If you’ve been following the hubbub about 3I/ATLAS, you’re probably either in the camp that thinks it’s just a comet from ridiculously far away that’s managed to find its way into our solar system, or you’re preparing for an alien invasion. (Lukewarm take: it’s just a fast moving comet.) But that doesn’t stop it from being interesting – its relatively fast speed and odd trajectory make astronomers wonder where it’s coming from, and give us clues about how old it is likely to be.
Astronomy is the odd-man-out in the natural sciences. In most branches of physics, chemistry, and even biology, you can run experiments. Even those non-experimental corners of the above fields, like botany, for instance, you can get your hands on the objects you’re talking about. Not so astronomy. When I was studying in college, one of my professors quipped that astronomers were pretty happy when they could hammer down a value within an order of magnitude, and ecstatic when they could get a factor of two or three. The deck is simply stacked against them.
With that background, I love two recent papers about 3I/ATLAS. The first tries to figure out why it’s moving so fast by figuring out if it’s been going that fast since its sun kicked it out, or if it has picked up a gravitational boost along the way. While they can’t go all the way back in time, they’ve worked out whether it has flown by anything close enough to get a significant boost over the last 10 million years. This is impressive that we can calculate the trajectory so far back, but at the same time, 10 million years is peanuts on the cosmic timescale.
According to another paper, there is a weak relationship between interstellar objects’ age and their velocity, with faster-moving rocks being older, they can estimate the age of 3I/ATLAS at between 7.6 and 14 billion years old, assuming no gravitational boosts along the way. While an age range of 7 billion years may seem like a lot, that’s only a factor of two. A winner for astronomy!
Snarkiness aside, its old age does make a testable prediction, namely that it should be relatively full of water ice. So as 3I/ATLAS comes closer to the sun in the next few weeks, we’ll either see it spitting off lots of water vapor, and the age prediction checks out, or we won’t, and they’ll need to figure out why.
Whatever happens, I appreciate how astronomers aren’t afraid to outline what they can’t know – orbital dynamics further back than a certain date, or the precise age of rocks based solely on their velocity. Most have also been cautious about calling the comet a spaceship. On the other hand, if it is, one thing’s for sure: after a longer-than-10-million-year road trip, whoever is on board that thing is going to be hungry.
Not sure about little Green Men, but there sure is a lot of little green click-bait on the net about all three comets in sight right now. Makes for a good distraction ahead of the next manufactured world changing event.
The things you here on the talk radio scene by People who should know better (Harvard Yah you) proves you cannot trust anything you hear on major name talk radio shows.
GIGO
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Comets are fascinating and amazing, I’m happy some things still are :-)
100% with you on that….
Had astronomy back in college in the mid 70s really enjoyed it.
Astrology is as much science as psychology is… shame on HaD for publishing such low quality articles. If you can’t repeat an experiment in controlled conditions then it isn’t science, period.
Ideally, yes, but practically, not so much: There are sciences that study the past and sciences that study large-scale or rare natural occurances that can’t be created in a lab that by your strict defintion are not science.
I’m thinking most sciences related to archeology and palientology, most sciences related to larger-than-lab-scale weather events, anything in space beyond where mankind can visit, and more.
You may be able to claim “repeatability” with some slop for things like “we studied records from 500 tornadoes from 1970-1980 and found …, then we studied 500 more from 1980-1990 and found the same thing” but rarely if ever could you claim the science was done “in controlled conditions.”
It’s about falsifiability. If you cannot perform the experiment that could falsify your claims, it’s not science yet. It doesn’t matter whether it’s done in the laboratory or using statistical evidence, if you cannot be proven wrong, you could say just about anything and maintain that you’re right.
So, the science isn’t really science until someone actually uses the criteria for falsehood and finds that they do not apply. At that point we’ve tested the science to be science, rather than conjecture. At that point we can say we know something rather than guessing it is so.
The problem with the distinction comes from the public understanding of Science with a capital S as pushed by popular media, as something definitive. Scientists are not producing science by default – what they are doing is research, and if that happens to turn into something that stands the test, that we can call science.
Astrology isn’t science at all. But you may be referring to astronomy. Astronomy has plenty of testable repeatable experiments – just look at the expansion rate hypothesis and use of detected novas.
Depending on the subfield – psychology is also most definitely science — there are many examples of testable repeatable psychological experiments.
You can repeat many experiments in controlled (known) conditions in astronomy. However, you cannot make the necessary conditions to repeat an experiment happen at will. That doesn’t mean experiments can’t be done.
Moreover, there are others parameters at stake to define a field of knowledge as a science. As an example, refutability in the popperian sense of the term is widely used methodologically to define discoveries and discard theories in astronomy and astronomers are well aware of the distinction between what can be considered real or plausible and an ad hoc explanation, for the very reason that they are not in complete control of their laboratory (which is our visible universe, and there’s only one). Astronomers are used to evaluate the degree of error of all their observations, hypotheses and theories, which shows good honesty regarding experimentalism.
I’d go as far as to say that the fact that astrophysics and cosmology are facing many issues and paradoxes today (dark energy, dark matter, defining the early universe before reionization, defining H0, …) is good proof that they are an experimental science with a methodology of refutation.
There is a good stack of philosophical litterature on the subject of realism, experimentalism and antirealism in astronomy, astrophysics and cosmology, dating as far back as the greek era which had established the first principle of astronomy for a long time, until the Renaissance at least: sozein tai phenomena, “to save the phenomena”. This long ago, the goal of astronomy was not to engage in ontological considerations – the question was not to define what the objects in the sky were made of. The greek goal, which was the occidental goal for a long time, was to give a geometrical representation of how the objects were moving. This led, as example, to the paradox of Hipparque’s epicycles: two differently defined geometrical representations that were phenomenologically equivalent.
It is the very emergence of the refractor (in the XVIIth entury) and the telescope (later) that directed astronomy toward a more empirical stance. Later the success of newtonian theories, combined with good observations, would prove a strong observational paradigm.
Experimentalism as such – investigating what astronomical objects are made of with instruments used in controllable environments – dates back from the XIXth century and early XXth century with the development of chemistry, the invention of spectroscopy and the invention of photography (which allowed to gather more light than the eye, and led to spectrophotography). Moreover, it also takes from philosophies of science developped in the mid XIXth century (Claude Bernard) and early XXth century (Frege, Poincaré, Mach) that were both looking for a way to establish strong experimentalism, a low tendancy toward metaphysics and a strong, free and well-structured mathematical and theoretical system in physics.
Astrophysics had reached an experimental stage before cosmology, which was not considered a science in the time of George Lemaître (early 20th century). Hubble’s Law, and later the CMB, definitely led to experimental tests of cosmology.
The state of cosmology and astrophysics today is one of an experimental science that has been successful with a strong predictive paradigm (general relativity and the cosmological principle) and good experimental tests of it (perihelion procession of Mercury, gravitational lensing) which is now facing strong experimental issues: a discrepancy between the rotational speed of galaxies and their luminous mass (dark matter), large issues in explaining the structure of the CMB and its evolution with baryonic matter only (inflation, dark energy and dark matter) and some other parameters which are still being revised (I recently learned through an article by Licia Verde (you’ll find it on arXiv) that H0 has no stable definition, and that the latest DESI data leads to a paradox).
So I think that if you look around, on philpapers, and on tests of general relativity, and mainly in the main texts of philosophy of physics, you’ll be able to educated yourself and define better what an experimental science is (or can be) and if astronomy (or cosmology, or astrophysics) is one.
Don´t mix Astronomy, a science, with Astrology ( something like a religion ) . One is science, other just works on faith and unicorns.
Psychology is, and have proved to be so, a science.
An age of 7.6 to 14 billion years old is kind of a cheater’s way to get a factor of two, since the latter is the age of the universe itself. :)
Agreed! And some of those heavier elements had to go through at least one, maybe two star cycles to even exist at all. So you can be pretty sure of that upper bound. :)
To be fair, though, that’s the 95% confidence band out of their statistical model, so it’s actually kinda reassuring that it lines up. If it were way older, you’d have to worry.
It seems that almost (?) all of the fooferall about this object emanates from Avi Loeb, a well credentialed well published astro nomer or physicist who unfortunately seems to have gone crazy about the topic of extra-solar objects. His goto explanation seems to be “spaceship”.
As for tracing the trajectory back, it seems to this reader that that necessarily assumes “and no interesting catastrophic events took place in the object’s (astronomical) vicinity for the last 10 million years.” Extraordinary, Captain. Extraordinary assumptions require extraordinary suspension of disbelief. Sadly Agent Mulder’s scripted line was always “I want to believe” rather than “I want to know”.
