Materialism Raises Fears You're a Soon-to-Die Boltzmann Brain

Let us imagine a disorderly universe consisting only of atoms randomly bouncing about. Materialists believe that minds and beliefs arise from certain combinations of matter in brains. If a disorderly universe existed for enough time and had enough mass, it might happen (under the assumptions of materialism) that some random combination of atoms might produce a self-conscious brain.

In the simplest case we can imagine, this might result in a mere flicker of self-consciousness that lasted only a few seconds. But in a more complicated case, the transient brain formed from random atom combinations might actually include beliefs and sensations that briefly persisted. Even though it might be surrounded by pure disorder, like a chunk of chicken in a big pot of soup, this short-lived brain could conceivably involve some random arrangements of atoms that might briefly convince the brain that it was viewing an orderly external world. The term philosophers and physicists use for such a hypothetical brain is a Boltzmann brain.

A Boltzmann brain is a hypothetical brain that arises from a random combination of atoms somewhere in space. A Boltzmann brain has internal states which make it seem like there is an orderly external world that doesn't exist. Just as a television playing a DVD can show a stream of images even when it is not receiving external television signals, a brain could conceivably have a set of internal states that might convince it that observations of an orderly external world were occurring, even though the brain was not actually getting light signals from such an orderly external world, and was actually surrounded by disorderly atoms bouncing around like the particles in a soup.

Let us imagine the brief appearance of a Boltzmann brain. First let us imagine a disorderly universe consisting not of planets and stars, but just random particles bouncing around. Because of some very improbable combination of atoms, some neurons come into existence, which create a consciousness that includes what seems like memories and perceptions of an external world. But the memories are false, and do not correspond to anything that happened. And the perceptions are also false, and do not correspond to anything in the external world.

Now, you may say that we can rule out such a possibility immediately, because it would just be too improbable that there could be so unlikely a random combination of atoms. One argument against the possibility is that there hasn't been enough time for there to be a significant chance of a Boltzmann brain, because the universe has only existed for about 13 billion years. But this does nothing to argue against the possibility that you may be a Boltzmann brain, because if you are a Boltzmann brain, the universe could really be far older than 13 billion years old (perhaps infinitely old); and your belief that the universe is 13 billion years old could simply be a belief that very recently appeared when random atoms combined to make your brain.

You may say think to yourself something like this:

I know in my mind so many things – all those things I learned in school. And I have so many memories – all the memories of a lifetime. It is way too unlikely that any random combination of atoms could ever produce a brain with all this knowledge and all these memories.

But there is a reason why such an argument is not convincing under materialist assumptions. Let us consider a possibility that we may consider a minimal Boltzmann brain. The minimal Boltzmann brain merely consists of the following:

1. A brain with a sense of self-hood.
   
2. A brain with the belief that it has lots of knowledge learned during years of life, and the belief that it has a lifetime in memories.
   
3. A brain that merely has the thoughts, recollections and sensations that you had during the past 30 seconds.
   

Now, under the assumptions of materialism, this minimal Boltzmann brain would be sufficient to account for your mental experience during the past 30 seconds. And under the assumptions of materialism, it could be that your mind is really only 30 seconds old, having arisen 30 seconds ago from a random combination of atoms in a disorderly universe, one that produced a minimal Boltzmann brain.

Assuming that memories can be stored in brains, it would require a most improbable combination of atoms to give you a Boltzmann brain with thousands of detailed memories. But it might require a vastly less improbable combination of atoms to give you a Boltzmann brain that did not really have all those memories, but merely had the belief it had thousands of detailed memories, and that merely had whatever memories you had recalled in the past 30 seconds. Under materialist assumptions, you could be such a Boltzmann brain, perhaps one that could have arisen only 30 seconds ago, from a random combination of atoms in a disorderly universe.

Now you may say that in regard to the possibility of a Boltzmann brain that had arisen only a few seconds or minutes ago, and one that didn't really have a lifetime of memories and knowledge but only the belief that it had a lifetime of memory and knowledge, it would still be too improbable that such a rare combination of atoms would occur by chance. So, you may reason, you can still believe in materialism and still think it is most improbable that you a recently formed Boltzmann brain. But such an argument is not a very convincing one. For while it is clear that while your recent appearance as a Boltzmann brain would be very improbable, it is not clear that it would be less improbable than your existence (under materialist assumptions) if you are not a Boltzmann brain, and everything you see around you is real.

The type of situation that we supposedly live in is one that is also fantastically improbable to occur by chance. Having an external universe like ours that is habitable with life (and with just the right fundamental constants allowing life to exist) requires a long series of coincidences, and some have estimated that the likelihood of all of these coincidences happening is less than 1 in ten to the hundredth power (much less than 1 in 1,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000). Then there is the origin of life, which seems to have required luck with a likelihood of less than 1 chance in 10 to the two hundredth power. Then there are all kinds of improbabilities in getting large multicellular organisms such as humans.

