astronomy

Magazyn ze zdalnego serwera może być niekompletny. Zobacz więcej na oryginalnej instancji.

prole, w Most Astronauts Get ‘Space Headaches.’ Scientists Want to Know Why

First symptom of space madness

wischi, w Most Astronauts Get ‘Space Headaches.’ Scientists Want to Know Why

Too much blood in their head because of zero g?

1024_Kibibytes,

The article suggests something similar:

“As gravity loosens its grip, blood, lymph and cerebrospinal fluid drift from their usual locations and begin to exert pressure elsewhere.”

MeanEYE, w A Nearby Star Is Expected to Go Nova This Year. Here's How You Can See It.
@MeanEYE@lemmy.world avatar

So, there’s nothing in universe that is longer than “soon”. This prediction of going nova this year, only means it already happened but you can’t see it yet. And since it’s going super nova, that means entire even will be boring anyway. You’ll see a white dot that will increase in intensity during this year and then fade away equally slowly.

For people wondering about dates, there are none. Just like Beetlejuice is expected to explode soon™, that actually means 3000-10000+ years of waiting. So don’t get your hopes up. Out lives are but a blink in universe. All you can do is be diligent and watch it constantly. Doesn’t mean you’ll see much either since at peak magnitude of 2.5 it will be dim enough that you’ll need telescope to see it.

XeroxCool,

Nova, not supernova. Novas happen multiple times. Supernova do not but it doesn’t say supernova. Soon, as in within the next 6 months since its following a cycle that happened about 80 and 160 years ago.

nulluser,

Visible with unaided eyes for several days (but still dimmer than about 120 stars in the sky), and with binoculars for about a week, according to NASA.

stockRot,

Did you read the article? Or do you just like talking?

WarmSoda, w A Nearby Star Is Expected to Go Nova This Year. Here's How You Can See It.

Humans have seen this nova lots of times before. It was first identified by astronomers in the late 1800s, and it bursts about every 80 years.

Indeed, the explosion heading our way would have taken place thousands of years ago, but requires all that time for the light to reach us.

Still, it’s worth checking it out – T Coronae Borealis last shone in 1946 and this will be the last viewing opportunity before the early 2100s.

Very cool.
That is, until the article says to check out Twitter for how to actually see it.

Immersive_Matthew,

Right. I avoid Twitter at every opportunity. I want nothing to do with that cease pit.

nulluser, (edited )

en.m.wikipedia.org/wiki/T_Coronae_Borealis

On 20 April 2016, the Sky and Telescope website reported a sustained brightening since February 2015 from magnitude 10.5 to about 9.2. A similar event was reported in 1938, followed by another outburst in 1946.[20] By June 2018, the star had dimmed slightly but still remained at an unusually high level of activity. In March or April 2023, it dimmed to magnitude 12.3.[21] A similar dimming occurred in the year before the 1945 outburst, indicating that it will likely erupt between March and September 2024.

And if I’m interpreting some of the other content correctly, it’ll come and go in one night? Maybe someone who knows more about these can confirm or correct me.. See update below.

Also …

Even when at peak magnitude of 2.5, this recurrent nova is dimmer than about 120 stars in the night sky.

So, maybe a bit anticlimactic. 😞

Update: … …nasa.gov/…/view-nova-explosion-new-star-in-north…

Once its brightness peaks, it should be visible to the unaided eye for several days and just over a week with binoculars before it dims again, possibly for another 80 years.

WarmSoda,

So no range of dates then? Still pretty damned cool.

nulluser,

Between March and September, but that’s a pretty wide range. I guess just keep an eye out for the, “IT’S HAPPENING” posts.

XeroxCool,

Reminds me of when Betelgeuse, the orange upper star of Orion, went dim in 2020. Lots of amateur reports on its brightness, 3x per night, for a few months waiting for it to go nova. It settled down a bit before disappearing behind the sun for the season and came back just fine. It was kinda fun to monitor, but soooo many false alarms from people trying to call it first

WarmSoda,

Definitely will keep an eye out. Already have the eclipse in the calendar too.

verity_kindle, w ESA's Euclid Telescope Has an Ice Problem
@verity_kindle@lemmy.world avatar

That is fascinating, I want to know, is there any way to prevent this during assembly? Even with extreme clean room protocols! Does it happen with other telescopes?! Down the rabbit hole, I must go.

