Implicit Bias
Some folks feel that thinking about a multiverse is unscienti c | toomuch like a bad sci movie.
I feel that imagining a single, unique universe is unscienti c | toomuch like the Book of Genesis.
There is nothing that we know of | that can be described in scienti cterms | that happens only once.
We can describe galaxy formation in scienti c terms | and there are many many
galaxies.
We can describe star formation in scienti c terms | and there are many manystars.
If we can describe universe formation in scienti c terms | the ultimate goal of
cosmology | then we should expect many many universes.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{1{

Implicit Bias
Some folks feel that thinking about a multiverse is unscienti c | toomuch like a bad sci movie.
I feel that imagining a single, unique universe is unscienti c | toomuch like the Book of Genesis.
There is nothing that we know of | that can be described in scienti cterms | that happens only once.
We can describe galaxy formation in scienti c terms | and there are many many
galaxies.
We can describe star formation in scienti c terms | and there are many manystars.
If we can describe universe formation in scienti c terms | the ultimate goal of
cosmology | then we should expect many many universes.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{1{

Implicit Bias
Some folks feel that thinking about a multiverse is unscienti c | toomuch like a bad sci movie.
I feel that imagining a single, unique universe is unscienti c | toomuch like the Book of Genesis.
There is nothing that we know of | that can be described in scienti cterms | that happens only once.
We can describe galaxy formation in scienti c terms | and there are many many
galaxies.
We can describe star formation in scienti c terms | and there are many manystars.
If we can describe universe formation in scienti c terms | the ultimate goal of
cosmology | then we should expect many many universes.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{1{

Implicit Bias
Some folks feel that thinking about a multiverse is unscienti c | toomuch like a bad sci movie.
I feel that imagining a single, unique universe is unscienti c | toomuch like the Book of Genesis.
There is nothing that we know of | that can be described in scienti cterms | that happens only once.
We can describe galaxy formation in scienti c terms | and there are many many
galaxies.
We can describe star formation in scienti c terms | and there are many manystars.
If we can describe universe formation in scienti c terms | the ultimate goal of
cosmology | then we should expect many many universes.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{1{

Implicit Bias
Some folks feel that thinking about a multiverse is unscienti c | toomuch like a bad sci movie.
I feel that imagining a single, unique universe is unscienti c | toomuch like the Book of Genesis.
There is nothing that we know of | that can be described in scienti cterms | that happens only once.
We can describe galaxy formation in scienti c terms | and there are many many
galaxies.
We can describe star formation in scienti c terms | and there are many manystars.
If we can describe universe formation in scienti c terms | the ultimate goal of
cosmology | then we should expect many many universes.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{1{

Implicit Bias
Some folks feel that thinking about a multiverse is unscienti c | toomuch like a bad sci movie.
I feel that imagining a single, unique universe is unscienti c | toomuch like the Book of Genesis.
There is nothing that we know of | that can be described in scienti cterms | that happens only once.
We can describe galaxy formation in scienti c terms | and there are many many
galaxies.
We can describe star formation in scienti c terms | and there are many manystars.
If we can describe universe formation in scienti c terms | the ultimate goal of
cosmology | then we should expect many many universes.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{1{

Implicit Bias
Some folks feel that thinking about a multiverse is unscienti c | toomuch like a bad sci movie.
I feel that imagining a single, unique universe is unscienti c | toomuch like the Book of Genesis.
There is nothing that we know of | that can be described in scienti cterms | that happens only once.
We can describe galaxy formation in scienti c terms | and there are many many
galaxies.
We can describe star formation in scienti c terms | and there are many manystars.
If we can describe universe formation in scienti c terms | the ultimate goal of
cosmology | then we should expect many many universes.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{1{

Implicit Bias
Some folks feel that thinking about a multiverse is unscienti c | toomuch like a bad sci movie.
I feel that imagining a single, unique universe is unscienti c | toomuch like the Book of Genesis.
There is nothing that we know of | that can be described in scienti cterms | that happens only once.
We can describe galaxy formation in scienti c terms | and there are many many
galaxies.
We can describe star formation in scienti c terms | and there are many manystars.
If we can describe universe formation in scienti c terms | the ultimate goal of
cosmology | then we should expect many many universes.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{1{

