Your doctor has suggested you have a Nuclear Cardiac Stress Test. A Cardiac Stress Test is a test to show how your heart functions when your heart rate is increased. You will exercise or be given a certain medicine to increase your heart rate. A Nuclear Cardiac Stress test is a specialized test. A very small amount of a radioactive tracer is given in an IV.
Open space is any open piece of land that is undeveloped (has no buildings or other built structures) and is accessible to the public. Open space can include: Green space (land that is partly or completely covered with grass, trees, shrubs, or other vegetation). Green space includes parks, community gardens, and cemeteries. Schoolyards; Playgrounds
An important feature of the Big Bang spacetime is the presence of horizons. Since the universe has a finite age, and light travels at a finite speed, there may be events in the past whose light has not had time to reach us. This places a limit or a past horizon on the most distant objects that can be observed.