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Predicting Eclipses

  1. Apr 9, 2005 #1
    Can anyone at all throw me a bone on how I can start to learn how to predict the next solar or lunar eclipse to a high degree of accuracy?

    Cheers.

    The Bob (2004 ©)
     
  2. jcsd
  3. Apr 9, 2005 #2
    good site

    This is a good site with several good links in it, it will get you started in the right direction.
     
  4. Apr 10, 2005 #3
    Cheers. :smile: I see that I am going to have to research this a lot. Thanks for the first stepping stone. Anyone got the next one at hand??? :wink:

    The Bob (2004 ©)
     
  5. Apr 10, 2005 #4
    Why are you trying to predict the next solar and/or lunar eclipses? Anything in particular? Just curious. :smile:
     
  6. Apr 11, 2005 #5
    Pure curiousity. :biggrin: It has been an interest of mine since I was 9 but I have never tried because I knew I couldn't but now I think I can, with some help from the genii on this forum. :smile:

    The Bob (2004 ©)
     
  7. Apr 11, 2005 #6

    tony873004

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    I wrote a computer program once that predicted eclipses to great accuracy. My numbers always agreed with published numbers to within +-5 minutes.

    I "borrowed" the formulas from a book called "Astronomy for the personal computer". Everything was in BASIC.

    http://www.amazon.com/exec/obidos/t...104-2779961-7690311?v=glance&s=books&n=507846

    The formulas are HUNDREDS of lines long. To accurately predict an eclipse, you must know EXACTLY where the Earth is, EXACTLY where the Moon is and EXACTLY where the Sun is at any given point in time. There are many things that perturb the positions off these three objects. And the objects that perturb them get pertubed too. So there's a lot of math involved. The formulas in this book takes care of all that for you. It's up to you how much you want to just copy & paste or how much you want to try to comprehend what's going on. I got my copy used for only about $5.
     
  8. Apr 11, 2005 #7
    Thanks for this.

    A few questions then:
    1. Can I see your programming?
    2. I assume you mean visual basic, no?
    3. How did you get your book for $5?

    Cheers. This book seems like the start of my book collection (next might be 'The Privileged Planet'). :smile:

    The Bob (2004 ©)
     
  9. Apr 11, 2005 #8

    tony873004

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    No, I don't mean Visual Basic

    10 Print "Hello World"
    20 Goto 10

    I translated part of into Visual Basic, so I could do sunrises and sunsets, moonrises and moonsets, but I never translated the eclipse routines.

    The translation is pretty straight forward. Visual Basic will let you use line numbers or labels if you want, but it's really just the loops that are a little tricky to translate.

    I'll see if I can dig it up. It's on my old computer. If I find it, you'll have to have GW Basic which runs under MS-DOS to use it. I think GW BASIC used to come with Dos.

    How did I get mine for $5? Click on the Amazon link. It says 12 used copies from $2.99. I think I got burned!
     
  10. Apr 12, 2005 #9
    The best motivation to advance your horizons of knowledge. :smile: Let me know how it works. I'd be very interested in what you discover. :biggrin:

    Since we're talking about eclipsees and stuff here's a few questions:
    1.) When a solar eclipse occurs spectators are advised not to look directly at the sun. If they sun is completely eclipsed by the moon then why can't you look at it?
    2.) I observed an excellent lunar eclipse a few months ago. It was awesome, but creepy because the moon tured a deep blood red color...any ideas on why that happened?

    (I do hope I'm spelling 'eclipse' correctly! :redface: )
     
  11. Apr 12, 2005 #10

    turbo

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    Your spelling is OK. It is OK to view the eclipse during totality, but warnings are generally issued to keep people from viewing as the totality begins and ends, because UV can cause serious damage to your eyes without your noticing it. I used to be on the Ski Patrol at a mountain in northern Maine, and I have gotten snow blindness from failing to wear proper eye protection. My grandfather was a heavy equiment mechanic, and when I went to his shop, he insisted that I wear a welding mask with a VERY dark plate to protect my eyes - it's easy to forget that the sun is a strong UV source when you're skiing and your eyes are letting in reflected UV from the white snow. You're not looking directly at the Sun, but believe me you can get a bad dose of UV that way, especially at high elevations.
    The lunar eclipses are often deep red because of the effects of the Earth's atmosphere on the light that is being refracted around the Earth and hitting the Moon. Shorter wavelengths interact more with the atmosphere, and so are attenuated more than long wavelengths. Think of a red sunset or sunrise. I have seen lunar eclipses where the moon looked a coppery color and one in particular in which the moon had a reddish-brown hue.
     
