OVER THE PAST YEARS WE HAVE WITNESSED COSMOLOGY TRANSFORM INTO PRECISION SCIENCE AND HAVE SEEN A STANDARD MODEL OF BIG BANG COSMOLOGY EMERGE. NEW DATA IS CONTINUOUSLY BECOMING AVAILABLE TO TEST THIS MODEL AND IMPROVE OUR UNDERSTANDING OF THE EARLY UNIVERSE. ONE OF THE BIGGEST OUTSTANDING CHALLENGES IS TO UNDERSTAND THE ORIGIN OF THE MINUTE PRIMORDIAL DENSITY FLUCTUATIONS WE INFER FROM MEASUREMENTS OF THE COSMIC MICROWAVE BACKGROUND (CMB). THE LEADING PARADIGM FOR THE GENERATION OF THESE PRIMORDIAL PERTURBATIONS IS INFLATION A PERIOD OF NEARLY EXPONENTIAL EXPANSION OF THE UNIVERSE CAUSED BY ONE OR SEVERAL SCALAR FIELDS. IN ADDITION TO THE OBSERVED DENSITY PERTURBATIONS THE SIMPLEST MODELS OF INFLATION ALSO PREDICT A MODERATE AMOUNT OF TENSOR PERTURBATIONS OR PRIMORDIAL GRAVITATIONAL WAVES WHICH IMPRINT A CHARACTERISTIC POLARIZATION PATTERN ONTO THE CMB. TO DISTINGUISH BETWEEN DIFFERENT HISTORIES OF THE VERY EARLY UNIVERSE SEVERAL CMB EXPERIMENTS ARE CURRENTLY SEARCHING FOR THIS POLARIZATION PATTERN AND MORE WILL BEGIN TAKING DATA SOON. ONE OF THESE EXPERIMENTS BICEP2 RECENTLY REPORTED THE DETECTION OF BMODE POLARIZATION ON DEGREE SCALES AT 150 GHZ AND ATTRIBUTED THE MEASUREMENT TO THE EXISTENCE OF PRIMORDIAL GRAVITATIONAL WAVES. THE OBSERVED EXCESS B-MODE POLARIZATION WAS SUBSEQUENTLY SHOWN TO CONSISTENT WITH THE AMOUNT EXPECTED FROM POLARIZED DUST INSIDE OUR OWN GALAXY. HOWEVER THE MEASUREMENT HAS DEMONSTRATED THAT EXPERIMENTS ARE REACHING THE SENSITIVITY REQUIRED TO DETECT THE SIGNAL PREDICTED BY THE SIMPLEST MODELS OF INFLATION AND THAT A CONVINCING DETECTION REQUIRES AN UNDERSTANDING OF THE CONTRIBUTION FROM FOREGROUNDS. FOREGROUND MODELS ARE TYPICALLY BASED ON DATA FROM THE PLANCK AND WMAP SATELLITES. THIS DATA OF COURSE HAS SIGNIFICANTLY HIGHER NOISE LEVELS THAN FUTURE EXPERIMENTS AND THE DATA CAN ONLY BE USED ON LARGE ANGULAR SCALES WHERE THE FOREGROUNDS ARE BRIGHTEST. ON THE ANGULAR SCALES OF INTEREST DUST AND SYNCHROTRON POLARIZATION ARE TYPICALLY INCLUDED IN THE FORM OF GAUSSIAN FLUCTUATIONS WITH AN AMPLITUDE THAT REPRODUCES THE DESIRED LEVEL OF POLARIZED FOREGROUNDS. IN SUCH AN APPROACH THE OBSERVED PROPERTIES LIKE THE RATIO BETWEEN E-MODE AND B-MODE POLARIZATION THE CORRELATION BETWEEN TEMPERATURE AND E-MODE FLUCTUATIONS IN FOREGROUNDS THE SPECTRAL DEPENDENCE AND SO ON MUST BE IMPLEMENTED BY HAND AND OTHER REAL-WORLD EFFECTS LIKE THE NON-GAUSSIAN NATURE OF THE FOREGROUNDS ARE COMPLETELY IGNORED. IN THE CLEANEST REGIONS OF THE SKY TARGETED BY CMB B-MODE EXPERIMENTS NEUTRAL HYDROGEN IS AN EXCELLENT TRACER OF DUST SO THAT HI DATA CAN BE USED TO AUGMENT THE CMB DATA IN MAKING DUST MODELS AND SEVERAL GROUPS HAVE RECENTLY EXPLORED THIS AS A PROMOSING EMPIRICAL WAY TO AUGMENT THE CMB DATA AND IMPROVE FOREGROUND MODELS. WE PROPOSE TO PERFORM AB INITIO MULTIPHASE MAGNETIZED ISM SIMULATIONS AS A COMPLEMENTARY APPROACH. ON THE ONE HAND THE RESULTS WILL PROVIDE INSIGHTS INTO THE PHYSICS UNDERLYING THE PROPERTIES OF THE POLARIZED DUST EMISSION OBSERVED BY PLANCK. ON THE OTHER HAND IT WILL ALLOW US TO PROVIDE REALISTIC SIMULATED MAPS OF GALACTIC FOREGROUND EMISSION URGENTLY NEEDED FOR THE PLANNING OF FUTURE CMB EXPERIMENTS. IN PARTICULAR THE SIMULATIONS WILL ALLOW US TO CONSTRUCT SELF-CONSISTENT MODELS OF GALACTIC FOREGROUNDS ACROSS THE FULL RANGE OF SCALES REQUIRED FROM DEGREE SCALES RELEVANT FOR THE RECOMBINATION PEAK TO ARCMINUTE SCALES RELEVANT FOR DELENSING. THE PROPOSED RESEARCH FALLS WITHIN THE SCIENCE GOALS OF NASA'S SPACE-ASTROPHYSICS PROGRAM AND IS DIRECTLY RELEVANT FOR FUTURE CMB EXPERIMENTS LIKE LITEBIRD AND PIXIE FOR NASA MISSION CONCEPT STUDIES AND ULTIMATELY FOR NEXT-GENERATION SPACE-BASED CMB EXPERIMENTS.