Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Crossing the galactic plane

  1. Jan 15, 2008 #1
    I am interested in verifying the following claim:

    The most interesting is that the sun will pass through the
    galactic center (from earth's vantage point) on Dec 21, 2012, which is when
    the Mayan calendar "ends" (and is also the winter solstice). ​

    I'm having a discussion where my argument is that the world won't end in 2012 like many doom predictors claim. Can this claim even be accurately proven/disproven?

    Also, if there any way to tell when our solar system will line up with the galactic plane? I have to imagine when dealing with such vast distances and taking measurements from the inside, it has to be difficult to pinpoint.
    Last edited: Jan 15, 2008
  2. jcsd
  3. Jan 15, 2008 #2


    User Avatar
    Science Advisor
    Homework Helper

    Sun will not pass through the center of Milky Way. Sun is orbiting around it.
  4. Jan 15, 2008 #3

    D H

    User Avatar
    Staff Emeritus
    Science Advisor

    Even if the Mayan calendar ended on December 21, 2012, so what? Does your car stop running when your odometer hits 100,000 miles? No. Moreover, the Mayan calendar does not end on December 21, 2012.
    The crossing of the galactic plane is BS piled on top of BS. First, we do not know the shape of the galaxy well enough to even say something as precise as this. Second, how exactly does this purported crossing of the galactic plane spell the end of the Earth? It doesn't.
  5. Jan 15, 2008 #4
    Clarification - when they said "the sun will pass through the
    galactic center (from earth's vantage point)", they don't mean physically pass through it, but that the three points of the earth sun and galactic center will form a straight line with the sun at the center.

    And I agree 100% with the absurdity of the claims. I'm just looking for as much evidence as possible to convince others of that fact.

  6. Jan 15, 2008 #5


    User Avatar

    Staff: Mentor

    Whether the sun, earth, and galactic center form a straight line on that date depends on how precise you want to be with calling it an "alignment". Here's a screenshot of Starry Night for that day. The sun, viewed from earth, is 6 degrees, 38 minutes away from being aligned with the galactic center. The actual closest alignment is on December 18th of every year (just 5 degrees, 41 minutes), with the alignment on that date changing very little from year to year. It oscillates 2.7 times per orbit, which is 225-230 million years. Given the length of that timescale, it would be impossible to measure a year-to-year change in our alignment to pinpoint an exact year (much less day) that we cross it. But I've found sites that say we are currently on an up-swing in our orbit, moving away from the galactic plane.

    But as DH said, there is no need to go to such lengths to debunk this. My calendar ends every year and the world hasn't ended yet. The Mayan's just need to go to Staples and pick up next milenia's version of their calendar or get the Y2012 update for Windows to make sure it rolls over.

    Attached Files:

    • sn.jpg
      File size:
      38.3 KB
    Last edited: Jan 15, 2008
  7. Jan 15, 2008 #6


    User Avatar
    Gold Member

    It most certainly can. Check back here on Dec 22, 2012.

    OK, all seriousness aside. It can't be proven or disproven. What can be shown (to a reasonable person) is that all these supposed confluences of events are nonsense and therefore there is no reason to think the world will end on that day any more or less than any other.
  8. Jan 16, 2008 #7
    Thanks for the insight folks. What is blatantly obvious to you and me (and other logically minded people), is often difficult to grasp for people who consider retirement planning to consist of buying lottery tickets. Having some real facts to reinforce my arguments helps dramatically.
  9. Mar 27, 2008 #8
    The only thing evident in these chaos is that people are making money by releasing books and I am sure as the date approaches, more are going to get panic like they did before Y2K and do wrong things. There was, though, a tv program on NOVA channel regarding the SUN crossing the center of the galaxy. There is a possibility, according to experts that the earth poles may switch and it could result in unexpected behaviour in lots of electronics. And the date is set to DEC 20012. So it's anybody's guess.
  10. Mar 27, 2008 #9


    User Avatar

    Staff: Mentor

    The earth is currently believed to be in a pole flip event. This happens occasionally and is little to worry about except that you'll need to relabel your compass - in a few thousand years. The worst effects that are possible come from the fact that the magnetic field is what deflects charged particles from solar flares and CMEs and as a result, the effects of these events (which already produce power outages and damage satellites) could be worse.
  11. Aug 26, 2008 #10
    While there might not be any truth to the claim of 'the end of time', referencing the Mayans, there should be some evidence BEFORE you begin to claim such items as facts, as stated.

    Now writing on the subject of the galactic plane: What evidence supports the effects of such a difference. The facts are that the world does go through these types of events and it does take some change in our solar enviorment to create such events. It seems that these changes, when passing through the plane, could be something we know little of and therefore cannot rule out an increased risk of such events.

