CORRESPONDENCE

Malabar and van Rheede

Mohan Ram’s article1 not only captures (= H. wightiana) (Dipterocarpaceae), which the botany as documented by van Rheede resemble sea urchins3, during his travels 1. Mohan Ram, H. Y., Curr. Sci., 2005, 89, (obviously well presented by K. S. Mani- in Malabar; mistaking the galls for ‘mini- 1672–1680. 2. Raman, A. and Takagi, S., Insecta Matsum., lal), but also other interesting and related ature fruits’, he assumed that the speci- 1992, 47, 1–32. aspects including those of 17th century mens of H. ponga bearing galls were 3. Mani, M. S., Plant Galls of , Macmillan Kerala and socio-linguistics brilliantly. Artocarpus (because van Rheede was al- India, New Delhi, 1973, p. 353. The following information may also interest ready familiar with A. heterophyllus)! van 4. Raman, A., Phytophaga, 1987, 1, 141– readers of Current Science, in support of Rheede also described the galls on the 159. Mohan Ram’s powerful and passionate leaves of Garuga pinnata (Burseraceae) article. Anglicization (used so here, for induced by Phacopeteron lentiginosum want of a better word to represent adop- (Homoptera; Psyllidae)4, and, interest- tion into ‘Dutch’) of tchakka (Malayalam ingly, these as galls only and not as fruits ANANTANARAYANAN RAMAN name for Artocarpus heterophyllus, Mora- or nuts! If my memory serves right, Manilal ceae) as ‘jack’ was done by van Rheede has mentioned the above in one of his Faculty of Rural Management, during his botanical adventures in erst- earlier publications, for which unfortuna- The University of Sydney, while Malabar. tely, I do not have the bibliographic details PO Box 883, Incidentally, van Rheede also saw the with me presently, nor could I locate it in Orange, NSW 2800, Australia insect-induced galls2 on Hopea ponga the bibliography in the Mohan Ram article. e-mail: [email protected]

Chandra–Eddington episode

This is concerning the review1 of the book known in the early decades of the twentieth mass of 2.1 solar masses. Even now we Empire of the Stars by Arthur Miller and century to be several times the solar mass, are not sure of the equation of state for the criticism2 of the accuracy of the e.g. Plaskett’s star has a mass 60 times the neutron star. book’s contents and analysis, including the solar mass. Stellar evolution studies So, Eddington did not delay any pro- the review itself. were then in a very primeval stage. Even gress. He just did not believe in black Most accounts of the Chandra–Eddington the source of stellar energy was not clear. holes. Nor did Einstein for that matter. It encounter of January 1935 are overcritical If one reads the earlier edition of Gamow’s was only after great progress in observa- of Eddington, perhaps unfairly so. In ret- Birth and Death of the Sun, even in the tional astronomy in the 1960s and 1970s rospect, it is surprising that at that time early 1950s, red giants were thought to and later, in all bands of the electromag- nobody seems to have taken seriously the be still contracting pre-main-sequence netic spectrum from radio to gamma rays, work of Baade and Zwicky3 at least one stars. In a later edition, Gamow says ‘our that evidence has become compelling for year before (in 1934), about neutron stars. views of red giants have meanwhile un- neutron stars and black holes. As they clearly state ‘We advance the dergone a complete change!’ The idea Again, it must be pointed out that view that supernovae represent transi- that massive stars can lose a considerable Fowler’s formula for non-relativistic de- tions from ordinary stars to neutron stars, amount of mass during evolution was generate stars is perfectly valid for the which in their final stages consist of ex- unheard of in Eddington’s time. Natu- hundreds of white dwarfs with masses tremely packed neutrons’. In their January rally, he was worried about the low value less than a solar mass2. Indeed, it (Fowler’s 1934 work, they even estimate the neutron of the limiting white dwarf mass (just 1.4 result) has been applied (apart from neu- star binding energy (as 3 ´ 1053 ergs!), solar mass!). He did not question the tron stars) to supermassive degenerate 12 16 which is the total energy emitted by the mathematical accuracy but felt that relati- neutrino configurations of 10 –10 MSun supernovae. So, a white dwarf cannot be vistic degeneracy formula used by Chandra (with the neutrino mass replacing the the remnant of a supernova. They also perhaps does not hold. Indeed, electron electron or proton mass), where the neu- conjecture that cosmic rays are produced interactions (later considered by Salpeter) triono degeneracy pressure balances the in such cataclysms. Here then was the do lower the mass somewhat. Besides self gravity of the neutrino (dark matter) possible answer to Eddington’s worry composition is important. A pure iron dominated structure. The same MR3 = about ‘speculating on other possibilities’. white dwarf would have a limiting mass constant result is used. This use of Fowler’s The neutron was discovered by Chadwick less than 1.2 solar mass. Again it may be degeneracy formula for massive neutrinos in 1932 and soon after, Landau got the pointed out that despite a lot of progress has a long tradition going back at least to limiting mass for a degenerate neutron in nuclear physics of dense matter, we Markov, Hayakawa, Zeldovich and others star (or core) as 1.4 solar masses. Indeed, still do not have a definitive limiting and lastly Cowsik and McCelland (see several neutron stars (pulsars) seem to value for the neutron star mass. It ranges reference list4). have masses around 1.3–1.4 solar masses! from 1.8–2.5 solar masses in most models Talking of colonial attitudes, Eddington One can understand Eddington’s concern. (some authors obtain larger values!). Re- did not halt Chandrasekhar from becoming Masses of several stars were already cently, a pulsar was estimated to have a Fellow of the Royal Society and a distin-

