IAU: Hubble-Lemaitre Law?

[Steve Willner]

The IAU is considering recommending that the expansion of the
universe be referred to as the "Hubble-Lemaitre Law" instead of the
"Hubble Law." More details, including the resolution text and
background material, are at
https://www.iau.org/news/announcements/detail/ann18048/

My French isn't as good as I'd like it to be, but in Lemaitre's paper
http://adsabs.harvard.edu/abs/1927ASSB...47...49L
I don't see any data, though the paper summarizes some data from
Hubble and Stromberg at the top of p 56 (or just above Eq 24 if I'm
not reading the page number correctly). Am I missing something?

Any comments on the resolution? If interested, please examine the
background material linked from the IAU announcement rather than rely
on my summary.

[Phillip Helbig (undress to reply)]

Post by Steve Willner
The IAU is considering recommending that the expansion of the
universe be referred to as the "Hubble-Lemaitre Law" instead of the
"Hubble Law." More details, including the resolution text and
background material, are at
https://www.iau.org/news/announcements/detail/ann18048/
My French isn't as good as I'd like it to be, but in Lemaitre's paper
http://adsabs.harvard.edu/abs/1927ASSB...47...49L
I don't see any data, though the paper summarizes some data from
Hubble and Stromberg at the top of p 56 (or just above Eq 24 if I'm
not reading the page number correctly). Am I missing something?

Lemaitre didn't have any data of his own, but he was the first to
actually calculate a numerical value for the "Hubble" constant. This
crucial bit was left out of the English translation for MNRAS, which is
one reason (Hubble's ego being another) why he wasn't given much credit.
Also, Hubble---otherwise not one to shy away from glory---remained
sceptical about the INTERPRETATION of the magnitude-redshift relation he
(and others) found.

Why it was left out of the English translation was something of a
mystery for a while, but has now been solved. Basically, he published a
paper in French, and it was later translated for MNRAS, but with (from
today's perspective) the most interesting bit left out. To make a long
story short, it turned out that he suggested leaving it out, because it
was of no current interest (he said "actual interest", but since
"actuel" means "current" in French, that is not what he meant). This is
an interesting story in itself. Check out Nussbaumer & Bieri's book
Discovering the Expanding Universe. I don't have the reference at hand,
but I believe that it was Mario Livio who solved the mystery.

See also a post from today on Peter Coles's blog "In the Dark".

Post by Steve Willner
Any comments on the resolution? If interested, please examine the
background material linked from the IAU announcement rather than rely
on my summary.

I think that one could make a case for calling it just Lemaitre's Law.
On the other hand, I'm not sure how effective such top-down resolutions
are nor whether, in general, they are a good idea. In this particular
case, I think that it is justified.

[Richard D. Saam]

Post by Phillip Helbig (undress to reply)

Post by Steve Willner
The IAU is considering recommending that the expansion of the
universe be referred to as the "Hubble-Lemaitre Law" instead of the
"Hubble Law." More details, including the resolution text and
background material, are at
https://www.iau.org/news/announcements/detail/ann18048/
My French isn't as good as I'd like it to be, but in Lemaitre's paper
http://adsabs.harvard.edu/abs/1927ASSB...47...49L
I don't see any data, though the paper summarizes some data from
Hubble and Stromberg at the top of p 56 (or just above Eq 24 if I'm
not reading the page number correctly). Am I missing something?

Lemaitre didn't have any data of his own, but he was the first to
actually calculate a numerical value for the "Hubble" constant. This
crucial bit was left out of the English translation for MNRAS, which is
one reason (Hubble's ego being another) why he wasn't given much credit.
Also, Hubble---otherwise not one to shy away from glory---remained
sceptical about the INTERPRETATION of the magnitude-redshift relation he
(and others) found.
Why it was left out of the English translation was something of a
mystery for a while, but has now been solved. Basically, he published a
paper in French, and it was later translated for MNRAS, but with (from
today's perspective) the most interesting bit left out. To make a long
story short, it turned out that he suggested leaving it out, because it
was of no current interest (he said "actual interest", but since
"actuel" means "current" in French, that is not what he meant). This is
an interesting story in itself. Check out Nussbaumer & Bieri's book
Discovering the Expanding Universe. I don't have the reference at hand,
but I believe that it was Mario Livio who solved the mystery.
See also a post from today on Peter Coles's blog "In the Dark".