So under materialist assumptions the total unlikelihood of any intelligent organism such as you existing in a physical universe like the one we see around us may be less than 1 in 10 to the 300th power. And while it would be very unlikely that atoms combining in space would combine to briefly give you an illusion of perceiving an external world that does not exist, it is not at all clear that this would be less likely than 1 in 10 to the 300th power. It therefore seems that if you regard your consciousness as being caused by a brain, then you should have no great confidence about whether the external world exists, and should think there is a significant chance that you are merely a Boltzmann brain who originated a short time ago from a random combination of atoms in a disorderly universe, your sensations being merely illusions created by random states in your random brain.

It has often been said that from a thermodynamic standpoint, a Boltzmann brain in a disorderly universe is far more likely than a universe as orderly as ours. The most likely thing from a thermodynamic standpoint is a universe consisting of a gas of fairly uniform temperature. Deviations from such a thing are called statistically unlikely, and it said that the higher the deviation, the higher the unlikelihood. A Boltzmann brain would seem to involve a thermodynamic deviation relatively small, and might be potentially much more likely than a universe such as ours, which is a gigantic thermodynamic deviation.

On page 316 of his book Fashion Faith and Fantasy in the New Physics of the Universe, cosmologist Roger Penrose says, “One can make a very rough estimate of the probability that life, as it now exists on Earth, with all its detailed molecular and atomic locations and motions, came about simply by chance encounters from particles coming in from space in, let us say, six days!” Penrose then estimates that such a thing would have a probability of about 1 in 10 to the ten to the sixtieth power. That is a probability not anything like the microscopic probability of 1 in 10⁶⁰ but instead an almost infinitely smaller probability. It's the probability you would have if you started out with one tenth and then kept multiplying by one tenth a total number of times equal to a trillion trillion trillion trillion trillion times. But then Penrose tells us that this fantastically unlikely event (a life-filled Earth like ours suddenly forming from random collisions of particles) would be far more probable than the existence of a universe as orderly as ours, saying it “would be a far 'cheaper' way of producing intelligent beings than the way in which it was actually done!” He's indicating that the incredibly improbable sudden formation of a life-stocked planet like ours would actually be much more likely than the chance of you getting a universe such as ours accidentally.

In light of such a calculation, under materialist assumptions an individual should perhaps suspect that he is merely a Boltzmann brain recently formed from random atomic collisions, as that might be far more likely than for him to be a regular brain in a universe such as ours.

Physicist Sean Carroll has written about Boltzmann brains, and seems to have the idea that the concept is mainly an issue in physics or cosmology. He seems to think we can get rid of the specter of Boltzmann brains by picking the right cosmology model, such as one that doesn't generate too many Boltzmann brains. Such ideas are not correct. Properly considered, Boltzmann brains are mainly an issue in the philosophy of mind rather than physics or cosmology. The real issue is whether random combinations of matter can briefly produce someone who had the same thoughts, beliefs and sensations you had in the past 30 seconds. If that is so, it is very troubling, and you cannot remove your worry about this by assuring yourself that the universe is too young to have produced Boltzmann brains. The very belief that the universe is only 13 billion years old is one that merely could have popped up a few seconds or minutes ago in your Boltzmann brain formed by a random combination of atoms. So under materialist assumptions it could still be true that the universe might have existed forever, and there would have been time for countless trillions of Boltzmann brains to have arisen, no matter how improbable they are.

Now, in response to this a materialist may say something like, “I don't care too much about such a possibility because it makes no practical difference, and my life will be the same regardless of whether I am or am not a Boltzmann brain.” But this isn't true at all. If you are a Boltzmann brain, it has the greatest immediate consequences, because if you a Boltzmann brain it is extremely likely that you will die today.

The longer a Boltzmann brain persists while seeming to have sensations of an orderly external world, the greater an unlikelihood is required. After all, brains presumably need blood, but a Boltzmann brain is presumably just a brain floating about that doesn't have a surrounding body to keep pumping it blood (although it may have a sphere of blood around it for a while). So it is overwhelmingly likely that any Boltzmann brain will have existed less than a day, and will continue to live for less than a day. Under materialist assumptions, your memory of experiencing things a long ago time does not rule out the idea that you are a Boltzmann brain that arose from chance combinations of atoms a few minutes ago or hours ago in a chaotic universe, for when that Boltzmann brain arose it could have simply included such memories.

So if you are a materialist, you should fear that you a Boltzmann brain that is going to die today, living only the very, very short typical lifespan of a Boltzmann brain. Another thing you should be terrified about if you are a materialist is that today you will either go blind and deaf, and experience no more sensations for the rest of your life, or that you will experience nothing but unintelligible visual noise and auditory noise for the rest of your life. After all, each second of sensations experienced by a Boltzmann brain (in which it seems merely by chance atom combinations to experience an orderly external world) requires a great coincidence in which random particle movements conspire to resemble a meaningful, orderly reality. Every minute that something so improbable continues is like an additional minute at the roulette table in which you are betting all your winnings on Red 14, and continuing to win (and actually far more improbable). Such luck is very unlikely to continue for very long.

