![]() ![]() We know about the system because of about 400 hundred clay tablets.All numbers can be represented with only 3 symbols! One for 10s, one for 1s, and one for 0s.Originally developed by the Sumerians around 2000BC!.The way we measure time, and angles is actually mixed radix – in which different positions in the number measure at different bases.Here are some fast facts on Babylonian numerals: I was perplexed – this is so interesting, even more than Roman numerals which are everywhere – why hadn’t I heard about this before? I can’t do the full history justice, but you can read more here: It turns out the Babylonians used a base 60 number system on which our measurements of time and angles are based. Today I stumbled upon a math puzzle in Babylonian numerals. I’ve often wondered, why the heck is the circled divided up in 360 degrees anyway? And why is a day divided in 24 hours, but then hours by 60 minutes, etc… ![]() I find myself doing the conversion so often I’ve considered getting the conversion 1″ = 4.848 urad tattooed to the back of my hand. Source: ESO īut as engineer, building a metric telescope with steel measured in metric, often have to convert form radians. The apparent diameter is almost 1 million times smaller than that of Mars. ![]() EHT image of black hole at the center of M87 – the first image of its kind. Back to the point of the post – fractions of arc-seconds is the way astronomers and astronomy fans use to keep measurements of the Universe in context. Lastly – the supermassive black hole recently imaged at the center of M87 had a diameter of about 50 micro-arcseconds using a technique resulting in unprecedented resolution. Imagine what treasures we might see when we get our resolution down to nano-arcseconds! (see gravitational lensing). So, it’s really hard to get high enough resolution to get a star to spread across multiple pixels. Betelgeuse, the red star in Orion, is one of the largest stars by angular diameter and has an apparent diameter of 50 thousands of an arc-second (or 50 milli-arcseconds) – which is the approximate resolution achieved by the Hubble Space Telescope. For example, the moon and the sun have apparent diameters of 30 arc-minutes diameter each, and Mars has an apparent angular diameter of 25 arc-seconds. Astronomers like to use units called arc-minutes and arc-seconds which subdivisions of a degree when viewing the sky. In astronomy, we tend to care a lot about really small angles. ![]()
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