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I'm a Particle Astrophysicist, ask me anything
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Tikktokk Tokkzikk
V0LTA
WE FORM V0LTA
#221 - 2012-02-21 04:11:59 UTC
Are all the eve weapons possible? Such as explosive missiles?
Tsadkiel
Aliastra
Gallente Federation
#222 - 2012-02-21 14:44:24 UTC
Selinate wrote:
Tsadkiel wrote:
Selinate wrote:
Tsadkiel wrote:
Amaroq Dricaldari wrote:
Are the Replicators from Stargate scientifically possible to build with any level of technology?


self replicating machinery is one of the holy grails of modern robotics. there have been several attempts at this in the past and the link is one i have heard the most about. as for the replicators themselves, there are strict limits that our current understanding of thermodynamics places on the minimum size of mechanical devices. as you make something smaller and smaller the heat of the thing plays a larger and larger role in its operation. heat is just a measure of "vibration" in an object and when something gets small enough, these vibrations can literally tear it apart. that said, who knows! there may very well be compounds out there that are exceptionally heat resistant and this may allow us to produce such nanoscale devices.



...No it's not.

"Vibration" in an object isn't even a truly correct explanation of temperature. But to use this explanation to describe heat?

....*suspicious*


ah! yes. you are correct. i have misused a term here. i did mean temperature, thank you. i will edit my post to correct it.

temperature is proportional to a systems mean kinetic energy. in solids, which have restricted degrees of freedom, this manifests as molecular vibration. this is the vibration i am referring to in my post. at small scales, these vibrations can destroy complex structures and is one of the primary obstacles to overcome in the development of nano scale technologies.


I cringe every time temperature is described as vibrations though, since when things get down to the atomic level, the describing their kinetic energy as simply vibrations is just a bit simplified....



very true as well, but as i stated in my original post, i am trying to get better at explaining science to people, especially those who may not have a background in it. i thought that molecular vibration was the best way to convey the idea of temperature causing thermal noise and why it is an issue when trying to create nanoscale technologies.

if you have a better description of it for the general reader i would really like to hear it! and no, i'm not trying to be an ass or anything. i am honestly interested =D
Lexmana
#223 - 2012-02-21 15:56:00 UTC  |  Edited by: Lexmana
Great thread. Who said science is not entertaining?

I would like to hear your opinion on the: Faster-than-light neutrino anomaly.
Was Einstein wrong? What are the possible implications? E=MC^2?

http://press.web.cern.ch/press/PressReleases/Releases2011/PR19.11E.html

Tsadkiel wrote:
both men have excellent points of views on the nature of science, but i consider myself to be a sophisticated falsifiacationist, so i would lean towards Kuhn. the ability for a theory to be proven false is CENTRAL to the very definition of what a scientific theory is.


Actually, it was Popper who put forward the idea of falsification as a solution to the problem of induction and being able to find support for most theories even if they were wrong. Kuhn was the one discussing "normal science", anomalies and paradigms.

Tsadkiel wrote:

we KNOW that Gravity and Evolution are true. why? because they are THEORIES. we have VERIFIED the associated HYPOTHESIS.


The nature of Poppers falsification paradigm is that nothing can be proven to be true (only corroborated) but a good theory can be proven wrong. Who knows, some day someone might put forward a new theory that better explain gravity. I believe it happened to Newton once.

Tsadkiel wrote:
Quote:
To put it rather bluntly (and make it sound far more trivial than it truly is), a lot of theoretical physics amounts to "this is our best guess until we get more data".


it's more like "these are the only explanations that fit the current data".


With "current data" do you mean all the data collected by everyone or are you sometimes excluding data that you can't explain? And by "only explanations" do you mean that a better explanation cannot surface tomorrow unless there is new data?