So it seems that if you are a materialist, you should be quite terrified that you a Boltzmann brain, and that you will either die today or that today you will stop having any more meaningful sensations, experiencing either blindness for the rest of your life, or meaningless noise sensations perhaps resembling what you see when you look through a kaleidoscope.

You can never prove that you are not a Boltzmann brain by having some long stream of sensations or recall experiences that you think are “too long and complicated for a Boltzmann brain to have.” Because once you start thinking along the lines of Boltzmann brains, you lose confidence that you actually had such a long stream of experiences and recall experiences. It could be that a few seconds ago you appeared when some random atoms combined in space, and that your belief that you recently had this “long stream of sensations and recall experiences” is merely a belief that arose a few seconds ago when your Boltzmann brain originated.

You may think: we can rule out the idea of Boltzmann brains, because it's too improbable that an organ as complicated as a brain would appear by a random combination of atoms. But because of the Boltzmann brain scenario, as a materialist you could not be confident that you actually have some very complicated brain. If you believe that consciousness and something like human mentality can arise from mere combinations of atoms, then you cannot rule out a scenario like the following:

1. Your mind arose after a relatively simple combination of a small number of atoms, forming only a very simple, tiny brain.
   
2. It could be that the mental state that arose after this relatively simple combination of a small number of atoms includes the untrue belief that mental experience like your present experience requires a very complicated brain.
   

If you are one of those persons who believes in a multiverse (an incredibly vast collection of universes), then if you are a materialist you should be particularly worried that you are a recently formed Boltzmann brain, because under materialist assumptions the more universes that exist, the more Boltzmann brains should be created.

Although the concept of a Boltzmann brain may sound silly, it is a serious philosophical problem for anyone who believes that consciousness can arise from combinations of matter. It seems that anyone who has such a belief can have no great confidence that everyone he observes at this instant really exists. And when you are lying with your eyes closed on your bed, waiting to fall asleep, experiencing no complex sensations, that is when (under materialist assumptions) you should be most afraid that you are merely a very recently formed Boltzmann brain who will not live another hour. For in that state you cannot say, “It is too unlikely that I would have such detailed sensations of the world if it did not exist, and I were just a Boltzmann brain that very recently appeared from random atom combinations.” For lying awake with your eyes closed, you are not having any complex sensations at all.

Is there some way to rule out the Boltzmann brain scenario, some way to slay this nasty specter? There is. The answer is to switch from the philosophical position of neuralism to the philosophical position of nonneuralism. Once we do that, the whole Boltzmann brain issue disappears.

We may use the term neuralism for the doctrine that minds come from brains. Although sometimes sold as science, neuralism is a philosophical position, not science. Scientists have no proof that minds are produced by brains, and the type of evidence they sometimes present to try to back up such a claim does not hold up well to critical scrutiny. The claim that brains make minds is a speech custom of neuroscientists rather than anything they have good evidence for believing.

An alternate position is that minds do not come from brains, and cannot come from brains or any other combinations of matter. We may use the term nonneuralism for this position. Nonneuralism is a non-sectarian position in the philosophy of mind that may be held without contradiction by Christians, Muslims, Buddhists, philosophical theists, agnostics or atheists, regardless of whether they do or not believe in Darwinism. Nonneuralism itself does not involve any specific belief about the source of human minds, although some nonneuralists may suspect such a source is cosmic or metaphysical or spiritual or transcendent rather than some local biological source.

Once you adopt the position of nonneuralism, Boltzmann brains are no longer a possibility that troubles you. If you believe minds cannot arise from brains, and cannot arise from any combination of matter, then you will believe that Boltzmann brains cannot possibly exist.

There are many reasons for adopting the position of nonneuralism. Explained in detail at this site, they include the following:

1. The fact that no one has ever advanced a credible explanation for how any type of matter (whether it be neurons or anything else) could produce self-hood, consciousness, thoughts, ideas or beliefs.
2. The fact that there is no credible theory of how a brain could be converting human mental experiences and sensations so that they can be stored for years as neural states.
3. The fact that there is no credible neural theory of how brains could achieve the instantaneous memory recall that humans have (which would be an "instantly finding a needle in a mountain-sized haystack" trick for a brain to perform).
4. The fact that there is no credible theory of how humans could be neurally storing memories that can last for 50 years, given the extremely short lifetimes of the protein molecules that make up synapses.
5. The fact that brains sometimes undergo enormous damage (such as loss of between 50% and 80% of their neurons through hydroencephaly or hemispherectomy) while showing only small changes in memory or cognition.
6. The fact that many people have vivid near-death experiences while their brains have electrically shut down during cardiac arrest, as the brain does within 30 seconds after the heart stops, such experiences suggesting our minds are not generated by our brains.

