Stedman Summaries #15
Om kosmisk anspråkslöshet, Zoom-utmattning, Spermageddon och kidnappningen som förändrade bilindustrin
Det här är det femtonde utskicket av nyhetsbrevet Stedman Summaries. Det kommer ut varje söndag och består av kommentarer, citat och länkar till intressanta artiklar jag läst under veckan som gått. Kommentera gärna via knappen längst ner, eller kom med privat feedback. Vidarebefordra gärna till andra om du gillar det! Och det är helt gratis att prenumerera själv.
—Jacob
Kosmisk anspråkslöshet
Avi Loeb är en av världens mest framgångsrika och etablerade astronomer. Han har publicerat 700 vetenskapliga artiklar och 4 böcker, varit professor på Harvard i 25 år, och var fram tills nyligen ordförande för dess institution för astronomi. Han är också ordförande för styrelsen för astronomi och fysik inom den amerikanska Vetenskapsakademien.
Loeb har också blivit en av världens mest kontroversiella astronomer. Han har nämligen gått i spetsen för det pånyttfödda sökandet efter utomjordiskt liv — något som anses lite excentriskt idag.
Kanske måste man vara dels extremt etablerad, dels väldigt nytänkande för att våga utmana fältets konventioner?
The colleagues and students I spoke to all noted that he has a rare combination of extreme efficiency and almost childlike open-mindedness to ideas, no matter how far-fetched. […] As Edwin Turner, a professor of astronomy at Princeton University, put it: “He is a batter who swings for the fences, which means he either hits home runs or strikes out.”
För 50 år sedan var sökandet efter utomjordisk intelligens (search for extraterrestrial intelligence, seti) tvärtom en viktig prioritet för rymdforskningen:
Scientific interest in seti was significant in the 1960s and 1970s. In America and the Soviet Union the hunt for alien life-forms formed part of the broader cold-war space race. Each power wanted the glory of being the first to make contact with another civilisation. From rural Ohio to the Caucasus, telescopes sought messages from other worlds.
Men när årtiondens ansträngningen inte ledde till några resultat tappade forskningsfältet i anseende och finansieringen drogs undan:
But no aliens showed up. Those supporting the search for extraterrestrial life began to grow weary. Congress withdrew funding from the official seti programme in 1993. Richard Bryan, a senator for Nevada, said he hoped this would mark “the end of Martian-hunting season at the taxpayer’s expense”. Lack of funding did little to quell the public’s fascination with alien narratives – “The X-Files” ran through much of the 1990s. Yet many mainstream scientists scorned the search for extraterrestrials as a speculative field of interest only to eccentrics.
På senare år, i takt med att teleskopen förbättrats, har intresset för att fortsätta söka efter utomjordiskt liv växt igen, och nu delvis med privat finansiering — och där har Loeb blivit en nyckelperson:
Loeb entered the field just as the chances of detecting life elsewhere seemed promising once more. In 2015 he was approached by Yuri Milner, a billionaire technology investor, to oversee a speculative project to send a probe four light-years away to Alpha Centauri, the closest star system to Earth.
Dessa sonder skulle behöva vara ultralätta och Loeb föreslog att de skulle drivas med ett “solsegel” (lightsail): av den solvind som strömmar ut från solen och det strålningstrycket som skapas när ljus reflekteras. (Solsegel är inte science fiction utan användes av IKAROS, en japansk sond, som 2010 flög förbi Venus.)
Sen hände något som cementerat Loebs position som en av världens mest omskrivna astronomer.
Den 19 oktober 2017 observerade en astronom på Haleakalā-observatoriumet på Maui, Hawaii ett oidentifierat objekt som rörde sig genom vårt solsystem med en hastighet på ca 25-50 kilometer i sekunden. Till skillnad från vanliga runda asteroider verkade det vara en avlång, ljusstark, några hundra meter lång platta. Objektet fick namnet ʻOumuamua, som betyder budbärare på hawaiiska. På kursen man kunde ganska snabbt konstatera att objektet kom utifrån vårt solsystem: det blev det första interstellära objekt människan formellt kategoriserat:
None of the approximately 750,000 known asteroids and comets in the Solar System is thought to have originated outside it […] Here we report observations and analysis of the object 1I/2017 U1 (‘Oumuamua) that demonstrate its extrasolar trajectory […] Designated as 1I/2017 U1, this object is clearly from outside the Solar System (Fig. 2) and as such is the first interstellar object (ISO) to have been detected.
