Discuss space-time dilation as stretching of time. Use image to show reflection of light pulse in distance/time as the source moves. Define and discuss the Lorentz formula used to determine time dilation.
Introduce and discuss that all motion is relative, ,and must include a reference frame. Determine that objects may have different velocities relative to different reference frames. Indicate that the speed of light postulate states that the speed does not change. Discuss that motion through space is related to motion in time. Einstein postulated that both space and time only exists within the universe. Space and time are the parts of the space-time continuum. If you stand still, you move through time, if you move a little you move through some space but mostly time. If you move at the speed of light, all travel is through space only. Introduce the time dilation as a "stretch of time".
Discuss " what is nuclear fusion". Define how fusion is the process by which two light nuclei combine to form a single heavier one, while releasing massive amounts of energy. Discuss how fusion takes place in a state of matter called plasma. Explain how this reaction takes place in the sun, and requires high temperature and gravity within a small space. Extreme pressure is a requirement. Discuss deuterium and tritium as the nuclei which fuse. Present a nuclear fusion equation. Discuss differences between fission and fusion and their operational conditions. Introduce and determine the mass difference which occurs when fusion happens, and the amount of energy given off.
