Starship Asterisk*

How can evolution favor an organism's death? In the big picture, no species can evolve for long if the old versions aren't eliminated. You need reproduction for adaptation and evolution, and you can't have reproduction without death in any system with limited resources. OK, let's say that hypotheti...

Yes, but why a tree can't live forever? I mean, some have been living for more than a millennia. Why this tree can't live that long? DNA gets damaged over time, toxins accumulate over time. Some pest, parasite, or disease will eventually win. And evolution doesn't favor organisms that don't die and...

Earth is sweeping up “particles” - charged, by the way - from solar flares. What charged particle? Electrons & protons - electricity. Now we get to see if it sis another Carrington event. My thought is: probably not, because there are a lot more wires and a lot more grounds than there were in 1...

Hello everybody, I have a question about the BHs' masses. I imagined that nothing could escape from a BH (except perhaps by Hawking radiation) but it seems that part of the mass of a couple of merging BHs is radiated as GW. I suspect that the energy emitted as GW comes from the kinetic/gravitationa...

Can you clear up that statement for me? Any missing words for example? I don't think there are any missing words. When a mass is allowed to move in a gravitational field, its velocity increases, which represents a conversion of gravitational potential energy to kinetic energy. Right? And any accele...

Kinetic energy can get converted into gravitational energy? In the mundane world, kinetic energy clearly can get converted into heat (a bullet hitting a steel plate for example), but does it also get converted to GWs (however miniscule an amount that might result in)? In the mundane world, gravitat...

Hello everybody, I have a question about the BHs' masses. I imagined that nothing could escape from a BH (except perhaps by Hawking radiation) but it seems that part of the mass of a couple of merging BHs is radiated as GW. I suspect that the energy emitted as GW comes from the kinetic/gravitationa...

Hello everybody, I have a question about the BHs' masses. I imagined that nothing could escape from a BH (except perhaps by Hawking radiation) but it seems that part of the mass of a couple of merging BHs is radiated as GW. I suspect that the energy emitted as GW comes from the kinetic/gravitationa...

Thanks! Btw, it mentions that "based on its species and history, it will probably be there for another 100 years." Why 100 years? What will happen after that? Well, they have a lifespan of a few hundred years, depending on conditions. Maybe it will be there for another 200. But not foreve...

Wow. Do you have a picture of the tree itself? Originally from that neck of the woods , I was curious too. :thumb_up: Thanks! Btw, it mentions that "based on its species and history, it will probably be there for another 100 years." Why 100 years? What will happen after that? Well, they h...

If one assumes that, according to theory, every black hole also has an accretion disk... What theory is that? I think the overwhelming majority of black holes in the Universe have no accretion disk. This simulation shows the appearance of a black hole with an accretion disk. Simulations have also b...

Is a black hole the brightest thing in the Universe because it keeps its light? In a black hole, things go to infinity, things go to zero, things go we know not. What does light do? Is there a limit to the number of possible photons, or is brightness theoretically infinite? Photons are just packets...

Is a black hole the brightest thing in the Universe because it keeps its light? In a black hole, things go to infinity, things go to zero, things go we know not. What does light do? Is there a limit to the number of possible photons, or is brightness theoretically infinite? Photons are just packets...

From the link posted just above: "You can roughly think of a black hole as a star that traps all of its light" . I like the " its " light. We normally read that "even light" can't escape a black hole, but saying "its" own light makes me wonder further. For in...

From the link posted just above: "You can roughly think of a black hole as a star that traps all of its light" . I like the " its " light. We normally read that "even light" can't escape a black hole, but saying "its" own light makes me wonder further. For in...

From the link posted just above: "You can roughly think of a black hole as a star that traps all of its light" . I like the " its " light. We normally read that "even light" can't escape a black hole, but saying "its" own light makes me wonder further. For in...

Fred the Cat wrote: ↑Tue May 07, 2024 3:31 pm Let's say a black hole is a four-dimensional object.

What about its jet?

All bodies with mass are 4D objects. Black holes. Stars. Atoms. So jets, too.

The singularity is small (infinitesimal) but isn't the BH's "size" and hence the gravitational effect - and collision window - determined by how large the event horizon is? A black hole's "gravitational effect" is determined by its mass. The event horizon isn't a real thing, jus...

I edited my post with more queries... The mass of the black hole doesn't matter, except to the extent that it's a factor in determining the orbit. Whether it hits the star depends on whether its orbit intersects the interior of the star. This is basically no different than two stars passing by each...

Can a black hole cause a star to supernova? Is the tidal force of a black hole more powerful than a supernova, either squelching it or, like Q, not being affected by it at all other than merely sucking it in like anything else? The tidal force of a black hole, because it is so small, is also small....

Can a black hole cause a star to supernova? Is the tidal force of a black hole more powerful than a supernova, either squelching it or, like Q, not being affected by it at all other than merely sucking it in like anything else? The tidal force of a black hole, because it is so small, is also small....

I suppose the "everything vanishes" part is a manner of speaking. Everything falls out of sight perhaps, but nothing "vanishes", rather what's left of the star's mass is added to the black hole's mass, increasing very slightly the event horizon radius, and dare I add: increasing...

Okay, cool, but... https://apod.nasa.gov/apod/image/2405/BhShredder_NASA_1080.jpg APOD 5 May 2024 annotated.png Can anyone answer my questions? Ann I fear this is another "artist's representation" that is not very connected to reality. So what needs to change in order to make it more real...

https://apod.nasa.gov/apod/calendar/S_240505.jpg A Black Hole Disrupts a Passing Star If the star directly impacts a massive black hole, then the star falls in completely -- and everything vanishes . I suppose the "everything vanishes" part is a manner of speaking. Everything falls out of...

Ann wrote: ↑Sun May 05, 2024 4:27 am Okay, cool, but...

A Black Hole Disrupts a Passing Star. Illustration Credit: NASA, JPL-Caltech

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APOD 5 May 2024 annotated.png

Can anyone answer my questions?

Ann

I fear this is another "artist's representation" that is not very connected to reality.