Evening star., 1952-08-01

Limit Put at 12O Miles
Earth and Space Boundary Line
Conditions Explained
By Thomos r. Henry
For all practical purposes the earth's
atmosphere stops at an altitude Of about
100 miles.
This Is the aeropause, the boundary
between this planet and space. accord
ing to q communication to the American
Association for the Advancement Of
Science here by Drs. Konrad j. K. Buett-
ner and Heinz Haber of the University
OF California.
Actually. particles Of atmosphere may
be found at attitudes as great as 600
miles, they say, but they have no real
significance. This atmosphere boundary
probably would be the location Of a
permanent satellite orbit, minute
moon, revolving around the earth. At
such an altitude It would be necessary
for 1t to travel at speed Of from 8
to 10 miles second In order to main
tain its position.
Above 100 miles, they calculate. the
conditions encountered by the satellite
and its crew would. with three excep-
tions. be the same as those Of inter-
planetary space. The crew still would
be shielded by the bulk Of the earth from
half the number Of meteors and cosmic
ray particles. The satellite still would
be In the magnetic field Of the earth
which defects some coSmic rays. There
Is a certain amount Of radiation re-
hected or emitted by the earth into
space. ....
Say the engineers: Unnamed rocket
craft now are reaching routinely beyond
the physically effective regions Of the
atmosphere and man flights beyond the
atmosphere into space must now be con-
sidered q definite possibility. Conse-
quently new concept of the borders Of
the atmosphere now seems necessary"
They propose the following ascending
scale, based on the attitudes at which
certain functions Of the atmosphere
come to an end:
Contributions Of breathing, 16 klms.
Preventing boiling Of blood, 10 klms.
Sustaining fuel combustion. 21 to 23
klms.
Absorbing heavy cosmic rays. 81 to 80
klms.
Absorbing solar ultraviolet, IS to Is
klmS.
Supplying aerodynamic lift. 80 to 10
klms.
Absorbing meteors. 10 to $50 klms.
Heating by friction, 100 to 1S0 klms.
An apparently potent protection
against deadly doses Of X-radiation is
afforded by injections Of the simple
compound, sodium nitrate.
This has Just been reported to the
American Association for the Advance
ment Of Science here by Drs. L. j.
Cole, v. p. Bond and M. G. FISHER Of
the Navy Pathological Defense Labora-
tory at San Francisco.
They were able to save all but Is
per cent Of mice given X-ray doses
which otherwise proved 100 per cent
fatal. Other substances, such as the
amino acids cysteine and glutathione.
have been found to have some protective
effect In the past. That men would re-
act in the same way as mice cannot
dogmatically be stated, although there
is a high probability that this is the
case.
This tends to confirm, the Navy ex-
perimenters say. the idea that the lethal
effect Of X-radiation-the gamma rays
Of the atomic bomb are essentially the
same thing-depends as much on the
chemical creation Of toxins in the body
as on the actual tissue destruction which
takes place.
Act Is Inhibitors.
None of the materials proposed acts
as an antidote for the radiation-pro-
duced poisons. once they have accumu-
lated in the body. They act, however.
as inhibitors to their production, DR..
Cole and his associates believe.
Previous experiments with sodium
nitrate had indicated 1t had little or no
protective effect. This may have been
due. say the Navy experimenters. to
the fact that radiation doses much above
those necessary to cause death were
used.
When mice were protected with So
dunn nitrate against lethal doses there
was slight weight loss extending for
about seven days. after which the ami
mails showed steady weight increase:
The untreated animals had a constant
weight loss up to the time Of death.