And finally, what do you think of this paper using Bayes theorem to "prove" (not really) that most published research findings are false. (not related to physics though)

http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0020124
rodyas
Tie Fighters Inc
#224 - 2012-02-21 22:28:13 UTC
Tsadkiel wrote:


very true as well, but as i stated in my original post, i am trying to get better at explaining science to people, especially those who may not have a background in it. i thought that molecular vibration was the best way to convey the idea of temperature causing thermal noise and why it is an issue when trying to create nanoscale technologies.

if you have a better description of it for the general reader i would really like to hear it! and no, i'm not trying to be an ass or anything. i am honestly interested =D


Yeah this is kind of interesting. The way I see it is that temperature(heat) is a big barrier to nanotech. Also we are surrounded by temperature, so I see why that is brought up first over the atomic level.

So if we did take away temperature being a barrier, and then free to focus on the kinetic energy at the atomic level. Would like to hear more on that, I dont know much about that.

Signature removed for inappropriate language - CCP Eterne
Tsadkiel
Aliastra
Gallente Federation
#225 - 2012-02-22 02:02:51 UTC
Lexmana wrote:
Great thread. Who said science is not entertaining?

I would like to hear your opinion on the: Faster-than-light neutrino anomaly.
Was Einstein wrong? What are the possible implications? E=MC^2?

http://press.web.cern.ch/press/PressReleases/Releases2011/PR19.11E.html


a couple of things here. even if we confirm the existence of FTL neutrinos, einstein wasn't "wrong". we may need to modify special and general relativity, but those theories have made some of the most precise and useful predictions in the history of science. to call such theories wrong is too broad and general a statement i think, especially when the natural course of science is self examination and correction.

that said, there has yet to be a repeat of the OPERA experiment to confirm their results. we have dissuading evidence in the form of high energy neutrinos created from supernovae (which arrive after the light of the novae), but these neutrinos are created in and travel through environments different to those in the aforementioned experiment. the effect may be a specific result of neutrinos traveling through dense matter, or perhaps from them passing through some random bit of extra dimensional space. long story short, there is not enough evidence yet to say either way.

if it WERE found to be correct, this would be the starting discovery for all things FTL (communicaiton, travel, etc...)

Quote:

Actually, it was Popper who put forward the idea of falsification as a solution to the problem of induction and being able to find support for most theories even if they were wrong. Kuhn was the one discussing "normal science", anomalies and paradigms.


i always get them confused, and my grades in my philosophy of science class show it.

Quote:

Tsadkiel wrote:

we KNOW that Gravity and Evolution are true. why? because they are THEORIES. we have VERIFIED the associated HYPOTHESIS.


The nature of Poppers falsification paradigm is that nothing can be proven to be true (only corroborated) but a good theory can be proven wrong. Who knows, some day someone might put forward a new theory that better explain gravity. I believe it happened to Newton once.


i think it is important to keep in mind the context of the discussion you are quoting. long story short, i get PISSED when people use "it's just a theory" to try and disprove evolution and the like, so i got ahead of myself here. a better statement would be, we KNOW that Gravity and Evolution are NOT FALSE. we know that they are not false because they allow us to make accurate predictions. this is not the same as saying that they are true because it allows for the possibility of future modification of the theory.


Quote:

With "current data" do you mean all the data collected by everyone or are you sometimes excluding data that you can't explain? And by "only explanations" do you mean that a better explanation cannot surface tomorrow unless there is new data?


by data i mean repeatable data, observations, and experiments. the key thing here is the repeatable bit. data can be excluded under very specific conditions that you must define before you start the experiment in question. these definitions are used to determine whether or not a datum can be considered an outlier and excluded. all physical measurements are reported with an uncertainty based on this definition, and we even have statistical methods allow us to calculate our confidence in a specific theory when applied to make predictions in a given experiment. that is to say, when a theory is experimentally tested, it is usually reported as "we have shown that the theory agrees with the results with a confidence level of 98%" or whatever was deemed acceptable by the investigators. even with lower confidence levels, as long as everything is reported, it is still valid science.

as for your second question, no, i don't think so. data is data. as long as the methods of its collection is properly reported and accounted for, a new theory can use it. whether or not the new theory is useful or valid is another question.

as for your last question this will take some time to read, but it is VERY interesting
Tsadkiel
Aliastra
Gallente Federation
#226 - 2012-02-22 03:58:14 UTC  |  Edited by: Tsadkiel
tikktokk tokkzikk wrote:
Are all the eve weapons possible? Such as explosive missiles?


i don't see any immediate physical principles that would prevent them. most of the weapons in EVE currently exist. a notable exception are hybrid weapons as they are described in the lore. the game describes such devices as firing spheres of super heated plasma. blasters may very well be some kind of plasma cannon, which could be possible, but railguns are real and work in a very different fashion.