Ett år senare, 2018, skrev Loeb en artikel där han hävdade att ʻOumuamua kunde vara en rymdfarkost skickat till oss av en främmande civilisation — och kanske just ett solsegel!
Alternatively, a more exotic scenario is that ‘Oumuamua may be a fully operational probe sent intentionally to Earth vicinity by an alien civilization. […] Considering an artificial origin, one possibility is that ‘Oumuamua is a lightsail, floating in interstellar space as a debris from an advanced technological equipment (Loeb 2018). Lightsails with similar dimensions have been designed and constructed by our own civilization, including the IKAROS project and the Starshot Initiative.
Loeb argumenterar för att objektet avviker från allt man vet om vanliga asteroider och kometer, bl a vad gäller dess hastighet och bana, och avsaknad av värmestrålning och gassvans:
[…] astronomers should examine any object that enters the solar system and study its properties. There is no doubt that the six peculiar features of ‘Oumuamua have the potential to usher in a dramatic new era in space science.
Samtliga dessa iakttagelser verkar dock kunna förklaras på andra sätt:
There are five pieces of “evidence” used to claim that ‘Oumuamua is an alien spacecraft. None stands up to even the gentlest scrutiny. […] That wraps up this point: there is no need to invoke aliens to explain ‘Oumuamua’s observed acceleration.
I forskarsamfundet etablerades snabbt en konsensus att han har fel — himlakroppen är naturlig:
Here we review our knowledge and find that in all cases, the observations are consistent with a purely natural origin for ‘Oumuamua. […] While ‘Oumuamua presents a number of compelling questions, we have shown that each can be answered by assuming ‘Oumuamua to be a natural object. Assertions that ‘Oumuamua may be artificial are not justified when the wide body of current knowledge about Solar System minor bodies and planetary formation is considered.
Loeb anklagades för att vara sensationssökande och att publicera teorier om utomjordingar bara för att få uppmärksamhet.
Och nu har Loeb skrivit en bok där han argumenterar för att ʻOumuamua är ett artificiellt objekt skickat av en annan civilisation (“Extraterrestrial: The First Sign of Intelligent Life Beyond Earth”). Här går han från rollen som forskare som provtrycker en hypotes till den självsäkre samhällsdebattören som vill öppna folks ögon:
Central to his argument is what he calls the “Oumuamua wager,” a takeoff on Pascal’s famous wager, that the upside of believing in God far outweighs the downside. Likewise, believing that Oumuamua could have been an alien spacecraft can only make us more alert and receptive to thinking outside the box. […] “If we dare to wager that Oumuamua was a piece of advanced extraterrestrial technology, we stand only to gain,” Loeb writes.
Loeb erkänner att han förstås påverkas i sina analyser över sin egen erfarenhet av solsegel:
So I had it in my vocabulary, and as a result of that, I imagined it as applied to ‘Oumuamua. Now, you might ask, “Okay, well, isn’t that a biased view?” I would say this occurs again and again in physics and in SETI. In the context of SETI, you know, once we developed radio technology, we started searching the sky looking for radio signals. It was the same for lasers. It’s just natural that once you work on some technology that you imagine maybe it exists out there and search for it.
Lika hårt som han har kritiserats av sina kollegor, lika hårt har han anklagat dem för att vara fega för att de inte vågar överväga möjligheten att det finns spår efter utomjordiskt liv:
Too many scientists are now mostly motivated by ego, by getting honors and awards, by showing their colleagues how smart they are. […] [Science is] about trying to understand the world, and it’s meant to be a learning experience in which we take risks and make mistakes along the way. You can never tell in advance, when you work on the frontier, what is the right path forward. You only learn that by getting feedback from experiments.
