.

>I didn't realize electrons and ions had fluxes.
A flux is something per unit area per unit time. Like particles per second per meter squared.
I mean what I said.

> they would indeed cause ion density changes and magnetic flux changes
No. You're claiming there's a current which could very well be steady state and would cause changes. If it's a current it has charge flowing. We can detect fluxes of charged particles.

>in the neighborhood of the sun these might be lost
How is this "model" superior to dark matter and the like? We should call them "dark currents" except unlike dark matter we have no idea what is required of them or if they could actually explain a damn thing. You don't know if this could work but for that doesn't bother you.

This model explains absolutely nothing, makes no testable predictions and has no basis in established observation. It's horseshit.

>>6369043
>would NOT* cause changes

>>6368840
>>6368896
Yes - plasma waves are acoustic. Just like sound waves they're characterized by compression and rarefication in a fluid.

The difference is that plasma waves take place in a charged fluid whose constituents are subject to electromagnetic interactions. Imposing different conditions on the electric and/or magnetic field components present yields different dispersion relations.


If you want to see some really neat examples of the acoustic nature of plasma waves, check out some of the data from the Voyager 1 mission
http://www.youtube.com/watch?v=sOjesIhqb6o
http://www.youtube.com/watch?v=LIAZWb9_si4

I'd also suggest looking up some of the plasma wave recordings from some of the Earth orbiting missions.

Epigenetic oxidative stress, also neurogenises and its own propagation of synaptogenic growth

I'M LOOKING INTO THE PSYCHOLOGICAL PATTERNS OF JOKE TELLING IN A COMPLETELY SEMI-MATHEMATICAL WAY

>>6368924
The research was NIH-funded--DEA allows its use in medicine/research

Yeah, then it's not in situ. That's the point I was trying to make. "In situ" means you perform the measurement in the location that the event occurs, i.e. in the solar flare.

Sure, you can measure the particles, but that doesn't make it in-situ (unless the solar flare itself extends out to the spacecraft/satellite where the measurement takes place).

>>6368842

SLACs are great; a lot of neckbeards think that "liberal arts college" means "you only learn liberal arts" but a lot of the top SLACs and engineering SLACs (Rose-Hulman, Harvey Mudd) have some of the best undergraduate math/science instruction, and you get a lot of one-on-one time with advisors.

Too bad most of the SLACs cater to rich white kids in New England prep schools, and economics is one of the top majors at Williams, Amherst, and the like. Most of the kids go to Wall Street, while math/science/engineering are mostly made up of first generation college students and international students.

>>6369043

Yup. flux of something is dsomething/dt.

>>6369048
thank you Carl for you answers.
what is the EIC wave frequency for CO2 ?

>>6368136
>Yes, different ions have different EIC spectra,

I'm trying to follow this. I watched the vids in >>6369048 and had seen the upper one b4 but in watching the lower one
>http://www.youtube.com/watch?v=LIAZWb9_si4

In it was the statement that the frequency would vary with the density of the ions. Does it also vary with magnetic field intensity?
I was wondering if my question about the frequency that the CO2 exhibits in your experiments mentioned in >>6367205 is kind of meaningless in this regard, because it's not a single frequency but an aggregate of frequencies sounded simultaneously?
Help me to see if I understand this.
When you said
>different ions have different EIC spectra
Can I take that to mean a multiple frequency "fingerprint" of sorts. Where the interval(s) between the individual frequencies involved is what is unique to each ion species. Such that when the density changes or some other factor changes and the "frequency of the wave" shifts the corresponding interval relationships are maintained?

Much as a "major chord" is always discernable from a "minor chord" no matter what key it is played in.

>>6370051
>>6370249
Hi, sorry to not get back to you sooner, I'm in the middle of getting ready to leave for work so I'll try and give you a more complete answer in a bit.

Yes - EIC frequencies depend heavily on magnetic field strength, as well as having a slight dependency on density and other factors.
>>6368055
The cyclotron frequency is the dominant part of the dispersion relation (and depends on the mass of the ion, the charge, and the magnetic field strength), the second largest contributor in the dispersion relation is the part which depends on the perpendicular component of the wave number, and the sound speed (which depends largely on ion temperature and density), the higher order terms mostly just lead to broadening and offsetting in the EIC spectra and don't have a huge impact on the actual peak frequencies unless you go to drastically different densities, temperatures etc.