Three Winds Blowing Us Towards the Multiverse
In the past decades, three important developments have pointed us
towards a multiverse.
1) Almost all inflationary models allow eternal inflation:

Once in ation starts, it never globally stops. It stops in places,
forming pocket universes, but elsewhere it continues.
The probability to remain at the top of thehill falls o exponentially with time. BUT:
in any successful model of in ation, theexponential expansion is faster. The volumeof space with   0 grows exponentially withtime.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{2{

1) Almost all inflationary models allow eternal inflation, cont:(Linde, 1986): If  starts high enough on
the hill, in ation will be eternal. Upwards
quantum uctuations will cause the volumeof space in which  is high to grow exponentially with time.
In either situation eternal in ation can be avoided if  starts toonear the bottom of the potential well, but both versions ALLOW
eternal in ation.
If eternal in ation is allowed, it seems to me that it would be the only
logical option. Its duration gives it an advantage over one-shotin ation by a factor of in nity, which is a large number. If eternalin ation starts just once in all of eternity, we have a multiverse.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{3{

1) Almost all inflationary models allow eternal inflation, cont:(Linde, 1986): If  starts high enough on
the hill, in ation will be eternal. Upwards
quantum uctuations will cause the volumeof space in which  is high to grow exponentially with time.
In either situation eternal in ation can be avoided if  starts toonear the bottom of the potential well, but both versions ALLOW
eternal in ation.
If eternal in ation is allowed, it seems to me that it would be the only
logical option. Its duration gives it an advantage over one-shotin ation by a factor of in nity, which is a large number. If eternalin ation starts just once in all of eternity, we have a multiverse.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{3{

1) Almost all inflationary models allow eternal inflation, cont:(Linde, 1986): If  starts high enough on
the hill, in ation will be eternal. Upwards
quantum uctuations will cause the volumeof space in which  is high to grow exponentially with time.
In either situation eternal in ation can be avoided if  starts toonear the bottom of the potential well, but both versions ALLOW
eternal in ation.
If eternal in ation is allowed, it seems to me that it would be the only
logical option. Its duration gives it an advantage over one-shotin ation by a factor of in nity, which is a large number. If eternalin ation starts just once in all of eternity, we have a multiverse.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{3{

1) Almost all inflationary models allow eternal inflation, cont:(Linde, 1986): If  starts high enough on
the hill, in ation will be eternal. Upwards
quantum uctuations will cause the volumeof space in which  is high to grow exponentially with time.
In either situation eternal in ation can be avoided if  starts toonear the bottom of the potential well, but both versions ALLOW
eternal in ation.
If eternal in ation is allowed, it seems to me that it would be the only
logical option. Its duration gives it an advantage over one-shotin ation by a factor of in nity, which is a large number. If eternalin ation starts just once in all of eternity, we have a multiverse.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{3{

1) Almost all inflationary models allow eternal inflation, cont:(Linde, 1986): If  starts high enough on
the hill, in ation will be eternal. Upwards
quantum uctuations will cause the volumeof space in which  is high to grow exponentially with time.
In either situation eternal in ation can be avoided if  starts toonear the bottom of the potential well, but both versions ALLOW
eternal in ation.
If eternal in ation is allowed, it seems to me that it would be the only
logical option. Its duration gives it an advantage over one-shotin ation by a factor of in nity, which is a large number. If eternalin ation starts just once in all of eternity, we have a multiverse.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{3{

1) Almost all inflationary models allow eternal inflation, cont:(Linde, 1986): If  starts high enough on
the hill, in ation will be eternal. Upwards
quantum uctuations will cause the volumeof space in which  is high to grow exponentially with time.
In either situation eternal in ation can be avoided if  starts toonear the bottom of the potential well, but both versions ALLOW
eternal in ation.
If eternal in ation is allowed, it seems to me that it would be the only
logical option. Its duration gives it an advantage over one-shotin ation by a factor of in nity, which is a large number. If eternalin ation starts just once in all of eternity, we have a multiverse.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{3{

