UNIVERSE

The Universe Is Not in a Box

Topic: 

  • UNIVERSE
https://vimeo.com/333853591

One of the great books in science was published in 1824 by a young Frenchman called Sadi Carnot. This is one of the most wonderful books, the title of which is Reflections on the Motive Power of Fire. In about six pages, he explains how you would make a steam engine that would work with the absolute maximum efficiency possible. It was almost entirely ignored, and he died before anything much could come out of it. It was rediscovered in 1849 when William Thomson, who later became Lord Kelvin, wrote a paper which publicized this work.

The Universe Is Not in a Box

[9.11.19]

One of the great books in science was published in 1824 by a young Frenchman called Sadi Carnot. It is one of the most wonderful books, the title of which is Reflections on the Motive Power of Fire. In about six pages, Carnot explains how you would make a steam engine that would work with the absolute maximum efficiency possible. It was almost entirely ignored, and he died before anything much could come out of it. It was rediscovered in 1849 when William Thomson, who later became Lord Kelvin, wrote a paper that publicized this work. Within a couple of years, thermodynamics had been created as a science.

It caused a tremendous lot of excitement from the 1850s onwards. The key thing about this work of Carnot's is that if you have a steam engine, the steam has to remain in a cylinder in a box. You want the steam engine to work continuously, so you keep on having to bring the steam and the cylinder back to the condition it was before. It's remarkable that the development of what's called statistical mechanics—to understand how steam behaves—led to the discovery of entropy, one of the great discoveries in the history of science, and with it the mystery of the arrow of time. And it all followed out of this work of Carnot on how steam engines work. And moreover, it was very anthropocentric thinking about how human beings could exploit coal to drive steam engines and do work for them. At that stage, nobody was thinking about the universe as a whole; they were just thinking about how they could make steam engines work better.

This way of thinking, I believe, has survived more or less unchanged to this day. You still find that people who work on this problem of the arrow of time are still assuming conditions that are appropriate for a steam engine. But in the 1920s and early 1930s, Hubble showed that the universe was expanding, that we live in an expanding universe. Is that going to be well modeled by steam in a box? My belief is that people haven't realized that we have to think out of the box. We have to think in different ways. My collaborators and I keep on finding ways in which the mathematics that was developed before to understand systems confined in a box have to be modified with quite surprising consequences and, above all, possibly to explain why we have an incredibly powerful sense of the passage of time, why the past is so different from the future.

JULIAN BARBOUR is a theoretical physicist specializing in the study of time and motion; emeritus visiting professor in physics at the University of Oxford; and author of The Janus Point (forthcoming, 2020) and The End of TimeJulian Barbour's Edge Bio Page

Looking in the Wrong Places

[4.30.18]

We should be very careful in thinking about whether we’re working on the right problems. If we don’t, that ties into the problem that we don’t have experimental evidence that could move us forward. We're trying to develop theories that we use to find out which are good experiments to make, and these are the experiments that we build.  

We build particle detectors and try to find dark matter; we build larger colliders in the hope of producing new particles; we shoot satellites into orbit and try to look back into the early universe, and we do that because we hope there’s something new to find there. We think there is because we have some idea from the theories that we’ve been working on that this would be something good to probe.

If we are working with the wrong theories, we are making the wrong extrapolations, we have the wrong expectations, we make the wrong experiments, and then we don’t get any new data. We have no guidance to develop these theories. So, it’s a chicken and egg problem. We have to break the cycle. I don’t have a miracle cure to these problems. These are hard problems. It’s not clear what a good theory is to develop. I’m not any wiser than all the other 20,000 people in the field.

SABINE HOSSENFELDER is a research fellow at the Frankfurt Institute for Advanced Studies, an independent, multidisciplinary think tank dedicated to theoretical physics and adjacent fields. She is also a singer-songwriter whose music videos appear on her website sabinehossenfelder.com (see video below). Sabine Hossenfelder's Edge Bio Page

Looking in the Wrong Places

Topic: 

  • UNIVERSE
https://vimeo.com/247562726

We should be very careful in thinking about whether we’re working on the right problems. If we don’t, that ties into the problem that we don’t have experimental evidence that could move us forward. We're trying to develop theories that we use to find out which are good experiments to make, and these are the experiments that we build.  

