The galaxy weighs in

Our little neighborhood

Our little neighborhood

In an exciting move, the European Space Agency will be launching Gaia in 2011 for the most comprehensive mapping survey of the galaxy ever. They will be measuring speeds and positions for about 1 billion nearby stars. From the link:

By establishing where things are in our galaxy, the spacecraft will help scientists measure the weight and distribution of mass in the Milky Way in much greater detail than ever before. These measurements are vital for models that attempt to describe how the pull of dark matter has shaped our galaxy.

It will be interesting to find what these results have to tell us about the distribution of dark matter, which in turn could yield clues as to how and when it formed. Most matter we know about interacts with the electromagnetic field making it possible for us to detect it. Thus, we can find out about things like stars and dust. However, the observed mass was not enough to account for things like rotational speeds of galaxies, orbital velocities of galaxies in clusters, and so forth. So a new form of matter, appropriately called dark matter was proposed. Another suggestion was modified gravity at large scales. However, dark matter has more explanatory power such as with anisotropy of the cosmic microwave background.

A hopeful test for is that if dark matter (hypothesized to be WIMPs, or weakly interacting massive particles) have a certain mass ranges, we could expect to create them in colliders such as the LHC. It is suggested that the mass of a WIMP is on the TeV scale. That is a Tera Electron Volt, which is 10**12 (10 to the 12th power). By comparison, the proton is about 938 MeV (Mega Electron Volts or order of 10**6). If you know that electron volts are measurements of energy and you’re not used to these types of units, it may puzzle you that I’m using mass and energy interchangeably. But than you’ll remember Einstein’s famous equation which relates mass to energy and you’ll know that they can indeed be interchanged. That is an enlightening discussion in and of itself, and perhaps the topic of a future post, but for now I’ll refer you to The Wiki if you want to dig into it a bit more.

So, going back to Gaia, I don’t know about you, but once we have a better map of the galaxy, I won’t feel so lost anymore.


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12 Responses to “The galaxy weighs in”

  1. PINKY Says:


  2. Suraj kp Says:

    Galaxy is first find out the INDIAN (HINDU) RUSHISWARA, The milky way galaxy is explained in hindu veda and upanishathu and bagavath geetha. every credit is must give to indian
    Suraj KP

  3. pomski Says:

    its not true’, to give every credit to indian’, you don’t have a proof’, its just a conjestion’.

  4. skate Says:

    fuck indian ppl…….they dont know shit about anything they only know how to kill ppl……..they are not smart!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

  5. juanita Says:

    esta increible todo loq q hacen me estoy aburriendo en la clase de science

  6. Halo Says:

    Re: Suraj kp

    Are you talking about the same Indians who believe in monkeys and cows!!!

    You must be kidding. lol

  7. vince raven landicho Says:

    it is so beautiful to look at.and it is good for our lesson in science

  8. suzanne Says:

    galaxy so amazing i love it ,thats arelesson in science too. . . . ;

  9. Herb O. Buckland Says:

    The galaxy picture is marvelous. However, I would like to make an appeal to all readers. I am working on a poster project on which may be used a black and white image of the earth by itself and also the milky way galaxy that gives some indication of where the earth is located. If it provides an iindication of the sun as well (such as is presented in the picture on the liquid thinker website), that is fine and dandy. The images are to be used as subtle background watermarks. If you can supply such an image or know of where I may get one, and if the image is found to be suitable, you will be given contributory credit.

    Thank you,

    Herb O. Buckland

  10. blossoms Says:

    Skate, Pomski and Halo – I am not in the credit fight….the larger interest should be served…if this discoveries shed light on some unique facts to improve our life, the source is incidental. Having said this, request to read Dan Brown’s – The Lost Symbol, where in he have openly credited ancient hindu scriptures which were way ahead of their time…including the Upanishads…in terms of scientific discoveries and inventions. There are innumerable instances been studied in Noetic Science where Mind controls Matter (or Mind over matter)…its physical study in two institutes viz., IONS, California and PEAR, Princeton to establish the co-relation between the focussed thought and its effect on inanimate object…Surprisingly, some 700 + years ago….Indian saints namely Dnyaneshwar physically moved a wall as was his desire and made an ox recite ‘mantras’.
    Wait for few more years before this will be technically be proved…. Infact, Rhonda Bryne in her book secret has stressed on the same phenomena of powerful and positive thinking…to make the reality the way you would like to be for yourself…Pl read both these books without fail.
    The simple truth is what you wish for others comes back to you in manifolds…so its in our best interest to be positive with our comments and criticism

  11. Anonny Says:

    > Skate, Pomski and Halo – I am not in the credit fight….

    Then kindly stop fighting.

    In case it has escaped you, “The Lost Symbol” is sold as FICTION

  12. mr.robert Says:

    i am a senior engineer in galaxy,,,and i want to tell that the picture is no valid,,,and i want to tell fuck of you who has fight in this mailist

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