    Do not just blow it off. Research and understand by the science of the matter, not what you want to believe or hear. Use more observation and look beyond the majority opinion.

    Seek truth and you cannot fail. I hope the fear mongers are wrong though I have not read supportive evidence to sugest a strong fact on either side of the arguemnt.

    I am trying to get people to actually do the research and stop making assumptions. Its too great of a risk to slack off in this area.

    The point is that one generation will be faced with an event that will threaten the world. Its likely that generation will be just as apathetic as we are today, unless we take changes to our solar enviorment seriously use fact as fact.

    As far as I can tell we don't know very much about this galactic plane and most certianly not enough to begin to make statements of 'safe' or 'sorry'.

    Keep researching there are answers, but there is only one truth.
  12. Aug 26, 2008 #11


    User Avatar

    Staff: Mentor

    The most important thing to take from this thread is that there is no science to "the matter". It's a basic crackpot hoax. That is why we blow it off.

    If there were something here to research, research would be done.
  13. Aug 26, 2008 #12


    User Avatar
    Science Advisor
    Gold Member

    I'm hosting a Mayan calendar party on Dec 22, 2012. Disregard this announcement if the world ends on Dec 21, 2012. Also, if the earth's magnetic field does not reverse by then, I'm planning to sponsor a pole flipping contest.
  14. Aug 27, 2008 #13
    I agree with statement entirely as far as the Mayan Myth is concerned. What I am interested in discussing is the crossing of the galactic plane within the context of astronomy. What I would like to know is how we can determine our present “plumb bob” distance above this imaginary plane and in what relative direction are we moving? I have done some researching on the www and it seems to me there is no real consensus on this as far as I can tell. Some related numbers I have come up with are:
    Distance from our solar system to galactic center ~ 26,000 lyr.
    Thickness of the galactic disk is anywhere from 1000 – 3000 lyr.
    Tilt of the galactic equator to the ecliptic is 62.6 degrees.
    Tilt of eatrh’s equator to the ecliptic is 23.5 degrees.
    Angle between the projection of the ecliptic on the earth and the center of galaxy ~ 2 degrees. This angle seems to me to be the most important for this calculation but it also is one of the most unreliable because of the precession of the equinoxes and the other tilts mentioned above.
    From this, I have made my own very crude calculation based on the tangent of 2 degrees as the angle between earth and galactic center and the baseline distance of 26,000 lyrs as being just tan 2 deg. multiplied by 26,000 = 907 lyrs as the height of the earth above the galactic plane. Before the “real” astronomers pounce on me, I admit this is a very crude approximation and I have no confidence in it at all. I am hoping someone can show me the proper way to calculate this as well as the correct height. Also, is there any way at all to know in what direction we are moving with reference to this plane? I realize with an orbit time of 250 million years in which the earth cycles through the plane 2.7 times, this would be extremely difficult to determine.
    Thanks for any and all inputs!
  15. Aug 27, 2008 #14
    Actually there is something to research. The whole point of the 'concept' of reseach is to learn about unknown frontiers. The galactic plane is one such frontier. There is a canadian group that is pouring out data from this plane on a daily basis. Like I said if you actually did the research you would have known this.

    Nothing is a 'hoax' until there is sufficient evidence to such claims for either side. As far as I can see many people are wasting time here creating false claims and using totals such as '100%' which does not exist in the science relm.

    This forum seems like an awesome idea but I have found the lack of researchers here a great disappointment. Good luck to you all and for those of you who actually do the experimental and observational reserach, I tip my hat to you.

    Good bye.
  16. Aug 27, 2008 #15


    User Avatar
    Gold Member

    Wait. You're going to get incensed and leave in a huff because you didn't like the way a thread went that was about 2012 doomsday claims? Oh come on.

    Are you trying to get painted with that same brush?

    If you wanted to explore something that has substance, feel free to start a new thread.

    Otherwise, there are plenty of other Fora out there that will be happy to indulge a desire for speculation, from the merely edgy to the truly silly.
  17. Aug 27, 2008 #16


    User Avatar

    Staff: Mentor

    Whether there is anything interesting about the galactic plane isn't the subject of this thread. The subject of the thread is the Mayan end-of-the-world hoax.
    That's not what a hoax is. A hoax is a made-up claim with made-up evidence. Ie, nothing. Nothing to prove, nothing to research.
  18. Aug 27, 2008 #17


