What we still don't know - Martin Rees Ch4 8pm tonight

Astronomer Royal, Professor Sir Martin Rees has a new series starting
tonight 5th December at 8pm on Channel 4 "What we still don't know".

He is a fantastic communicator so it promises to be good stuff. Tonights
programme asks the tricky question "Are we alone?"

It has had very favourable reviews on Radio 4 and in the Independent.
(and perhaps elsewhere)

It should be worth watching.

Regards,
Martin Brown

"Martin Brown" wrote in message
...
Astronomer Royal, Professor Sir Martin Rees has a new series starting
tonight 5th December at 8pm on Channel 4 "What we still don't know".

He is a fantastic communicator so it promises to be good stuff. Tonights
programme asks the tricky question "Are we alone?"

It has had very favourable reviews on Radio 4 and in the Independent.
(and perhaps elsewhere)

It should be worth watching.

Regards,
Martin Brown

Talking head woman seated in a cloister somewhere.
Viewed through the colonade was someone, at one point, cycling backwards,
all other shots were normal walking persons etc.
After that I was concentrating on activity in the background and there
wasn't any
mor weirdness.
Design , gremlin, or just some alien humanoid life-form cycling backwards ?

Yes, I saw the cyclist going backwards as well !
Programme was OK, but not as good as the Sky at Night - see above.

"John Hirst" wrote in message
...
Yes, I saw the cyclist going backwards as well !
Programme was OK, but not as good as the Sky at Night - see above.



Ah well at least I'm not going round the bend.

I liked the Fermi paradox explanation of all
intelligent life-forms doing the same thing -
sitting/squatting/sprawling back and waiting

What they aren't telling you about DNA profiles
and what Special Branch don't want you to know.
http://www.nutteing2.freeservers.com/dnapr.htm
or nutteingd in a search engine

Valid email (remove 4 of the 5 dots)
Ignore any other apparent em address used to post this message -
it is defunct due to spam.

Wasn't it Paul Nutteing who wrote:

I liked the Fermi paradox explanation of all
intelligent life-forms doing the same thing -
sitting/squatting/sprawling back and waiting

That's the only bit I didn't like.

The problem with that explanation is that in order for a species to have
evolved successfully, it almost certainly has to have a biological
imperative to reproduce hardwired into it. When you get an intelligent
species with such a biological imperative, it's going to use its
intelligence and technology to break through the natural limits of the
population numbers that the home system can support. The conditions in
the home system are heading for disaster, but meanwhile interstellar
colony ship technology is starting to become possible. A few of the
richest or most powerful guys in the system recognise that the only hope
for a decent life for their children is to pack them off to other solar
systems a few tens of light years away.

The kids land and start a colony on the new worlds, but they've still
got the biological imperative to breed without limit. So in a few
thousand years the new systems are full. The new richest guys in each
system build new starships and pack their children off to the next
available locations.

After a few cycles like this, all the nearby systems are populated, and
they start having to move further afield. Such expansion - travelling a
few tens of light years and then colonising for a few thousand years -
might spread across the galaxy at a rate of a few thousand years per
light year, thus occupying the entire galaxy in a few hundred million
years. Once such an interstellar colonisation expansion process gets
started, it would be unstoppable until every scrap of real estate in the
galaxy is occupied.

It was suggested in the programme there could well be civilizations out
there that got started billions of years earlier than ourselves.

So why aren't they here?

--
Mike Williams
Gentleman of Leisure

Paul Nutteing wrote:
"Martin Brown" wrote in message
...

Astronomer Royal, Professor Sir Martin Rees has a new series starting
tonight 5th December at 8pm on Channel 4 "What we still don't know".

He is a fantastic communicator so it promises to be good stuff. Tonights
programme asks the tricky question "Are we alone?"

It has had very favourable reviews on Radio 4 and in the Independent.
(and perhaps elsewhere)

Talking head woman seated in a cloister somewhere.
Viewed through the colonade was someone, at one point, cycling backwards,
all other shots were normal walking persons etc.

Were we watching the same programme?