Three Winds Blowing Us Towards the Multiverse
2) Cosmic Acceleration:

It was discovered in 1998 that the universe has been accelerating forthe past 5-6 billion years.
Simplest explanation: Vacuum energy density vac > 0; but
4vac  10 120 MPlanck:

Result: there seems to be no way to avoid the conclusion that theuniverse is EXTREMELY ne-tuned.
WHY?
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{4{

Three Winds Blowing Us Towards the Multiverse
2) Cosmic Acceleration:

It was discovered in 1998 that the universe has been accelerating forthe past 5-6 billion years.
Simplest explanation: Vacuum energy density vac > 0; but
4vac  10 120 MPlanck:

Result: there seems to be no way to avoid the conclusion that theuniverse is EXTREMELY ne-tuned.
WHY?
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{4{

Three Winds Blowing Us Towards the Multiverse
2) Cosmic Acceleration:

It was discovered in 1998 that the universe has been accelerating forthe past 5-6 billion years.
Simplest explanation: Vacuum energy density vac > 0; but
4vac  10 120 MPlanck:

Result: there seems to be no way to avoid the conclusion that theuniverse is EXTREMELY ne-tuned.
WHY?
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{4{

Three Winds Blowing Us Towards the Multiverse
2) Cosmic Acceleration:

It was discovered in 1998 that the universe has been accelerating forthe past 5-6 billion years.
Simplest explanation: Vacuum energy density vac > 0; but
4vac  10 120 MPlanck:

Result: there seems to be no way to avoid the conclusion that theuniverse is EXTREMELY ne-tuned.
WHY?
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{4{

Three Winds Blowing Us Towards the Multiverse
2) Cosmic Acceleration:

It was discovered in 1998 that the universe has been accelerating forthe past 5-6 billion years.
Simplest explanation: Vacuum energy density vac > 0; but
4vac  10 120 MPlanck:

Result: there seems to be no way to avoid the conclusion that theuniverse is EXTREMELY ne-tuned.
WHY?
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{4{

Three Winds Blowing Us Towards the Multiverse
3) String Theory Landscape:String theory plus the multiverse o ers a possible explanation of the
ne-tuning.
If there are 10500 or more vacuum-like states, with vac ranging from4
4
O( MPlanck) to O(+MPlanck), then there will be plenty with4
vac  10 120 MPlanck.
4, then the lifetime of the universe
Selection e ect: if jvac j  MPlanck1
 10 43 seconds.
is  MPlanck
Is it plausible that no life can form in 10 43 seconds? I think so!
4Life can only form if jvac  MPlanck. This selection e ect is certainlyin the right ballpark to explain the observed value of vac .
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{5{

Three Winds Blowing Us Towards the Multiverse
3) String Theory Landscape:String theory plus the multiverse o ers a possible explanation of the
ne-tuning.
If there are 10500 or more vacuum-like states, with vac ranging from4
4
O( MPlanck) to O(+MPlanck), then there will be plenty with4
vac  10 120 MPlanck.
4, then the lifetime of the universe
Selection e ect: if jvac j  MPlanck1
 10 43 seconds.
is  MPlanck
Is it plausible that no life can form in 10 43 seconds? I think so!
4Life can only form if jvac  MPlanck. This selection e ect is certainlyin the right ballpark to explain the observed value of vac .
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{5{

Three Winds Blowing Us Towards the Multiverse
3) String Theory Landscape:String theory plus the multiverse o ers a possible explanation of the
ne-tuning.
If there are 10500 or more vacuum-like states, with vac ranging from4
4
O( MPlanck) to O(+MPlanck), then there will be plenty with4
vac  10 120 MPlanck.
4, then the lifetime of the universe
Selection e ect: if jvac j  MPlanck1
 10 43 seconds.
is  MPlanck
Is it plausible that no life can form in 10 43 seconds? I think so!
4Life can only form if jvac  MPlanck. This selection e ect is certainlyin the right ballpark to explain the observed value of vac .
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{5{