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

This model explores the notion that the forces of nature diminish over cosmic time and that light loses energy over vast distances

Losing energy… to what?

troyunrau,
@troyunrau@lemmy.ca avatar

Wildass hypothesis I just pulled out of my ass with an undergraduate degree in applied physics: maybe interaction with particles emerging from quantum vacuum?

Okay, that sounds like great technobabble. I’m going to watch star trek now ;)

atzanteol,

Seems you may be on to something. Virtual particle interactions seems to be a hypothesis for tired light.

To test this I suggest we reprogram the deflector dish to emit a low-power tachyon pulse to see if we can excite the non-baryonic mass interactions.

CitizenKong,

Don’t forget to reverse the polarity of the neutron flow!

felbane,

Shit, if only my turbo encabulator wasn’t broken!

umbrella,
@umbrella@lemmy.ml avatar

those are old tech.

obsolete even.

RageAgainstTheRich,

You sound like you know what you’re talking about. I’m taking notes. 📝🧐

circuitfarmer,
@circuitfarmer@lemmy.world avatar

It’s those damn inertial dampeners again

riskable,
@riskable@programming.dev avatar

It’s probably not that the light is losing energy it’s just that the distance it travels over time (the time we “know” is supposed to take for a given distance) appears compressed because of unknown/unseen gravitational forces.

Think of it like this: If there were only one star in the universe and it emits a particle of light we could calculate the distance it would travel over time. Yet we know that star will still have a gravitational effect on that light… No matter how far away it gets.

That’s what they mean by light “losing energy”. Is the energy actually “lost”? Not really. Is this slowing (aka appearance of lost energy) caused by dark energy/dark matter or something more fundamental like spacetime itself being stretched or compressed due to the gravity of astronomical objects we can see or “dark matter”/“dark energy” or… ? We don’t really know for certain yet!

atzanteol,

It’s probably not that the light is losing energy it’s just that the distance it travels over time (the time we “know” is supposed to take for a given distance) appears compressed because of unknown/unseen gravitational forces.

This doesn’t seem to be at all what tired light proposes though. What you’re explaining sounds like red-shift due to an expanding universe. From what I can tell they claim it actually loses energy through interaction with “other things” in the universe.

xionzui,

This doesn’t answer the question in the context of this theory, but the current understanding is that light does lose energy as it travels through expanding space. As the space it’s in expands, the wavelength gets longer, and the energy goes down. It doesn’t go anywhere; energy just isn’t conserved in an expanding space-time.

HereIAm,

If the light loses energy, then it must surely lose it to something? And if your last point that energy isn’t being conserved in our universe, in which case we are either in some deep shit with the first law of thermodynamics, or our universe isn’t an isolated system.

atzanteol,

Seems energy is not conserved.

preposterousuniverse.com/…/energy-is-not-conserve…

The thing about photons is that they redshift, losing energy as space expands. If we keep track of a certain fixed number of photons, the number stays constant while the energy per photon decreases, so the total energy decreases.

Scribbd,

Ok. Smarter people probably thought of this, and probably found my hypothesis to be impossible. But what if… It is the the other way around. What if photons are losing energy because they are expanding spacetime. Like tiny little springs expanding out.

Live_your_lives,

Further into the article he says that, "It would be irresponsible of me not to mention that plenty of experts in cosmology or GR would not put it in these terms. We all agree on the science; there are just divergent views on what words to attach to the science. In particular, a lot of folks would want to say “energy is conserved in general relativity, it’s just that you have to include the energy of the gravitational field along with the energy of matter and radiation and so on.” "

So energy is conserved on the whole, it’s just not conserved if you consider photons apart from their greater context.

SkyeStarfall, (edited )

The energy is actually not conserved across the universe in general relativity, as it is currently understood. Conversation of energy is due to the time symmetry, which the expansion of space breaks.

atzanteol,

BTW, thanks! This comment sent me down a fascinating rabbit hole. It had simply never occurred to me that energy conversation didn’t apply in an expanding universe!

Live_your_lives,

“Energy is conserved in general relativity, it’s just that you have to include the energy of the gravitational field along with the energy of matter and radiation and so on.”

