The first step in measuring the distance between the Earth and the Sun is to measure the distance between Earth and another planet in terms of the distance between Earth and the Sun. So, let us assume that the distance between Earth and the Sun is a.Now, let us consider the orbit of Venus.To first approximation, the orbits of Earth and Venus are perfect circles around the Sun. Take a look at the diagram below (not to scale).nyway, the relevant numbers are: Earth-Sun distance, d = roughly 150 million km (defined as 1 Astronomical Unit). Radius of the Sun, R sun = roughly 700,000 km. Orbital speed of Earth, v = roughly 30 km/s. References: 1  Great Moments in the History of Solar Physics 1.
Marijuana Lighting, Marijuana Grow Lights and Lamps. To grow the indoor marijuana plants is to learn the right types of lighting systems. There are three types of systems of lighting that are excellent ones for the cannabis plants, these are: the incandescent, fluorescent, and the high intensity discharge.
Watts per square foot. The average LED grow light draws about 32 watts to cover 1 sq ft for flowering cannabis. Compare this to a typical HID fixture which rings in at 40 watts per square foot (assuming a 5â x 5â area, or 25 sq ft coverage area). Using an HID in a 4â x 4â will bring the power coverage up to 62.5 watts per sq ft.