Isn’t this idea included or a product of the Big Bang Theory?
The second part of the question is, how come there are new galaxies being discovered if the universe is expanding faster than the speed of light?
Does light travel an infinite amount of distance? Isn’t luminosity or intensity of light a thing?
In: 7
[removed]
>The second part of the question is, how come there are new galaxies being discovered if the universe is expanding faster than the speed of light?
The limitations of telescope technology and the absolute vastness of the Universe. We can’t see to the edge of the visible Universe yet and the part we see at maximum power is so small it would take centuries to observe it all.
Is there any possibility that light itself degrades over time and the wavelength simply gets redshifted because of wave decay rather than the space its travelling through becoming stretched? I think it could be plausible lets get a scientician to do a study. Just need a lab 12bn ly long and we can test it.
Yes. It’s as plain as day. There’s simply no other explanation for what we observe.
>Isn’t this idea included or a product of the Big Bang Theory?
Yes
>The second part of the question is, how come there are new galaxies being discovered if the universe is expanding faster than the speed of light?
Not sure what you think the connection is here. Our ability to detect extremely dim, far away galaxies with better telescopes isn’t related to the rate of expansion of the universe.
>Does light travel an infinite amount of distance? Isn’t luminosity or intensity of light a thing?
Light will travel forever unless and until interacts with something, whether that be 5 meters or 5 billion light years. In our expanding universe, light gets redshifted as the universe expands, but it doesn’t stop existing unless and until it interacts with something. Luminosity isn’t the correct term, but if you mean “light from far away is less bright”, yes, that’s true because light spreads out as it travels so less of it hits the same area, but again, it still exists, it’s just spread out more.
>is it an accepted truth the universe is expanding?
Yes. We can measure it from the red-shift of other galaxies. The faster things move to or away from us, the wavelengths of light they emit get compressed or stretched.
>Isn’t this idea included or a product of the Big Bang Theory?
Tied to the hip with it. The “bang” in the big bang really wasn’t an explosion of stuff. It was more like “and explosion of space”. Space had to expand REALLY fast before the first second. And then of course, expansion slowed down from that rate. The question for a long time was “is it still expanding? Is it reversing? Is it going to reach a point of stability?” And the best answer we have so far, unless models change with new info, is that the rate of expansion is ACCELERATING. So maybe it’s just comes in jutters, for whatever reason.
>The second part of the question is, how come there are new galaxies being discovered if the universe is expanding faster than the speed of light?
Because plenty of galaxies are close enough that their light still reaches us. I could discover a new bistro down the lane if I hadn’t previously seen it. That’s not that far away and while the universe is expanding, it’s not going to escape my cone of causality any time soon. Likewise, a lot of galaxies are relatively “next door”. If you take a powerful telescope and point it at pretty much any section of inky black in the sky, and collect enough photons for long enough, you’ll find so many galaxies that they just look like stars. Which is what the [Hubble did](https://en.wikipedia.org/wiki/Hubble_Deep_Field).
>the universe is expanding faster than the speed of light?
Yeah, let’s hit that part again. There’s two concepts here: 1) The universe is most likely infinite. It just goes on forever. So no matter how small the rate of space expansion is, being cumulative, there will be a point X distance away that is expanding away from us at light-speed. Infinity plays weird games with a lot of math. 2) The VISIBLE universe is a known finite number. It’s the speed of light times the age of the universe in all directions. (~~minus a little~~ plus quite a lot (I got it backwards initially) since the playing field itself was expanding during that time). Every year, it’s diameter grows by 2 lightyears. It has a real and definite edge, but it’s OUR visible universe. Alpha Centari has it’s own visible universe, but shifted over that way a few light-years.
Since the visible universe grows every year, the rate of expansion at the EDGE increases. Even if the expansion wasn’t accelerating, we’d eventually hit a point where the expansion of space overcomes new space entering our visibility. But with the historic and current rate of expansion, and the age of the universe, we’ve already hit that point. Every year the edge of visible space is a lightyear farther away, but the stuff there is falling outside of our view. We’ll never interact with it.
>Does light travel an infinite amount of distance?
Yes. And infinitely fast, since it’s massless. That’s “at the speed of light”. It experiences no time in transit.
>Isn’t luminosity or intensity of light a thing?
For sure. Stuff at the edge of visible space is getting dimmer and dimmer. We’re making some really kick-ass and sensitive telescopes though.
Observing the Red Shift (kind of like visual doppler effect) we can see objects closer to us are moving away at a smaller relative velocity than objects further away. This tells us that the universe is expanding.
>The second part of the question is, how come there are new galaxies being discovered if the universe is expanding faster than the speed of light?
Because the Universe is really bloody big
>Does light travel an infinite amount of distance?
Effectively, yes
> Isn’t luminosity or intensity of light a thing?
Yes. The amount of visible light refracted does indeed drop off after distance and amount of light, but photons can travel pretty much forever.
There is something called the Doppler effect basically as things move away from you the waves created by the retreating object flattens out any waves from the object this is why the note from a siren changes when it passes you, for star this means the wavelength of light flattens which changes light towards a more reddish colour this red shift can be observed in all the stars around us and other galaxies so they are all moving away some at very fast speeds.
Latest Answers