Are there any figures for the number of galaxies in the unobservable universe ?

I read somewhere that it was more than seven.

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

No. we don’t even know how big that bit is.

sibeen said:

I read somewhere that it was more than seven.

well there’s the 5G autismmunisation galaxy
the religious fanatics, things like Hillsong Islamic Pentecostal State of matter
then the Second Amendmentalists
Fossil Fuelled Climate Denialists
need a few more to boldly go out there

forgot the Undead Elvisians, and then the Scientologists

there’s the possibility they’re all in the same galaxy though

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

There could be a reasonable guess on the minimum.

There is no upper limit.

sibeen said:

I read somewhere that it was more than seven.

Yes. I’d say “at least seven” too.

Bogsnorkler said:

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

No. we don’t even know how big that bit is.

Can they wok out how big it is from the expansion speed from the past ?

Tau.Neutrino said:

Bogsnorkler said:

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

No. we don’t even know how big that bit is.

Can they wok out how big it is from the expansion speed from the past ?

well look if it’s anything like the prawn crackers then you’d get quite rapid inflation

Tau.Neutrino said:

Bogsnorkler said:

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

No. we don’t even know how big that bit is.

Can they wok out how big it is from the expansion speed from the past ?

No. Because we don’t know how big it started out as…could be infinite or just really really big, we don’t know. Although current measurements, WMAP, along with GR indicate it is infinite.

According to these people,

>using the new WMAP data, we can say that there are at least 21 patches out there the same volume as ours, at 95% confidence.

https://arxiv.org/abs/astro-ph/0605709

So, given that there at least 2 trillion galaxies in our observable, we can assume there are at least 42 trillion galaxies beyond our view.

Bubblecar said:

According to these people,

>using the new WMAP data, we can say that there are at least 21 patches out there the same volume as ours, at 95% confidence.

https://arxiv.org/abs/astro-ph/0605709

So, given that there at least 2 trillion galaxies in our observable, we can assume there are at least 42 trillion galaxies beyond our view.

our observable patch

Tau.Neutrino said:

Bogsnorkler said:

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

No. we don’t even know how big that bit is.

Can they wok out how big it is from the expansion speed from the past ?

No.

Bogsnorkler said:

Tau.Neutrino said:

Bogsnorkler said:

No. we don’t even know how big that bit is.

Can they wok out how big it is from the expansion speed from the past ?

No. Because we don’t know how big it started out as…could be infinite or just really really big, we don’t know. Although current measurements, WMAP, along with GR indicate it is infinite.

No they don’t.

No measurements could possibly do that.

The Rev Dodgson said:

Bogsnorkler said:

Tau.Neutrino said:

Can they wok out how big it is from the expansion speed from the past ?

No. Because we don’t know how big it started out as…could be infinite or just really really big, we don’t know. Although current measurements, WMAP, along with GR indicate it is infinite.

No they don’t.

No measurements could possibly do that.

sorry you’re wrong.

Bogsnorkler said:

The Rev Dodgson said:

Bogsnorkler said:

No. Because we don’t know how big it started out as…could be infinite or just really really big, we don’t know. Although current measurements, WMAP, along with GR indicate it is infinite.

No they don’t.

No measurements could possibly do that.

sorry you’re wrong.

Prove it.

The Rev Dodgson said:

Bogsnorkler said:

The Rev Dodgson said:

No they don’t.

No measurements could possibly do that.

sorry you’re wrong.

Prove it.

wmap results indicate flat universe, within a very small degree of error, gr says flat universe is infinite.

I think it’s near infinite a lot.

Bogsnorkler said:

The Rev Dodgson said:

Bogsnorkler said:

sorry you’re wrong.

Prove it.

wmap results indicate flat universe, within a very small degree of error, gr says flat universe is infinite.

I know that, but that doesn’t indicate infinite, it indicates very big.

The Rev Dodgson said:

Bogsnorkler said:

The Rev Dodgson said:

Prove it.

wmap results indicate flat universe, within a very small degree of error, gr says flat universe is infinite.

I know that, but that doesn’t indicate infinite, it indicates very big.

prove it

Bogsnorkler said:

The Rev Dodgson said:

Bogsnorkler said:

wmap results indicate flat universe, within a very small degree of error, gr says flat universe is infinite.

I know that, but that doesn’t indicate infinite, it indicates very big.

prove it

Sure:

wmap results indicate flat universe, within a very small degree of error.

The Rev Dodgson said:

Bogsnorkler said:

The Rev Dodgson said:

I know that, but that doesn’t indicate infinite, it indicates very big.

prove it

Sure:

wmap results indicate flat universe, within a very small degree of error.

but high precision.

