Likely Topics
(You don't need to limit yourself to these.)

glacial climate records & ice cores
extra-solar planets (even though it's astronomy)
fatpase & nanotechnology motors
inexpensive new methods of reaching space
linear no-threshold radiation approximation
neutrinos, neutrino mass, solar neutrino problem
optical molasses or magneto-optical traps
solar cells, concentrating solarpanels
why brazil nuts rise to the top

bar code scanners             bird navigation
booming sands                 buckyballs
cerenkov radiation            chromatography
effective field theory
free radicals & aging         fractals       
fusion power                   high temperature superconductors
hybrid electric cars
ion propulsion                iris recognition
lake-effect snow              laser eye surgery
micromachines                        magnetic resonance imaging    
monitoring nuclear tests      music & harmony
nuclear facility cleanup      nuclear reacter stability
photoelectric effect          plastic leds
quantum wells/ dots           positron emission tomography 
short wave radio propagation  radiology          
stern-gerlach experiment      sickle cell anemia
uranium mill tailings         solar ponds           
stealth aircraft              somoluminescence
sunburns/sunscreens           thunderstorms
ultrashort pulses             tsunamis        
solar sails