Yes - EIC spectra are like 'chords' in that the spectra is composed of a fundamental and successive harmonics, which are unique to a given ion species.


I will post more and try to include some actual data within the next hour or two but I've really gotta run right now.

>mfw this thread
actual science on a science board... who woulda thunk it possible!?

>>6370288

So, if I'm following you, the "spectra" consists of several fundamental frequencies accompanied by associated harmonics. And the experiment showed the introduction of neutral gasses dampens these harmonics. Did this make it easier to discern the fundamentals?

Since you are using a magnetic field to excite this "cyclotronic" motion in the CO2 ions is there a radiated EM associated with the motion or are you keeping the energies below that required for this radiation to occur?

Is the "bias" on the Langmuir probe of a particular waveform, polarity etc… and does modulation of this "bias" have an effect on the "excitation" of the waves?

I hope I'm not asking too many questions but this is very interesting to me.

I have a further question about
>the second largest contributor in the dispersion relation is the part which depends on the perpendicular component of the wave number

"dispersion relation" does this mean how the energy from the cyclotronic motion of the ion is transfered to the acoustic plasma wave?

"wave number" is describing what? I'm pretty sure it's more than just the number of waves per unit something.

>>6368227
sorry I took so long to reply. i'm studing applied mathematics and applied physics. outside of school I am learning the pure sides of both maths and physics while touching some astronomy/cosmology.

>>6369043
>We can detect fluxes of charged particles
I understand, but with
>Faraday cups, solid state detectors, electrostatic analysers... They detect particles.

aren't they all subject to being in the flow? and all this presupposes all the energy is in a DC form. ITT information about the process whereby plasma "sings", we all know great power can be transmitted from place to place with no "charge flow" just harmonic motion of the ions is all that is needed.

I will agree with
>It's horseshit.
from the standpoint that it's a great fertilizer

>>6370680
The biases on the Langmuir probe (at least for the experiments we've been doing) are DC biases. When taking normal probe characteristics in order to check things like ion density, temperature, etc - we typically using a ramping DC bias that runs ±10 V (sometimes a wider range if necessary). When exciting waves we pick a fixed DC bias to excite the waves.


Wave number is just another means of measuring the wavelength of the acoustic waves.
<span class="math">\omega = 2 \pi f[/spoiler]
<span class="math">k = 2 \pi / \lambda[/spoiler]


A dispersion relation, just like in electromagnetism, describes the dispersive behavior of the waves, what frequencies the waves will oscillate at, etc.


I've attached a quick animation of what the signal from the langmuir probe looks like when we run it through a spectrum analyzer. The y axis isn't calibrated but the x axis is calibrated to the frequency in kHz. The sequence starts at about 0.6 T and runs up through 3.4 T

I guess I should divulge my situation since I am curious. I'm a 19yo HS drop-out in the process of getting my GED, and I basically did fuck all in math class for just about all of my time in public school.. and I really want to go into physics for astro and shit

Is it too late for me? Should I just not even attempt to learn the years worth of mathematical practices that I slept through?

I am going to apply to my community college soon and I just don't know if I should waste my effort if its too late for me

also this is probably the wrong thread to ask in

>>6371070
thank you very much Carl.

in regards the analogy of music what I saw in the gif was not a "chord" it was a "fundamental with overtones".

I'm confused about the bias being ramped (a slow rise over a period of seconds?) during normal operations and a steady DC bias being responsible for the excitement of waves.

>>6371081
I've heard good things about Kahn academy
It's never too late to learn anon, the GED is a start and I wish you all the best.

>>6371102
Yes, sorry, overtones was what I was thinking of.


Applying a bias to a Langmuir probe creates a relative drift between negatively and positively charged particles in the plasma which creates a current that the probe can measure.

Applying a ramping voltage from negative to positive produces what we call a characteristic, which can reveal properties of the plasma - the flat part in the negative part of the graph corresponds to the ion saturation current and can be used to determine the ion density in the plasma, the shape of the curve can be used to determine electron temperature, etc

>>6371161
Is the y axis calibration off or is the current negative?
The region from A to B is what you use to determine " ion density?
I'm guessing by shape of the curve you mean slope between region B & C as well as the point of inflection B in relationship to the voltage?
The area beyond C is the chaotic region that produces the waves ?