An additional reason for adopting the position of nonneuralism is that if you adopt such a position, you will not think there is any possibility that you are a Boltzmann brain, and that you will not suspect that maybe the people you see in front of you are mere illusions who will disappear (as you will disappear) a few minutes or hours in the future when your Boltzmann brain (floating about in a disorderly universe) dies. The nonneuralist can consistently say to himself: Boltzmann brains can never exist because brains by themselves do not and cannot produce minds.

NASA's Flawed Plan to Search for Life on Mars

Last week the Daily Express had a headline, “NASA announcement shock: space agency closing in on finding alien life.” The paper quotes the agency as saying, “As we continue checking off items on the habitability list, we'll draw closer and closer to finding a world bearing recognizable signs of life.”

The headline and the statement are both bunk. NASA is not closing in on finding extraterrestrial life, and it is not getting “closer and closer” to finding a world with extraterrestrial life.

A fundamental truth about extraterrestrial life (one that NASA never tells us) is that the natural origin of life on another planet would require fantastically improbable arrangements of matter. You can get a rough analogy of the unlikelihood of this by imagining how improbable it would be if someone were to throw a large box of 1000 scrabble blocks on the ground, and the blocks were to accidentally spell out a very complex computer program.

In fact, such an analogy greatly underestimates the improbability of life accidentally appearing from mere chemicals. By all accounts the most primitive cell requires at least 100 functional proteins, most of which require more than a hundred amino acids arranged in just the right way. So a better analogy would be a dumpster of scrabble blocks dumped on the ground, with the totality of 10,000 tossed scrabble blocks forming into a single coherent computer program accomplishing some fantastically complex task. It is not at all true that if a single protein of the 100 or more required were to form by chance, that such a protein would stick around for a long time until the other required proteins originated. Protein molecules don't self-reproduce unless they are part of a living cell requiring 100 or more proteins. So you would need to have a fantastically improbable stroke of luck in which all or almost all of the minimum required proteins by chance originated at about the same time.

This is merely one mountainous difficulty for the origin of life. A separate but equally great mountainous difficulty is the need for a genetic code (a complex system of symbolic representations), the need for self-reproducing nucleic acids, and the need for homochirality, something with apparently less than one chance in a quintillion of occurring accidentally.

Using only chemical considerations, we can therefore compare the search for extraterrestrial life on any planet to buying a lottery ticket. But we would have to imagine a lottery with insanely bad odds, in which the chance of winning is much smaller than the chance of you winning a billion dollars in the Powerball lottery.

Given such a reality, is it correct for NASA to suggest that the more planets are searched for signs of extraterrestrial life, the “closer and closer” we get to finding it? No, it is not correct. You don't get “closer and closer” to getting a billion-dollar jackpot in the lottery by buying more tickets. If one is trying to design some new type of machine, and your designs get better and better, beginning to more closely resemble your desired design, then you could honesty say that you are getting “closer and closer” to your target. But you do not get “closer and closer” to reaching some incredibly improbable result by making additional searches that are each very unlikely to succeed. You don't get “closer and closer” to finding Bigfoot with each additional search of a forest patch, and you don't get “closer and closer” to finding extraterrestrial life with each new planet searched.

The latest baloney on this topic from NASA is only the latest of quite a few overconfident statements NASA experts have made on this topic. In 2015 Ellen Stofan (a chief scientist at NASA) predicted, “I think we are going to have strong indications of life beyond Earth within a decade, and I think we're going to have definitive evidence within 20 to 30 years.” There is no scientific basis for such optimism, and based on purely natural considerations it would be reasonable to predict no success will occur in the next 100 years.

Stofan tried to support her prediction by stating “we know where to look.” No, we absolutely do not know where to look. We would know where to look if we had some reason to believe that a particular extraterrestrial planet had a high chance of having life. We have no reason to believe that about any planet. A NASA scientist predicting that extraterrestrial life will soon be found on the basis of “we know where to look” (habitable planets) is about as convincing as a Loch Ness monster specialist claiming that the Loch Ness monster will soon be found because we know where to look (in the Loch Ness lake in Scotland).

The people who make such statements seem to be believers in a kind of Easy Abiogenesis tenet, which maintains (contrary to the relevant scientific facts) that life will naturally appear from non-life on any planet with suitable conditions. Such a belief is contradicted by the following:

• The abundant biological reasons (previously discussed) for thinking that abiogenesis (a natural origin of life from non-life) would require a state of organization fantastically unlikely to naturally occur by chance on even 1 in a million planets.
  