    User Avatar
    Science Advisor
    Gold Member

    Crossing the galactic 'plane' is almost as much myth as the Mayan calender. The galaxy is not a rigid, symmetrical object with a clearly definable axis, or plane perpendicular to that axis. The time when the solar system will cross the galactic 'plane' is fuzzy. Proclaiming to know the the exact year, month, day, hour and minute - priceless: Ascribing deep, metaphysical significance to the 'event' - goofy. Earth crosses the 'plane' of some galaxy somewhere in the universe every day.
  19. Aug 28, 2008 #18
    Personally, I have no time to spend on Mayan Myths, so I attempted to steer this thread to the practical matter of astronomy and ask some questions which I thought were interesting. I understand that there is no physical galactic plane any more than the earth has a physical equator. But they do both exist as imaginary planes in space, and as such we should be able to make at least an estimate of where our solar system is with respect to that plane. Am I mistaken in this belief? Since it has already been determined that the solar system oscillates above and below said plane, I believe it is fair and even scientifically correct to say that at some point we do cross the plane. Whether or not “things happen” when we cross this plane is of no interest to me at all. I simply would like to determine where we are with respect to the plane and if possible in what direction we are headed. Thanks again!
  20. Aug 28, 2008 #19


    User Avatar

    Staff: Mentor

    Well, you are saying contradictory things. The earth's equator can be defined and located with exquisite precision. An imaginary line, for sure, but one with a clearly-defined position. But at the same time, you seem to acknowledge no such level of accuracy is possible for the galactic plane. It is both imaginary and only locatable by estimation.

    This is because a galaxy is not a single coherent object (unlike earth), it's 100 billion, so finding the plane of rotation is really just averaging the orbital planes of all the objects in it.

    Lets try a different angle: You're an astronomer and you want to do a research project to better locate the galactic plane. I'm your boss/funding source. What does your proposal say? Why are you doing the project? Why is it worthy of funding (not to mention your time and effort)? What theory are you attempting to test/phenomena are you trying to explore?
    Last edited: Aug 28, 2008
  21. Aug 28, 2008 #20

    As a scientist (but not an astronomer) I was simply interested in how accurately we can determine the position of our solar system within the galaxy. One parameter would be the distance from the center, which I believe has been determined to be approximately 26,000 lyr. Another would be the distance from the plane of the disk, which is what I was asking about. However, for whatever reason, it seems no straight forward answers are forthcoming. And, with all due respect, Russ, you are not my boss!
  22. Sep 19, 2008 #21
    The mayan culture used the stars to create their calender. it only makes sence that they believed once they reached a point where they couldnt predict the placement of the stars in the sky that time ends because there way to keep time ends.i agree with the y2k-mayan calender similarities. we worried about our computers and how they keep time as the mayans worried about how their (computer) kept time. anyone can say hey this is the day the world will end all im saying is give me some proof some hard scientific evidence that says we wont exsist beyond dec 2012 then i might believe it. dont just come at me with the calander of an ancient culture. even as advanced as they were theres no way that their calander holds that kind of merit.
  23. Sep 19, 2008 #22

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2017 Award

    I don't understand why this doesn't just die.

    (1) The claim that celestial mechanics predicts the earth will pass through the galactic center on December 21, 2012 is false.

    (2) The claim that celestial mechanics predicts the earth sun and galactic core will form a line on December 21, 2012 is false.

    (3) The claim that the Mayan calendar cannot represent a date after December 21, 2012 is false.

    I don't think there is a single true statement in the set.
  24. Sep 21, 2008 #23

    Interesting that a lot of the replies were very quick to dismiss the existence of the galactic plane/equator/whatever you want to call it. I’m guessing the ones quick to dismiss the whole thing are probably not involved in any studies like the one referenced in the link below..


    From various other articles I have read, it doesn’t look like we can put an exact time and date on the passage, but it should happen at some point in the next 7 years or so.

    As for the Mayans, I don’t think their calendar stops on the date mentioned, it just notches up to another set of numbers (like 1999 to 2000) I remember reading somewhere its in base 15 where the prediction it stops assumes its in base 8 or something.

    I doubt any of what I have written really helps, but it is debate, and that is what science is all about isn’t it? well that and peer review. Good luck on your quest to pin the date down though, let us know what you dig up in your efforts, I’ll certainly read it with an open mind.

  25. Sep 21, 2008 #24


    User Avatar

    Staff: Mentor

    Do you have any sources for that? I posted image caps of planetarium software that does not support that.
  26. Sep 21, 2008 #25

    Nah, not really, it was something I remember reading while looking for the orbital period of Sol around the galaxy itself. As it wasn’t the focus of the study at the time it just got filed under ‘Interesting junk I can bore the crap out of people at parties with’, hence the word should rather than will.

    If I come across a firm article again, Ill note the link and post it up.

    What software do you have? I’m on the look out for something I can use to show my little boy how to locate stars with, he saw his first shooting star last night and is well chuffed up!

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook