Colonizing the universe

Retired mathematical physicist Freeman Dyson writes:

When humans begin populating the universe with Noah’s Ark seeds, our destiny changes. We are no longer an ordinary group of short-lived individuals struggling to preserve life on a single planet. We are then the midwives who bring life to birth on millions of worlds. We are stewards of life on a grander scale, and our destiny is to be creators of a living universe. We may or may not be sharing this destiny with other midwife species in other parts of the universe. The universe is big enough to find room for all of us.

Some ppl are ready to go:

Elon Musk is preparing to reveal further details of his hugely ambitious plan to build a city on the surface of Mars.

Tomorrow, the billionaire’s SpaceX is holding an event called “Making Humans An Interplanetary Species” which will shed light on the Red Planet exploration scheme.

Ahead of the event, Musk shared images of a new rocket booster called the Raptor, which will power an “Interplanetary Transport System”.

His firm has carried out a test-firing of the device, which is designed to propel a spaceship all the way to the Red Planet.

But even Dyson does not believe in quantum gravity.

Cosmologist Lawrence M. Krauss wrote last year:

How can we tell if gravity is quantum?

Freeman Dyson, who is a brilliant physicist and a contrarian, he had pointed out based on some research — he’s 90 years old, but he had done some research over the years — I was in a meeting in Singapore with him when he pointed out that we really don’t know if gravity is a quantum theory. Electromagnetism is a quantum theory because we know there are quanta of electromagnetism called photons. Right now they’re coming, shining in my face and they’re going into the camera that’s being used to record this and we can measure photons. There are quanta associated with all of the forces of nature. If gravity is a quantum theory, then there must be quanta that are exchanged, that convey the gravitational force; we call those gravitons. They’re the quantum version of gravitational waves, the same way photons are the quantum version of electromagnetic waves. But what Freeman pointed out is that there’s no terrestrial experiment that could ever measure a single graviton. He could show that in order to build an experiment that would do that, you’d have to make the experiment so massive that it would actually collapse to form a black hole before you could make the measurement. So he said there’s no way we’re ever going to measure gravitons; there’s no way that we’ll know whether gravity is a quantum theory.

What I realized, and Frank and I codified in our paper, is that actually the universe acts like a graviton detector, in [the] sense that processes in the early universe produced phenomena that could be observed today as gravitational waves. But those events, those processes, will only work if gravity is a quantum theory. If gravity isn’t a quantum theory, we won’t see these gravitational waves from the very early universe, which BICEP thought they saw. Now BICEP may not have seen gravitational waves from the early universe, but the fact that we recognize that if this phenomena called inflation happens in the very early universe, and if it produces gravitational waves, that will tell us that gravity is a quantum theory; therefore, all of the problems of quantum gravity will need to be addressed by theorists, giving job security for generations.

Dyson is right here, and all the talk about quantum gravity is unscientific speculation.

Junk science in TED Talk

Jerry Coyne reports on some populist bogus social science:

The second most popular TED talk of all time, with over 32 million views on TED, is by Harvard Business School associate professor Amy Cuddy, called “Your body language shapes who you are”. (You can also see the talk on YouTube, where it has over 10 million views. Cuddy appears to be on “leave of absence.”)  Her point, based on research she did with two others, was that by changing your body language you can modify your hormones, thus not only influencing other people in the way you want, but changing your own physiology in a way you want.

The kindest thing you can say is that her results were not replicated. All the other studies gave opposite conclusions.

Statistician Andrew Gelman also laments the sorry state of social science. It is overrun by poor studies and p-hacking.

No-Cloning is not fundamental

Complexity theorist Scott Aaronson makes a big deal out of the No-cloning theorem:

The subject of this talk is a deep theorem that stands as one of the crowning achievements of our field. I refer, of course, to the No-Cloning Theorem. Almost everything we’re talking about at this conference, from QKD onwards, is based in some way on quantum states being unclonable. ...

OK, but No-Cloning feels really fundamental. One of my early memories is when I was 5 years old or so, and utterly transfixed by my dad’s home fax machine, ...

The No-Cloning Theorem represents nothing less than a partial return to the view of the world that I had before I was five. It says that quantum information doesn’t want to be free: it wants to be private. There is, it turns out, a kind of information that’s tied to a particular place, or set of places. It can be moved around, or even teleported, but it can’t be copied the way a fax machine copies bits.

So I think it’s worth at least entertaining the possibility that we don’t have No-Cloning because of quantum mechanics; we have quantum mechanics because of No-Cloning — or because quantum mechanics is the simplest, most elegant theory that has unclonability as a core principle.

No-Cloning sounds fundamental, but it is not.

The theorem says that there is no physical process that always perfectly duplicates a given physical entity. You can have a laser beam that emits identical photons in identical states, but you can not have some trick optical device that takes in any photon and copies it into an additional photon in the same state.