• The complete failure of scientists to reproduce abiogenesis in a lab, or even produce a single functional protein in a lab simulating early Earth conditions (a single one of the building blocks of life).
  
• The complete failure of all attempts to search for extraterrestrial radio signals, which presumably would be abundant if it were true that abiogenesis was relatively easy.
  
• The existence of only one genetic code in all of Earth's life, something we would not expect if abiogenesis was relatively easy, in which case life would have arisen multiple times on Earth, with each separate origin having a different genetic code.
  

NASA has a plan to look for signs that life once existed on Mars. It is a plan that is rather stupid. They plan to send in 2020 a new Mars rover that will dig into the Martian soil and retrieve samples. Will the samples then be analyzed in a way sufficient to prove living things or traces of life that once existed? Not really (see the postscript at the end of this post for a technical note on this). Will the samples be sent back to Earth for analysis by human scientists? No, the 2020 mission will have no such capability.

Instead, the not-very-brilliant plan is to simply gather soil and rock samples and just leave them on the ground as “caches” that might be retrieved by some future “Mars cache retrieval” mission, which might then return them to Earth for analysis by human scientists. There are no firm plans for such a retrieval mission, and no one knows how it might work.

Giving us an example of why you can't trust the journal Nature as a very reliable source of information, a Nature article has the title “The $2.4-billion plan to steal a rock from Mars,” and the headline “NASA is now building the rover that it hopes will bring back signs of life on the red planet.” But the article then states something very different:

Once it arrives, the rover will drive across the Martian surface and fill each tube with dirt, rock or air. Then it will seal the tubes, place them on the ground, and wait — for years, or possibly decades — for another spacecraft to retrieve them and fly them back to Earth.


This is how a NASA page describes this bizarre plan:

The mission takes the next step by not only seeking signs of habitable conditions on Mars in the ancient past, but also searching for signs of past microbial life itself. The Mars 2020 rover introduces a drill that can collect core samples of the most promising rocks and soils and set them aside in a "cache" on the surface of Mars. A future mission could potentially return these samples to Earth. That would help scientists study the samples in laboratories with special room-sized equipment that would be too large to take to Mars.

This seems like a rather absurd way to spend money looking for extraterrestrial life. The Mars 2020 mission will cost billions, and some future mission that might retrieve these surface “caches” would cost billions more. The chance of actually finding evidence that life once existed on Mars would be very, very small, because of the reasons previously discussed. There would also be a high risk that the samples would never be returned, because no one has ever done anything like retrieving samples from another planet and returning them to Earth.

A manned mission to Mars could retrieve these “sample caches,” but why would the astronauts even go to the trouble of searching for them, when it would be much easier for them to just drill themselves to get a soil sample wherever they were?

The NASA Mars 2020 mission sounds poorly conceived compared to a European 2020 Mars rover mission that will drill for soil samples and actually analyze them for life. The European Space Agency site says, “The rover will collect samples and analyse them with next-generation instruments – a fully fledged automated laboratory on Mars.” (I discuss in the technical postscript of this post the key thing the ESA rover will have that the NASA rover won't.) 

One of the astrobiology scientists has the same unfounded optimism as the previously quoted NASA scientist, and stated that there's a “50-50” chance of finding life on Mars. Based on the actual difficulty of life appearing from chemicals under the best of conditions, we should instead assume the actual chance of success as very much less than 1 in a thousand.

Spending billions to search for life on Mars makes little sense as a way to spend astrobiology dollars. If you want to search for extraterrestrial life in a way that gives you “bang for the buck,” the most sensible strategy is to search for radio signals from other solar systems. For one tenth of the cost of an unmanned Mars mission, you can check not just one planet but 1000 planets, looking for radio signals.

In the very unlikely event that it succeeds, the best we would ever get from a Mars soil retrieval mission is evidence of microbes on Mars. That would be a relatively boring find that might hold the public's interest for no more than two weeks. A search for extraterrestrial radio signals, on the other hand, might actually produce photos of extraterrestrials and photos of extraterrestrial cities (visual data can be transmitted over radio using the right coding system). That would hold the public's interest permanently.

A scientist named Golombek claims that the NASA Mars 2020 rover is “our best chance of finding out if life evolved independently on another world and that life here is not just a lucky accident.” It is not any such thing. The best chance of finding out if life evolved independently on another world is to have a much less expensive mission that checks many planets looking for radio signals from civilizations.

A statement such as Golombek's reveals the ideological motivation of looking for life on Mars. It's all about scientists hoping to prove (against all indications) that Earth getting life was not a very lucky event. Our scientists are troubled by the idea that when life originated here, Earth seemingly got some specially lucky blessing, some miracle that seems providential; and they want to spend billions as a kind of analgesic to remove this discomfort (finding life on a planet like Mars with bad conditions might prove that the origin of life is rather automatic). The scientist who asks for billions to search for underground traces of Mars life to try to prove a far-fetched belief (the Easy Abiogenesis tenet that the origin of life on Earth wasn't very lucky or providential) is rather like some fundamentalist who asks for millions so he can search for underground wooden traces of Noah's Ark.  

