BSC Posted May 7, 2012 Share Posted May 7, 2012 (edited) Hi all, new to the forum but not to science! As all of you probably know, the transit of venus event is coming up on June 5th and 6th and what better way to witness this historical event by building a sun funnel! The sun funnel will allow a large group of people to view this event by using rear-projection screen material. You can check out Rick Fienberg's guide to building a sun funnel for step-by-step instructions!! The key element to safely viewing the sun and to building the sun funnel is the Da-Lite High Contrast Da-Tex rear-projection material. The material is also linked in Rick's guide to building the sun funnel. They have free shipping and a great price and there is still plenty of time to get it before this once in a life time event! Who here plans to see it? I know I am! Edited May 7, 2012 by CaptainPanic links removed Link to comment Share on other sites More sharing options...
CaptainPanic Posted May 7, 2012 Share Posted May 7, 2012 ! Moderator Note Dear BSC,Our forum rules say you shouldn't open a thread specifically to advertise your blog, or anything else for that matter (see the rules, section 2.7). I'm guessing you hadn't seen the rules yet, because you're new here, so I have removed the links for you. It's nothing personal.Feel free to put your non-commercial link in a signature. Back on topic... what's so fascinating about the passage of Venus in front of the sun? Doesn't it mean you can see less of venus, rather than more, because of the huge contrast? Is it just because it doesn't happen often? Link to comment Share on other sites More sharing options...
John Cuthber Posted May 7, 2012 Share Posted May 7, 2012 From http://en.wikipedia.org/wiki/Transit_of_Venus "Aside from its rarity, the original scientific interest in observing a transit of Venus was that it could be used to determine the distance from Earth to the sun, and from this the size of the solar system, by employing the parallax method and Kepler's third law. The technique involved making precise observations of the slight difference in the time of either the start or the end of the transit from widely separated points on the Earth's surface. The distance between the points on the Earth was then used as a baseline to calculate the distance to Venus and the Sun via triangulation.[12] Although by the 17th century astronomers could calculate each planet's relative distance from the Sun in terms of the distance of the Earth from the Sun (an astronomical unit), an accurate absolute value of this distance had not been determined." Historically itr was an important observation: now I think it's just rarity value. Link to comment Share on other sites More sharing options...
swansont Posted May 7, 2012 Share Posted May 7, 2012 Historically itr was an important observation: now I think it's just rarity value. Precisely. They also represent the limited opportunities to observe and test hypotheses of the "black drop" effect; it's not all due to limitations of the optics http://www.transitofvenus.org/history/black-drop Link to comment Share on other sites More sharing options...
zapatos Posted May 7, 2012 Share Posted May 7, 2012 I read this story in 'A Short History of Nearly Everything' by Bill Bryson. A very enjoyable book! Transits of Venus come eight years apart but are then absent for about 100 years. In 1760 Guillaume le Gentil left France for India to observe the transit that was to occur in 1761. Unfortunately for him, due to problems he found himself on a ship in rolling seas on the day of the transit which meant he was unable to take his measurements. Being a dedicated scientist he continued on to his viewing site in India to prepare for the transit in 1769. Everything was perfect until just before the transit began when a large cloud slid in front of the sun, blocking his view needed for his measurements, and stayed there for almost exactly the duration of the transit. He packed his equipment and headed home, only to get dysentary and be laid up for a year. He eventually made it to a ship and was headed home but the ship was hit by a hurricane and wrecked off the coast of Africa. He finally arrived home 11 1/2 years after setting out, having achived nothing on his trip. When he arrived home he found that his relatives had had him declared dead and 'had enthusiastically plundered his estate'. Link to comment Share on other sites More sharing options...
Joatmon Posted May 7, 2012 Share Posted May 7, 2012 (edited) If you have a telescope or binoculars you can see the transit of Venus. The attachment is one I saw in 2004 using my telescope. The black dot is Venus against the sun. The distortion is because my projection is onto a vertical wall. If interested just follow the link. Please, please don't try to see it with your naked eye! 3 You may project a magnified view of the sun through a reflector telescope or binoculars onto a white surface, http://www.transitof...ransit-of-venus Edited May 7, 2012 by Joatmon 2 Link to comment Share on other sites More sharing options...
the asinine cretin Posted June 5, 2012 Share Posted June 5, 2012 I'm so stoked about this. It should star in a couple hours from my point of view. Link to comment Share on other sites More sharing options...
