Posted on 09/11/2018 11:27:07 AM PDT by ETL
Monty Python says it best.
https://www.youtube.com/watch?v=buqtdpuZxvk
All motion is relative, since there is no absolute reference frame.
Zero.
This doesn’t seem to match the flat earth theory.
“All motion is relative, since there is no absolute reference frame.”
But not all frames of reference are relative at once.
Once one frame is referenced, all others are measurable.
67,000 mph. Give or take. lol
That is why ‘Time Travel’ is impractical.
Even if you perfected a Time Machine, just going back ONE SECOND in TIME would leave you stranded in the middle of a very cold dead space.......................
I thought the ballpark, relative to some sort of “background”, is an average of 1.3 million MPH.
Average, because the various speed components may be additive or subtractive, depending on their direction at the moment.
How come we can tell what motion we have with respect to the CMB? Doesn’t this mean there’s an absolute frame of reference?
The theory of special relativity is based on the principle that there are no preferred reference frames. In other words, the whole of Einstein’s theory rests on the assumption that physics works the same irrespective of what speed and direction you have. So the fact that there is a frame of reference in which there is no motion through the CMB would appear to violate special relativity!
However, the crucial assumption of Einstein’s theory is not that there are no special frames, but that there are no special frames where the laws of physics are different. There clearly is a frame where the CMB is at rest, and so this is, in some sense, the rest frame of the Universe.
But for doing any physics experiment, any other frame is as good as this one. So the only difference is that in the CMB rest frame you measure no velocity with respect to the CMB photons, but that does not imply any fundamental difference in the laws of physics.
How Fast Is Earth Moving?
With respect to what? We are moving at a significant fraction of the speed of light wrt the most distant galaxies in the observable universe. WRT the most distant galaxies beyond the edge of the observable universe? Your guess is as good as mine. Maybe greater than c, since the expansion of space can be faster than c.
“The cosmic microwave background (CMB, CMBR) is electromagnetic radiation as a remnant from an early stage of the universe in Big Bang cosmology. In older literature, the CMB is also variously known as cosmic microwave background radiation (CMBR) or “relic radiation”.
The CMB is a faint cosmic background radiation filling all space that is an important source of data on the early universe because it is the oldest electromagnetic radiation in the universe, dating to the epoch of recombination. ...”
https://en.wikipedia.org/wiki/Cosmic_microwave_background
We are in fact travelling about 600 kilometers per second with respect to the cosmic microwave background, which means we are moving about 600 kps relative to the Big Bang. The Big Bang itself represents the universe’s reference frame. However, it is just as valid to say we are stationary while the universe is moving as to say we are moving while the universe is stationary.
With respect to what?
The article clearly refers to motion with 'respict' to axis spin and orbits around the sun and galaxy. Beyond that there is motion within the "Local Group" and larger super cluster galaxy groupings.
Thanks! Looks interesting. Will check out later.
The title doesn't make it clear that that's all they're talking about. And as you say, they go beyond those two cases themselves. So I did, too.
Any good intro astronomy course will cover all the types of motion in space and there are a LOT more than two of them... I'm a little disappointed in space.com on this one. Not criticizing you. Please don't take it that way. Cheers!
self ping
I watched a youtube video that made some interesting claims last weekend.
1) The cosmic background radiation has some cold spot patterns that basically make a giant x that intersects where Earth is. Verified by 3 differnent scopes/methods. Indicating the earth may be the center of the Universe.
2) According to relativity, whether the earth rotates around the sun or the sun rotates around the earth along with the entire universe, is simply a matter of perspective.
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