Contrary to the overblown hype you may have read last summer (debunked here), scientists have not at all found the building blocks of life on Mars. The building blocks of life are proteins and nucleic acids, and no such things have been found on Mars.  And since no one has even found a single amino acid on Mars, it is not even true that the building blocks of the building blocks of life have been found there.  For this reason, a mission to look for life on Mars is rather like calling in a structural engineer to determine whether a habitable apartment building exists at some site when no one has even reported seeing bricks at that site. 

Postscript: Referring to the 2020 NASA Mars mission, the National Geographic has a story calling a scientist someone who designed "a device to look for signs of past life on Mars." The device in question is called PIXL, short for planetary instrument for X-ray lithography. But it is mainly an instrument for detecting elemental compositions, and does not seem capable of actually verifying that microbes once existed in the soil. You can't distinguish between non-biological organic compounds and traces of life merely by looking at elemental compositions.  The instrument's optical resolution of .1 millimeter (100 microns) isn't powerful enough to see something bacteria-sized, which would only be about .5 micron to 5 microns. What we would like to see in the technical documents related to this PIXL instrument is mention of some test in which the device was able to distinguish between sterile soil and soil that contained (or once contained)  bacteria.  I don't see that in the technical documents, although one of them refers to a too-easy test involving blueberries. 

But apparently the ESA rover scheduled for 2020 will have the ability to find a unique signature of life, for according to this page, their rover will be able to detect homochirality.  Homochirality is one of the little-discussed marvels of life -- the fact that virtually all amino acids in living things are left-handed, and virtually all sugars are right-handed (which is not at all what we see when such things are synthesized in labs).  Checking for homochirality is a great way to search for life, but the very requirement of homochirality (an incredibly improbable thing for you to get by chance) is an additional reason for thinking Mars won't have accidentally spawned life.  Why isn't the NASA 2020 Mars rover also looking for homochirality? 

Fake News Academia-Style

One of the big problems in the culture of modern science is that web sites very often give us hype-filled stories that do not accurately state the findings of new scientific research. The problem is not at all limited to popular web sites. A large part of the problem is university press offices, which nowadays are shameless in exaggerating the importance of research done at their university. The authors of such press releases know the more some scientific research done at their institution is hyped, the more glory and attendees will flow to their university.

A scientific paper reached the following conclusions, indicating a huge hype and exaggeration crisis both among the authors of scientific papers and the media that reports on such papers:

Thirty-four percent of academic studies and 48% of media articles used language that reviewers considered too strong for their strength of causal inference....Fifty-eight percent of media articles were found to have inaccurately reported the question, results, intervention, or population of the academic study.

At this link you can find analysis of recent misleading press releases on health research, many of them issued by major organizations such as universities and hospitals. Here are some of the article titles from the past several months, each corresponding to a faulty scientific press release:

• Claim that milk protein alleviates chemotherapy side effects based on study of just 12 people
• University PR misleads with claim that preliminary blood test detects early pancreatic cancer
• Supposed ‘breakthrough’ for detecting gut disorders tested in only 12 healthy people
• Announcement oversells blood test for predicting treatment outcomes in prostate cancer
• No, an asthma drug tested in mice does not bring 'new hope' to Alzheimer's patients, at least not yet
  
• University touts new device to protect women from HIV, buries fact it was only tested in rabbits
• ‘Daily ibuprofen can prevent Alzheimer’s disease’ and other unproven claims by Canadian neuroscientist

But in none of these cases do we have a press release as faulty as a particular press release issued by Johns Hopkins University, a press release that very much misled the reader about an important scientific study. The study was one led by Richard Huganir to look for long-lived proteins in synapses. There is a reason why such a study was of considerable philosophical interest.

The most popular scientific doctrine concerning how memory is stored is the doctrine that memory is stored by a process of the strengthening of synapses of brains. But what we know about the lifetimes of proteins in synapses contradicts this doctrine. Humans can remember old memories for as long as 50 years. But as far as we know, the proteins in synapses have average lifetimes no longer than a few weeks. How could memories be stored in synapses that have their parts being constantly replaced? That would be like storing an essay written on leaves on a table, when the wind is frequently blowing away the leaves, and replacing them with other falling leaves -- not something suitable for long-term information storage.

The Huganir study was one specifically looking for long-lived proteins in synapses. If lots of long-lived proteins could be found in synapses, with lifetimes of many years, then it might be that the main theory of a brain storage of memories (the synapse memory doctrine) is not so unbelievable as it once seemed. But if few or no brain proteins were found with very long lifetimes, it would bolster the case that brains are not up to the job of storing human memories that can last for 50 years.

