Does the earth have a net direction of movement in space?

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GIUSEPPE asked the Naked Scientists:
Hi Guys. Love the show!

I'm no astronomer but I have a question about the Earth's motion.

Every 10-year-old kid knows that the Earth rotates and revolves around the Sun. Smarter kids (and certainly scientists) also know about a number of other motions such as the Axial and Apsidal precessions, etc.

All these motions, however, are oscillatory.

On the other hand, it is also widely said that the universe is expanding...

So, my question is: Does the Earth also move (translate, mechanically) TOWARDS any direction? In other words, are we "going" somewhere? What about other bodies?

To explain, obviously due to all the complex wobbles and spins and orbital motions cosmic bodies have, if there is a translational motion towards any direction that would have to be in average terms. That's understood.

Also, it is obvious that we may be getting farther (or closer) to other distant objects. But that's not what I'm asking.

What I wonder is, take the geometric center of every object in the Universe. Are we moving anywhere relative to that point?

If the Universe is expanding, and one could measure where planets and stars are "going", then one could tell the location where Big Bang happened.

But instead I heard someone once say that it is physically impossible to figure out where the Big Bang occurred...


Sorry for the long question. :P

Thanks and cheers!

What do you think?
« Last Edit: 29/04/2011 11:01:02 by _system »


Offline Kryptid

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Does the earth have a net direction of movement in space?
« Reply #1 on: 29/04/2011 20:22:47 »
Since the Earth moves around the Sun and the Sun moves around in the Milky Way and the Milky Way moves through's rather difficult to tell exactly what direction the Earth is moving in at any particular time. Directions in space are relative anyway; there is no east, west, north, south, up nor down.

As far as your Big Bang location goes; the Big Bang cannot be said to have happened at any given location. All locations in the Universe used to be at the same place in the Big Bang singularity. The Andromeda Galaxy, the Sun, the refridgerator in your kitchen...all of them used to be in the exact same spot. So, in a sense, the Big Bang happened everywhere all at once.
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Offline myself

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Does the earth have a net direction of movement in space?
« Reply #2 on: 29/04/2011 20:51:46 »
Actually we do know approximately which direction the Earth is moving at any time due to asymmetries in the Cosmic Microwave Background Radiation (CMBR).  More important, we know it is moving forward in one dimension.