Hubble telescope finds 'never-seen' galaxies

"Phillip Helbig---undress to reply"
schreef in bericht ...
In article , "Nicolaas Vroom"
writes:

What does a red shift of 6 physical mean.

It means that the universe now is 7 times larger than when the light
was
emitted.

Are you sure you mean universe ?
Does this picture http://antwrp.gsfc.nasa.gov/apod/ap091209.html
proves your point of view ?
What that picture shows is an image of the past and not what
the present situation is.
In fact this picture says nothing IMO about the total Universe.

That is what it means assuming that the universe is described by the
Friedmann-Lemaitre equations, i.e. that it a) is described by general
relativity and b) it is homogeneous and isotropic on large scales (for
which there is observational evidence, so this is not really an
assumption).

The evidence exists of for example what "this picture" shows and
that is an image of the past.
And if I interpret that picture correct than it shows an evolution
in galaxy structures.
To claim anything about the present situation is inferred and based
on assumptions.
That does not mean that the present universe is not homogeneous.

But even if the Universe is homogeneous there is a problem with
the law v = H * d with v and d being the proper distance
(i.e. the present distance).
The problem is the relation z = (H/c) * d with d being the
distance at emission (i.e. in the past)
This relation is used to calculate the Hubble constant H
(based on observations of both z and d).
The problem is that the two Hubble constants can not be
the same.
This problem is explained he
http://users.telenet.be/nicvroom/bigbangh.htm
which explains that the two laws are in conflict with
each other.
The problem is identical if H is constant in time or variable

Nicolaas Vroom.

In article , "Nicolaas Vroom"
writes:

But even if the Universe is homogeneous there is a problem with
the law v = H * d with v and d being the proper distance
(i.e. the present distance).
The problem is the relation z = (H/c) * d with d being the
distance at emission (i.e. in the past)
This relation is used to calculate the Hubble constant H
(based on observations of both z and d).
The problem is that the two Hubble constants can not be
the same.

This problem of yours has been addressed here in the newsgroup many
times. Why do you keep asking it?

Please state, clearly and exactly, what you think the problem is.

"Phillip Helbig---undress to reply"
schreef in bericht ...
In article , "Nicolaas Vroom"
writes:

But even if the Universe is homogeneous there is a problem with
the law v = H * d with v and d being the proper distance
(i.e. the present distance).
The problem is the relation z = (H/c) * d with d being the
distance at emission (i.e. in the past)
This relation is used to calculate the Hubble constant H
(based on observations of both z and d).
The problem is that the two Hubble constants can not be
the same.

This problem of yours has been addressed here in the newsgroup many
times. Why do you keep asking it?

Please state, clearly and exactly, what you think the problem is.

The problem is threefold.
First you have the law : v = H * d
With v and d (and H) being the present values. (proper values)
The question is how do you calculate those based on observations ?
The problem is neither one of those values can directly be observed.

For the sun a similar problem exits. What is observed is a position
in the past 8 minutes ago. To calculate the present position
you need a "model".

Second you have the law: z = (H/c) * d.
d is the distance in the past and z is the present value.
This is the equation used to calculate the Hubble Constant H.

Third again you have the law: v = H * d
but now with v, d and H values in the past.

IMO the real problem is that each of those three values
for H is different.
Q: is this "assumption" correct ?

For more information read:
http://users.telenet.be/nicvroom/bigbangh.htm

Nicolaas Vroom

Thus spake Nicolaas Vroom
"Phillip Helbig---undress to reply"
schreef in bericht ...
In article , "Nicolaas Vroom"
writes:

But even if the Universe is homogeneous there is a problem with
the law v = H * d with v and d being the proper distance
(i.e. the present distance).
The problem is the relation z = (H/c) * d with d being the
distance at emission (i.e. in the past)
This relation is used to calculate the Hubble constant H
(based on observations of both z and d).
The problem is that the two Hubble constants can not be
the same.

This problem of yours has been addressed here in the newsgroup many
times. Why do you keep asking it?

Please state, clearly and exactly, what you think the problem is.

The problem is threefold.
First you have the law : v = H * d
With v and d (and H) being the present values. (proper values) The
question is how do you calculate those based on observations ? The
problem is neither one of those values can directly be observed.

For the sun a similar problem exits. What is observed is a position in
the past 8 minutes ago. To calculate the present position you need a
"model".

Second you have the law: z = (H/c) * d.
d is the distance in the past and z is the present value. This is the
equation used to calculate the Hubble Constant H.

Third again you have the law: v = H * d
but now with v, d and H values in the past.

IMO the real problem is that each of those three values
for H is different.
Q: is this "assumption" correct ?

No, it is not correct. The three laws you cite are approximations which
hold for near galaxies, and all three are equivalent within the range in
which these approximations hold. For greater distances the issue
(emission of light in the past) you describe does affect things, but
then you have to use the mechanisms and laws of general relativity, not
these simple approximations.

Regards

--
Charles Francis
moderator sci.physics.foundations.
charles (dot) e (dot) h (dot) francis (at) googlemail.com (remove spaces and
braces)

http://www.rqgravity.net

In article , "Nicolaas Vroom"
writes:

"Phillip Helbig---undress to reply"
schreef in bericht ...
In article , "Nicolaas Vroom"
writes:

But even if the Universe is homogeneous there is a problem with
the law v = H * d with v and d being the proper distance
(i.e. the present distance).
The problem is the relation z = (H/c) * d with d being the
distance at emission (i.e. in the past)
This relation is used to calculate the Hubble constant H
(based on observations of both z and d).
The problem is that the two Hubble constants can not be
the same.

This problem of yours has been addressed here in the newsgroup many
times. Why do you keep asking it?

Please state, clearly and exactly, what you think the problem is.

The problem is threefold.
First you have the law : v = H * d
With v and d (and H) being the present values. (proper values)

OK.

The question is how do you calculate those based on observations ?
The problem is neither one of those values can directly be observed.

Right.

For the sun a similar problem exits. What is observed is a position
in the past 8 minutes ago. To calculate the present position
you need a "model".

Right.

Second you have the law: z = (H/c) * d.
d is the distance in the past and z is the present value.
This is the equation used to calculate the Hubble Constant H.

Right. It is valid at low redshift; it is a limit.

Third again you have the law: v = H * d
but now with v, d and H values in the past.

Right.

IMO the real problem is that each of those three values
for H is different.
Q: is this "assumption" correct ?

The first two are the same. The third is, in general, different. But
this is not a problem. We can determine the cosmological parameters
from observations (this was worked out in the 1930s) and then calculate
H at any time.

For more information read:
http://users.telenet.be/nicvroom/bigbangh.htm

I had a look. After clicking away 4 pop-ups informing me that I was the
one-millionth visitor or whatever, I had a read through it. My advice
is to read Edward Harrison's textbook COSMOLOGY: THE SCIENCE OF THE
UNIVERSE cover to cover. That should clear up any confusion.

In article ,
"Nicolaas Vroom" writes:
For the sun a similar problem exits. What is observed is a position
in the past 8 minutes ago.

Actually, because of aberration of light, what is observed is very
nearly the position of the Sun "now."

To calculate the present position you need a "model".

You need a model to interpret any observation you make. (In some
cases, the model may be fairly simple.)

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA