astronomy

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Zachariah, w Asteroid Ryugu samples suggest presence of salty water in outer solar system
@Zachariah@lemmy.world avatar

tears?

bahbah23,

Damn it, my head went straight to pee and yours is so much better, I got to get off the internet

technohacker, w Eliminating singularities: Physicists describe the creation of black holes through pure gravity
@technohacker@programming.dev avatar

Gonna hijack this post to ask a somewhat related but possibly stupid question, would it be possible that instead of a singularity there happened to be a region of space with non-negligible size (ie, not a point sized region) that acted like a well instead? Things could “fall” into that well and not be able to escape, but it’s not like everything in the well is at a single point.

e0qdk,
@e0qdk@reddthat.com avatar

I may be misunderstanding your question, but black holes are regions of space that have non-negligible size; the boundary between what can escape and what can’t is called the event horizon. The singularity is what happens at the center.

technohacker,
@technohacker@programming.dev avatar

Ah right I worded that wrong, sorry!

I guess what I mean to say is, would a non-negligible sized “singularity” (I know I’m messing with that term quite a bit, I’ll stray from the mathematical definition) be consistent with our current theories?

BaroqueInMind,

No one can get information from beyond the event horizon, so no one can truly know besides predict with math.

Tarquinn2049, (edited )

Basically, what makes sense logically isn’t backed up by what data and math we have. Logically, we would assume as enough stuff is pulled together that the density hits a point where gravity is stronger than the bonds that hold matter together, that those bonds would break and the individual elements, initially atoms, but as gravity gets stronger and stronger the bonds between the components of atoms and so on and so forth also break down.

At some point, there is a limit to how much matter can break back down into further and further smaller components. What specifically happens when that limit is reached? That is a huge part of what could be throwing the math off. We don’t really know, but we have some guesses. Could be at the end, one of the components is weightless, and unaffected by the gravity, we do see some energy radiating out of some black holes in a straight line or “jet”. Hard to say for sure. Logic doesn’t always get us there when we don’t have enough data and need to make a leap. It might eventually, as we can slowly tie more and more stuff together with more data. Could be whatever energy starts that jet either immediately or already on the way out, mixes/mixed with other components and particles to become what we end up detecting it as. But if we could see it earlier, it maybe would be completely different before that.

gnutrino,

Depends what you mean by “our current theories”. In classical General Relatively the answer is pretty conclusively no but many people think that a quantum theory of gravity should be able to remove the singularities. In fact, this article is about an attempt to do just that with a fairly natural extension to GR (albeit one that is only mathematically tractable in 5 or more dimensions) and seems to have succeeded for the static spherically symmetric case at least.

lemming,

Nobody really thinks singularities exist. It’s only what comes out from our math. That’s also how we know our math is wrong, we’re just not sure yet how to do it better.

FreakinSteve, w Don’t panic, but an asteroid has a 1.9% chance of hitting Earth in 2032

Can we speed that up a bit?

InFerNo, w Don’t panic, but an asteroid has a 1.9% chance of hitting Earth in 2032

If we are able to nudge an asteroid, would an asteroid of this size nudge the earth?

threelonmusketeers,

Technically the solar system is a multi-body system, and everything nudges everything else, but the mass of the earth is far greater than the mass of the asteroid, to the point that it doesn’t matter.

pageflight, w The IAC confirms the existence of a Super-earth in the habitable zone of a Sun-like Star

20ly away. I guess that does qualify as “nearby,” astronomically.

themoken,

In a certain way, it does feel close. We can’t figure out how to go faster than light, but we could theoretically get to a significant fraction of c and 20 years isn’t such a long time to plan for in terms of getting a probe there to start relaying messages that take 20 years to get back.

I mean, it’s the span of a career, but people could conceivably work on the launch and live to see it return data.

LordTrychon,

Breakthrough Starshot project is working towards accelerating a probe close to 20% of C. That’s a significant fraction of C in these terms.

Even if we could get to .25 C, that would be 80 years for the probe to get there, and then 20 more for the data to come back.

But yes, that is still VERY close.

darvocet, w Astronomers seek global ban on space advertising

Apparently these “astronauts” dont understand the world we are living in. They should just be happy we’re allowing them to visit the Tesla ® Moon.

SweetCitrusBuzz, w The IAC confirms the existence of a Super-earth in the habitable zone of a Sun-like Star
@SweetCitrusBuzz@beehaw.org avatar

Absolutely not until lifeforms on this planet have learned to look after this one first.

WalkingOnEggshells, w The IAC confirms the existence of a Super-earth in the habitable zone of a Sun-like Star

My life for Super Earth!

anarchrist, w See 6 Planets Align on January 21

I thought I had seen a documentary about this…

The planetary alignment is a celestial event that occurs periodically within the solar system where Gaia and the other five planet gods known as the Astra Planeta align. The event was prophesied by the Fates to occur again 18 years after Hercules’ birth and would allow Hades to conduct a “hostile takeover” against Mt. Olympus with the help of the Titans.