“Even those non-experimental corners of the above fields, like botany,“
Did you enjoy dinner? Thank a botanist. Genetics? Thank a botanist. Arabadobsis Thaliana for the win. https://en.wikipedia.org/wiki/History_of_research_on_Arabidopsis_thaliana
However did people get by before botanists invented vegetables and purpose-bred animals?
They didn’t, that’s why they are all dead now :o
Seems reasonable enough to assume you were indicating you like that old style sound when you said “It’s a shame I no longer have a glowing tube radio to listen on.”
And that you might be aided in achieving that with a tube(/MOSFET) headphone amp.
What? Where? The image above this article is surely handcrafted as always.
And if you mean that, then what’s wrong with Mr Spock the alien when talking about the suggestion of an alien spaceship?
Oh wait.. are you a AI generated comment? Hallucinating on, boldly going where all AI has gone before?
And again my goddamn reply to [ED] goes to the wrong place?
Why do I even bother commenting on HaD anymore? I must be insane letting it piss on my efforts each time.
It’s probably some interaction of browser settings / script blocking, and whatever WordPress’ comment engine uses to attach comments to their parents.
There could also be a race condition with comment ID numbers? But so far, it looks like it’s happening to some individuals more heavily.
What “blocking” plugins do you use, on which browser? We’d love to figure this out.
How did people travel before aerospace engineers invented passenger airplanes?
Absolute touche! I apologize to all botanists for the misclassification. :) Tons of experimental botany, now that I think of it.
It was late at night, and I was trying to come up with an example.
So what is another hard science branch that can’t do experiments? Oceanography? Weather?
Nope, both of those have experiments.
More to the point, even if you don’t have a repeatable test and you only have data from an event that happened once, you can still do experimentation on the data. By holding off some of the data, you can then build a model and test it against the withheld data to see if it makes correct predictions.
Of course that doesn’t prevent you from coming up with false theories that happen to fit the data, or over-fitting your models – it’s just less likely that your model happens to fit both sets equally well if it’s completely wrong.
“No one would have believed, in the early years of the twenty first century, that human affairs were being watched from the timeless worlds of space. No one could have dreamed that we were being scrutinised as someone with a microscope studies creatures that swarm and multiply in a drop of water. Few men even considered the possibility of life on other planets. And yet, across the gulf of space, minds immeasurably superior to ours regarded this earth with envious eyes, and slowly, and surely, they drew their plans against us…”
Ah the classics.
And who also knew the Edorians were involved in so many pivotal events in Human history!
That reminds me. The time is close approaching for me to turn out the lights and listen to that radio broadcast by the other Mr Welles. You never tire of a classic. It’s a shame I no longer have a glowing tube radio to listen on.
Allow me to recommend this hybrid tube/MOSFET headphone amplifier:
https://github.com/Darmur/tubeamp. I’ve built a few of them now and love their retro sound.
If you decide to make one I recommend:
Increasing RV2 and RV3 to 50K so you can use a wider range of tubes (e.g. JJ Electronic).
Decreasing the value of the resistor for the power LED – use one of the online calculators to calculate a suitable resistance for the LED of your choice
When assembling the amp, insert the LED into the PCB, place the tube socket over it, solder the tube socket, then use the legs of the LED to push the LED into the bottom of the tube socket, and only then solder the LED. This will give you maximum illumination.
The project includes the STL file for a case but doesn’t include an STL file for the potentiometer knob. Here’s one that has worked really well for me: https://www.printables.com/model/911627-knob-for-6mm-encoderpotentiometer-with-or-without/files
What does this have to do with my post? I mentioned a tube radio, not a headphone amp.
And allow me to add, some people just like the glow of the tubes, the authentically old design of the case, and yes, the smell. I’m one of those.
The schematics say “Trim RV2 to obtain VDC/2 on TP1”.
TP1 is connected to circuit ground. The instructions should mention that we need to use the Baron Von Munchausen method for trimming it.
You definitely need to avoid the conspiracy theorists more than you do this comet that will pass through our solar system when our planet is on the OPPOSITE side of the sun. Just relax, intelligent people of the Earth.
What makes you think it’s a comet?
Whatever happens, I appreciate how astronomers aren’t afraid to outline what they can’t know…
Yes, that is part of being a good Scientist. Too many fellow Engineers I know take a measurement, do some math, and will maybe truncate a number or two. It is rare that I see accompanying error analysis.