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.
There are two types of HID grow lights used for growing marijuana, metal halide (MH) and high pressure sodium (HPS) . Although high quality LEDs are a better bet as they save you money in the long term and eliminate heating issues, they do cost more for an initial setup when compared to HPS lighting.ED grow lights run on around 50% of the electricity when compared to the same HPS grow light so a 500 Watt (true draw) LED grow light will offer better output in terms of yield than a 1000 Watt HPS unit.