Bogsnorkler said:

The Rev Dodgson said:

Bogsnorkler said:

prove it

Sure:

wmap results indicate flat universe, within a very small degree of error.

but high precision.

High precision is not infinite precision.

There is an infinite range of possible sizes beyond the minimum size indicated by any measurement which has finite error.

Bogsnorkler said:

The Rev Dodgson said:

Bogsnorkler said:

prove it

Sure:

wmap results indicate flat universe, within a very small degree of error.

but high precision.

you realise that nobody is saying it definitely is infinite just that the measurement plus GR say it is. As i pointed out earlier, no one knows how big it was before.

The Rev Dodgson said:

Bogsnorkler said:

The Rev Dodgson said:

Sure:

wmap results indicate flat universe, within a very small degree of error.

but high precision.

High precision is not infinite precision.

There is an infinite range of possible sizes beyond the minimum size indicated by any measurement which has finite error.

wibble.

see what we mean about number of intelligent lifeforms in the visible universe, or indeed any universe

Bogsnorkler said:

Bogsnorkler said:

The Rev Dodgson said:

Sure:

wmap results indicate flat universe, within a very small degree of error.

but high precision.

you realise that nobody is saying it definitely is infinite just that the measurement plus GR say it is. As i pointed out earlier, no one knows how big it was before.

I am not saying that the probability of a finite universe is very small but non-zero.

I am saying we have no way of putting a number on that probability.

Bogsnorkler said:

The Rev Dodgson said:

Bogsnorkler said:

but high precision.

High precision is not infinite precision.

There is an infinite range of possible sizes beyond the minimum size indicated by any measurement which has finite error.

wibble.

What does that mean?

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

It can be calculated, even for a flat Euclidean universe outside the observable limit. The metastability of the universe gives a space-time scale for where the universe breaks down. Take that distance to get a volume and multiply it by the density of galaxies in the observable universe.

Do you want me to do the calculation?

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

No

dv said:

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

No

that’s what I said.

Bogsnorkler said:

dv said:

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

No

that’s what I said.

Now we just need to hear from DO and we’ll have a quorum

The Rev Dodgson said:

Bogsnorkler said:

The Rev Dodgson said:

High precision is not infinite precision.

There is an infinite range of possible sizes beyond the minimum size indicated by any measurement which has finite error.

wibble.

What does that mean?

Wibble

mollwollfumble said:

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

It can be calculated, even for a flat Euclidean universe outside the observable limit. The metastability of the universe gives a space-time scale for where the universe breaks down. Take that distance to get a volume and multiply it by the density of galaxies in the observable universe.

Do you want me to do the calculation?

Yes Please.

mollwollfumble said:

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

It can be calculated, even for a flat Euclidean universe outside the observable limit. The metastability of the universe gives a space-time scale for where the universe breaks down. Take that distance to get a volume and multiply it by the density of galaxies in the observable universe.

Do you want me to do the calculation?

Yes please

Ian said:

The Rev Dodgson said:

Bogsnorkler said:

wibble.

What does that mean?

Wibble

Thanks Ian.

Any thoughts on how that relates to what I said?

Tau.Neutrino said:

mollwollfumble said:

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

It can be calculated, even for a flat Euclidean universe outside the observable limit. The metastability of the universe gives a space-time scale for where the universe breaks down. Take that distance to get a volume and multiply it by the density of galaxies in the observable universe.

Do you want me to do the calculation?

Yes Please.

I wonder how many Yes Pleases moll needs.

The Rev Dodgson said:

Ian said:

The Rev Dodgson said:

What does that mean?

Wibble

Thanks Ian.

Any thoughts on how that relates to what I said?

I’m guessing that boris is feigning madness or has actually gone mad. Probably the latter.

Ian said:

The Rev Dodgson said:

Ian said:

Wibble

Thanks Ian.

Any thoughts on how that relates to what I said?

I’m guessing that boris is feigning madness or has actually gone mad. Probably the latter.

Oh, that’s alright then :)

The Rev Dodgson said:

mollwollfumble said:

Tau.Neutrino said:

Are there any figures for the number of galaxies in the unobservable universe ?

It can be calculated, even for a flat Euclidean universe outside the observable limit. The metastability of the universe gives a space-time scale for where the universe breaks down. Take that distance to get a volume and multiply it by the density of galaxies in the observable universe.

Do you want me to do the calculation?

Yes please

Dang. I suppose that means I’ll have to.

