Philosophy Now Forum

You've offered no evidence to back your claim against me, Age, so it's not that I can't defend myself: I simply don't have to.

You got nuthin', so -- yeah -- we're done.

henry quirk wrote: ↑Wed Aug 24, 2022 5:02 am You've offered no evidence to back your claim against me, Age, so it's not that I can't defend myself: I simply don't have to.

You got nuthin', so -- yeah -- we're done.

Again, why do not use my name in your replies to me so that I can then be informed that you have replied?

Now, what do you think or BELIEVE my claim is exactly, which you claim that I have offered no evidence to?

And, why you propose that it is 'against you'?

I was just showing the absurdity of your own insights here.

henry quirk wrote: ↑Fri Aug 19, 2022 12:43 pm Astro,

I am a free man with an inalienable right to my, and no other's, life, liberty, and property. You are a free woman with an inalienable right to your, and no other's, life, liberty, and property.

You ought not screw around with my life, liberty, or property without just cause. I ought not screw around with your life, liberty, or property without just cause.

Just cause: self-defense, defense of another.

Assess & discuss, please.

Hey Henry,

I promise I'm not ignoring anybody. My semester started in earnest and I have a whole lot of other stuff going on aside from that in my life as well right now.

I'm hoping to be able to have the kind of time to post again by next week maybe <3

Astro Cat wrote: ↑Fri Aug 26, 2022 4:28 am

henry quirk wrote: ↑Fri Aug 19, 2022 12:43 pm Astro,

I am a free man with an inalienable right to my, and no other's, life, liberty, and property. You are a free woman with an inalienable right to your, and no other's, life, liberty, and property.

You ought not screw around with my life, liberty, or property without just cause. I ought not screw around with your life, liberty, or property without just cause.

Just cause: self-defense, defense of another.

Assess & discuss, please.

Hey Henry,

I promise I'm not ignoring anybody. My semester started in earnest and I have a whole lot of other stuff going on aside from that in my life as well right now.

I'm hoping to be able to have the kind of time to post again by next week maybe <3

..a quick one then, is the James Webb T. providing data that is making you question previously held theories and perhaps has even thrown a tiger amongst the pigeons? (a simple yay or nay on that later would be appreciated.)

Astro Cat wrote: ↑Fri Aug 26, 2022 4:28 am Hey Henry,

I promise I'm not ignoring anybody. My semester started in earnest and I have a whole lot of other stuff going on aside from that in my life as well right now.

I'm hoping to be able to have the kind of time to post again by next week maybe <3

See you next week, then...

attofishpi wrote: ↑Fri Aug 26, 2022 5:05 am

Astro Cat wrote: ↑Fri Aug 26, 2022 4:28 am

henry quirk wrote: ↑Fri Aug 19, 2022 12:43 pm Astro,

I am a free man with an inalienable right to my, and no other's, life, liberty, and property. You are a free woman with an inalienable right to your, and no other's, life, liberty, and property.

You ought not screw around with my life, liberty, or property without just cause. I ought not screw around with your life, liberty, or property without just cause.

Just cause: self-defense, defense of another.

Assess & discuss, please.

Hey Henry,

I promise I'm not ignoring anybody. My semester started in earnest and I have a whole lot of other stuff going on aside from that in my life as well right now.

I'm hoping to be able to have the kind of time to post again by next week maybe <3

..a quick one then, is the James Webb T. providing data that is making you question previously held theories and perhaps has even thrown a tiger amongst the pigeons? (a simple yay or nay on that later would be appreciated.)

Not so far, a team tested whether G was different in the past (no, it wasn’t)

Astro Cat wrote: ↑Sun Aug 28, 2022 7:00 am

atto wrote: ..a quick one then, is the James Webb T. providing data that is making you question previously held theories and perhaps has even thrown a tiger amongst the pigeons? (a simple yay or nay on that later would be appreciated.)

Not so far, a team tested whether G was different in the past (no, it wasn’t)

One more quick one then. I was under the impression that red shift was a result of light emitting objects moving at speed further away from the observer, however the article that Henry posted is suggesting that (many) galaxys may not actually be moving away from us the observer (and indeed not at an accelerating speed as previously considered via Mr Hubble)

So.

Would we normally expect light that is emmitting from a source of great distance to continue with its originating wavelength (not taking into account other factors such as gravitational lensing\refraction - sorry if they are incorrect terms here) IF it is at a stationary point with respect to distance from us?

attofishpi wrote: ↑Sun Aug 28, 2022 7:20 am

Astro Cat wrote: ↑Sun Aug 28, 2022 7:00 am

atto wrote: ..a quick one then, is the James Webb T. providing data that is making you question previously held theories and perhaps has even thrown a tiger amongst the pigeons? (a simple yay or nay on that later would be appreciated.)

Not so far, a team tested whether G was different in the past (no, it wasn’t)

One more quick one then. I was under the impression that red shift was a result of light emitting objects moving at speed further away from the observer, however the article that Henry posted is suggesting that (many) galaxys may not actually be moving away from us the observer (and indeed not at an accelerating speed as previously considered via Mr Hubble)

So.