Joatmon Posted June 5, 2012 Share Posted June 5, 2012 (edited) I'm so stoked about this. It should star in a couple hours from my point of view. I see you reside in Uranus so its not your turn More seriously, I hope you are lucky with the weather. You wont get another chance for 105 years (or so I read). I'm sure you must have thought about it - but have a camera handy. Edited June 5, 2012 by Joatmon Link to comment Share on other sites More sharing options...
the asinine cretin Posted June 5, 2012 Share Posted June 5, 2012 I see you reside in Uranus so its not your turn More seriously, I hope you are lucky with the weather. You wont get another chance for 105 years (or so I read). I'm sure you must have thought about it - but have a camera handy. Haha. Well, actually the sky is pissing me off today. I might be enjoying the event from within Starry Night. Link to comment Share on other sites More sharing options...
Airbrush Posted June 5, 2012 Share Posted June 5, 2012 (edited) I read this story in 'A Short History of Nearly Everything' by Bill Bryson. A very enjoyable book! Transits of Venus come eight years apart but are then absent for about 100 years. In 1760 Guillaume le Gentil left France for India to observe the transit that was to occur in 1761. Unfortunately for him, due to problems he found himself on a ship in rolling seas on the day of the transit which meant he was unable to take his measurements. Being a dedicated scientist he continued on to his viewing site in India to prepare for the transit in 1769. Everything was perfect until just before the transit began when a large cloud slid in front of the sun, blocking his view needed for his measurements, and stayed there for almost exactly the duration of the transit. He packed his equipment and headed home, only to get dysentary and be laid up for a year. He eventually made it to a ship and was headed home but the ship was hit by a hurricane and wrecked off the coast of Africa. He finally arrived home 11 1/2 years after setting out, having achived nothing on his trip. When he arrived home he found that his relatives had had him declared dead and 'had enthusiastically plundered his estate'. Now that was an interesting story. I heard on the radio they were able to estimate the distance of the Earth to the Sun at 95 Million miles using the "Venus Transit Method". What is so interesting about seeing a tiny dot on the sun? This looks boring. Edited June 5, 2012 by Airbrush Link to comment Share on other sites More sharing options...
the asinine cretin Posted June 5, 2012 Share Posted June 5, 2012 Plenty of live webcasts going on for those who can't observe. http://www.ustream.tv/nasaedge I've been experiencing lag on NASA Edge, but not with the following. http://www.exploratorium.edu/venus/ Link to comment Share on other sites More sharing options...
John Cuthber Posted June 6, 2012 Share Posted June 6, 2012 Not officially available outside the UK, but you might find that this answers Airbrush's question. http://www.bbc.co.uk/iplayer/episode/b01jszy4/Horizon_20112012_The_Transit_of_Venus/ Link to comment Share on other sites More sharing options...
Joatmon Posted June 6, 2012 Share Posted June 6, 2012 (edited) ....................................................What is so interesting about seeing a tiny dot on the sun? This looks boring. Think about this for a moment - Venus and the Earth are approximately the same size. Then compare the size of Venus with the size of the sun (Actually Venus is smaller than it looks because it is a lot nearer us than the sun). Then consider that the sun is quite an ordinary star among millions of stars in our galaxy. Then think about the number of galaxies that are known to exist. Then try to guess how many galaxies exist without our knowledge. Then think that it is possible that all intelligent life in the universe may exist on a "dot" the size you see. Think of your place on that "dot". Think of how fragile the whole existence of intelligent life in the universe may be, let alone your own existence. I find this train of thought quite interesting, perhaps even frightening. Edited June 6, 2012 by Joatmon 1 Link to comment Share on other sites More sharing options...
Airbrush Posted June 6, 2012 Share Posted June 6, 2012 Think about this for a moment - Venus and the Earth are approximately the same size. Then compare the size of Venus with the size of the sun (Actually Venus is smaller than it looks because it is a lot nearer us than the sun). Then consider that the sun is quite an ordinary star among millions of stars in our galaxy. Then think about the number of galaxies that are known to exist. Then try to guess how many galaxies exist without our knowledge. Then think that it is possible that all intelligent life in the universe may exist on a "dot" the size you see. Think of your place on that "dot". Think of how fragile the whole existence of intelligent life in the universe may be, let alone your own existence. I find this train of thought quite interesting, perhaps even frightening. Good answer Joatmon! I will try to think of that. Link to comment Share on other sites More sharing options...
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