Railguns are actually currently being tested by the US military. they function based on a principle from classical electrodynamics called Faraday's law of induction, which relates a change in magnetic flux to an electromotive force (this is a direct manifestation of something called Lenz's Law, which is used to determine the sign and direction of the aforementioned force without the use of mathematics). the design of a basic railgun consists of two long conducting rails, a conducting projectile that rests between them, and a large and FAST power supply. the rail-projectile-power supply form a complete circuit, and when current is passed through it, it creates a magnetic field. this means that the magnetic flux through the area enclosed by the circuit is increasing. this induces an EMF via Faraday's Law of Induction such that the projectile accelerates in such a way as to increase the area enclosed by the circuit (this force can be found exactly with a dash of vector calculus and a touch of Stokes Law. the result is the classic Lorentz force equation, F = q( E + v X B) ). railgun projectiles can reach TREMENDOUS speeds, to the point where the friction forces between the projectile and the atmosphere is enough to ignite the air itself! unfortunately, the accelerating force pushing the projectile also pushes the rails outwards... current prototypes can fire only a finite number of times before the rails are so deformed that the weapon ceases to function.

i actually tried to build my own rail gun when i was a sophmore. i was able to show that i could significantly cut the power requirements of the device by making the projectile roll along the rails, instead of slide. what i didn't take into account was that the rolling would create point contacts on the rails (spherical bullet on cylindrical rails)... so i made a very good arc welder heheheh
Tsadkiel
Aliastra
Gallente Federation
#227 - 2012-02-22 17:40:39 UTC
Sturmwolke wrote:
Got one, http://www.rexresearch.com/maxwell.htm
Your comments on this?


ok so, after reading what i could find on the site i think this is probably (practically certainly) bunk...

the author is one Thomas E. Bearden. he links his paper "proving" his ideas on the website, but the paper in question not only offers no real logical basis for its claims, but also no evidence. furthermore, the claims fly directly in the face all the evidence that has been accumulated to the contrary... the vast majority of the paper is him quote mining other papers to support his idea, a logical fallacy known as a "plead to authority". all interviews i can find with the man show him outright refusing to explain counter examples put forth by other people (the existence of polarization being the most glaring and obvious counter to his ideas). his "free energy" machine appears to be nothing more than a transformer with a permanent magnet core and some actuated coils tacked on... i could go on and on and on with this...

to be blunt, this guy appears to be the EM equivalent of the time-cube guy: "I'm right! You're wrong! And anyone who disagrees is a part of the conspiracy!"
Tikktokk Tokkzikk
V0LTA
WE FORM V0LTA
#228 - 2012-02-22 18:21:15 UTC
And what about the fire that comes from the hull when you get into structure? Is that also possible?
Professor Alphane
Les Corsaires Diable
#229 - 2012-02-22 18:40:34 UTC  |  Edited by: Professor Alphane
How is gravity measured, I've seen pictures (heat maps) of variance in Earths gravity field, but don't really understand a couple of things. How do we 'perceive' gravity and is there any explanations for these discrepencies?

Also the sun is made mostly of hydrogen apparently, atomically one of the lightest things, they explain this as 'it's under great pressure' , how many more hydrogen atoms fit into the same space in the sun when compared to hydrgoen at atmospheric pressure.