Perhaps a starting point is https://www.frontiersin.org/articles/10.3389/fspas.2018.00040/full “Cosmological Aspects of Higgs Vacuum Metastability”.

That reference mentions vacuum decay rate, but does it calculate it, that’s what I need. Let’s go down to section 4. Equation 4.1 applies for calculation of transition rate, but need to find numbers to plug into it. Then down to equation 4.12, “In quantum field theory, the decay rate per unit volume and time of a metastable vacuum decays was first discussed by Coleman (Coleman, 1977; Callan and Coleman, 1977)”. “Precise calculations of the pre-factor A in the Standard Model were performed in Isidori et al. (2001)”.

“The decay rate for a flat false vacuum” is B = 1805.8, but what units? If B were less than 540 then the universe would not have survived to the current day.

Nope, not getting anywhere, try an easier to read account.

Try this one. https://www.researchgate.net/publication/258345824_Vacuum_Stability_and_the_Higgs_Boson

“The decay probability rate of the EW vacuum per unit time and unit volume can be calculated by semiclassical methods, it is basically …one gets for the decay rate the numerical estimate d p/(dV dt)∼h^4 exp(−2600/(|λ|/0.01)).”

Here h is the Hubble constant, but what is λ?

“This has to be multiplied by the 4-d space-time volume inside our past light-cone, which is basically the fourth power of the age of the Universe”

For the present calculation I’m looking outside the observable universe so the the volume is larger than inside the light cone by an amount that I still have to determine. The following diagram looks like sufficient information.

The correct curve to use is the CDM curve, the LambdaCDM curve is for the far future where dark energy dominates over dark+baryonic matter. So, we’ve got our number. 10^200 years. Next step is for me to find the 4-volume of the unobserved universe at the present time that corresponds to the 4-volume of the observed universe at that future time. Age of universe is 1.38*10^10 years. 10^200/10^10 = 10^190 times the ago oif the universe. 4-volume goes as the fourth power of time. So the unobserved universe top the edge of instability has (10^190)^4 = 10^760 times the 4-volume of the observable universe. We’re talking present time so age is constant and the unobserved universe also has 10^760 times the 3-volume of the observable universe.

So far so good.

There are 2 trillion galaxies in the observable universe. That’s 2*10^12. So a ballpark estimate the number of galaxies in the unobservable universe is 10^760 * 2*10^12 = 2*10^772. Give or take a factor of 10^200.

mollwollfumble said:

The Rev Dodgson said:

mollwollfumble said:

It can be calculated, even for a flat Euclidean universe outside the observable limit. The metastability of the universe gives a space-time scale for where the universe breaks down. Take that distance to get a volume and multiply it by the density of galaxies in the observable universe.

Do you want me to do the calculation?

Yes please

Dang. I suppose that means I’ll have to.

Perhaps a starting point is https://www.frontiersin.org/articles/10.3389/fspas.2018.00040/full “Cosmological Aspects of Higgs Vacuum Metastability”.

That reference mentions vacuum decay rate, but does it calculate it, that’s what I need. Let’s go down to section 4. Equation 4.1 applies for calculation of transition rate, but need to find numbers to plug into it. Then down to equation 4.12, “In quantum field theory, the decay rate per unit volume and time of a metastable vacuum decays was first discussed by Coleman (Coleman, 1977; Callan and Coleman, 1977)”. “Precise calculations of the pre-factor A in the Standard Model were performed in Isidori et al. (2001)”.

“The decay rate for a flat false vacuum” is B = 1805.8, but what units? If B were less than 540 then the universe would not have survived to the current day.

Nope, not getting anywhere, try an easier to read account.

Try this one. https://www.researchgate.net/publication/258345824_Vacuum_Stability_and_the_Higgs_Boson

“The decay probability rate of the EW vacuum per unit time and unit volume can be calculated by semiclassical methods, it is basically …one gets for the decay rate the numerical estimate d p/(dV dt)∼h^4 exp(−2600/(|λ|/0.01)).”

Here h is the Hubble constant, but what is λ?

“This has to be multiplied by the 4-d space-time volume inside our past light-cone, which is basically the fourth power of the age of the Universe”

For the present calculation I’m looking outside the observable universe so the the volume is larger than inside the light cone by an amount that I still have to determine. The following diagram looks like sufficient information.

