Multiverse: have astronomers found evidence of parallel universes?

a reply to: seasonal

one theory is it is from a collision between our universe and a bubble universe.

Is it an ongoing collision or bubble universe bounced off ours? The 'cold spot' should grow or diminish over some period of time, otherwise collision theory has no means to be verified. And I take it, the article implies our universe is also a 'bubble'.

On a side note I wonder, if CMBR map remains unchanged since we started to monitor it?

originally posted by: Moresby
Some have suggested that there may be some problems with the reliability of red shift. And that could explain anomalies like this or dark matter.

originally posted by: nerbot
Perhaps another "big bang" off in the distance of space created a decelleration of the redshift at that point we see, therefore cancelling out the redshift in that area to create the apparent void/cold spot.

originally posted by: Moresby
Fascinating. Thanks for sharing.

I like the way you're thinking.

It could well be something of that nature.

A red shift from another universe, or some other part of the universe that may be off for some reason, wouldn't cancel out another red shift unless is was 180 degrees out of phase with it. The positive wave of one red shift wave would have to be in the same spot as a negative wave of the other to cancel it out. If what you describe were two wave fronts out of phase, but less than 180 degrees, then it would display the characteristics of a comb filter (a well known effect).

To understand phasing, it is the same effect you can see when light is viewed through two window screens, one on top of the other. When the holes are lined up perfectly, it looks like a normal screen, but when they get out of alignment, you see larger or smaller phantom square screen holes as they get more out of phase.

In acoustics, when you have the same sound coming out of two speakers and one speaker has the + & - polarities reversed, when you place the speakers closely facing each other, the sound is greatly reduced in volume and frequency range due to the cancelling effect.

To create a red shift cold spot due to phase canceling, you'd need another universe that has the same red shift, but the opposite polarity, to cancel out the background heat and create the cold spot. That would be highly improbable, very nearly impossible to occur naturally.

ETA: Another consideration is that a red shift is caused when the signal is heading away from us (the Doppler effect). So there would have to be another universe (or signal source) that was not only 180 degrees out of phase, but traveling away from us at the same rate as our universe is expanding, or at least radiating at the same frequency as our universe's background radiation. Impossible I would think.

originally posted by: greenreflections
a reply to: seasonal

one theory is it is from a collision between our universe and a bubble universe.

Is it an ongoing collision or bubble universe bounced off ours? The 'cold spot' should grow or diminish over some period of time, otherwise collision theory has no means to be verified. And I take it, the article implies our universe is also a 'bubble'.

On a side note I wonder, if CMBR map remains unchanged since we started to monitor it?

Just to add a bit....If universes are a "bubble", we should see not only one collision signature but 'cold spots' in other places as well..No? In addition, having only one single 'cold spot' would imply there are only two universes -- ours and the one which penetrates into ours (or got bounced off, leaving imprint of impact).

...people spend too much time bubble bathing...