/edit haven't taken in the whole threadnaught yet so sorry if this has been asked before

[center]YOU MUST THINK FIRST....[/center] [center]"I sit with the broken angels clutching at straws and nursing our scars.." - Marillion [/center] [center]The wise man watches the rise and fall of fools from afar[/center]
Sturmwolke
#230 - 2012-02-22 20:11:52 UTC
Tsadkiel wrote:

ok so, after reading what i could find on the site i think this is probably (practically certainly) bunk...


Perhaps. Generally, imo, his writings are a little bit too detailed from the average folks that are into the "fringe" free energy research. The average scientists are usually quick to dismiss something un-conventional, basing their proofs from the conventional theories - ignoring empirical results (usually as random chance). You can go around in circles not finding anything when the fundamental flaws are the conventional equations trying to explain the un-conventional.

I was piqued by the FTL neutrinos announcement and claims of a debunk from the folks at Imaging Cosmic and Rare Underground Signals (ICARUS) - basing it on the energy level of the neutrinos (Cohen–Glashow effect - a sort of Bremsstrahlung loss for neutrinos). Problem with that is no one actually knows what happens to neutrinos at speed >= c. Think about it, when you apply Newton's theories to relativity, it won't fit ... however, it's still valid for lesser systems. Essentially, the ICARUS's debunk, imo was only a confirmation there was no bremsstrahlung loss for superluminal neutrinos detected ... and that's about it.
rodyas
Tie Fighters Inc
#231 - 2012-02-22 20:36:34 UTC
tikktokk tokkzikk wrote:
And what about the fire that comes from the hull when you get into structure? Is that also possible?


The ships have crews onboard, which means they need oxygen to breathe, which means at hull O2 would release and fires would start. Or if after that an explosion. Some oxygen in a pod as well so explosion could happen there.

Signature removed for inappropriate language - CCP Eterne
Tsadkiel
Aliastra
Gallente Federation
#232 - 2012-02-22 22:17:49 UTC
on the topic of FTL neutrinos, this just in!

http://news.sciencemag.org/scienceinsider/2012/02/breaking-news-error-undoes-faster.html

turns out one of the computers had a bad fiber optic connection. it is likely this is the cause, as it would modify the times used to calculate the time of flight of the beam.
Professor Alphane
Les Corsaires Diable
#233 - 2012-02-23 14:47:39 UTC
If your still answering questions could you take a look at post #229.

If not looks like a fun thread will check it all out when I get the chance Blink

[center]YOU MUST THINK FIRST....[/center] [center]"I sit with the broken angels clutching at straws and nursing our scars.." - Marillion [/center] [center]The wise man watches the rise and fall of fools from afar[/center]
JinSanJong
Doomheim
#234 - 2012-02-23 15:07:24 UTC
Ok herees a few to chew on m8

1) Big Bang Theory - What a load of old rubbish? Right? - I mean really...All of a sudden there was on bang and wow the universe was created..Please.... Its worse than saying god made the world in 6 days.. If the universe was suddenly created, then what was it created INTO.. surely there was a universe in the first place...(i know its mental)

2) Why do scientists insist on saying - "Hmm we not sure there is life anywhere else" - Surely they cant be so dumb or arrogant t believe we are the only life in the universe! There are BILLIONS of stars just in our galaxy, all with potential planets. Then there are millions of galaxies. I mean we cant even get the nearest planet! never mind nearest star..

3) Do you think that neutrinos really can go faster than light, or was that a messed up test (all 15000 of them) they are now saying there could of been sme GPU glitch! Hmmm im not so sure..

4) Why do we take theories so literal, when they are only theories...
Tsadkiel
Aliastra
Gallente Federation
#235 - 2012-02-23 15:38:51 UTC
tikktokk tokkzikk wrote:
And what about the fire that comes from the hull when you get into structure? Is that also possible?


I can't see why not. the actual fire part of a fire is a low temperature plasma. so if the fire is inside the ship and there is a hull breach, the plasma, smoke, and other debris can be vented into space.
Tsadkiel
Aliastra
Gallente Federation
#236 - 2012-02-23 15:57:22 UTC
Professor Alphane wrote:
How is gravity measured, I've seen pictures (heat maps) of variance in Earths gravity field, but don't really understand a couple of things. How do we 'perceive' gravity and is there any explanations for these discrepencies?