The proof assumes that any such process would have to perfectly represent the entity (eg photon) by a wave function, to apply a unitary transformation to duplicate it, and to perfectly realize that result.

So you have to believe that a physical entity is exactly the same as a mathematical wave function, and a physical process is exactly the same as a unitary transformation.

But isn't that the essence of quantum mechanics? No, it is not.

Quantum mechanics is a system of using wave functions to predict observables. But there is no good reason to believe that there is a one-to-one correspondence between physical entities and wave functions.

The no-cloning theorem is a big headache for quantum computing because it means that qubits can never be copied. Ordinary computers spend most of their time copying bits.

But scalable qubits may not even be possible.

The no-cloning theorem is not something with any direct empirical evidence. It is true that we have no known way of duplicating an atomic state, but that is a little misleading. We have no way of doing any observations at all on an atomic state without altering that state.

China claims to invent quantum radar

ExtremeTech reports:

The Chinese military says it has invented quantum radar, a breakthrough which, if true, would render the hundreds of billions of dollars the United States has invested into stealth technology obsolete. Like the original invention of radar, the advent of modern artillery, or radio communications, quantum radar could fundamentally transform the scope and nature of war. ...

Quantum radar would exploit quantum entanglement, the phenomena that occurs when two or more particles are linked, even when separated by a significant amount of physical space. In theory, a radar installation could fire one group of particles towards a target while studying the second group of entangled particles to determine what happened to the first group. The potential advantages of this approach would be enormous, since it would allow for extremely low-energy detection of approaching enemy craft. Unlike conventional radar, which relies on an ability to analyze and detect a sufficiently strong signal return, quantum radar would let us directly observe what happened to a specific group of photons. Since we haven’t invented cloaking devices just yet, this would seem to obviate a great deal of investment in various stealth technologies.

China is claiming to have developed a single-photon radar detection system that can operate at a range of 100km, more than 5x that of a lab-based system developed last year by researchers from the UK, US, and Germany. Research into quantum radar has been ongoing for at least a decade, but there are significant hurdles to be solved.

Let me get this straight. The quantum radar entangles two photons, and fires one at the stealth plane. Then there is no need to look for any return signal because you can figure out what happened by examining the entangled photon that never left.

This is impossible, of course. Either someone has some massive misunderstandings of quantum mechanics, or someone is perpetrating a scam. Or maybe China thinks that Americans are dumb enuf to believe a story like this.

Nobel site on relativity

The Nobel Prize site has a page on the History of Special Relativity

1898 Jules Henri Poincaré said that "... we have no direct intuition about the equality of two time intervals."

1904 Poincaré came very close to special relativity: "... as demanded by the relativity principle the observer cannot know whether he is at rest or in absolute motion."

1905 On June 5, Poincaré finished an article in which he stated that there seems to be a general law of Nature, that it is impossible to demonstrate absolute motion. On June 30, Einstein finished his famous article On the Electrodynamics of Moving Bodies, where he formulated the two postulates of special relativity.

Here is that 1905 Poincare paper. It is really just an abstract of a longer paper. Poincare states that general law of nature in the first paragraph.

The most important points in that Poincare abstract are that the Lorentz transformations form a group, and that all forces, including electromagnetism and gravity, are affected the same way. Poincare is quite emphatic about both of these points.

Einstein had access to Poincare's abstract before writing his
1905 relativity paper, but he does not quite get these two points, altho he is often credited with them. Here is what they say.

Poincare: "The sum of all these transformations, together with the set of all rotations of space, must form a group; but for this to occur, we need l = 1; so one is forced to suppose l = 1 and this is a consequence that Lorentz has obtained by another way."

Einstein: "we see that such parallel transformations — necessarily — form a group."

Poincare: "Lorentz, in the work quoted, found it necessary to complete his hypothesis by assuming that all forces, whatever their origin, are affected by translation in the same way as electromagnetic forces and, consequently, the effect produced on their components by the Lorentz transformation is still defined by equations (4). It was important to examine this hypothesis more closely and in particular to examine what changes it would require us to make on the law of gravitation."

Einstein: "They suggest rather that, as has already been shown to the first order of small quantities, the same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good."

As you can see, Poincare had a deeper understanding of relativity, and he published it first.

Randomness does not need new technology

SciAm reports:

Photonic Chip Could Strengthen Smartphone Encryption

The chip uses pulses of laser light to generate truly random numbers, the basis of encryption. Christopher Intagliata reports.

Random numbers are hugely important for modern computing. They're used to encrypt credit card numbers and emails. To inject randomness into online gaming. And to simulate super complex phenomena, like protein folding or nuclear fission.

But here's the dirty secret: a lot of these so-called random numbers are not truly random. They're actually what’s known as "pseudo random numbers," generated by algorithms. Think of generating random numbers by rolling dice. If you know the number of dice, it’s simple to figure out something about the realm of possible random numbers—thus putting probabilistic limits on the randomness.