Energy released by the planets lining up created a vortex that moved the water away from the place in the ocean where the Titans had been imprisoned by Zeus back when the Earth was new. Hades then broke the energy gate covering their prison and the Titans climbed free to begin an assault on the home of the gods. However, in their anger, they initially headed in the wrong direction until Hades got them turned around.

AngryCommieKender,
BaroqueInMind, w Astronomers discover an ultra-massive grand-design spiral galaxy

Putting on my sci-fi hat; a distant galaxy that is likely a billion years older than ours, very likely has had enough time to develop life somewhere in the trillions of stars that formed within it, by the time the photons of that galaxy finally reached us and hit that very specific telescope sensor at that very specific moment the JWT engineers were observing.

conciselyverbose, w Check Out the Highest-Resolution Images Ever Captured of the Sun's Entire Surface
lunarul, w ESO VLT discovers new exoplanet around the nearby Barnard star, only 6 light years away.

Barnard b [2], as the newly discovered exoplanet is called, is twenty times closer to Barnard’s star than Mercury is to the Sun. It orbits its star in 3.15 Earth days and has a surface temperature around 125 °C. “Barnard b is one of the lowest-mass exoplanets known and one of the few known with a mass less than that of Earth. But the planet is too close to the host star, closer than the habitable zone,” explains González Hernández. “Even if the star is about 2500 degrees cooler than our Sun, it is too hot there to maintain liquid water on the surface.

foofiepie, w Astronomers discover biggest ever seen black hole jets, which blast hot plasma well beyond their own host galaxy

Ok. Permission to ask a mad question. Apologies in advance.

If black holes ‘suck’ everything in… could there be the equivalent of the ‘other side’ of one, that’s mysteriously ejecting a tonne of plasma?

Not saying that’s what this is, just prompted the thought.

imakeninjascry,

Mathematically, it’s possible, but scientists are still skeptical about whether or not they are real. They’re called white holes and you can actually create a model of one in your kitchen sink. If you let the water just hit the bottom and spread out evenly in all directions, you can kind of visualize the way it’s supposed to work. Action Lab on YouTube actually has a pretty good video about it which I suggest watching if you’re interested. youtu.be/p3P4iKb24Ng?si=b3_RHuj0J3F_7DC1

chuckleslord,

Tangent, but you don’t need to include the question mark or anything after in most urls. Definitely not YouTube links. It’s just YouTube telling itself who shared the info (you) and they use that to track shit. But the link works just as well without it, and you’re not voluntary spying on yourself.

imakeninjascry,

Neat! I didn’t know that. I just copied and pasted. Thanks for the info.

shirro, (edited ) w Elon Musk destroys astronomy

I have not heard a car for a few hours. Not even the rumble of traffic in the distance and I can see the night sky without light pollution. It is a very privileged experience in some ways and while it has its advantages we are measurably disadvantaged in most human development metrics: health, education, income etc compared to people living in urban areas of our own country. The disadvantage is real and pops up everywhere from cancer survivability to suicide rates. Equitable internet access is more important than many people appreciate. If we can improve services to everyone AND protect radio astronomy that is a worthy goal.

jmcs,

Fiber is dirty cheap, just saying. If you consider externalities, much cheaper than starlink. You just want us to subsidise your lifestyle.

palitu,

Maybe they are farmers? Apparently they have to live quote remote.

I have family that use it as there is nothing else available

Edit: fiber is cheap, but the land and labour required is not.

ShepherdPie,

How does fiber being cheap help them if no ISP is willing to dig miles and miles of trenches to lay it and connect to their home? I live in the middle of suburbia and don’t have access to fiber.

Your comment about subsidizing their lifestyle doesn’t really make sense. What are you subsidizing exactly? This tech is also useful in poorer countries that don’t have the infrastructure at all.

AbouBenAdhem, w Elon Musk destroys astronomy

Any chance the Starlink satellites could be built to double as a sort of large-array telescope themselves, to compensate for the ground-based interference?

NotMyOldRedditName, (edited )

What’s more likely to happen is Starship’s will be launched where the entire ship becomes the telescope, and then we’ll have arrays of these much further away.

Not sure if it’s the same for radio, but for optical that means we can get a 9 meter mirror up there without any expensive folding mechanism, and who knows how big if we fold them as the fairing is not only wider but also longer.

Cost would go from billions to hundreds of millions or less. James Webb cost 10b.

The James Webb folding mirror is 6.5m and was folded into a 4.5m fairing…

threelonmusketeers,

From my brief look into the topic, interferometry tech is not quite there yet, but might be in the next few decades. Interferometry is more difficult with shorter wavelengths.

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