astronomy

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TropicalDingdong, w Webb Discovers Methane, Carbon Dioxide in Atmosphere of K2-18 b - NASA

If there was oxygen, I’d basically say its alive.

HurlingDurling,
@HurlingDurling@lemmy.world avatar

Not necessarily, life on earth has existed since before there was oxigen in the atmosphere and was mostly carbon monoxide.

TropicalDingdong,

Yeah not in a way detectable to radio telescopes though. If an atmosphere is stoichemetrically ‘far’ from equilibrium, this implies a biogeochemcical process that is pushing it out of equilibrium.

Oxygen very quickly gets reduced out of the atmosphere. Thats the whole point of it as a bioindicator molecule. There aren’t many other species of molecule that are such a clear indicator of the presence of redox reactions. Preter oxidative respiration, If nitrogen was the electron receptor, but its species like ammonia might be visible via radio telescope. Google great oxygen holocaust. We know photosynthesis was happening before then, but oxygen wasn’t the terminal electron receptor.

Oxygen would be a smoking gun, because you don’t keep oxygen in an atmosphere if something isn’t replenishing it.

HurlingDurling,
@HurlingDurling@lemmy.world avatar

I understand, good point

Jimmyeatsausage,

I think the methane is a better marker…AFAIK, it’s almost always a byproduct of some biological process.

TropicalDingdong,

bruh

…nasa.gov/…/trapping-of-methane-in-enceladus-ocea…

We know of abiogenic sources of methane in this solar system.

Jimmyeatsausage,

Bruh…that’s why I said almost.

I also got about 1/2 way through typing almost the same response below about gases that naturally degrade quickly, not being able to accumulate to high enough concentrations to be detectable at these distances but @TropicalDingDing did so more eloquently than their name would indicate possible, so I’ll let you read theirs here: lemmy.world/comment/8258449

TropicalDingdong,
ShittyBeatlesFCPres,

It’s a good biosignature but a real smoking gun would be if a planet has intelligent life that’s not always so intelligent. Then, we might detect chlorofluorocarbons or some other synthetic pollutant.

“Well, we detected an alien civilization but their atmosphere is in way worse shape than 1950’s London and they’re 100 light years away. I guess we’ll keep checking and see if they get their act together or not.”

NotMyOldRedditName,

Plot twist, they’re already dead by the time we detect them, the light from them exploding the planet just hasn’t reached us yet.

troyunrau, w Want to be a NASA astronaut? Applications are open
@troyunrau@lemmy.ca avatar

A half dozen years ago, or thereabouts, I entered the Canadian version of this competition, just to see how I’d fare, and to look at the process. Made it through the first couple levels of screening (from 3200 applicants, I was still in the hunt at 300 remaining) but then got filtered.

Some interesting bullet points if you’re thinking of applying, assuming the NASA questions are similar to the CSA ones:

(1) ham radio, morse code, or other amateur radio operator experience is an asset.

(2) Anything aviation or amateur rocketry is an asset, but in particular a pilot’s license. Anything aviation adjacent is still useful.

(3) Russian language (this might be changing in the current political environment)

(4) Experience in an “operational environment” – I suspect this is military jargon, but if you’d don’t field research as a scientist out of wilderness camps, or anything like that where you’re in a small group for work/adventure might apply here.

(5) Medical degrees, or advanced science degrees.

(6) Physical fitness and perfect vision

When I applied, my Russian sucked, my aviation experience was tangential (but copious), and I was a grad school dropout (from a planetary science program), so I didn’t float to the top. But it was enough to make it through the first layers.

There person who ended up winning was a medical-degree air force pilot. Hard to compete haha.

thebardingreen, w Juno measures oxygen production on Europa - NASASpaceFlight.com
@thebardingreen@lemmy.starlightkel.xyz avatar

It’s interested that they say “oxygen could travel below the ice and support life.”

I would expect life on Europa to be anaerobic, given the obvious lack of photosynthesis.

Rascabin, w Juno measures oxygen production on Europa - NASASpaceFlight.com

Man, we were warned not to go to Europa!

RandomLegend, w Juno measures oxygen production on Europa - NASASpaceFlight.com
@RandomLegend@lemmy.dbzer0.com avatar

German here, can confirm we have Oxygen here in Europa.

troyunrau, w Regulation needed to protect space tourists from cosmic rays
@troyunrau@lemmy.ca avatar

Easy. If you can afford to be a space tourist, you can afford to put $5M in escrow for your future medical expenses.

Let’s take risks people!

MushuChupacabra, w Regulation needed to protect space tourists from cosmic rays
@MushuChupacabra@lemmy.world avatar

I have the same safety concerns for billionaire space tourists as I do for billionaire deep sea exploration tourists.

Tippon,

Usually I’d agree, but if these morons fry themselves, there’s even less of a chance that the rest of us will ever be able to go.

navigatron, w Regulation needed to protect space tourists from cosmic rays

I’m so glad society has teams allocated to identifying these hard-hitting issues. It’s true - we don’t have enough consumer protections in place for space tourists. A poor innocent space tourist could “go to space” without fully understanding that “space can be dangerous”. Thankfully, these analysts discovered this issue before too many people were “at risk”. Future space tourists will have to sign a waver, or watch a presentation, or something.