Han vänder sig mot att teorier om multiversum och strängteori anses legitima, trots att de är icke-falsifierbara, medan han bara vill öka uppmärksamheten till ett område som i grunden är empiriskt:
The multiverse is a mainstream idea—that anything that can happen will happen an infinite number of times. And I think that is not scientific, because it cannot be tested. Whereas the next time we see an object like this one, we can contemplate taking a photograph. My motivation, in part, is to motivate the scientific community to collect more data on the next object rather than argue a priori that they know the answer. In the multiverse case, we have no way of testing it, and everyone is happy to say, “Ya!”
Another mainstream idea is the extra dimension. You see that in string theory, which gets a lot of good press, and awards are given to members of that community. Not only has it not been tested empirically for almost forty years now but there is no hope it will be tested in the next forty years.
Loeb menar att vi borde vara ödmjuka för att vi knappast är ensamma i universum:
Before he started the whole alien spaceship thing last year, the chairman of Harvard University's astronomy department was known for public lectures on modesty. Personal modesty, which Avi Loeb said he learned growing up on a farm. And what Loeb calls "cosmic modesty" — the idea that it's arrogant to assume we are alone in the universe, or even a particularly special species.
Även om han betonar att han ser fram emot att kunna få falsifiera sina teorier ("if someone shows me evidence to the contrary, I will immediately back down") så är han också tydlig med att inget skulle kunna ena människor så mycket som ett yttre hot:
"It changes your perception on reality, just knowing that we're not alone," he says. "We are fighting on borders, on resources. … It would make us feel part of planet Earth as a civilization rather than individual countries voting on Brexit."
Det verkar i alla fall som det inte blir inte sista gången vi får läsa i tidningarna om mystiska objekt från andra solsystem:
The hunt for alien life is nonetheless undergoing a renaissance. Astrobiology, a field that engages in the search for signs of habitability and biological life on near and distant planets, is booming. China, an emerging scientific superpower, recently finished constructing the largest radio telescope in the world, which will be used to look for other technological civilisations in our galaxy, among other things. […] Astronomers hope that in the coming years the mystery of ‘Oumuamua will be solved indirectly as they learn more about other interstellar objects.
Zoom-utmattning
Nu till någon mer jordnära: Zoom-möten.
Många har nog upplevt en känsla av matthet efter en lång dag fylld med videomöten. Nu pekar forskningen till att det finns åtminstone fyra anledningar till att Zoom-möten är jobbigare än vanliga möten:
1) Excessive amounts of close-up eye contact is highly intense. Both the amount of eye contact we engage in on video chats, as well as the size of faces on screens is unnatural. […]
2) Seeing yourself during video chats constantly in real-time is fatiguing. […]
3) Video chats dramatically reduce our usual mobility. In-person and audio phone conversations allow humans to walk around and move. But with videoconferencing, most cameras have a set field of view […]
4) The cognitive load is much higher in video chats. […]
En annan sak som stressat många under pandemin är förstås avsaknaden av fysiska kontakter.
Människor har tydligen runt 150 “stabila sociala relationer”, och det är ju väldigt få av dem vi träffat i år:
there may be a cognitive limit to the number of people with whom you can comfortably maintain stable social relationships – or, as Stephen Fry put it on the TV show QI, the number of people “you would not hesitate to go and sit with if you happened to see them at 3am in the departure lounge at Hong Kong airport”. Human beings, Dunbar found when he conducted his research in the 1990s, typically have 150 friends in general (people who know us on sight, and with whom we have a history), of whom just five can usually be described as intimate.
Amanda Mull skriver i The Atlantic om hur vi först nu förstår vikten även av mer ytliga vänner:
Close relationships were long thought to be the essential component of humans’ social well-being, but Granovetter’s research led him to a conclusion that was at the time groundbreaking and is still, to many people, counterintuitive: Casual friends and acquaintances can be as important to well-being as family, romantic partners, and your closest friends. In his initial study, for example, he found that the majority of people who got new jobs through social connections did so through people on the periphery of their lives, not close relations. […]
Apropå avsaknad av närhet så verkar unga (18-23 år) ha mindre sex utanför relationer, även innan pandemin (2007-17):
Among young women, the decline in the frequency of drinking alcohol explains about one quarter of the drop in the propensity to have casual sex. Among young men, declines in drinking frequency, an increase in computer gaming, and the growing percentage who coreside with their parents all contribute significantly to the decline in casual sex.
