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.
HID or High Intensity Discharge lamps are the most common type of marijuana grow lights used for indoor growing and are arguably the most efficient way of producing good yields indoors. The HID family includes, Metal Halide (MH) and High Pressure Sodium (HPS).umens and Kelvin. The main terms used when people refer to light in marijuana growing are lumens and kelvin, which are the brightness and warmth of light. Lumens are a measurement of the total amount of visible light and Kelvin is a measure of the colour temperature the bulb is emitting.