CURRENT SCIENCE, VOL. 90, NO. 2, 25 JANUARY 2006 145 CORRESPONDENCE

guished Professor barely a decade after 1. Sreeram Chaulia, Curr. Sci., 2005, 89, 33, 538; Zeldovich, JETP Lett., 1966, 4, 120; Cowsik and McCelland, Ap. J., 1973, 180, 7. their unpleasant encounter. Again, Ein- 401–402. stein is sometimes blamed for not giving 2. Mallik, D. C. V., Curr. Sci., 2005, 89, Bose enough credit. It was he who trans- 1455–1456. C. SIVARAM lated the Bose paper pointing out its im- 3. Baade, W. and Zwicky, F., Phys. Rev., 1934, 45; Proc. Natl. Acad. Sci. USA, 1934, 20, portance and it was Einstein, who dis- Indian Institute of Astrophysics, 254–259; 259–263. covered the Bose–Einstein condensation 4. Markov, M. A., Phys. Lett., 1964, 10, 122; Koramangala, in a later paper. Hayakawa, Progr. Theor. Phys. Suppl., 1965, Bangalore 560 034, India

Disposal of dredge spoil from Sethusamudram Ship Channel Project

The Sethusamudram Ship Channel Project and spawning period. Another condition area of about 6 km2 (2000 m ´ 3000 m ´ (SSCP) across the and Adam’s is that the suspended matter at the dredg- 12 m). Location A is suggested as it is Bridge between India and is ing sites should not spread more than a midpoint between Adam’s bridge and finally commissioned and it was inaugu- km on either side of the channel route. Palk Strait and it is sufficiently away from rated by the Prime Minister of India on 2 Dumping 82.5 million cubic metres in the Mandapam group of coral islands and July 2005 at Madurai. The SSCP has al- the highly turbulent open sea either in the Muthupet mangrove swamps. On the ready generated a lot of controversies or in the other hand if the total dredged spoils are over its implementation and the conse- east of Kodiyakkarai will naturally gen- dumped at water depth of <10 m (loca- quent environmental issues with regard erate turbidity in the water column and tion B; Figure 1) it will create land area to dredging and safe disposal of dredged submergence of large bottom community of more than 8 km2 (8000 m ´ 1000 m ´ spoil1–3. As per the present alignment, by the sand contained in the dredged sedi- 10 m). The dredged sediment from Palk dredging is needed only in two stretches ments. Such environmental effect over vast Strait alone will create a small island if covering a distance of 89 km along the areas for considerably long time-span dumped in the shallow western , proposed 167 km long channel between will have long-term impact. It is sugges- which will be a boon to fishermen for Tuticorin and Kodiyakkarai – in a NS ted here that instead of disposing the safe landing in case of an emergency. stretch for a length of 35 km (east of Da- dredged spoil in the distant open sea, it Dumping of sediment in a limited area nushkodi) in the Adam’s Bridge and may be dumped at one or two specified will minimize spreading of suspended 54 km in the Palk Strait in a NE–SW di- areas within the shallow western Palk sediments to larger areas and havoc to rection south of Kodiyakkarai and east of Bay so that considerable land area can be bottom communities. Since the Palk Bay Manalmelkudi (Figure 1). No dredging is reclaimed. The Palk Bay region does not is very shallow with water depths ranging needed for the rest of 78 km stretch (Fig- have any island within the Indian territorial from 5 to 10 m along the coastal areas and ure 1) as the depth is more than 20 m. waters. Ever since Katchatheevu (Figure less than 20 m in most other places (Fig- The total quantum of materials that 1) was transferred to Sri Lanka, there is a ure 1), the sea becomes turbid during will be dredged from these two sectors demand from politicians and fishermen southwest and northeast monsoon periods4 amounts to 82.5 million cubic metres of communities of to get back due to re-suspension of bottom sediments. which the Adam’s Bridge sector will the island for the use of fishermen. In However, in general the Palk Bay is very generate 48 million cubic metres while case an island is made artificially using the calm during most of the time because of the Palk Bay sector will generate 34.5 dredged spoil within the Palk Bay it will the protection offered by the shallow million cubic metres of sediments. As per help the fishermen as temporary landing Palk Strait on the north and Pamban Pass the plan, the materials dredged from area or the Coast Guard/Navy for regular and Adam bridge on the south (Figure 1) Adam’s Bridge area will be dumped in monitoring of the territory in the future. and so powerful currents and waves do the Gulf of Mannar region at 20–30 km Acquiring of land using dredged spoil is enter into Palk Bay. The sediments are water depths within the Indian territorial a common phenomenon globally. For in- primarily silty clay close to coast and sandy waters about 30 km away from Adam’s stance, the Wellington Island near Cochin mud little away from the coast. The sedi- Bridge. Sediments dredged from Palk port was formed mostly by the dredged ment contains high organic matter due to Bay will be dumped in the spoil. Such large-scale land reclamation is decay of sea grass. During NE monsoon at about 25–30 m water depths. Dredging going on in places where acute land scar- huge quantum of fine sediments are trans- Corporation of India is assigned to carry city exists like in Singapore. ported into the Gulf of Mannar from Karai- out the first phase of dredging in the Palk In case a major part of the dredged kal–Nagapattinam–Vedaraniyan coast5–7. Bay to the tune of about 13 million cubic spoil generated through the capital dredg- Therefore, dumping of dredged sedi- metres of sediments. During dredging ing is dumped at one place in the western ments in a selected site within the shal- several environmental management acts Palk Bay (location A; Figure 1), having a low Palk Bay will not add further stress will have to be followed including cessa- water depth of about 12 m (30–35 km off to existing marine environment. Further- tion of dredging during the fish breeding Tondi), it will create an island with land more, the amount of dredged spoil that

146 CURRENT SCIENCE, VOL. 90, NO. 2, 25 JANUARY 2006