Harvard Club, Sociëteit de Witte, Den Haag, March 22, 2007 The Harvard Club of the Netherlands invites you to a popular lecture by Nobel prize winner

Harvard Club, Sociëteit de Witte, Den Haag, March 22, 2007

The Harvard Club of the Netherlandsinvites you to a popular lecture

by Nobel prize winnerProf. Dr. Gerard ’t Hooft

Science ≠ fiction


Gerard ’t HooftUtrecht University

and


Harvard Club, Sociëteit de Witte, Den Haag, March 22, 2007Cassini – Huygens mission


Foundations ofModern Science



What modern science has taught us:

There are very strict rules

The rules can be derived from what is NOT possible:

● Energy is conserved: 1) No energy out of nothing2) No energy out of heat !

Unless there are temperature differences !

● All masses generate the same gravitational force

Anti-gravity is not possible !


● There are speed limits !

1) The speed of sound

2) The speed of light

Air: 344 m/secCopper: 3100 m/sec

Stone: 5971 m/sec

299 792 458 m/sec


The speed of sound is approximately the limit of all velocities that can be obtained using chemical substances only:


The Earth’s escape velocity isapproximately 11 km /sec

The exhaust velocity in most rockets is limitedby approx. 3 km/sec

To reach Earth orbit, you needabout 9 km/sec


The same numbers are decisivefor the concept of a space elevator

The limiting factor is the strengthof a tether relative to its weight

It is expressed in terms of GigaPascal / specific weight, orNewton meter / kg

2 2Nm / kg kgm / sec m / kg (m / sec)

Steel: 154 kNM/kg = 392 m/sec ²

Nanotubes: 48,462 kNm/kg= 7 km/sec ²


Consisting of carbon atoms only

Nano tubes


The space elevator

tethered satellites

Catapulting spacecraft tohigher velocities

But never velocity differences much beyond the sound velocity of a few km / sec

Also the wheels of anautomobile would explode if you would drive faster than that ...

Applications of tethers:


To reach much greater velocities in space, you must use nuclear propellants (or solar energy if you can ...)

The characteristic velocities in nuclear reactions is one tenth of the speed of light ...

Freeman Dyson



A black hole


Important restrictions:

Space travel: people will probably never be able to travel faster than approx. 1000 km/sec, a lot slower than light velocity ... !

“Space-warp” will remain fiction forever ....

Black holes are no “worm holes”

The mass would have to exceed 10 000 solar masses (so you can’t bring them along in your space ship), and even if ...

Communication and transport to other stars (than our sun) will remain

problematic.

Black hole diameter is proportionalto its massOne solar mass = 3 km.Velocity of light = 300 000 km / sec


What fantastic things can we still imagine without clashing with science ?

Information technology

Truly intelligent computers do not contradict any of our present knowledge –it is just difficult !

The IT revolution has only just started !


The basic units in computer chips can still becomea lot smaller – and faster !


Richard Feynman, 1959, APS CalTech:

“There is plenty of Room at the Bottom!”


The information period has only barely begun

Computer software and hardware can become a lot better and faster

Computers can become intelligent, indeed a lot more intelligent than humans ...

Robots (automated machines, controlled by computers), may become tiny and universal, but:

if they are tiny, their vision will be very bad ... !

Moore’s Law


Will NANO TECHNOLOGY determine our future?


A proteineand DNA

10 nm


The Human

Genome

Genetic engineering offers fantastic possibilities in the future

Food

water

energy

space colonization


How will space be colonized ?


The Solar System Can we go there ?

The Moon: 3 - 4 days Mars: 8 months

Asteroids: ~ 1 yearJupiter moons ~ 2 years ?Saturnus moons ~ 3 years ?

Then: Uranus, Neptune, etc. Pluto and beyond ?


Our motives: curiosity and expansionism

But human colonization will onlyhappen if affordable !

SF authors perhaps underestimate:

the Media the Internet

To keep funding agencies interested

For essential information

remotely controlled machines (robots)

Human Colonization ...






The first colonies willbe small and under ground ...

Glass can be made onany planet

Ice is also a magnificent buildingmaterial

The Lunar hotel


John von Neumann:Robots can reproduce themselves.Robots can become semi-intelligent .

Self-reproduction and intelligence are not possible today

but not forbidden by science !

Neumannbots


Travelling to the stars will take thousands or millions of years

But perhaps living oranisms can be spread and cultivated.

Humans of flesh and blood will not be interested in such long-lasting trips

To the stars ?


Our science is also the science for intelligentcreatures elsewhere in the Universe

if these creatures exist at all, they will be subjectto the same limitations

therefore, we should not expect visits by creatures of flesh and blood

But their neumannbots might be able to reach us

they haven’t done so yet.



Are neumannbots dangerous ?

Not if we adhere to some fundamental principles. Read Richard Dawkins

All “evolutions” must be orchestrated from one central point (on Earth)

Then all neumannbots will be genetically identical. They behave like termites. The “queen” stays on Earth.


Cassini





Atomic nucleus

electron

More than 10 000 x greater distance !

Matter as we know it: atoms


Proton

Neutron

Quarks

Atomic nucleus


Documents

Harvard Club, Sociëteit de Witte, Den Haag, March 22, 2007 The Harvard Club of the Netherlands invites you to a popular lecture by Nobel prize winner