Skip navigation

Monthly Archives: July 2016

I was thinking of Vija Celmins as we crossed the channel.  The surface of the water was just like one of her graphite drawings/prints – gentle, endless, small waves.  Not quite as choppy as the waves in most of her drawings.

photo

Vija Celmins Ocean print detail

Visited Whitechapel Gallery to see Mary Heilmann:  Looking at pictures.  Heilmann, now in her 70’s, makes it in the art world!  It’s nice to see an older woman artist being recognised.   Jason Farago explains Heilmann’s life and art in a Guardian newspaper review.   Keith Sonnier:  Light works, using coloured flourescent tubes is also at Whitechapel Gallery.  I didn’t realise that so many different colour florescent tubes were available in the late 1960’s.

Over at the White Cube Bermondsey to see Raqib Shaw‘s paintings.  Intricate and colourful they remind me of a psychiatric patients’ artistic output.  Intriguing but ultimately nauseating.  Also on exhibition were Christine Ay Tjoe‘s paintings that were marginally more interesting.

I’ve never heard of Mary Heilmann, Keith Sonnier, Raqib Shaw and Christine Ay Tjoe.  By next week I will have forgotten all of them.  All their works somehow miss the mark with me.  But I will never forget Vija Celmins.

 

Advertisements

 

photo

Cliff end, near Pett Levels. This is where samples of the Lower Wadhurst, Bone Bed can be collected. From the Lower Cretaceous of The Weald, Valanginian in age, it is about 135 -140.3 million years old.

photo

Carbonized woody material collected from The Bone Bed at Cliff End, Pett Level. c 140 MA

photo

Carbonized woody material in a matrix of Thanet Sand collected from Beltinge. c.50MA

 

I’ve collected some carbonized ‘wood’ from The Bone Bed at Pett Levels.  Similar material is found in the Thanet’s at Beltinge.  Now I need to find an astronomical object whose light took 140 million years to arrive on the Earth.  But this is not easy or straightforward:

A REMINDER OF HOW TO CONVERT LIGHT YEARS TO PARSECS:

There are plenty of internet sites that can do what you need. Firstly though you need to be able to convert your 46.4 million years into quantities these websites use, because for various historical and technical reasons the astronomy websites don’t tend to use light years.

Astronomers tend to use parsecs rather than light years, and the conversion factor is about 0.3066. To convert a distance in light years to parsecs, multiply by this number, e.g.
46.4 million light years = (46.4 x 0.3066) million parsecs = 14.2 million parsecs

This is also referred to as 14.2 megaparsecs, or 14.2 Mpc (one megaparsec =
1 Mpc = 1 million parsecs).

The other way distances are referred to is as an apparent recession velocity.
The expansion of the Universe makes it look like distant galaxies are moving away from us. The conversion is known as the Hubble constant, which is about 73 km/s per Mpc.

So, to convert a Mpc distance to an apparent recession velocity, multiply by 73. Example:
46.4 million light years = (46.4 x 0.3066) million parsecs
= 14.2 million parsecs
= 14.2 Mpc
= (14.2 x 73) km/s
= 1037 km/s
Now, the final conversion factor (Hubble constant) isn’t known that accurately, so I would aim for anywhere between 994 and 1065 km/s.

There is an astronomical website to find galaxies: the NASA Extragalactic Database, or NED. It’s at http://nedwww.ipac.caltech.edu

There’s an all-sky search there, and to save you the hassle I’ve done the search for you. Here’s a (very long) URL for the result:
http://nedwww.ipac.caltech.edu/cgi-bin/nph-allsky?ra_constraint=Unconstrained&ra_1=&ra_2=&dec_constraint=Unconstrained&dec_1=&dec_2=&glon_constraint=Unconstrained&glon_1=&glon_2=&glat_constraint=Unconstrained&glat_1=&glat_2=&hconst=73&omegam=0.27&omegav=0.73&corr_z=1&z_constraint=Between&z_value1=994&z_value2=1065&z_unit=km%2Fs&flux_constraint=Unconstrained&flux_value1=&flux_value2=&flux_unit=Jy&frat_constraint=Unconstrained&ot_include=ALL&in_objtypes1=Galaxies&nmp_op=ANY&out_csys=Equatorial&out_equinox=J2000.0&obj_sort=RA+or+Longitude&of=pre_text&zv_breaker=30000.0&list_limit=5&img_stamp=YES

Clicking on the numbers down the left give you links to galaxy images.
You first get to a page on detailed info – eg here’s the one for NGC7814:
http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsearch?search_type=Obj_id&objid=30&objname=2&img_stamp=YES&hconst=73.0&omegam=0.27&omegav=0.73&corr_z=1

Then you click on images and get a whole selection.
http://nedwww.ipac.caltech.edu/cgi-bin/nph-imgdata?objname=NGC+7814+++++++++++++++++++++&hconst=73.0&omegam=0.27&omegav=0.73&corr_z=1

Here I think the one on the bottom is what you want.

I wouldn’t download the FITS images – this is a technical binary format that is hard to view unless you have the software and know how to use it.
I’d stick with the preview JPEG / GIF images.

photo

Photographing in RAW format produces a bad pincushion effect.

photo

Painting photographed as Fine JPEG minimises the pincushion effect.

photo

01/07/2016