Now, judging from the press release about this study that was released by Johns Hopkins University, you would think that the study was a great success. The press release was entitled “In Mice, Long-Lasting Brain Proteins Offer Clues to How Memories Last a Lifetime.” Talking about two proteins in the body that last for years (crystallin in eyes and collagen in connective tissue), the press release states the following, ending with a quote from Richard Huganir, the leader of the study:

His team also knew of long-lasting proteins such as crystallin, which makes up the lens of the eye, and collagen, found in connective tissue. Proteins within nuclear pores, the transport tunnels in and out of a cell’s nucleus, and histones, a kind of “spool” that DNA winds around, also are very stable. “So, we reasoned, there must be proteins in those synapses that are long-lasting, too, and we believe we have found a lot of them.”

The problem is that this statement does not at all match what is in the actual scientific paper, which found no such thing. Quite to the contrary, the paper found the following:

• Studying thousands of brain proteins, the study found that virtually all proteins in brains are very short-lived, with half-lives of less than a week.
  
• Table 2 of the paper gives specific half-life estimates for the most long-lasting brain proteins, and in this table only 10 out of thousands of brain proteins had half-lives of 10 days or longer.
  
• Of the proteins whose half-life is estimated in Table 2, only one of them has a half-life of longer than 30 days, that protein having a half-life of only 32 days.
  
• A graph in the paper indicates that none of the synapse proteins had a half-life of more than 35 days.
  

Below is a graph from the Huganir paper. It shows that the study found that virtually all proteins in synapses are very short-lived.

Below is another graph from the same paper. It shows that the study found that virtually all proteins in synapses are very short-lived.

Judging from these graphs, none of the proteins found had a half-life of longer than 35 days, and only a few had a half-life of more than 14 days.

Given these results, it is extremely misleading for Huganir to be saying in the press release that he found “a lot” of “long-lasting” proteins in synapses. He found no such thing, and did not even find a single protein with an average lifetime of years.

So far from offering “clues to how memories last a lifetime,” as the misleading Johns Hopkins press release states, this study gives us all the more reason for thinking that memories would not even last a year if they were stored in our synapses as our neuroscientists maintain. An accurate title for the press release would have been “Study Indicates Synapses Cannot Store Memories for Longer Than a Month.”

The results in the Huganir paper are consistent with the results from this 2018 paper by German scientists that studied a similar topic. The paper starts out by noting that one earlier 2010 study found that the average half-life of brain proteins was about 9 days, and that a 2013 study found that the average half-life of brain proteins was about 5 days. The study then notes in Figure 3 that the average half-life of a synapse protein is only about 5 days, and that all of the main types of brain proteins (such as those in the nucleus, mitochondrion, etc.) have half-lives of less than 20 days. The 2018 study here precisely measured the lifetimes of more than 3000 brain proteins from all over the brain, and found not a single one with a lifetime of more than 75 days (figure 2 shows the average protein lifetime was only 11 days). 

In this paper by German scientists, tubulin proteins are the only type of brain proteins identified as having a half-life of longer than 14 days. Tubulin proteins are used in tube-shaped microtubules. But there's no chance that such microtubules could be a stable storage site for memory, because microtubules are known to be very short-lived. A scientific paper tells us how short-lived these microtubules are:

Neurons possess more stable microtubules compared to other cell types (Okabe and Hirokawa, 1988; Seitz-Tutter et al., 1988; Stepanova et al., 2003). These stable microtubules have half-lives of several hours and co-exist with dynamic microtubules with half-lives of several minutes.

The Johns Hopkins press release misleadingly suggested that there were some proteins in synapses that could account for memories that lasted for decades, something completely contrary to the actual data in the paper it was discussing, and also entirely contrary to the data in the other paper I have cited above. This reminds us of a type of bogus language use that has been going on among neuroscientists for decades.  For decades neuroscientists have been trying to suggest that an effect misleadingly called long-term potentiation might account for human memory. But the term long-term potentiation is a great misnomer. The effect is actually a short-term effect that almost always disappears within a few weeks, and has never been observed to last for years. Neuroscientists have known from the time of its discovery that so-called long-term potentiation is really a very short-lived effect. So why do they keep using this deceptive term “long-term potentiation”?

In this case of the Hopkins press release, personnel at a university are to blame for bad science reporting. That is very often how it is. An article entitled, “How Scientists Contribute to Bad Science Reporting” refers to a study that found that about one third of science press releases contain exaggerated causal claims. The article states the following:

But a recent study suggests that journalists aren't the weakest link. The source of misrepresentations and exaggerations in science news stories is often much closer to the scientists themselves: press releases put out by researchers' own institutions. Surveying hundreds of news stories and press releases about medical research, a group of scientists at Cardiff University found that most exaggerations and misrepresentations of science in print news "did not occur de novo in the media but was already present in the text of the press releases produced by academics and their establishments." …. When a press release had no exaggerations or misleading claims, relatively few—less than 20 percent—of the related news stories carried misleading claims. But when a press release did include an exaggerated or misleading claim, the majority of the associated news stories also featured exaggerations and misleading claims....More than a third of the press releases examined contained misleading statements or exaggerations, so the bad influence of academic institutions on science reporting is very likely substantial.

