# Presentation: 540624

## THE FUTURE OF PHYSICS

- DAVID GROSS
- FERMILAB
- October 19, 2005

## On October 7, 2004 the KITP celebrated:

- 25 years of the Institute for Theoretical Physics

- The inauguration of the new wing of the KITP

- The “ Future of Physics ”  conference

## Slide 3

## THE DISCOVERY,EXPLORATION,

- VERIFICATION AND UNDERSTANDING
- OF QCD IS DUE TO THE REMARKABLE
- WORK OF MANY EXPERIMENTERS
- AND THEORISTS OVER 40 YEARS !

## WE HAVE LEARNED A LOT

-  IN THE LAST 25--35 YEARS

**Notes:**
WE DIDN’T KNOW: THE FORCES OF NATURE, GRAVITY SEEMED SEPARATE,

WE DIDN’T KNOW THE FUNDAMENTAL PARAMETWERS OF THE UNIVERSE, HOW FORMATION OF STRUCTURE OCCURRED, INFLATION

WE DIDN’T HAVE A THEORY OF CONTINUSOUS PHASE TRANSTIONS, REN GROUP
COMPLEXITY, PATTERN FORMATION   QUANTUM HALL, STRONGLY CORRELATED, NANOSCIENCE, QUANTUM COMPUTING

## Slide 6

## THE ORIGIN OF THE UNIVERSE

-     How far back can we probe?

- How Did the Universe Begin?

- Can String theory determine the initial 	conditon?

- Time itself is an emergent concept?

- Was there a time before the big bang
- Big crunch-->Big Bang or cyclic?

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## DARK MATTER

- What is the Nature of Dark Matter?

- How does dark matter interact with ordinary
- baryonic matter ? Is it wimpy?

-  25%

- 2

- Can we detect the dark matter wind
- flowing through the laboratory?

- Can we produce the dark matter
- in the laboratory?

- Is it made of Supersymmetric Neutralinos, Axions or ?

**Notes:**
SUSY NEUTRILINO
AXIONS
SOMETHING ELSE

## 		Can We Tell?

- What is the Nature of the Dark Energy?

-  70%

- 3

- Is it constant or varying in time?

- Is it just Einstein’s cosmological constant, Λ

- 		Can We Tell?

**Notes:**
IS IT JUST THE COSMOLOGICAL CONSTANT

IS IT CONSTANT

CAN WE TELL

STRING THEORY SUGGESTS NO.

## FORMATION

-    How do we understand the spectrum of masses, 	frequency of binarys, and cluster?

- How Do Stars Form?

- How Do Planets Form?

-    What is the frequency of habitable planets ?

- 4

**Notes:**
EARLY STARS----NEW STARS---DOES METALICITY HAVE A BIG EFFECT

## GENERAL RELATIVITY

- Is Our Current Understanding of General Relativity
- Correct at All Scales ?

- Will strong gravity survive observational tests via gravitational
- wave astronomy?

- 5

- Can we use astrophysical observations to determine whether the Kerr metric correctly describes the geometry around black holes?

## QUANTUM MECHANICS

- At very short distances
- In large complex systems
- In conscious systems
- As a description of the universe ?

- 6

- Is Quantum Mechanics the
- ultimate description of nature,
- or will it fail somehere?

## MYSTERIES OF THE 
STANDARD MODEL

- STANDARD MODEL

- The masses and mixings of the quarks and leptons

- The origin of baryons & the proton lifetime

- 7

- ...

**Notes:**
CAN THE DETERMINATION OF THESE PARAMETERS TEACH US SOMETHING FUNDAMENTAL?

## SUPERSYMMETRY

- IS THERE LOW ENERGY SUPERSYMMETRY?

- ONCE WE KNOW THE SPECTRUM, CAN WE WORK
-  THE OTHER WAY, TO FIND EVIDENCE FOR THE
-  INTERACTIONS OR GEOMETRY THAT IS PRESENT AT THE GRAVITY SCALE?

- 8

- HOW IS IT BROKEN?
- WHAT IS THE SPECTRUM
- OF THE SUPER-PARTICLES

## Q C D

- CAN WE SOLVE QCD?

- 9

- CAN WE CONSTRUCT A USEFUL DUAL STRING DESCRIPTION
- OF HADRONS ?
-      (FOR LARGE NUMBER OF COLORS)

## BUT WE DO NOT REALY KNOW WHAT STRING THEORY IS

-  STRING THEORY HAS MANY SUCCESSES

- A Consistent and Finite Quantum Theory of Gravity

- 10

- A Consistent, Logical Extension of the Conceptual Framework of Physics

- A Rich Structure That Could Yield a Unique & Comprehensive Description of the Real World

- THE STRING REVOLUTION IS YET TO COME

## WHAT IS SPACE-TIME?  

- Is space-time doomed?