The interesting question here is who paid for this “study”, and who from the register accepted the bribes to get this dogshit published.

tate, w Dark Energy Camera captures remains of a massive star that exploded nearly 11,000 years ago in huge gigapixel image

wtf is a “dark energy camera?” smh

This thing is just a mosaic of ordinary CCDs. I’m sure the name has something to do with it’s specific scientific goals, but that’s not explained at all in this article. They didn’t even attempt to make any kind of connection between the veil and dark energy. Or even between supernovae and dark energy.

ZeroCool, (edited )
Fiivemacs, w Giant volcano discovered on Mars

I dunno about giant. Looks pretty small from here.

oDDmON, w Study: Dark matter does not exist and the universe is 27 billion years old

Link to original study cited by article.

kvartsdan,

As I suspected, I did not understand the summary.

quilan, w Study: Dark matter does not exist and the universe is 27 billion years old

I didn’t see anything in the paper about the rotational speed of galaxies. Was that accounted for?

atzanteol,

Or the effect we see on gravitational lensing that is accounted for by “dark matter”? I don’t see how that could be explained by “light losing energy”…

Donjuanme,

Modified Newtonian dynamics attempts to account for that.

whotookkarl,
@whotookkarl@lemmy.world avatar

Not an astronomer but if I read the article correctly the observations gathered about galaxies rotating and colliding would be explained instead by regional changes in what were previously assumed universal constants, which would be very interesting if true but 1 paper isn’t consensus yet

kvartsdan, w Study: Dark matter does not exist and the universe is 27 billion years old

The whole “dark matter” thing has never sat right with me. It always seemed like a desperate attempt to explain what we see. I’m not saying I know enough to have an informed opinion, but it has always seemed wrong. It is matter we can’t detect in any way except for gravity? Nah. The forces of nature changing due to expansion? Fits better somehow. Anyway, what do I know? I entertained the idea that it was time that was changing due to the expansion, but I couldn’t get it to fit. This seems more plausible.

NABDad,

I too don’t really know enough to have an informed opinion, but I don’t think “plausible” has much meaning in physics. It’s more a question of whether the mathematics supports the theory and/or if it can be proved somehow.

There are plenty of things that the mathematics predicted that seemed completely implausible, but were later verified to be true. “Quantum Entanglement” jumps to mind as something Einstein dismissed as “spooky action at a distance”, but it has since been confirmed.

I think you could consider all of physics or even all of science to be made up of placeholders meant to keep things moving until a better explanation comes along.

jadero,

I think you could consider all of physics or even all of science to be made up of placeholders meant to keep things moving until a better explanation comes along.

I agree. I would add that intuition, common sense, and ideologies are also just placeholders in our journey to a better world.

kvartsdan,

Yeah, “plausible” was the wrong word to use. Maybe “more elegant”? Then again, the truth (not that there is one, precisely) isn’t always elegant.

maryjayjay,

When we discover someone we don’t understand we often make a simplistic metaphor to fit the data until we have better understanding. Like the Bohr model of the atom, or Newton’s theory of gravity. Dark matter plugs the hole right now and does it with a minimum of contrivance (Occam and whatnot)

kvartsdan,

Or the aether or the flat earth model. I know all this, but I still believe it is a bad and lazy model that stopped a lot of people from trying to find something else that could explain what we’re seeing, or not seeing actually. There is too much gravity, yes. What could produce that effect? Shit we aren’t seeing, dark matter, sure. But what if there’s no ‘extra’ matter? What other thing could produce the appearance of too much matter? Is time changing in some way we don’t know? Is light slowing down/going faster due to the expansion? Is there something else that we thinks is constant that is actually changing over time? Should I really smoke this much? I don’t know any of this obviously but I have a distinct feeling we are missing something with ‘dark matter’ as a model. I get why we use it, but I don’t like it. When we create a model, we fix it in our minds and it is very hard to break free from that mindset. Look what it took before we accepted that time is relative. What else is relative? What, besides mass, aren’t we seeing?

maryjayjay, (edited )

deleted_by_author

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  • kvartsdan,

    Of course I’m not the first to think about it and of course I’m not as smart as many, or most of those guys. But if you put up a grand model that’s largely unsubstantiated too early and everyone and their dog runs with it, you create a bias to try and prove it and more resources will be added to that than to find alternative explanations that night also fit the data. That is basically my gripe with dark matter as a name for the discrepancy between observable matter and “invisible” matter. It is too ad hoc, mostly added to try and save as much as possible of present understanding of how shit works. Must’ve stepped on a toe there, chief.

    I really shouldn’t feed the trolls, but I have to ask - is she hot or is she a used up tramp like your mum?

    mipadaitu,

    That’s exactly what Dark Matter is. Scientists saw that galaxies were spinning faster than expected, did some math, and figured out that based on current, known physics, they wouldn’t be able to stay together.