Skulle inte ingenjörerna kunna lösa avsaknaden av närhet för oss?
Long before the COVID-19 pandemic, interest in what researchers call ‘haptics’ had been increasing, particularly the idea of replacing a missing sense through touch sensations. For example, there’s a device that assists blind and visually impaired people to ‘see’ via a belt with vibrating parts that provide information about incoming stimuli. Meanwhile, another device – a ‘tongue display unit’ – can deliver pulses into the mouth to help navigate the surrounding space, for use in neurorehabilitation, for example. […]
Missing hugs from your grandma? Well, you might both be the target market for a trademarked ‘Hug Shirt’ that vibrates in the areas where someone has ‘saved’ a hug: just ‘record’ a hug in your shirt and send it to your grandma’s receiving shirt. Sounds intriguing, right? Even more alluring are the products aimed at long-distance romantic couples that fall under the delightful name ‘teledildonics’ or remote sex devices. One such kit contains a sensor-coated obelisk and futuristic fleshlight, which allow for some sort of virtual sex.
Men det är förstås inte riktigt så enkelt:
The need for touch is a fundamental part of being human. There’s a danger that if and when we start to replace it with technological devices, we could end up reducing our real human touch situations even more, as is already happening for other forms of communication. After all, some of us have replaced actual conversations with sending emails or texts back and forth, so many now talk less. If we can send electronic hugs, won’t we end up hugging less too? […]
There are real consequences to letting technology intervene with social touch. Do you fear the day when you attempt to console your child only to have her turn to a device that can comfort her in a way you couldn’t even conceive of? Perhaps you should. With the rise of touch-replacement technology, socially distanced lives could become permanent, and we might end up with even greater levels of isolation than today.
Spermageddon
Vi har ju i det här nyhetsbrevet tidigare diskuterat dramatiska hot mot mänskligheten — t.ex. AI, pandemier — och vi kommer säkert snart tillbaka till det. Men det finns ett annat hot som kan tyckas mer alldagligt, men likväl riskerar vår framtid - “Spermageddon”:
This comprehensive meta-regression analysis reports a significant decline in sperm counts […] between 1973 and 2011, driven by a 50–60% decline among men unselected by fertility from North America, Europe, Australia and New Zealand.
Utöver att antalet spermier hos män alltså sjunkit 50-60% finns det andra problem:
Sperm counts have been dropping; infant boys are developing more genital abnormalities; more girls are experiencing early puberty; and adult women appear to be suffering declining egg quality and more miscarriages.
It’s not just humans. Scientists report genital anomalies in a range of species, including unusually small penises in alligators, otters and minks. In some areas, significant numbers of fish, frogs and turtles have exhibited both male and female organs.
Hormonstörande ämnen (endocrine-disrupting chemicals, EDCs) finns i tusentals konsumentprodukter. Foster är särskilt känsliga:
These endocrine disruptors are everywhere: plastics, shampoos, cosmetics, cushions, pesticides, canned foods and A.T.M. receipts. They often aren’t on labels and can be difficult to avoid.
Dessa ämnen har studerats intensivt de senaste tio åren:
The Endocrine Society's first Scientific Statement in 2009 provided a wake-up call to the scientific community about how environmental endocrine-disrupting chemicals (EDCs) affect health and disease. Five years later, a substantially larger body of literature has solidified our understanding of plausible mechanisms underlying EDC actions and how exposures in animals and humans—especially during development—may lay the foundations for disease later in life.