Would we normally expect light that is emmitting from a source of great distance to continue with its originating wavelength (not taking into account other factors such as gravitational lensing\refraction - sorry if they are incorrect terms here) IF it is at a stationary point with respect to distance from us?

Most galaxies are moving away, but they will have peculiar motion when they're near us (that's their "actual" motion, not the motion of the Hubble flow), so they'll deviate from the Hubble flow (which is the general movement away):



For instance here you can see a lot of galaxies that deviate a lot from the Hubble Flow because they're in the Virgo Cluster (the blue oval). There's a lot of gravity there so a lot of "true" motion going on: some towards us, some away.

Astro Cat wrote: ↑Wed Aug 31, 2022 10:14 am For instance here you can see a lot of galaxies that deviate a lot from the Hubble Flow because they're in the Virgo Cluster (the blue oval). There's a lot of gravity there so a lot of "true" motion going on: some towards us, some away.

Hi Astro thanks for the above, but not sure if I made my question rather ambiguous, or I still just don't comprehend.

Let me put it another way.

Let's say there are two identical stars (I know this scenario is totally unlikely), one is 1000 light years from us, and is stationary in relation to us. The other is 1,000,000 light years from us, and is also stationary in relation to us.

Does the wavelength that arrives to us remain identical from both stars? Or does the wavelength of the star that is futher away have a greater wavelength (more "red" shifted)?

attofishpi wrote: ↑Wed Aug 31, 2022 12:58 pm

Astro Cat wrote: ↑Wed Aug 31, 2022 10:14 am For instance here you can see a lot of galaxies that deviate a lot from the Hubble Flow because they're in the Virgo Cluster (the blue oval). There's a lot of gravity there so a lot of "true" motion going on: some towards us, some away.

Hi Astro thanks for the above, but not sure if I made my question rather ambiguous, or I still just don't comprehend.

Let me put it another way.

Let's say there are two identical stars (I know this scenario is totally unlikely), one is 1000 light years from us, and is stationary in relation to us. The other is 1,000,000 light years from us, and is also stationary in relation to us.

Does the wavelength that arrives to us remain identical from both stars? Or does the wavelength of the star that is futher away have a greater wavelength (more "red" shifted)?

The one from the star that's further away is more redshifted, but it is technically not the Doppler effect: it is a consequence of the peaks and troughs being further and further apart as the space between them expands (and we see radiation with increasing distance between peaks as a redshift).

So, to try to digest your question in the different ways I can think you might be curious about:

1) If you mean that these two test objects are literally stationary in relation to us (some alien civilization thinks our world is special, and they hold these two stars stationary in relation to us against the expansion of the universe), then with a completely clear path (dust will attenuate light to look like redshift, too) there would not be any redshift from either object.

2) If you mean that these two test objects simply aren't orbiting anything (have no peculiar/true motion) but they do "move" as the universe expands, like two points on an expanding balloon (they're not "moving," but the space around them sweeps them along for the ride), then yes there would be redshift, and the further one would be redshifted more.

So, you originally mentioned someone saying something like that most galaxies aren't moving (I don't remember how you phrased it exactly). What I suspect is probably a case of misinterpretation: there is a distance away from an observer where peculiar motion (think of this like "true" motion: the dots on the balloon are actually moving on the balloon) is completely negligible because the expansion overpowers it.

The closer objects are, the more their peculiar motion matters: Andromeda is blueshifted from our perspective because of its peculiar motion (straight towards us) for instance. Or consider all of those galaxies all over the place on the plot I posted in the Virgo Cluster: they're near enough to us as observers that their peculiar motion matters a lot.

But peculiar motion has an upper speed limit (and we will see that speed limit in galactic clusters, where gravity is the craziest). The expansion (the Hubble flow), however, gets stronger and stronger the further away something is. Since peculiar motion caps out at a few thousand km/s, there is a distance at which peculiar motion becomes completely negligible and all that matters is the Hubble flow.

This is probably what the article you were mentioning is talking about. It's not that galaxies out there aren't moving: they're moving in all sorts of directions, even towards us. It's that the expansion so vastly outstrips their peculiar motion that it's utterly negligible.

Astro Cat wrote: ↑Thu Sep 01, 2022 5:06 am

attofishpi wrote: ↑Wed Aug 31, 2022 12:58 pm

Astro Cat wrote: ↑Wed Aug 31, 2022 10:14 am For instance here you can see a lot of galaxies that deviate a lot from the Hubble Flow because they're in the Virgo Cluster (the blue oval). There's a lot of gravity there so a lot of "true" motion going on: some towards us, some away.

Hi Astro thanks for the above, but not sure if I made my question rather ambiguous, or I still just don't comprehend.

Let me put it another way.

Let's say there are two identical stars (I know this scenario is totally unlikely), one is 1000 light years from us, and is stationary in relation to us. The other is 1,000,000 light years from us, and is also stationary in relation to us.

