From the rather short title you may guess this is going to get to be a bit of a rant – at least it’s based on things astronomical. I am getting asked stupid questions by a number of people (who should frankly know a lot better) about comet Elenin and the havoc it is about to cause on Earth. This is about all the earthquakes and tidal waves the gravitational attraction from the comet is going to create. If you have “O”-level maths (probably called GCSE nowadays) you can actually work it out for yourself – you don’t even need a calculator. You know the equation for the gravitational force exerted between two bodies of mass M1 and mass M2 separated by a distance r (if you don’t look it up, preferably in an elementary Physics textbook in case some genius blogger has put their own interpretation on the equation) and then stick the numbers into the equation. What numbers? Well Elenin’s closest approach will be around 34.9 million km, that’s the r bit in the equation, and Elenin’s mass is roughly 20 billion metric tonnes so make that M1, you can leave the mass of the Earth as just M2. Why? Because now you can work out the gravitational attraction between you and the Earth as you walk across the surface of the planet and compare this to Elenin’s efforts – the radius of the Earth is 6378km, you need that for the r in second bit (you standing on the Earth’s surface).
And please don’t even think about asking “Will Mars really appear as big as the Moon this year?” because even stone age man knew better than that.
Get a grip people and don’t believe what some idiot with no scientific education whatsoever has to say about things they don’t understand on the Internet. In fact – do me a favour and don’t believe anything I have to say either – go off, look up the numbers in a textbook or in a refereed scientific paper and work it out for yourself. Yes it does hurt, but at least you won’t be needlessly taking your hired camper van up the Highlands to keep clear of the Tsunamis.