Also the sun is made mostly of hydrogen apparently, atomically one of the lightest things, they explain this as 'it's under great pressure' , how many more hydrogen atoms fit into the same space in the sun when compared to hydrgoen at atmospheric pressure.

/edit haven't taken in the whole threadnaught yet so sorry if this has been asked before



most of those heat maps are result of direct measurements of the local gravitational acceleration, g. this is usually done with something called a Gravimeter. they are basically very high precision accelerometers. there are a number of effects that need to be taken into account when measuring gravity. relative altitude is one factor, because the force due to gravity decreases as 1/r^2, where r is the distance between the masses of interest. because of this we see that the acceleration due to gravity on top of mount Everest is ever so slightly smaller than that measured in death valley. another factor to account for is the fact that the earth rotates, and so every object on the earth carries an angular and linear acceleration. because of this we measure a change in gravitational acceleration as we move from either pole towards the equator. this effect on the acceleration is similar to the changing acceleration on a roller coaster as it goes through a loop. there are other effects as well, but these are the two big ones we can calculate. once these are accounted for, the resulting map is a direct measure of the specific gravity (density) of the material underneath the meter. this allows us to use gravitational measurements to "scan" the earth for resources like oil or rare minerals and elements.

as for your question about the sun, i don't know off the top of my head. i would have to calculate it, but the difference would be A LOT. the important thing to understand is that the "pressure" you are referring to is caused by gravity pulling the mass of the sun towards the center. hydrogen is the lightest of the elements, so to get a large enough pressure at the center to initiate fusion you need a great deal of it.
Tsadkiel
Aliastra
Gallente Federation
#237 - 2012-02-23 16:01:18 UTC
Sturmwolke wrote:
Tsadkiel wrote:

ok so, after reading what i could find on the site i think this is probably (practically certainly) bunk...


Perhaps. Generally, imo, his writings are a little bit too detailed from the average folks that are into the "fringe" free energy research. The average scientists are usually quick to dismiss something un-conventional, basing their proofs from the conventional theories - ignoring empirical results (usually as random chance). You can go around in circles not finding anything when the fundamental flaws are the conventional equations trying to explain the un-conventional.

I was piqued by the FTL neutrinos announcement and claims of a debunk from the folks at Imaging Cosmic and Rare Underground Signals (ICARUS) - basing it on the energy level of the neutrinos (Cohen–Glashow effect - a sort of Bremsstrahlung loss for neutrinos). Problem with that is no one actually knows what happens to neutrinos at speed >= c. Think about it, when you apply Newton's theories to relativity, it won't fit ... however, it's still valid for lesser systems. Essentially, the ICARUS's debunk, imo was only a confirmation there was no bremsstrahlung loss for superluminal neutrinos detected ... and that's about it.


but he provides no empirical evidence... and he claimed he needed at least $11 million to start manufacturing his device, WITHOUT a working prototype (he claims it was destroyed shortly after he tested it)

as for the neutrinos, newtons laws have nothing to do with the predictions made by ICARUS. the just found dissuading evidence and put forward a hypothesis that may explain the effect.
Tsadkiel
Aliastra
Gallente Federation
#238 - 2012-02-23 16:26:38 UTC
JinSanJong wrote:
Ok herees a few to chew on m8

1) Big Bang Theory - What a load of old rubbish? Right? - I mean really...All of a sudden there was on bang and wow the universe was created..Please.... Its worse than saying god made the world in 6 days.. If the universe was suddenly created, then what was it created INTO.. surely there was a universe in the first place...(i know its mental)

2) Why do scientists insist on saying - "Hmm we not sure there is life anywhere else" - Surely they cant be so dumb or arrogant t believe we are the only life in the universe! There are BILLIONS of stars just in our galaxy, all with potential planets. Then there are millions of galaxies. I mean we cant even get the nearest planet! never mind nearest star..