Post by Steve Willner
Any comments on the resolution? If interested, please examine the
background material linked from the IAU announcement rather than rely
on my summary.

I think that one could make a case for calling it just Lemaitre's Law.
On the other hand, I'm not sure how effective such top-down resolutions
are nor whether, in general, they are a good idea. In this particular
case, I think that it is justified.

In this continuing discussion towards Lemaitre,
perhaps Fred Hoyle's physical universe beginning notion
expressed as the pejorative Big Bang
will be replaced by George Lemaitre's notion:
"hypothesis of the primeval atom" or the "Cosmic Egg"
RDS

[Steve Willner]

Post by Phillip Helbig (undress to reply)
Lemaitre didn't have any data of his own, but he was the first to
actually calculate a numerical value for the "Hubble" constant.

Thanks. On that basis, it seems to me the response should be to
change "Hubble constant" to "Lemaitre constant." As an observer, I
favor those papers that actually present data, so my initial thought
is that "Hubble Law" should remain.

Post by Phillip Helbig (undress to reply)
Basically, [Lemaitre] published a paper in French, and it was
later translated for MNRAS, but with (from today's perspective) the
most interesting bit left out. ... I don't have the reference at
hand, but I believe that it was Mario Livio who solved the mystery.

Yes, that's one of the references in the IAU link. Livio's paper is
behind the _Nature_ paywall, though. I haven't looked for an open
version.

Post by Phillip Helbig (undress to reply)
On the other hand, I'm not sure how effective such top-down resolutions
are nor whether, in general, they are a good idea.

Both valid concerns, to be sure. Probably changing "Hubble constant"
is more of a stretch than "Hubble law," and that may have influenced
the IAU body proposing the change.

Hubble also has a "variable nebula" (NGC 2261 associated with R Mon).
You missed that one. :-)

[Phillip Helbig (undress to reply)]

Post by Steve Willner

Post by Phillip Helbig (undress to reply)
Lemaitre didn't have any data of his own, but he was the first to
actually calculate a numerical value for the "Hubble" constant.

Thanks. On that basis, it seems to me the response should be to
change "Hubble constant" to "Lemaitre constant." As an observer, I
favor those papers that actually present data, so my initial thought
is that "Hubble Law" should remain.

Ironically, many of "Hubble's" redshifts came from other people, often
without due credit. In the biography Edwin Hubble, Mariner of the
Nebulae by Gale Christensen (not sure if the spelling is right), he
comes across as someone who was not only interested in his own fame, but
was also willing to take credit where it was also due others. He had
more than enough work of his own to be proud of, but some folks just
can't get enough. :-|

See also https://arxiv.org/abs/1307.2289 .

Post by Steve Willner
Both valid concerns, to be sure. Probably changing "Hubble constant"
is more of a stretch than "Hubble law," and that may have influenced
the IAU body proposing the change.

There are two things to keep in mind: the observational relation between
redshift and apparent magnitude, and the theoretical relationship
between velocity and distance. Both are sometimes referred to as
Hubble's Law. The latter must be completely linear in any model which
remains homogeneous and isotropic with time; no physics here, only
kinematics. The former is linear at low redshift (taking redshift as a
proxy for velocity and apparent magnitude as a proxy for distance). In
general, things are more complicated. Probably the best description, as
is often the case, comes from Ted Harrison:

@ARTICLE {EHarrison93a,
AUTHOR = "Edward R. Harrison",
TITLE = "The Redshift-Distance and
Velocity-Distance Laws",
JOURNAL = APJ,
YEAR = "1993",
VOLUME = "403",
NUMBER = "1",
PAGES = "28",
MONTH = jan
}

Post by Steve Willner
Hubble also has a "variable nebula" (NGC 2261 associated with R Mon).
You missed that one. :-)

So did Sandage. :-)