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WHAT IF THE SUN WENT OUT


	Disasters are in fashion these days, and somehow I have been led
to think about a really big one - what if the sun went out?  The first
question to ask before writing our tale of panic and paranoia is this.
How many people could survive how long?

	Not many and not long is the obvious answer, and we envisage the
scene in the movie as the last survivors in the underground bunker shiver
and draw lots as to who will be eaten next and secretly plot to fix the
lottery.

	Unfortunately for you fans of disaster movies, the obvious answer
is mistaken.  The more one thinks about it, the more possibilities for
survival come to mind, and my final conclusion is that most Americans
would die of old age, and their descendants would survive almost as long
as they would without the disaster - for a few billion years.  I have not
so far been able to find a way to save most of the inhabitants of India.

	The first problem that comes to mind is that it would begin to get
cold.  How cold and how soon?  During the winter in Antarctica, it is dark
all the time, but it takes months to get to -100F even at the pole.  At
the coast, it doesn't get anywhere near that cold because of the sea.  The
facts seem to be as follows:

	The thermal time constant of the atmosphere is a few weeks.
However, the time constant of the ocean is many years.  Because of
convection in the ocean, the surface can't freeze until the whole ocean
reaches 4 degrees Celsius.  Because of convection in the atmosphere, the
atmosphere can't get much below freezing near the coasts or much below
Antarctic temperatures inland until the ocean surface freezes.  Therefore,
we will have very cold winter temperatures near the coasts and had better
evacuate the inland areas.

	We will be unable to heat all our houses, because we already use 40%
of our energy for that purpose, and we couldn't even get through one year
with our available energy production.  Therefore, we would start dying off
in a few months, right?  Wrong, we just wouldn't be able to afford so much
housing.  In fact, we would have to abandon 90% of our housing and live in
the remaining 10% and insulate the walls of that 10% by piling up dirt.
At barracks levels of crowding and good insulation, we could get by on
body heat if we could find the food to generate the body heat.

	However, if insulation is too good, it is necessary to provide
specifically for ventilation, and simply pumping in fresh air loses the
heat content of the air that is pumped out.  Therefore, it is necessary to
use heat exchangers that warm the incoming fresh air with the heat of the
outgoing stale air.  These are in commercial use in Europe and could be
manufactured quickly.

	The next big problem is food.  How long would the initial supplies
last, and what would we do when they ran out?  Since most crops are
annual, we normally have a substantial fraction of a year's supplies of
most foods.  Some foods are in surplus and larger supplies are on hand.
We have larger supplies just after a harvest than just before.  We would
stop feeding animals grain to make it last longer, and we would ration
food severely.  We would keep the cattle going as long as there was hay,
and then they would be slaughtered and the beef frozen.  Probably this
would give us two or three years to get a new food supply.

	There are several long range possibilities, but the main short
range one is petroleum.  We presently produce about 500 million tons of
petroleum per year, and processes are in use for feeding it to bacteria
that produce proteins that are used for animal food supplements.  These
processes would have to be used on a very much larger scale.  It would be
more pleasant to feed the bacterial products to chickens and eat the
chickens, but quite likely we would have to eat the bacterial products
ourselves for quite a few years.

	The 500 million tons of petroleum would produce more than enough
food for 200 million people.  A person eats about three pounds per day,
but three quarters of its content is water, so one can estimate that our
population would use only about 160 million tons per year of the
petroleum.  Our ten year's reserves would then stretch to thirty years.

	The next critical problem may be the freezing of the atmosphere.
How long this would take is hard to calculate, because it depends on the
exchange of heat between the oceans and the atmosphere.  The easy
calculation is that the ocean can supply several hundred times the amount
of heat in currently in the atmosphere before the surface freezes.  This
would probably give us a breathable atmosphere for about ten years.

	After that the oxygen we need to breathe will still be around, but
it will have to be vaporized to be used.  It will therefore be better to
recirculate what we use in our buildings, and this mainly means separating
out the carbon dioxide from the atmosphere and splitting it into oxygen
for breathing and carbon for food.

	This separation and splitting is now performed by green plants
with the aid of sunlight.  This is a possibility, but it would require
enormous underground rooms and an enormous amount artificial light used at
an efficiency of around one percent.  More likely, we would use
electrochemical processes to do the splitting and get food for our
bacteria.  Some products like sugar and some basic edible starch would be
synthesized directly from water and carbon dioxide.

	All this requires electricity, and the solution is nuclear fission
reactors.  We would build standard fission reactors very fast.  At present
we spend 12 years building a reactor, but France and Taiwan build them in
5, and experts think it could be done in two and a half years with a crash
program.  My bet is that we would discover that we could turn them out in
six months if we had to.  We might have to postpone some of the safety
facilities such as the pressure vessel.

	Unfortunately, in order to conserve uranium, we would have to
switch to breeder reactors as quickly as possible, and we don't have a
good design.  Parallel crash programs, one of which would copy the French
Super-phoenix design would be required.

	How long will the uranium last?  There is a substantial stockpile
of enriched uranium and plutonium in weapons and an enormous stockpile of
depleted uranium usable in breeder reactors.  At present energy prices,
there is 20 trillion dollars worth of depleted uranium.  Presently,
depleted uranium is useful only for weights, and some of the airport tow
trucks used for moving big planes away from the gates use it.  If that's
what they use mainly, there is much more available energy in those tow
truck weights than in all the jet fuel in the airport.