3) Do you think that neutrinos really can go faster than light, or was that a messed up test (all 15000 of them) they are now saying there could of been sme GPU glitch! Hmmm im not so sure..

4) Why do we take theories so literal, when they are only theories...


wow, obvious troll is obvious :p

1) oh man, yep! you totally caught us! we've NEVER even THOUGHT about anything like that before! well done!

2) it's actually a massive international conspiracy. you see, all scientists secretly serve the all mighty Zod, lord of the two dimensional slaughtering rat people! we keep ET on the down low so we can prepare you for the cheese and pestilence filled invasion to come!

3) i think neutrinos are secretly your mom.

4) FFFFFFFFFFFFFFFFFFFFUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU *explodes*
rodyas
Tie Fighters Inc
#239 - 2012-02-23 19:12:47 UTC  |  Edited by: rodyas
Sorry, but that invading troll bit me and now have a fever in my blood.

Does physics explain why minorities are easier to teach physics to? Even Stephen Hawking is looking for a black Albert Einstein.

Also wondering, what profession you are looking at going into once the Ph.d is over with? Suppose with you handling trolls well, maybe a teaching one perhaps.

Edit: Also what is a Particle Astrophysicist? Don't think I have heard of those put together before. Keep thinking of particles in space and how they operate or function.

Like you would handle the particle accelerator in space or something, rather then one on earth.

Signature removed for inappropriate language - CCP Eterne
Tsadkiel
Aliastra
Gallente Federation
#240 - 2012-02-23 20:25:01 UTC
rodyas wrote:
Sorry, but that invading troll bit me and now have a fever in my blood.

Does physics explain why minorities are easier to teach physics to? Even Stephen Hawking is looking for a black Albert Einstein.

Also wondering, what profession you are looking at going into once the Ph.d is over with? Suppose with you handling trolls well, maybe a teaching one perhaps.

Edit: Also what is a Particle Astrophysicist? Don't think I have heard of those put together before. Keep thinking of particles in space and how they operate or function.

Like you would handle the particle accelerator in space or something, rather then one on earth.


i don't know if the whole physics-and-minorities thing is true (i haven't heard anything about it before) but if it is, i would have to attribute it to work ethic. i would say it is downright common for minorities to encounter hostility and adversity in society while growing up. this could be a motivation to work towards whatever it is that person wants to do, to "prove" themselves.

as a gay guy i definitely felt this in high school. it sucked. i hated pretty much everyone there. i've always had a love for science and especially physics, and i used that as an outlet. i worked my ass of to get to where i am today, and the fact that i didn't feel like i fit in anywhere helped push me. i wanted to be better than them.

on a side note: when i tell people what i do i usually get things like "wow! you must be really smart!" or "hey! you must be great at math!". this is bullshit. i'm terrible at math and i am TURBO stupid sometimes (if you knew the number of times i have almost been hit by a car...). but i love what i do and i work hard to be good at it. if anyone here is thinking about getting into the sciences, don't sell yourself short. if you want to do it, do the work!. don't make excuses. do what you love, love what you do, and work at it! you will be fine! =D

as for what i want to do, i have thought a great deal about setting off on the path to professorship because i do enjoy teaching. i've been teaching labs/recitation and tutoring for about 6-7 years now. it's a good time! but i also have been thinking a lot about industrial R&D or software design. i love programming (i do it for fun all the time) and most corporations have much better funding than most universities. also, most industrial R&D would require me to learn new science and i really REALLY enjoy that.

as for your last bit: a particle astrophysicist is someone who does both particle physics and astrophysics (and specifically use the former to help with the latter and visa versa). so i examine particle interactions like the ones produced at CERN, but instead of producing the particles myself, i use natural sources like supernovae, gamma ray bursts, and active galactic nuclei. some of these sources produce particles with energies far FAR beyond anything we can make on earth, and so this gives me an opportunity to study particle interactions i may never otherwise see. the nature of the particles i observe also gives me information about the source that produced them, so i get to examine the physics there as well!