Does the wavelength that arrives to us remain identical from both stars? Or does the wavelength of the star that is futher away have a greater wavelength (more "red" shifted)?

The one from the star that's further away is more redshifted, but it is technically not the Doppler effect: it is a consequence of the peaks and troughs being further and further apart as the space between them expands (and we see radiation with increasing distance between peaks as a redshift).

So, to try to digest your question in the different ways I can think you might be curious about:

1) If you mean that these two test objects are literally stationary in relation to us (some alien civilization thinks our world is special, and they hold these two stars stationary in relation to us against the expansion of the universe), then with a completely clear path (dust will attenuate light to look like redshift, too) there would not be any redshift from either object.

2) If you mean that these two test objects simply aren't orbiting anything (have no peculiar/true motion) but they do "move" as the universe expands, like two points on an expanding balloon (they're not "moving," but the space around them sweeps them along for the ride), then yes there would be redshift, and the further one would be redshifted more.

Ah! Thank you Astro Cat

attofishpi wrote: ↑Thu Sep 01, 2022 5:10 am

Astro Cat wrote: ↑Thu Sep 01, 2022 5:06 am

attofishpi wrote: ↑Wed Aug 31, 2022 12:58 pm

Hi Astro thanks for the above, but not sure if I made my question rather ambiguous, or I still just don't comprehend.

Let me put it another way.

Let's say there are two identical stars (I know this scenario is totally unlikely), one is 1000 light years from us, and is stationary in relation to us. The other is 1,000,000 light years from us, and is also stationary in relation to us.

Does the wavelength that arrives to us remain identical from both stars? Or does the wavelength of the star that is futher away have a greater wavelength (more "red" shifted)?

The one from the star that's further away is more redshifted, but it is technically not the Doppler effect: it is a consequence of the peaks and troughs being further and further apart as the space between them expands (and we see radiation with increasing distance between peaks as a redshift).

So, to try to digest your question in the different ways I can think you might be curious about:

1) If you mean that these two test objects are literally stationary in relation to us (some alien civilization thinks our world is special, and they hold these two stars stationary in relation to us against the expansion of the universe), then with a completely clear path (dust will attenuate light to look like redshift, too) there would not be any redshift from either object.

2) If you mean that these two test objects simply aren't orbiting anything (have no peculiar/true motion) but they do "move" as the universe expands, like two points on an expanding balloon (they're not "moving," but the space around them sweeps them along for the ride), then yes there would be redshift, and the further one would be redshifted more.

Ah! Thank you Astro Cat

I edited that last response with more info that I think might address the original article you were mentioning

Astro Cat wrote: ↑Thu Sep 01, 2022 5:12 am

attofishpi wrote: ↑Thu Sep 01, 2022 5:10 am Ah! Thank you Astro Cat

I edited that last response with more info that I think might address the original article you were mentioning

Ok cheers, will have a look later...busy preparing for my stand-up comedy act tonight, I think if I was in the US i'd be packing a gun just in case I got heckled and the heckler out-witted me, at least more than once.

attofishpi wrote: ↑Thu Sep 01, 2022 5:10 am

Astro Cat wrote: ↑Thu Sep 01, 2022 5:06 am This is probably what the article you were mentioning is talking about. It's not that galaxies out there aren't moving: they're moving in all sorts of directions, even towards us. It's that the expansion so vastly outstrips their peculiar motion that it's utterly negligible.

I wanted to clarify this further maybe using the balloon analogy, because when I say "even towards us," I don't want to give the wrong impression.

Imagine drawing a big dot on a balloon and a smaller one orbiting it. Then draw a dot some distance away (this second dot is us).

As the balloon expands, the big dot is moving away from our dot. The dot orbiting the big dot, though, has peculiar ("true") motion: it's actually moving on the skin of the balloon rather than just being swept along with the skin of the balloon.

Put yourself in our dot's point of view and look at the dot/orbiting dot that's heading away from us as the balloon expands. Sometimes, the orbiting dot will be moving away from us faster than the big dot (when its orbit has it moving a direction away from our dot), and sometimes the orbiting dot will be moving away from us slower than the big dot (when it swings back around and seems to be moving towards our dot momentarily).

At all times, the orbiting dot is still moving away from us ultimately, so it will be redshifted. But, in terms of "true" motion, during parts of its orbit it's moving "towards" us. That make more sense?

attofishpi wrote: ↑Thu Sep 01, 2022 5:17 am

Astro Cat wrote: ↑Thu Sep 01, 2022 5:12 am

attofishpi wrote: ↑Thu Sep 01, 2022 5:10 am Ah! Thank you Astro Cat

I edited that last response with more info that I think might address the original article you were mentioning

Ok cheers, will have a look later...busy preparing for my stand-up comedy act tonight, I think if I was in the US i'd be packing a gun just in case I got heckled and the heckler out-witted me, at least more than once.

Good luck, hope you knock 'em dead!