Three Winds Blowing Us Towards the Multiverse
3) String Theory Landscape:String theory plus the multiverse o ers a possible explanation of the
ne-tuning.
If there are 10500 or more vacuum-like states, with vac ranging from4
4
O( MPlanck) to O(+MPlanck), then there will be plenty with4
vac  10 120 MPlanck.
4, then the lifetime of the universe
Selection e ect: if jvac j  MPlanck1
 10 43 seconds.
is  MPlanck
Is it plausible that no life can form in 10 43 seconds? I think so!
4Life can only form if jvac  MPlanck. This selection e ect is certainlyin the right ballpark to explain the observed value of vac .
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{5{

Three Winds Blowing Us Towards the Multiverse
3) String Theory Landscape:String theory plus the multiverse o ers a possible explanation of the
ne-tuning.
If there are 10500 or more vacuum-like states, with vac ranging from4
4
O( MPlanck) to O(+MPlanck), then there will be plenty with4
vac  10 120 MPlanck.
4, then the lifetime of the universe
Selection e ect: if jvac j  MPlanck1
 10 43 seconds.
is  MPlanck
Is it plausible that no life can form in 10 43 seconds? I think so!
4Life can only form if jvac  MPlanck. This selection e ect is certainlyin the right ballpark to explain the observed value of vac .
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{5{

Three Winds Blowing Us Towards the Multiverse
3) String Theory Landscape:String theory plus the multiverse o ers a possible explanation of the
ne-tuning.
If there are 10500 or more vacuum-like states, with vac ranging from4
4
O( MPlanck) to O(+MPlanck), then there will be plenty with4
vac  10 120 MPlanck.
4, then the lifetime of the universe
Selection e ect: if jvac j  MPlanck1
 10 43 seconds.
is  MPlanck
Is it plausible that no life can form in 10 43 seconds? I think so!
4Life can only form if jvac  MPlanck. This selection e ect is certainlyin the right ballpark to explain the observed value of vac .
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{5{

Three Winds Blowing Us Towards the Multiverse
3) String Theory Landscape:String theory plus the multiverse o ers a possible explanation of the
ne-tuning.
If there are 10500 or more vacuum-like states, with vac ranging from4
4
O( MPlanck) to O(+MPlanck), then there will be plenty with4
vac  10 120 MPlanck.
4, then the lifetime of the universe
Selection e ect: if jvac j  MPlanck1
 10 43 seconds.
is  MPlanck
Is it plausible that no life can form in 10 43 seconds? I think so!
4Life can only form if jvac  MPlanck. This selection e ect is certainlyin the right ballpark to explain the observed value of vac .
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{5{

Does the Selection Effect Explanation
Amount to Giving Up?
A number of physicists regard an \anthropic" explanation as
simply giving up.
In my opinion, the selection e ect explanation is both logicaland scienti c. I think we all accept anthropic explanations forsome facts | for example, the fact that we nd ourselves livingon the surface of a planet, in spite of the fact that planetary
surfaces make up an unbelievably small fraction (maybe 10 35 )of the volume of the visible universe. Is this explained by Divine
Providence? By extremely good luck? Or is it a selection e ect?
But I would advocate that anthropic explanations be thought of as
the explanation of last resort | the best evidence for an anthropic
explanation is the absence of any other.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{6{

Does the Selection Effect Explanation
Amount to Giving Up?
A number of physicists regard an \anthropic" explanation as
simply giving up.
In my opinion, the selection e ect explanation is both logicaland scienti c. I think we all accept anthropic explanations forsome facts | for example, the fact that we nd ourselves livingon the surface of a planet, in spite of the fact that planetary
surfaces make up an unbelievably small fraction (maybe 10 35 )of the volume of the visible universe. Is this explained by Divine
Providence? By extremely good luck? Or is it a selection e ect?
But I would advocate that anthropic explanations be thought of as
the explanation of last resort | the best evidence for an anthropic
explanation is the absence of any other.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{6{