The correct curve to use is the CDM curve, the LambdaCDM curve is for the far future where dark energy dominates over dark+baryonic matter. So, we’ve got our number. 10^200 years. Next step is for me to find the 4-volume of the unobserved universe at the present time that corresponds to the 4-volume of the observed universe at that future time. Age of universe is 1.38*10^10 years. 10^200/10^10 = 10^190 times the ago oif the universe. 4-volume goes as the fourth power of time. So the unobserved universe top the edge of instability has (10^190)^4 = 10^760 times the 4-volume of the observable universe. We’re talking present time so age is constant and the unobserved universe also has 10^760 times the 3-volume of the observable universe.

So far so good.

There are 2 trillion galaxies in the observable universe. That’s 2*10^12. So a ballpark estimate the number of galaxies in the unobservable universe is 10^760 * 2*10^12 = 2*10^772. Give or take a factor of 10^200.

Could you explain the basis of the calculations though, so I can understand how the numbers you have selected put an upper limit on universe volume.

The Rev Dodgson said:

mollwollfumble said:

The Rev Dodgson said:

Yes please

Dang. I suppose that means I’ll have to.

Perhaps a starting point is https://www.frontiersin.org/articles/10.3389/fspas.2018.00040/full “Cosmological Aspects of Higgs Vacuum Metastability”.

That reference mentions vacuum decay rate, but does it calculate it, that’s what I need. Let’s go down to section 4. Equation 4.1 applies for calculation of transition rate, but need to find numbers to plug into it. Then down to equation 4.12, “In quantum field theory, the decay rate per unit volume and time of a metastable vacuum decays was first discussed by Coleman (Coleman, 1977; Callan and Coleman, 1977)”. “Precise calculations of the pre-factor A in the Standard Model were performed in Isidori et al. (2001)”.

“The decay rate for a flat false vacuum” is B = 1805.8, but what units? If B were less than 540 then the universe would not have survived to the current day.

Nope, not getting anywhere, try an easier to read account.

Try this one. https://www.researchgate.net/publication/258345824_Vacuum_Stability_and_the_Higgs_Boson

“The decay probability rate of the EW vacuum per unit time and unit volume can be calculated by semiclassical methods, it is basically …one gets for the decay rate the numerical estimate d p/(dV dt)∼h^4 exp(−2600/(|λ|/0.01)).”

Here h is the Hubble constant, but what is λ?

“This has to be multiplied by the 4-d space-time volume inside our past light-cone, which is basically the fourth power of the age of the Universe”

For the present calculation I’m looking outside the observable universe so the the volume is larger than inside the light cone by an amount that I still have to determine. The following diagram looks like sufficient information.

The correct curve to use is the CDM curve, the LambdaCDM curve is for the far future where dark energy dominates over dark+baryonic matter. So, we’ve got our number. 10^200 years. Next step is for me to find the 4-volume of the unobserved universe at the present time that corresponds to the 4-volume of the observed universe at that future time. Age of universe is 1.38*10^10 years. 10^200/10^10 = 10^190 times the ago oif the universe. 4-volume goes as the fourth power of time. So the unobserved universe top the edge of instability has (10^190)^4 = 10^760 times the 4-volume of the observable universe. We’re talking present time so age is constant and the unobserved universe also has 10^760 times the 3-volume of the observable universe.

So far so good.

There are 2 trillion galaxies in the observable universe. That’s 2*10^12. So a ballpark estimate the number of galaxies in the unobservable universe is 10^760 * 2*10^12 = 2*10^772. Give or take a factor of 10^200.

Could you explain the basis of the calculations though, so I can understand how the numbers you have selected put an upper limit on universe volume.

Define “basis”? Do you want the quantum mechanics? Or the assumptions? To put it in a nutshell, the maximum size of the unobserved universe is limited by the probability of the destruction of that universe approaching 100%.

I can get the same answer more directly from the left hand diagram above.

The probability of the observable universe exploding is 10^-750, give or take a factor of about 10^200. So the upper limit on the volume of the unobserved universe is about 10^750 times the volume of the observable universe. Multiplying by the 2 trillion galaxies in the observable universe gives 10^750 * 2*10^12 = 2*10^762. Give or take a factor of 10^200.

There are various assumption here. The main three are that:
1) The curvature of the universe is either zero or negative. The arguments are not invalidated if the universe is hyperbolic.
2) Local ruptions of the quantum vacuum are ignored. These include black holes, magnetars and hypernovae.
3) The era of cosmic inflation expanded fast enough to make a bubble big enough to contain all these galaxies.

I can’t do anything about the first two. The second could severely limit the size of the unobserved universe. But I wonder if there’s enough information out there for me to calculate the third?

Not keen on delving into the scientific papers to find out.

https://www.sciencealert.com/the-inevitable-abyss-each-year-we-lose-yet-another-section-of-the-universe