>>6371243
oops
>pic related to above post

>>6371161
I knew I'd seen that graph (not the one you just posted) relationship before. I'm trying to recall what the area of hysteresis is between area D E & F in this graph
>pic related

it's the same graph relationship that you present only extened to show further modes and the axis for current and voltage are exchanged.

>>6371243
Yes

Yes

Specifically the curve right around B where it starts to transition away from the ion saturation current.

The area beyond C is the electron saturation current, which usually has a lot of thermal noise in it. When we bias the probe at a high enough positive voltage all you get is the electron part of the characteristic and you can excite the EIC waves.

>>6371274
so basically the EIC waves happen in the area of "Townsend discharge"?

thank you for your replies and I have one further question.

Is there part of that gif you posted that is characteristic of CO2 specifically?

>>6371365
The gif I posted is strictly Cesium, nothing else.

As I said - the results of our CO2 tests were inconclusive since Cesium has almost exactly three times the mass of CO2 - meaning even if negative CO2 ions were being formed, we wouldn't be able to identify the peaks in the spectra from them.

I used to have some comparisons from the tests we did with SF6 if you wanted to see how the addition of negative ions changes the spectrum, but I don't know if I still have any of that data.

>>6371365
The gif I posted is strictly Cesium, nothing else.

As I said - the results of our CO2 tests were inconclusive since Cesium has almost exactly three times the mass of CO2 - meaning even if negative CO2 ions were being formed, we wouldn't be able to identify the peaks in the spectra from them.

I used to have some comparisons from the tests we did with SF6, if you wanted to see how the addition of negative ions changes the spectrum, but I don't know if I still have any of that data. If I find it I'll be sure to post it.

>>6371390
>>6371274
Carl, where can I get your 13 part series without having to pay an ass load of money? Jewtube took down all your episodes

>>6371390
thank you again Carl. If more anons would at least attempt to achieve your level of civility this board would be greatly improved and if only a tiny fraction would post with the quality of information you have provided /sci/ could make a very positive difference in the world.

On a related subject, how do you feel about the Open Access Journal idea?

Five-star thread guys, keep it up.

Don't be nervous - tell us all about the neat stuff you're working on!

How common is it to get involved in research as an undergrad? Is it recommended? Should you start early or wait until you've got some more advanced coursework under your belt?

>>6366786
Explained an previously unknown mechanism for vesicle differentiation in cells, opens up whole new pathways for specialisation without requiring complicated protein interactions. Its also a strong contender for vesicle pools in synapses.

Paper pending (nat. chem. bio.). Shitstain of a PI didnt want to give me a PhD anyhow. Anybody out there hiring?

>>6368047
Hello Carl, more questions from a curious mind.

I've been trying to firmly wrap my head around these EIC waves. I was wondering, since the gyro radius is determined by the mass of the particle (among other things) would the various isotopes be discernable via this method?

The "shear driven component" you speak of, this is part of the mechanism that imparts the acoustic energy to the wave from the cyclotronic motion of the ions?
Are these waves in part a result of the synchronization of the motions of the population of ions?
I'm not sure if this is phrased correctly but, is the motion of the wave perpendicular to the axis of drift?

>>6372237
Non-bio here, could you go into a little more detail about what these vesicles do and what your mechanism changes? It sounds interesting.

>>6372235
you need to ask this guy
>>6368047
>>6367205

from what he's said and what I gather it's a matter of inerest, talking to the professors and just plain doing it. If you go in expecting to lead a team you will be in for a rude awakening, but if you are willing to count buttons and sort paperclips (grunt lab work) it seems to be fairly easy in most institutions.
It's mostly about how interested and motivated you are.

>>6372243
Pub. pending, so I you will have to forgive me if I dont go into too much detail.

Basically its a fundamental aspect of vesicles that doesnt directly depend on proteins. Its unheard of in any of the literature, my (former) group has been sitting on it for a couple years, with the correct guess but no definitive evidence, and I cracked it while doing my masters thesis.