Who should we blame for all this exaggeration and misinformation coming from college and university press offices? You might want to blame it on lowly press office staff members, but remember that any careful scientist will review the press release describing any study he led.  

An Absurd Proposal Reminds Us of the Limits of Science

At the “Science-Based Medicine” web site there is currently an essay advocating one of the most absurd proposals I have ever heard. Entitled “A right to science,” the essay advocates that there should be a new amendment to the United States constitution, one that reads, “Neither Congress nor any State shall make or enforce any law unless it is based on the best available science.” The author, a lawyer, notes “I cannot find a single mention of any such proposal in the legal literature.” I can think of a reason why no one has ever previously proposed such an amendment. It is that if such an amendment were enacted, we could no longer enforce laws against murder, theft, fraud, or kidnapping.

Science tells us about physical realities, and it can tell us some things about human behavior and human thinking. But science tells us nothing at all about value, morality, or right or wrong. There is no scientific evidence that murder is wrong. The judgment that murder is wrong is one that humans reach because we have a conscience. So if we could no longer enforce any law “unless it is based on the best available science,” we would have to stop enforcing laws against murder. We would also have to stop enforcing laws against theft. There has never been a single shred of scientific evidence showing that it is wrong to steal from someone else.

You could try to argue against the opposite by arguing for some principle that whatever produces sadness or pain is wrong, and that science can show that certain actions tend to produce suffering. But the principle that whatever produces sadness or pain is wrong is a debatable philosophical principle, not a scientific principle. And such a principle doesn't even work as an ethical principle, as it would prevent us from paying our income taxes (a source of sadness), and prevent us from forcing students to study hard subjects like physics (a source of pain).

Science cannot prove the morality or rectitude of anything. Scientific evidence can prove that some particular person killed someone. But science is absolutely mute about what should be done as a consequence of such an event. Science has nothing to say about whether it is better to hang murderers or to give them a second chance and let them go free.

If all laws had to be based on scientific evidence, we would have to repeal any law gathering taxes to help pay for a military to defend the country against foreign threats. Science tells us nothing about whether it is better for an American flag, a Chinese flag or a Russian flag to be the main flag flying over United States soil.

Here are some of the things that science can measure: mass, charge, weight, speed, momentum, heat and position. Here are some of the things that science cannot measure: value, justice, rightness and morality.

There were many scientists involved in the building of the first atomic bomb. But not one of them protested to his superiors that such a weapon should never be used. They could not see in their physics equations or data anything suggesting it would be wrong to incinerate 100,000 people. Scientists later developed hydrogen bombs that helped put mankind on the brink of destruction. The hydrogen bomb scientists did not let moral considerations stop their work, seeing nothing in their equations suggesting it would be wrong to create a bomb that might kill 10 million people at a time. Warning of the risks of gene splicing, a recent scientific paper stated, “Given the pace of biotechnology’s progress, the irresistible pressure to continue that progress for universally-desired medical purposes, the dual-use potential of the technology, and its potential worldwide reach, many humans could soon have the capacity to end Earth’s technical civilization.” But the paper's warning has attracted little attention, and today's scientists show unbridled enthusiasm for gene-splicing. Why should we be surprised by such things, given that there is scarcely a moral statement to be found in the average textbook on physics, chemistry and biology?

Their equations didn't tell them it was wrong to invent H-bombs

Science tells us that our planet is getting warmer, and that this is mainly because of man-made activity. But science tells us nothing about whether we should inconvenience ourselves to help limit global warming. Should we build smaller cars with less legroom to try to help save thousands of little-known animal species from extinction? Science is mute on this, and almost all other moral questions.

Morality is something that does not come from science, and moral sentiments are something that cannot be well-explained by science. The science of sociology can explain why certain group taboos can arise that may include things that are forbidden largely as the result of custom. But science cannot explain the basic fact of human conscience. Why is a person troubled if he does some bad act causing pain, injury or death for another, even if he thinks there is no chance he will be punished? Science cannot explain this. The idea that it comes from our genes or DNA is nonsense, as are all claims that attempt to genetically explain unique human mental characteristics. Genes merely specify the linear polypeptide sequences in proteins, and cannot possibly express behavior rules or subtle mental feelings.

It is reasonable to assume that the moral light that shines within us comes us from our souls, the very existence of which many a scientist would deny.  Scientific facts can be morally relevant, but what is right and what is wrong is never or almost never something that can  be scientifically determined.