But truly random numbers can be generated through quantum mechanical processes. So researchers built a photonic chip — a computer chip that uses photons instead of electrons. The chip has two lasers: one shoots continuously; the other pulses at regular intervals. Each time the two lasers meet, the interference between the light beams is random, thanks to the rules of quantum mechanics. The chip then digitizes that random signal, and voila: a quantum random number generator.

This distinction between truly random and pseudo random numbers is entirely fallacious.

They act as if quantum hanky panky magically makes something more random than other random things.

See the Wikipedia article on Hardware random number generators. There are lots of them on the market already. They are already cheap enuf for smart phones, if there were any commercial need.

I actually think that it would be nice to have such a random number function in PCs and phones. But the fact is that there are suitable workarounds already. There is no need for a fancy 2-laser device like in this research.

Massimo Pigliucci is a philosophy professor who specializes in calling things pseudoscience, and argues strenuously that it is a useful term:

Pseudoscience refers to “any body of knowledge that purports to be scientific or to be supported by science but which fails to comply with the scientific method,” though since there is no such thing as the scientific method, I would rather modify the above to read “with currently accepted scientific standards.” ...

Burke then goes on to cite a 2011 dissertation by Paul Lawrie that argues that “dismissing… scientific racism as ‘pseudo-science,’ or a perversion of the scientific method, blurs our understanding of its role as a tool of racial labor control in modern America.”

Maybe it does, maybe it doesn’t. But scientific racism is a pseudoscience, and it is widely recognized — again by the relevant epistemic community — as such.

It seems to me that the term pseudoscience is mainly used for political purposes and unscientific name-calling, such as for denouncing racism.

But if anything is pseudoscience, then why not the creation of "truly random numbers"? Why is it acceptable to distinguish truly random numbers from not-truly random numbers, but only pseudoscience to distinguish Caucasians from Orientals?

Current philosophers like Pigliucci should be called pseudo-philosophers. They sound as if they are doing philosophy, but they fail to follow minimal standards.

Coyne is not a freely acting agent

Leftist-atheist-evolutionist Jerry Coyne regularly attacks religion and believers for being irrational. He has written books on the subject.

Here he quibbles with physicist Sean M. Carroll over free will:

Lack of information simply means we cannot perfectly predict how we or anybody else will do, but it doesn’t say that what we’ll do isn’t determined in advance by physical laws. Unpredictability does not undermine determinism. And therefore, if you realize that, I don’t know how you can assert that “it’s completely conceivable that we could have acted differently.” ...

What I would have added to this is that nobody who downloads child pornography is in control of his actions, at least in the sense that they could have avoided downloading the pornography. I’m sure Sean would agree. Whether you have a brain tumor, some other cause of hypersexuality, were abused yourself as a child, were mentally ill in a way with no clear physical diagnosis, or simply have been resistant to social pressures to avoid that kind of stuff — all of this is determined by your genes and your environment. ...

But what does predictability have to do with this? We already know that people are not freely acting agents in the sense that they are free from deterministic control by their brains. We already know that people are predestined. ...

I’ve already given my solution to this issue. We recognize that, at bottom, nobody could have done otherwise. If they are accused of something that society deems to be a crime, you find out if they really did commit that crime. If they’re found guilty, then a group of experts — scientists, psychologists, sociologists criminologists, etc. — determine what the “punishment” should be based on the person’s history (a brain tumor would mandate an operation, for instance), malleability to persuasion, likelihood of recidivism, danger to society, and deterrent effects. None of that needs the assumption that someone is a “freely acting agent.”

I know many of you will disagree on that, or on the ramifications of determinism for our punishment and reward system. But at least I have the satisfaction of knowing that Sean agrees with me on this: if science shows the way our behaviors are determined, that knowledge should affect the way we punish and reward people.

So why is he saying what ppl should do if no one has any choice about it?

How can he distinguish between predictability and determinism, if no science experiment can make that distinction? What sense does it make to say something is determined, if there is no conceivable empirical way of making that prediction?

Coyne is pretty good on some evolution-related science that is closer to his expertise, but on subjects like this, I do not see how he is any more scientific than the religious believers he attacks.

Our most fundamental laws of physics are not deterministic. And even if they were, they would not be so predictable as to predict ppl's free choices.

Many theists believe in a God that is all-knowing. Most Christians believe that God gives us free will to make our own choices. Coyne mocks all of this, but he believes in some unobservable force or system that determines everything we do.

I am beginning to think that if a man says that he is driven by voices in his head, I should just believe him. Ditto for demons in his head, or any other equivalent. That is, I choose to believe him.

For more from Carroll, listen to this recent lecture:

Sean Carroll discusses whether space and gravity could emerge from quantum entanglement -- and rewrites physics in terms of quantum circuits.