    So they said “huh, must be additional matter that we can’t account for, let’s call it Dark Matter for the time being, cause we can’t see it.” It might be one big type of thing, it might be a thousand smaller types of things that all add up to this collective Dark Matter, but whatever it is, it doesn’t behave the same way we expect normal, everyday matter behaves.

    Other scientists said that we must not understand something about physics and gravity at larger scales.
    Other scientists said that light must not act the way we expect, and it’s throwing off our measurements.
    Based on follow up research, there is more evidence for unaccounted for matter, than the other options.

    It’s entirely possible that none of those options are correct, but most of the data we have right now points to Dark Matter is the best fit for the evidence we have.

    Carrolade,

    Excellent summary.

    kvartsdan,

    I’m aware we’ll never find the bottom truth, whatever that may be, it’s only better and better models. Sometimes though, the model chosen by the scientific community isn’t really a good one, despite fitting most of the data. I think dark matter, like the aether(spelling?), is one of those models. Again, I base this solely on the clunky, ad hoc feeling of the dark matter model and not of anything more substantial than that. If I’m wrong and they manage to find a chunk of dark matter I’m fine with that. The chunk part was a joke, btw, I’ll settle for detection or proof of existence.

    Stelus42,

    The way I see it, Dark Matter is just a psuedonym for “Whatever is causing gravity to work differently at a galaxy scale than at a solar system scale”. And further, Dark Energy is just a term for “Whatever is causing gravity to work differently at an inter-galactic scale than at a intra-galactic scale or solar system scale”.

    But, if we want to entertain the technical aspects of the thought, there’s nothing in the definition of Matter that says it interacts with anything besides gravity (light, magnetism, etc) on its own. Just that it has mass (ie generates gravity) and cant occupy the same space as other mass. We already know via colliders that the higs bosson is the sub-particle solely responsible for Mass, way smaller than the scale of an atom. And we also know that magnetism, electric charge, and by extension light rely on electrons, which exist only at the atomic scale. So its not implausible to think that mass can exist separate from any of the things that we can detect with our other favorite methods (pretty much just different wavelengths of light) besides just the gravity they generate. In this case, gravity IS the thing we’re using to detect it.

    xionzui,

    A few things not quite right here. Particles are given mass through interacting directly with the Higgs field itself. They don’t need the boson to be involved. Due to the way the math works out, the Higgs field has a non-zero value everywhere, so everything that interacts with that field is given mass by that.

    Also, we know of weakly interacting matter such as neutrinos that can pass directly through other matter most of the time already. Things can be in the same place as long as the fields they’re part of don’t interact in a way that stops it.

    Magnetism, electric charge, and light rely on photons, not electrons. Photons are the bosons of the electromagnetic field. Bosons are called force carriers. They get exchanged any time an electromagnetic force acts on anything. Electrons are a particle and made from the electron field. They are involved in a lot of electromagnetic interactions via photons, but not all of them.

    btaf45,

    “Whatever is causing gravity to work differently at a galaxy scale than at a solar system scale”.

    Nothing is. Gravity works the same. We don’t just infer dark matter from gravity fields. We can detect and map the exact locations of dark matter thru gravitational lensing.

    science.nasa.gov/…/hubbles-dark-matter-map/

    Gwaer, (edited ) w Study: Dark matter does not exist and the universe is 27 billion years old

    I read several articles to try to understand this. This one was the most helpful to me.

    bigthink.com/…/universe-13-8-or-26-7-billion-year…

    Non paywalled version hopefully

    archive.is/AUBdZ

    Feathercrown,

    I’m sure the article is great… IF I COULD READ IT

    https://lemmy.world/pictrs/image/9334ed38-d660-42d1-bbb0-1c30268fafa0.jpeg

    Gwaer,

    Sorry I have so many paywalls and ad blockers going I had no idea it even had one.

    Feathercrown,

    Same for me but only on Desktop :/

    Gwaer,

    Added it to that archive place for you and updated my first post.

    archive.is/AUBdZ

    Feathercrown,

    Greatly appreciated! I love this site :D

    BeigeAgenda,
    @BeigeAgenda@lemmy.ca avatar

    It says right there that the Galaxy is Folded into a Z…

    /J

    HurlingDurling,
    @HurlingDurling@lemmy.world avatar

    Made me spill my tea

    HurlingDurling,
    @HurlingDurling@lemmy.world avatar
    1. Don’t use Chrome
    2. Use Firefox
    3. Install unlock origin on android Firefox
    4. ???
    5. Profit!
    Ultraviolet,

    How long until the young earth dipshits jump on this as “evidence” to claim that if there’s room to question whether the universe is 13.8 billion or 26.7 billion years old, that means it must actually be 6000?

    mipadaitu, w Study: Dark matter does not exist and the universe is 27 billion years old

    “Tired light” has been theorized before, and it just doesn’t hold up to most of the evidence gathered.

    It’s entirely possible that there’s something there, but most data currently backs up the Lambda-CDM model of the universe.
    en.wikipedia.org/wiki/Lambda-CDM_model

    Only time will tell if this theory pans out, but I wouldn’t put much money on it.

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