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Wyvernrider t1_j4a9gse wrote

How are they able to make sense of galaxies so far away that the light would be so heavily distorted from the immense spacetime between?

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skofan t1_j4a9xu8 wrote

Thats what redshift is, and they're using that "distortion" to measure the age of the galaxies.

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Wyvernrider t1_j4agei3 wrote

I'm not talking about simply the speed at which objects are moving away from each other's effect. I'm talking about the effects of all the objects in-between such as other galaxies.

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jstenoien t1_j4ahxzw wrote

Space is really REALLY empty.

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Socky_McPuppet t1_j4b61x5 wrote

Yes and the matter that is in it is not evenly distributed - it tends to bunch together, and at the largest scales, it looks like a foam, with all the matter distributed along the edges of the bubbles, and really big empty spaces in between. I mean, there's an area of space that's a billion light years across, and there's nothing in it, as far as we can tell.

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aris_ada t1_j4arvf4 wrote

Unless you're watching in a busy direction (galactic plane, galaxy clusters etc.) Space is mostly empty. The expansion of the universe does not alter the shape of far objects, but changes the redshift and also the scale.

It's very paradoxal, but starting from a certain distance/time in the past, objects start looking bigger in the sky than closer same-sized objects, because the universe was much smaller when its light was emitted. So in practice we should be able to watch the earliest galaxies of the universe.

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Riegel_Haribo t1_j4cspoc wrote

This is reporting on Yan et al, which is a paper using data of one of the first-release JWST publicity images planned by the telescope institute, and has already been called out as with issues. It is of SMACS 0723-27, one of the most significant gravitational lenses yet discovered, so yes, the warping of space-time is problematic, as galaxies are indeed amplified, stretched, multiplied by this distortion, and given in some cases a significantly deeper view than direct observation.

This should be first a study in further mapping the gravitational gradient, the nature of dark matter, and not jump right to finding redshifts from imaging. JWST's NIRCam imaging is actually a bit wrong for Lyman break astronomy at the (unexcitingly not-so-deep) redshifts being found, as the coarse transition from 200W to 277W is across two different instruments of different resolution and still faltering calibration and backgrounding even across adjacent sensors, along with cosmic ray flux and algorithmic removal that makes almost nothing pristine light.

Also it is clear that the nature of what is found early, but closer and actually resolvable, is going to create biases. Various radiance of active galactic nuclei, early formation of globular clusters, mergers, etc skew the spectra, and we still don't have spectral observations deep enough to show emission lines (Arizona paper).

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