I thought the picture of Martin Rees's disembodied talking head against
the black background was a bit wierd - reminiscent of "Holly" the ships
computer in Red Dwarf. Their IQs are probably similar.

I was disappointed he didn't interview some of the folk with interesting
ides from QM on why we have around 20 amino acids and a 3base DNA code.
But they did get something in about emergent self organising behaviour
in so basically it was OK.

After that I was concentrating on activity in the background and there
wasn't any
mor weirdness.
Design , gremlin, or just some alien humanoid life-form cycling backwards ?

Who knows? But I really prefer to listen to experts discuss their
subject without the accompanying repetative pop video of special effects
that Horizon producers insist on adding to everything.

Regards,
Martin Brown

Mike Williams wrote:

Wasn't it Paul Nutteing who wrote:

I liked the Fermi paradox explanation of all
intelligent life-forms doing the same thing -
sitting/squatting/sprawling back and waiting

That's the only bit I didn't like.

But it is actually quite a compelling argument. Unless we find some
extraordinary way of doing it inter stellar travel is not going to be
possible for humans for a very long time, if ever.

Fusion power has been 40 years away now for more than 50 years. And as
for nuclear electricity too cheap to meter.

The problem with that explanation is that in order for a species to have
evolved successfully, it almost certainly has to have a biological
imperative to reproduce hardwired into it. When you get an intelligent
species with such a biological imperative, it's going to use its
intelligence and technology to break through the natural limits of the
population numbers that the home system can support.

They can also choose not to reproduce despite having the hardwiring just
look at the falling birth rate in the developing world and Japan for
instance.

The conditions in
the home system are heading for disaster, but meanwhile interstellar
colony ship technology is starting to become possible. A few of the
richest or most powerful guys in the system recognise that the only hope
for a decent life for their children is to pack them off to other solar
systems a few tens of light years away.

You are probably better off shipping off the telephone sanitisers,
advertising execs and image consultants. Then the ships don't have to be
well built or even working properly. Eugenics is frowned upon though.

The kids land and start a colony on the new worlds, but they've still
got the biological imperative to breed without limit.

There is your assumption. It isn't necessarily true. Intelligence can be
used to override hardwired behaviour.

After a few cycles like this, all the nearby systems are populated, and
they start having to move further afield.

"Nearby" is actually so far away that it would take generations living
on a space vehicle even to get to it. I am inclined to the view that
most technological civilisations do look at the sky and probe for signs
of life by radio astronomy but don't bother trying to leave home beyond
sending out robotic probes. One day we may see one...

But a civilisation like ours will only be radio bright for about 100
years from the invention of radio. After that fibre optics, downward
facing satellite broadcasts at low power with clever encoding and much
lower power signals that look like noise. All our mobile phone signals
barely get out of the planets atmosphereand so we disappear.

years. Once such an interstellar colonisation expansion process gets
started, it would be unstoppable until every scrap of real estate in the
galaxy is occupied.

If there was a means to travel between stars quickly and efficiently.
But unless there is some way to get between planetary systems and even
detect which ones are worth going to in the first place you aren't
likely to get far sending off the idle super rich to a "better" life.

Just look at our own planet - they end up being scammed by cryonics and
every other parasitic con merchant looking for a fast buck.

It was suggested in the programme there could well be civilizations out
there that got started billions of years earlier than ourselves.

So why aren't they here?

There are two main ways out.

1. They are here but so well disguised we don't see them any more than a
bluetit notices the camera in its nest box. An ET David Attenborough
could be wondering around at this very moment ;-)

2. The problem is too difficult - stars are too far apart. As HHGG put
it "Space is big. You just won't believe how vastly, hugely,
mind-bogglingly big it is".

Regards,
Martin Brown

JRS: In article , dated Tue, 7 Dec
2004 08:43:41, seen in news:uk.sci.astronomy, Martin Brown |||newspam||
posted :

But it is actually quite a compelling argument. Unless we find some
extraordinary way of doing it inter stellar travel is not going to be
possible for humans for a very long time, if ever.

