tomc

Hi, Thank you, DH, for your response. The dots make sense now. You are right on - it was the second derivative for the potential energy of a spring. Tom

Hi, I have been viewing some physics lecture videos and have come across a notation that is not familiar. Any help will be appreciated. The following is part of an equation for wave motion: ε(epsilon) φ(phi -with 2 dots above it) = c^2÷ε [(φ sub i - φ sub i+1)+(φ sub i - φ sub i-1)] φ(phi with a dot above it) and φ(with 2 dots above it) What do the dots above φ indicate? Thanks, Tom

Hi, A bit confused - is gravity a result of graviton interaction, warped spacetime, or a combination of the two? Tom C

The aliens would have to be technologically advanced if capable of interstellar travel. By extension, they would probably have seen/visited other planets in our galaxy or other galaxies. What makes earth so special? Why would they bother? Maybe they stumbled across us by chance thousands of years ago and found evolution on earth worth studying. That might explain the ufo sightings over the years. In my opinon, however, the occurrence of such a chance encounter with earth would be astronomical (no pun intended). Tomc

losfomot, You are right - Prof. Muller's lectures are excellent. A great review of many scientific principles and he explains quantum theory in a way that even a dummy like me can understand (well, at least most of it). Thanks for the link. TomC

Granpa, I am not sure how to interpret your answer. Tom C

Thank you, Martin and Severian, for your informative replies. I believe that I now have a more reasonable approach to further research the concept of space-time. Tom C

Hi, I am not a scientist so my understanding of space-time is based on books, magazine articles, and internet searches that are light on math. If space-time is a fabric or foam that can be warped, what makes up the fabric or foam? From what I understand, so far, string and M theories may fit in somewhere. Do strings make up the "membrane" in M theory? Is this "membrane" the fabric or foam of space-time? I am probably way off track and thought I might find some answers here before I become terminally confused. Thanks, Tom C

Hello, My name is Tom - I'm new to the Science Forums. I am not a scientist - just someone who has a general interest in physics. Not sure if this is the proper area in which to ask for HELP regarding the spin of a particle. Up to now, my searches have lead me to believe that "spin" is a term that refers to a paticular "behavior" of a particle with fractional and whole number notation and does not imply actual rotation of a particle. This "behavior" could have been given any term. However, I don't quite understand what this particle "behavior" is. Any help would be appreciated. Thanks, Tom C

Please excuse my ignorance - but what is a "PAH" in space? TomC

GILDED, Thanks for your response. I will check out the Wikipedia article. Tom C

Hello, My name is Tom and I am new to this Forum. I am not a physicist but I have an interest in some of the ideas regarding cosmology. I do not pretend to understand all the math and intricacies of cosmic theories. However, I would appreciate any suggestions regarding web sites where a layperson, such as myself, could learn more about worm holes. Thank you Tom C