Quote taken from Atzanteol’s article.

RvTV95XBeo,

You try being a bright ray of sunshine for everything around you all day every day. Sometimes you just get tired, ya know?

Naz,

To the dark matter, of course.

;)

RizzRustbolt,

Entropy, capital “E”.

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

There’s no dark matter, only dimension flattening weapons being fired at each other by advanced aliens.

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

Man, lots of people in this thread seem happy to accept any wild, physics-breaking idea rather than accept that there’s just a bunch of matter we can’t see.

DAMunzy,

I think it goes beyond not being able to “see” it and goes to we can’t detect it at all. Doesn’t dark matter just fill in the mathemagical holes with some numbers to make it all work?

SkyeStarfall,

We can detect its gravitational influence, as it interacts via gravity. The issue being that gravity is a weak force, and so there’s a lot of room for speculation.

But there is a lot of evidence backing up dark matter existing. But it’s not definitive yet.

DAMunzy,

I get that but it still sounds woo-woo since we can’t directly detect it. I’m not naysaying since I realize it’s the best we have and I’m not smart enough to come up with anything better.

iknowitwheniseeit,

I mean, I guess it depends on what you mean by “directly detect”. We measure neutrinos by having photoreceptors in huge tanks of very pure water deep under old salt mines… which hardly seems more direct than looking at where galaxies and stars are moving and calculating the gravitational pull and noticing that something is missing…

Leate_Wonceslace,
@Leate_Wonceslace@lemmy.dbzer0.com avatar

Dark matter is matter that we infir to exist only on its gravitational effects. We’ve observed its existence by the fact that it seems to clump up in the middle of two massive super-solar structures following a collision.

btaf45,

We can indirectly detect dark matter thru gravitational lensing. That is how NASA created this map showing the actual locations of dark matter in tinted blue.

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

DAMunzy,

That’s a cool one!

jenny_ball,
@jenny_ball@lemmy.world avatar

you can also sort of directly see it with certain colliding galaxies

electric_nan, w The US government seems serious about developing a lunar economy

Develop the fucking US economy.

kalkulat, w The US government seems serious about developing a lunar economy
@kalkulat@lemmy.world avatar

Sure, why not? It’s not like we have any other pressing issues to address. Let’s keep pouring 100s of billions into the right pockets and press on.

threelonmusketeers,

“Por que no los dos?”

Humanity can pursue multiple awesome endeavours simultaneously.

atzanteol,

NASA’s 2024 budget is around $25 billion.

By comparison Apple’s revenue for last quarter was around $120 billion.

Linkerbaan, w The US government seems serious about developing a lunar economy
@Linkerbaan@lemmy.world avatar

I thought economists were the stupidest people. Military economists proved me wrong.

conditional_soup, w The US government seems serious about developing a lunar economy

Nope. No. Nuh-uh. Stop fucking up this planet, then we can talk. I’m drawing a line in the sand, I’m going to become an eco-terrorist if I see a fucking Coca-Cola ad when I look into the night sky.

Audacious,

All I think of is the movie, The Time Machine. Spoiler, the main character goes forward in time and sees the moon breaking apart, causing a collapse of civilisation.

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

  • Loading...
  • 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/

    FreudianCafe, w The US government seems serious about developing a lunar economy

    Cant wait to see how they will use moon real estate to produce a new kind of homeless people

    NegativeLookBehind, w The US government seems serious about developing a lunar economy
    @NegativeLookBehind@lemmy.world avatar

    What’s the USD to MOONBUX conversion rate?

  • Wszystkie
  • Subskrybowane
  • Moderowane
  • Ulubione
  • muzyka
  • Blogi
  • sport
  • giereczkowo
  • lieratura
  • Spoleczenstwo
  • rowery
  • esport
  • slask
  • Pozytywnie
  • fediversum
  • astronomy@mander.xyz
  • FromSilesiaToPolesia
  • niusy
  • Cyfryzacja
  • krakow
  • tech
  • kino
  • LGBTQIAP
  • opowiadania
  • Psychologia
  • motoryzacja
  • turystyka
  • MiddleEast
  • zebynieucieklo
  • test1
  • Archiwum
  • NomadOffgrid
  • m0biTech
  • Wszystkie magazyny