Att hormonstörande ämnen i mat och ekosystem påverkar djur är alltså inte bara en lös teori. Man har till exempel noterat i England att hanfiskar feminiseras sedan de fått i sig östrogen från p-piller genom avloppsvatten:
In recent years there has been considerable concern over the ability of substances discharged into the environment to disrupt the normal endocrine function of wildlife. In particular, the apparent widespread feminization of male fish in rivers has received significant attention from regulators in the United Kingdom, the United States, Europe, and Japan. […] Extensive laboratory data sets confirm that steroid estrogens are capable of eliciting the effects observed in wild fish at concentrations that have been measured in effluents and in the environment.
Vissa åtgärder har redan genomförts. BPA, en av världens vanligaste plastkemikalier, är ett exempel på hormonstörande ämne. Sedan tio år tillbaka är det förbjudet inom EU för användning t.ex. i nappflaskor.
Nicholas Kristof hävdar i NYT att det här är ett fält där vi om några årtionden kommer att kolla tillbaka och inte förstå hur naiva vi var:
Chemical companies are as reckless as tobacco companies were a generation ago, or as opioid manufacturers were a decade ago. They lobby against even safety testing of endocrine disruptors, so that we have little idea if products we use each day are damaging our bodies or our children. We’re all guinea pigs.
Forskaren Shanna Swan, som just skrivit en bok i ämnet (“Count Down: How Our Modern World Is Threatening Sperm Counts, Altering Male and Female Reproductive Development, and Imperiling the Future of the Human Race“) menar att mänsklighetens framtid står på spel:
Swan explicitly compares what she sees as a fertility crisis to climate change, another global threat that has been difficult to combat because its causes are also largely invisible and it unfolds over a long time scale. Just as CO2 accumulating in the environment over decades adds momentum to climate change, the damage done to human reproduction may be accumulating, with each new generation starting life with increasingly degraded fertility.
She notes that human beings — despite our numbers — arguably already fit three of the five criteria for an endangered species: destruction of our environment, inadequate regulatory mechanisms, and man-made factors that affect our continued existence. […] "The current state of reproductive affairs can't continue much longer without threatening human survival," Swan writes.
Vissa av hennes kollegor är mindre alarmistiska, men lyfter ändå fram hur infertilitet kan påverka enskilda familjers framtid även om det inte avgör mänsklighetens öde:
“I do not see humans becoming extinct, but I do see family lines ending for a subset of people who are infertile,” Andrea Gore, a professor of neuroendocrinology at the University of Texas at Austin, told me. “People with impaired sperm or egg quality cannot exercise their right to choose to have a child. That may not devastate our species, but it is certainly devastating to these infertile couples.”
Kidnappningen som förändrade bilindustrin
För 25 år sedan var Janette Fennell och hennes man med om en mardrömslik händelse — de låstes in i sin egen bils bagageutrymme mot sin vilja:
As the Fennells exited their white Lexus, two armed intruders in Halloween masks forced them into the trunk of the family car. The intruders removed [their 9-month-old son] from the backseat and placed him, unharmed, inside the foyer. Then — with Fennell and her husband locked in the trunk — they backed out the car and peeled out into the night. […]
An hour later, the car came to a stop in a wooded area south of the city. The assailants demanded everything the Fennells had on them: $5k in jewelry, $200 in cash, and debit card PIN numbers. Then, they slammed the trunk shut and fled.
The couple was alone. It was pitch black. And there was no way out.
Det visade sig senare att Fennells inte var ensamma om sitt olyckliga öde:
Through this tedious process, she was able to dig up 931 incidents involving 1,082 people getting locked in car trunks over the preceding 20 years. In one in four cases, the victim died — either from heat stroke, asphyxiation, or hypothermia.
These incidents fell into two major categories:
* Children who accidentally locked themselves in a trunk while playing.
* Kidnapping victims who’d been forced into a trunk by assailants.
Janettes story är väl värd att läsa — ibland kan en motiverad person flytta på berg, eller i alla fall, påverka miljoner bilar varje år. (Tyvärr verkar hennes ansträngningar inte hjälpt europeiska konsumenter.)
Det var allt för idag.
Vidarebefordra gärna nyhetsbrevet till dina vänner om du gillar det, och prenumerera om du inte redan gör det (det är helt gratis!). Vi hörs nästa söndag. Ha en bra vecka!
—Jacob