Does the Selection Effect Explanation
Amount to Giving Up?
A number of physicists regard an \anthropic" explanation as
simply giving up.
In my opinion, the selection e ect explanation is both logicaland scienti c. I think we all accept anthropic explanations forsome facts | for example, the fact that we nd ourselves livingon the surface of a planet, in spite of the fact that planetary
surfaces make up an unbelievably small fraction (maybe 10 35 )of the volume of the visible universe. Is this explained by Divine
Providence? By extremely good luck? Or is it a selection e ect?
But I would advocate that anthropic explanations be thought of as
the explanation of last resort | the best evidence for an anthropic
explanation is the absence of any other.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{6{

Does the Selection Effect Explanation
Amount to Giving Up?
A number of physicists regard an \anthropic" explanation as
simply giving up.
In my opinion, the selection e ect explanation is both logicaland scienti c. I think we all accept anthropic explanations forsome facts | for example, the fact that we nd ourselves livingon the surface of a planet, in spite of the fact that planetary
surfaces make up an unbelievably small fraction (maybe 10 35 )of the volume of the visible universe. Is this explained by Divine
Providence? By extremely good luck? Or is it a selection e ect?
But I would advocate that anthropic explanations be thought of as
the explanation of last resort | the best evidence for an anthropic
explanation is the absence of any other.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{6{

Does the Selection Effect Explanation
Amount to Giving Up?
A number of physicists regard an \anthropic" explanation as
simply giving up.
In my opinion, the selection e ect explanation is both logicaland scienti c. I think we all accept anthropic explanations forsome facts | for example, the fact that we nd ourselves livingon the surface of a planet, in spite of the fact that planetary
surfaces make up an unbelievably small fraction (maybe 10 35 )of the volume of the visible universe. Is this explained by Divine
Providence? By extremely good luck? Or is it a selection e ect?
But I would advocate that anthropic explanations be thought of as
the explanation of last resort | the best evidence for an anthropic
explanation is the absence of any other.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{6{

Does the Selection Effect Explanation
Amount to Giving Up?
A number of physicists regard an \anthropic" explanation as
simply giving up.
In my opinion, the selection e ect explanation is both logicaland scienti c. I think we all accept anthropic explanations forsome facts | for example, the fact that we nd ourselves livingon the surface of a planet, in spite of the fact that planetary
surfaces make up an unbelievably small fraction (maybe 10 35 )of the volume of the visible universe. Is this explained by Divine
Providence? By extremely good luck? Or is it a selection e ect?
But I would advocate that anthropic explanations be thought of as
the explanation of last resort | the best evidence for an anthropic
explanation is the absence of any other.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{6{

Does the Selection Effect Explanation
Amount to Giving Up?
A number of physicists regard an \anthropic" explanation as
simply giving up.
In my opinion, the selection e ect explanation is both logicaland scienti c. I think we all accept anthropic explanations forsome facts | for example, the fact that we nd ourselves livingon the surface of a planet, in spite of the fact that planetary
surfaces make up an unbelievably small fraction (maybe 10 35 )of the volume of the visible universe. Is this explained by Divine
Providence? By extremely good luck? Or is it a selection e ect?
But I would advocate that anthropic explanations be thought of as
the explanation of last resort | the best evidence for an anthropic
explanation is the absence of any other.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{6{

Does the Selection Effect Explanation
Amount to Giving Up?
A number of physicists regard an \anthropic" explanation as
simply giving up.
In my opinion, the selection e ect explanation is both logicaland scienti c. I think we all accept anthropic explanations forsome facts | for example, the fact that we nd ourselves livingon the surface of a planet, in spite of the fact that planetary
surfaces make up an unbelievably small fraction (maybe 10 35 )of the volume of the visible universe. Is this explained by Divine
Providence? By extremely good luck? Or is it a selection e ect?
But I would advocate that anthropic explanations be thought of as
the explanation of last resort | the best evidence for an anthropic
explanation is the absence of any other.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{6{

Do Physicists Take theMultiverse Seriously?

Martin Rees, the Right Honourable Lord Rees of Ludlow, Astronomer

Royal of Great Britain, (former) President of the Royal Society,(former) Master of Trinity College, Gruber Prize in Cosmology,
Crafoord Prize, Templeton Prize, Isaac Newton Medal, has said
that he is suÆciently con dent about the multiverse to bet his
dog's life on it.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{7{

Do Physicists Take theMultiverse Seriously?