    Last edited: Apr 12, 2005
  12. Apr 12, 2005 #11

    tony873004

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    When it is completely eclipsed you CAN look at it. It's just that the area that view the eclipse is large and the area that views the TOTAL eclipse is small. And even the area that sees a total eclipse is seeing a partial eclipse most of the time. Bottom line... Don't look at the Sun's photosphere with your naked eye.

    The moon turned blood red because the only light that was reaching it was refracted around the Earth. If you stood on the Moon and looked at the backlit Earth, it would appear as a very thin blood red circle. You'd be looking at all the sunsets and sunrises in the world at the same time! And sunsets are red.
     
  13. Apr 12, 2005 #12
    Turbo, thanks for the excellent explanation (seriously :smile:). So what can the UV waves do to your eyes? Can they actually blind you or cause severe damage to your retina and lens? I'll have to remember to wear eye protection if its sunny when my BF teaches me to snowboard. By the way, what is the ZPE field? Just curious, :biggrin:.

    Tony your explanation was really good too! :blushing:
     
  14. Apr 12, 2005 #13

    turbo

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    UV is very energetic EM radiation, and very energetic radiation can damage the tissues that we are made out of. It can cause our skin to sunburn and it can cause damage to the tissues of the retina (the backs of our eyeballs that connect pretty darned closely to our visual cortexes). Our retinas are beautifully evolved sensors. They can persuade our brains to incorrectly accept the persistence of some images (giving rise to odd optical effects) and they can be so insenitive as to not properly register the happenings that might be visible, if we were sufficiently cognizant.

    Just watch out for your eyes, and if you are at high northern/southern latitudes and high elevations in bright sunlight, always wear decent sunglasses with good UV protection when you are out in the snow. It's important.

    The ZPE field is the Electromagnetic field of the Zero Point Energy (vacuum energy). Quantum physics tells us that even in a vacuum, even at the lowest temperature we can imagine (0 degrees Kelvin) the empty space of the universe is filled with a teeming field of virtual particle pairs. For every particle that might arise, there is an antiparticle, and as long as they arise and recombine in symmetrical pairs before they violate the Heisenburg Uncertaincy Principle, the existence of these virtual pairs is not only permitted, but is in fact required. The existence of these pairs is demonstrated by the Casimir effect. This is shown by puttting two plates VERY close to one another, which by a boundary effect prevents the formation of the longer-wavelength pairs of the ZPE field, which in turn results in a net attraction of the two plates.

    This effect shows us that empty space is not empty at all, but is teeming with activity, as is predicted by quantum theory. Many of the big questions in cosmology today cluster around the failings of the standard model (BB cosmology and GR) to properly predict the gravitational binding of galaxy clusters and the failure to predict the rotational curves of galaxies. It is up to you, Misskitty, and other up-and-coming physicists to solve these problems.

    I believe that the all-pervasive fields of ZPE will be found to be the mediating field of gravity and inertia, and I believe that the examples of "gravitational" lensing that we see in the literature can be easily explained by by the densification and polarization of these ZPE fields. Do not espouse this as you pursue your academic career, but hold it out as a possibility. The conservative, orthodox physicists will not help you if you are leaning in this direction, although some of the folks pursuing Loop Quantum Gravity or String Theory might give you a shot. Good Luck!
     
    Last edited: Apr 12, 2005
  15. Apr 13, 2005 #14
    Cheers. :smile:

    The Bob (2004 ©)
     
  16. Apr 13, 2005 #15
    Turbo, again another very awesome explanation :biggrin:. So these virtually particle pairs, do they make up anything? What do they do?

    I think I might want to consider another major possiblity when I start applying to my schools. I don't know much about Quantum Loop Theory and String Theory so do you think you could give me an idea of what it is? If its not to much trouble that is. :blushing:
     
  17. Apr 13, 2005 #16

    tony873004

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    Check your e-mail.

    Do you have GW BASIC? If you end up converting this, send me a copy. I don't have GW BASIC on my new computer and firing up the old computer is such a chore.
     
  18. Apr 14, 2005 #17
    I think I might have to convert it. Any preference on the language???

    The Bob (2004 ©)

    P.S. Cheers for the file. :biggrin:
     
  19. Apr 14, 2005 #18

    tony873004

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    I prefer Visual Basic 6.0 or .net. I converted a small portion of it to VB6 so I could have a sun/moon rise/set calculator. But I made a typo somewhere and I can't find it yet. Causes the Moon to rise and set exactly 1 hour early depending on daylight savings settings. The typo seems like a simple find, but I got unmotivated.

    Speed is not an issue here so no need to complicate things with C++ unless that's what you're comfortable with. It would be neat to have it in Java or even Javascript so a web version could be possible. Javascript would work since there's no file I/O. But it's up to you. Do what you're comfortable with.
     
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