	Mobilization

	The above is a general description, but what happens first when
the scientists announce that the sun, which went out yesterday, may not go
on again.  Since I know no mechanism that would extinguish the sun, there
is no reason to ask how they would know.  However, I suppose it could be
considered part of this exercise to ask what would happen if some said it
would come back and others said no.

	The first step is for scientists to convince the President to go
on TV with the above scenario for survival in the above amount of detail
and introduce whoever is taking technological charge.  There is no doubt a
difference of opinion about how the public would react.  Perhaps some
people would think that the public would simply panic and refuse to pay
attention to any plans for survival.  There are certainly people with a
death wish, but I think a large enough majority would be willing to
mobilize for survival so that the irreversibly panicked would be merely a
police problem - though perhaps a serious one.

	The first physical step is to start crowding and rationing food
and fuel.  It might be best to start in a decentralized way.  Every city
mayor and council is told to form a survival authority with a scientific
advisory committee.  Centralized national control would be established
later.

	The buildings that will be used for housing are designated by the
local authorities.  Where there are subways, they might be used.  One or
two story factories producing non-essentials, shopping center buildings
and schools might be best because they can be insulated quickly.  They
have to be filled with improvised bunks, and kitchens have to be
improvised.  As soon as this is done, utilities are cut off to residential
areas, so the holdouts have to move in.  Probably people could move in in
less than a week, but refitting would have to continue much longer.

	Industries must be divided into essential and non-essential.  The
essential go on three shifts and the non-essential are abandoned.  More
than three quarters of our present activities would be found
non-essential, and the people working in them would be available to put
the essential activities on 24 hour days.

	For example, all educational activities are postponable, and all
high school and college students and teachers would be mobilized for
essential work.  Even junior high school students might be used.  Grade
school activities would be moved into the buildings taken for living, but
class size would be doubled.  Almost all commercial, entertainment and
legal activity is postponable.  Manufacturing would change its emphases as
at the beginning of World War II.

	Here are some of the essential activities.

	#. Building insulation and going underground.  This alone would
put the construction industry on working around the clock.  It can absorb
much unskilled labor transferred from inessential activities.

	#. Design and manufacture of heat exchangers so that ventilation
won't cost heat.  Existing models would be chosen and factories making
things out of sheet metal would go on 24 hour days.

	#. The telephone industry must figure out the effect of cold on
communication lines and make sure communication will survive.

	#. The chemical industry must scale up the bacterial production of
protein from oil.

	#. The oil industry must figure out how to keep oil flowing.

	#. Clothing for extreme cold has to be made on a large scale.
Present down clothing is good down to the -125 Celsius met in Antarctica
if piled on.

	In preparation for the time when the atmosphere freezes, several
steps are necessary.  Probably we would have some years to prepare.

	#. The living and working places need to be made airtight and to
stand an internal atmospheric pressure.  We might have to use oxygen at 5
pounds per square inch rather than the normal nitrogen oxygen mixture in
order to reduce the pressurizing required.

	#. A pressure suit for working outside with a self-contained
oxygen supply.  Provision for replenishing the supply every few hours from
larger tanks.

	#. A system for collecting oxygen and distributing it.

	#. A system for modifying vehicles to operate at extreme low
temperatures and with oxygen tanks as well as fuel tanks.  It isn't
obvious whether present vehicles could be modified or whether new designs
would be required.  Railroads might become more important than trucks,
because they might be easier to keep operating.  This might mean extending
tracks into the areas with lots of buildings for people to live and work
and choosing buildings near railroads.


	Remarks:  .item←0

	#. Until the atmospheric pressure dropped substantially, airplanes
would remain usable.

	#. Less developed countries would not be able to save everyone,
and this might cause fighting.  We would probably have to be able to fight
off or accept a Mexican invasion.  Most likely, we could save most of the
Mexicans too.  The Canadians could probably save themselves and so could
most European countries.  The Russians might have organizational
difficulties and are behind us in deployed nuclear plants.

	If there were transferable resources that would make a large
difference in survival, there might be wars when countries would fight
others for them.  The only resource I can think of that has this property
is oil.  The amounts of oil required for conversion to food is very much
less than is currently being consumed for fuel, so the U.S. could be
independent again.  However, countries like Japan would have to put a
major part of their effort into keeping the oil transportation system
working as long as see conditions would permit.  Coal could also be used
as a feedstock for bacterial conversion.

	The point of this exercise is to show that the present dangers
that cause many intellectuals to express panic are minor compared to
dangers that our civilization could actually survive.  Our interdependent
society is easily annoyed because of the interdependence, but it is very
survivable because most people are in occupations that can be abandoned in
emergency.

	1984 Note:

	I wrote this essay in 1976 after thinking about the problem for
some time.  I had started believing that humanity wouldn't last long and
only gradually invented ways out.  If it were a real problem, a million
times the effort would go into inventing ways out, and much more would be
discovered.  On the other hand there would be difficulties which haven't
occurred to me.  A good scientific negative thinker could no doubt come up
with some rather easily and it would be interesting to see if we positive
thinkers could get around them.  Perhaps some of the readers would enjoy
corresponding about problems and solutions.

	Although nuclear winter hadn't been thought of then (at least I
hadn't heard of it), the problems are similar.  Nuclear winter wouldn't be
as bad climatically, but there would be the destruction of war to contend
with.  It would be especially bad if the war didn't end even after the
climatic disaster started.  I haven't tried to revise this essay to deal
with nuclear winter, because I don't know what the nuclear winter problem
would really be like.