astronomy

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mookulator, in Zooming Black Holes Can Reach ~10% The Speed of Light, Scientists Say

Relative to what exactly?

teft,
@teft@startrek.website avatar

Relative to their point of origin.

dudinax,

At that speed, relative to most nearby large object

mookulator,

But what if all nearby objects are moving towards it at a similar speed? Or away? At such a large scale speed becomes a mind bending thing.

dudinax,

No other large object will be moving close to that speed so it’ll be almost like they are standing still.

menturi,

Probably relative to the CMB (the frame of reference where there is no redshift or blueshift bias in any direction).

mookulator,

Thank you! At that scale the simpler answers just don’t feel sufficient

Ashyr, in Zooming Black Holes Can Reach ~10% The Speed of Light, Scientists Say

What would cause them to move so quickly?

teft,
@teft@startrek.website avatar

Colliding with another black hole.

NegativeInf,

Multibody Black Hole Slingshot

Manifish_Destiny,

Light up shoes

Ashyr, in Astronomers Find Strange Star Is a Powerful Magnet

Someone help me out: maybe that’s really magnetic for a star, but 43,000 gauss isn’t insanely strong, is it? We measure some magnets in teslas, which is 10,000 gauss.

So it’s a 4.3 tesla star.

I’m guessing this is somehow proportionate to the mass of the magnet, so a 1 tesla, 1 gram magnet is going to be much less powerful than a 1 tesla, 1 kg magnet? So something the size of a star would still have a massive magnetic field?

Kata1yst,
@Kata1yst@kbin.social avatar

Well you have to put it in perspective. The earth has a magnetic field of 0.3 - 0.5 gauss. That puts this star at 143,000x as strong. Then you compare to the sun, which is 1 gauss, so this star is 43,000x as strong.

Okay, you might say, that's a lot, but this star is also 4x as massive as the sun. What about other stars bigger than the sun?

Beltugese is 16.5 - 19x the mass of the sun, and it's magnetic field has been carefully studied and measured to be about 1 gauss.

So yes, for a main sequence star this beast is a huge outlier.

Remavas,
@Remavas@programming.dev avatar

According to the article, this seems to be a Wolf-Rayet star though, decidedly not main sequence.

But your point remains, it is a massive outlier.

Treczoks, in The largest Black Hole compared to Our Solar System

Lucky for us, it is to far away.

Aimhere, in The largest Black Hole compared to Our Solar System

How big is this, in real numbers?

President_Pyrus,
@President_Pyrus@feddit.dk avatar

More than 1 AU.

thepianistfroggollum,

That’s technically correct.

CrabAndBroom,

About 1600 AU, according to wikipedia.

Shdwdrgn, in ‘Head-scratcher’: first look at asteroid dust brought to Earth offers surprises

I thought the “head-scratcher” was trying to figure out what that thumbnail was supposed to be.

AnomalousBit, (edited ) in ‘Head-scratcher’: first look at asteroid dust brought to Earth offers surprises

Well no joke, if you sprinkle asteroid dust on someone’s head it’s going to itch

NAXLAB, in James Webb Telescope Captures Image of Supernova That 'Absolutely Shattered' a Star

It’s interesting the types of phrasing they use, like shatter. I never think of stars as rigid, more ethereal even though I know how they work

Rozz, in SpaceX rockets keep tearing blood-red 'atmospheric holes' in the sky, and scientists are concerned

…not a threat to humanity

Well that’s good at least

GummySquirrel, in Mars Needs Insects
@GummySquirrel@startrek.website avatar

Because humans introducing species to new environments always goes well 😩

Coldgoron, in Mars Needs Insects

So desert plant life plus desert bugs equals terraforming capable species?

kalkulat, in NASA Requests Funding for $1 Billion 'Space Tug' to Deorbit the ISS
@kalkulat@lemmy.world avatar

Pay a billion to burn it up?

It’d cost a lot less to put it in a higher orbit for a thousand years where it could be a museum for space travellers.

canis_majoris, (edited )
@canis_majoris@lemmy.ca avatar

You can’t do that because it will physically fall apart. That’s the main issue with boosting it up higher and just leaving it there. It was never designed to be existing for a thousand years, and eventually wear and tear will make the station naturally break apart. It’s significantly more dangerous for small fragments to drop over time as compared to a deorbit and decomm. At least the deorbit is planned, while the disintegration would be pretty random and not fun to deal with.

kalkulat,
@kalkulat@lemmy.world avatar

You can’t do that because it will physically fall apart.

Don’t know where you ever got that idea. It raises and lowers itself all of the time these days to avoid debris.

It could easily be raised to 2-5000 miles by adding energy from a similar small engine (with a decent-sized fuel tank) over a few months/years.

‘Wear and tear’ from what? Micrometeorites? The orbits of any ‘small fragments’ (of what?) would decay very slowly and instantly burn-up many centuries later.

DanglingFury, in The echoes from inflation could still be shaking the cosmos today

The inflation is transitory

btaf45, in The echoes from inflation could still be shaking the cosmos today

[More recent work has seen pulsar timing arrays (PTAs) such as NANOGrav successfully identify a specific flavor of gravitational wave known as the stochastic gravitational wave background (SGWB). The SGWB is similar in concept to the cosmic microwave background—a consistent glow from the early universe that astronomers can see as a series of microwaves coming from all directions at once.]

First time I’ve heard of this concept.

teft, in Brightest gamma-ray explosion of all time scrambled Earth's upper atmosphere
@teft@startrek.website avatar

BOAT is lame. Should be B-GREAT.

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