Agreed. For it to be technically and economically feasible, the
technology needs to be, by present knowledge, indistinguishable from
magic.

Enormous power and energy availability, but in a manner not destructive
here; or enormous proven longevity of equipment; or really new physics.

Note that a possible C.21 Earth population of 1E10, if all dissipating
energy at the rate of the most prodigal present-day Americans, is
dissipating an amount at least nearing non-negligible in comparison with
absorbed insolation, which is around 120PW - and that's disregarding
greenhouse. URL:http://www.merlyn.demon.co.uk/astro2.htm#CE.
Insolation would be 1.2 MW/head, and US average consumption is now about
10kW/head.


Fusion power has been 40 years away now for more than 50 years.

I cannot agree. For parts of that period it was no more than 30 years
away, sometimes considerable less.

--
© John Stockton, Surrey, UK. Turnpike v4.00 MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
some Astro stuff via astro.htm, gravity0.htm; quotes.htm; pascal.htm; &c, &c.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

Wasn't it Dr John Stockton who wrote:
JRS: In article , dated Tue, 7 Dec
2004 08:43:41, seen in news:uk.sci.astronomy, Martin Brown |||newspam||
posted :

But it is actually quite a compelling argument. Unless we find some
extraordinary way of doing it inter stellar travel is not going to be
possible for humans for a very long time, if ever.

Agreed. For it to be technically and economically feasible, the
technology needs to be, by present knowledge, indistinguishable from
magic.

All of the technology being used by a civilization that got a few
hundred million year head start on us will be indistinguishable from
magic. Take a look at how far our technology has advanced in just the
last thousand years.

Note also that we are already pretty close to having the technology to
build an interstellar ship along the lines of Project Daedalus. We
already do have the technology to build unmanned interstellar probes
such as Project Longshot. Other considerations than the technology
currently prevent us from using nuclear drives for spacecraft in this
way. Other inhabitants of our galaxy might not be so reticent when the
future of their children's children are in the balance, or they might
develop safer alternatives over time.

--
Mike Williams
Gentleman of Leisure

Mike Williams wrote:
Wasn't it Dr John Stockton who wrote:

JRS: In article , dated Tue, 7 Dec
2004 08:43:41, seen in news:uk.sci.astronomy, Martin Brown |||newspam||
posted :

But it is actually quite a compelling argument. Unless we find some
extraordinary way of doing it inter stellar travel is not going to be
possible for humans for a very long time, if ever.

Agreed. For it to be technically and economically feasible, the
technology needs to be, by present knowledge, indistinguishable from
magic.

All of the technology being used by a civilization that got a few
hundred million year head start on us will be indistinguishable from
magic. Take a look at how far our technology has advanced in just the
last thousand years.

Even a hundred years difference in technology levels would be enough to
scare people witless. But unless there is some cunning way to get around
the speed limit imposed by relativity it will take a very long time and
an immense amount of energy to make an interstellar journey.

You cannot demand Star Trek physics to provide a means of doing
something just because you would like it to be possible. It is far more
likley that we are all governed by the same laws of physics.

NB Whenever someone famous stands up and announces physics will be
solved within the next decade the experimentalists have a bad habit of
finding some new interesting effect. Quantum mechanics was the last one.

Note also that we are already pretty close to having the technology to
build an interstellar ship along the lines of Project Daedalus. We
already do have the technology to build unmanned interstellar probes

Do the sums for how long it will take for the fastest man made object
ever made Helios at 150,000 mph at solar perihelion. Where as light
travels at 186000 miles/second

http://www.aerospaceweb.org/question...t/q0109c.shtml

It is only going to take it a mere 4400 years to cover a light year or
about 18000 years to reach the nearest star.

currently prevent us from using nuclear drives for spacecraft in this
way.

It would take sustainable nuclear fusion power to get anything like the
required specific impulse and longevity. Terrestrial nuclear fission
reactors last about 50 years tops due to neutron damage to their
metallic structure. And uranium/plutonium are heavy metals to carry.

Regards,
Martin Brown