Martin Rees, the Right Honourable Lord Rees of Ludlow, Astronomer

Royal of Great Britain, (former) President of the Royal Society,(former) Master of Trinity College, Gruber Prize in Cosmology,
Crafoord Prize, Templeton Prize, Isaac Newton Medal, has said
that he is suÆciently con dent about the multiverse to bet his
dog's life on it.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{7{

Do Physicists Take theMultiverse Seriously?

Martin Rees, the Right Honourable Lord Rees of Ludlow, Astronomer

Royal of Great Britain, (former) President of the Royal Society,(former) Master of Trinity College, Gruber Prize in Cosmology,
Crafoord Prize, Templeton Prize, Isaac Newton Medal, has said
that he is suÆciently con dent about the multiverse to bet his
dog's life on it.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{7{

Do Physicists Take theMultiverse Seriously?

Martin Rees, the Right Honourable Lord Rees of Ludlow, Astronomer

Royal of Great Britain, (former) President of the Royal Society,(former) Master of Trinity College, Gruber Prize in Cosmology,
Crafoord Prize, Templeton Prize, Isaac Newton Medal, has said
that he is suÆciently con dent about the multiverse to bet his
dog's life on it.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{7{

Do Physicists Take theMultiverse Seriously?

Martin Rees, the Right Honourable Lord Rees of Ludlow, Astronomer

Royal of Great Britain, (former) President of the Royal Society,(former) Master of Trinity College, Gruber Prize in Cosmology,
Crafoord Prize, Templeton Prize, Isaac Newton Medal, has said
that he is suÆciently con dent about the multiverse to bet his
dog's life on it.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{7{

Do Physicists Take theMultiverse Seriously?

Andrei Linde, awarded the Kavli Prize in Astrophysics, the Break-through Prize in Fundamental Physics, the Gruber Prize in
Cosmology, the Dirac medal, has said that he is so con dent
that he would bet his own life.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{8{

Do Physicists Take theMultiverse Seriously?

Andrei Linde, awarded the Kavli Prize in Astrophysics, the Break-through Prize in Fundamental Physics, the Gruber Prize in
Cosmology, the Dirac medal, has said that he is so con dent
that he would bet his own life.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{8{

Do Physicists Take theMultiverse Seriously?

Andrei Linde, awarded the Kavli Prize in Astrophysics, the Break-through Prize in Fundamental Physics, the Gruber Prize in
Cosmology, the Dirac medal, has said that he is so con dent
that he would bet his own life.
Alan Guth
Massachusetts Institute of Technology
Cosmic Controversies: The Multiverse, October 7, 2019{8{

Do Physicists Take theMultiverse Seriously?

Steven Weinberg,

awarded the Heineman Prize, the BenjaminFranklin Medal, the Andrew Gemant Award, the National Medalof Science, the 1979 Nobel Prize in Physics, has said \I have justenough con dence about the multiverse to bet the lives of bothAndrei Linde and Martin Rees's dog."{9{

Do Physicists Take theMultiverse Seriously?

Steven Weinberg,

awarded the Heineman Prize, the BenjaminFranklin Medal, the Andrew Gemant Award, the National Medalof Science, the 1979 Nobel Prize in Physics, has said \I have justenough con dence about the multiverse to bet the lives of bothAndrei Linde and Martin Rees's dog."{9{

Do Physicists Take theMultiverse Seriously?

Steven Weinberg,

awarded the Heineman Prize, the BenjaminFranklin Medal, the Andrew Gemant Award, the National Medalof Science, the 1979 Nobel Prize in Physics, has said \I have justenough con dence about the multiverse to bet the lives of bothAndrei Linde and Martin Rees's dog."{9{

Do Physicists Take theMultiverse Seriously?

Steven Weinberg,

awarded the Heineman Prize, the BenjaminFranklin Medal, the Andrew Gemant Award, the National Medalof Science, the 1979 Nobel Prize in Physics, has said \I have justenough con dence about the multiverse to bet the lives of bothAndrei Linde and Martin Rees's dog."{9{