Shut Up and Measure

Topic: 

  • UNIVERSE
https://vimeo.com/229124300

What is fascinating to me is that we are now hoping, with modern measurements, to probe the early Universe. In doing so, we’re encountering deep questions about the scientific method and questions about what is fundamental to physics. When we look out on the Universe, we’re looking through this dirty window, literally a dusty window. We look out through dust in our galaxy. And what is that dust? I like to call it nano planets, tiny grains of iron and carbon and silicon—all these things that are the matter of our solar system.

Shut Up and Measure

[10.20.17]

What is fascinating to me is that we are now hoping, with modern measurements, to probe the early Universe. In doing so, we’re encountering deep questions about the scientific method and questions about what is fundamental to physics. When we look out on the Universe, we’re looking through this dirty window, literally a dusty window. We look out through dust in our galaxy. And what is that dust? I like to call it nanoplanets, tiny grains of iron and carbon and silicon—all these things that are the matter of our solar system. They’re the very matter that Galileo was looking through when he first glimpsed the Pleiades and the stars beyond the solar system for the first time.

When we look out our telescopes, we never see just what we're looking for. We have to contend with everything in the foreground. And thank goodness for that dust in the foreground, for without it, we would not be here.

Professor BRIAN KEATING is an astrophysicist with the University of California San Diego’s Department of Physics. He and his team develop instrumentation to study the early universe at radio, microwave, and infrared wavelengths. He is the author of over 100 scientific publications and holds two U.S. patents.  Brian Keating's Edge Bio page

Curtains For Us All?

Topic: 

  • UNIVERSE
https://vimeo.com/214719867

Here on Earth, I suspect that we are going to want to regulate the application of genetic modification and cyborg techniques on grounds of ethics and prudence. This links with another topic I want to come to later, which is the risks of new technology. If we imagine these people living as pioneers on Mars, they are out of range of any terrestrial regulation. Moreover, they've got a far higher incentive to modify themselves or their descendants to adapt to this very alien and hostile environment.                                 

Curtains For Us All?

[5.31.17]
Here on Earth, I suspect that we are going to want to regulate the application of genetic modification and cyborg techniques on grounds of ethics and prudence. This links with another topic I want to come to later about the risks of new technology. If we imagine these people living as pioneers on Mars, they are out of range of any terrestrial regulation. Moreover, they've got a far higher incentive to modify themselves or their descendants to adapt to this very alien and hostile environment.                                 
 
They will use all the techniques of genetic modification, cyborg techniques, maybe even linking or downloading themselves into machines, which, fifty years from now, will be far more powerful than they are today. The posthuman era is probably not going to start here on Earth; it will be spearheaded by these communities on Mars. 
 
LORD MARTIN REES is a Fellow of Trinity College and Emeritus Professor of Cosmology and Astrophysics at the University of Cambridge. He is the UK's Astronomer Royal and a Past President of the Royal Society. Martin Rees's Edge Bio Page

Quantum Hanky-Panky

Topic: 

  • UNIVERSE
https://vimeo.com/155828770

Thinking about the future of quantum computing, I have no idea if we're going to have a quantum computer in every smart phone, or if we're going to have quantum apps or quapps, that would allow us to communicate securely and find funky stuff using our quantum computers; that's a tall order. It's very likely that we're going to have quantum microprocessors in our computers and smart phones that are performing specific tasks.

Sounds of the Skies

Hear the Spacetime Ringing
[3.23.16]

The effect of these gravitational waves is to squeeze and stretch space. If you were floating near these black holes, you would literally be squeezed and stretched. If you were close enough, you would feel the difference between the squeezing and stretching on your face or your feet. We’ve even conjectured that your eardrum could ring in response, like a resonant membrane, so that you would literally hear the wave, hear it even in the absence of a medium like air. Even though we think that empty space is silent, in these circumstances you would hear the black holes collide but you wouldn’t see them; it would happen in complete darkness. The two black holes would be completely dark, and your only evidence of their collision would be to hear the spacetime ringing.

JANNA LEVIN is a professor of physics and astronomy at Barnard College of Columbia University. She is the author of How the Universe Got Its Spots; A Madman Dreams of Turing Machines; and most recently, Black Hole Blues and Other Songs from Outer SpaceJanna Levin's Edge Bio Page 

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