- CAN WE IMAGINE
- THAT TIME IS EMERGENT?

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-  WE CAN BEGIN TO SEE HOW
- SPACE IS EMERGENT.

## IS PHYSICS AN ENVIRONMENTAL SCIENCE ?

- “ NATURE    IS	CONSTITUTED	 SO   THAT    IT   IS
-     POSSIBLE  TO  LAY  DOWN  SUCH  STRONG
-     DETERMINED  LAWS  THAT  WITHIN  THESE LAWS
-     ONLY RATIONALLY COMPLETELY DETERMINED
-    CONSTANTS   OCCUR,   NOT   CONSTANTS  THEREFORE
-     THAT COULD BE CHANGED WITHOUT COMPLETELY
-     DESTROYING  THE THEORY. ”
- ALBERT  EINSTEIN

**IS PHYSICS AN ENVIRONMENTAL SCIENCE ?**

- THE LANDSCAPE

- 12

- THE ANTHROPIC PRINCIPLE

## Kinematics, Dynamics and Initial Conditions

- I suspect that, as we learn to understand string theory and explore the nature of space-time, the distinction between Kinematics and Dynamics will be blurred.
- Quantum Mechanics may emerge as more inevitable and perhaps less mysterious.

- 13

## NEW STATES OF MATTER

- Are there generic non-Fermi liquid behaviors of interacting condensed matter systems which are, in principle, accessible experimentally in a routine manner
- (e.g. topological quantum matter)?

- 14

## COMPLEXITY

- What is the theory of very large complex dynamical systems. As our computers become more and more powerful, we are trying to use them to make predictions about the earth's climate, chemical processes in biological cells, and ultimately the human brain.
- We know that intrinsic limits of predictability must exist because these systems generally have chaotic features; however, we usually have lots of trouble identifying those features and separating them from less interesting behaviors.
- 			So what do we do??

- 15

## QUANTUM COMPUTERS

- The key obstacle is decoherence: outside perturbations that reduce the quantum computer to a merely classical one.  Two almost opposite strategies to combat this problem are to reduce as much as possible this offending noise by isolating the quantum bits far from any “environment”, or instead to construct “topological” quantum bits that are delocalized and subtly expressed so that they are decoupled from the noise all around them.

- CAN WE CONSTRUCT A REAL QUANTUM COMPUTER? (>10,000 QUBITS)

- WILL QUANTUM COMPUTERS BE QUIET OR DEAF?

- 16

## APPLICATIONS

- Can we understand how to make a material that is superconducting at room temperature and beyond?

- 17

-  Can we understand how to make a room temperature ferromagnet out of engineerable  electronic (semiconducting) materials?

## THEORETICAL BIOLOGY

- Can theoretical physics help? Is new mathematics required?

- 	 How do we think about, analyze and model systems, like many in biology, that exhibit dynamics over many, wide-ranging time scales?

- 18

## Can the theory of evolution be quantitative and predictive?

- Can one tell the shape of an organism by looking at its genome?

- GENOMICS

- 19

## What are the principles that underlie the self-organization responsible for memory and consciousness?

- Can one measure the onset of consciousness in an infant?

- Can one make a machine with free will, with teleonomic behavior?

- CONSCIOUSNESS

- 20

##  COMPUTATIONAL PHYSICS

-    How will we train them?

- When will computers become creative theoretical physicists?

- Will computers replace analytic techniques?

-   If so how should we modify the training of physicists?

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##  BALKANIZATION

- Given the diversity of physics---from string theory to wet biology could physics splinter into identifiable subgroups offering separate graduate education?

- Will the balkanization of physics continue, so that we will become a bunch of specialized sub-fields and important centers of excellence, such as the KITP, will no longer be relevant?

- 22

## REDUCTIONISM

- We tend to take it for granted that  because big things are made of little things,the behavior of the big things must be entirely determined,at least in principle,by that of the little things.
- Is this any more "obviously" true than (was) the idea that nature cannot tell the difference between her left hand and her right hand??

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## THE ROLE OF THEORY

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## What New Approaches Should Be Considered 

- 25

- What New Approaches Should Be Considered
- Now?

- One can see traditional particle accelerators becoming
- unrealizable in the next 25 years.

- The big questions are still likely to be there.

## YES?

- TO BE IMPORTANT?

- WILL THE KITP CONTINUE
- TO BE IMPORTANT?

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## THE END