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Scientists discover the highest energy gamma-rays ever from a pulsar

phys.org

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Re: Scientists discover the highest energy gamma-rays ever from a pulsar

#21

Post by FluffyClouds »

tomohelix wrote: post #14
mikub wrote: post #8

Earlier quoted context omitted.

I find all this really incredible as well. But at the same time I also find it really 'mindblowing' that I am able to think about why and how all of this stuff was made, and while thinking about it, there will always come a point where you have to at least 'think' about an creator. Not that I think it was made especially for us, but it's still very strange. Somewhere I read when you think about the universe it is lik…

I agree. I actually think that is a very common thought, at least from what I have seen with my colleagues who are mostly scientists in engineering and biotech. It could be because of our background but the kind of complexity and seemingly genius engineering solutions in some biological systems just boggle the mind and make us question how it happened. We often handwave them with evolution and sure we can come up wit…

We are a tad beyond handwaving, but with all the information overload it's hard to recognize scientific breakthroughs anymore.

Anyway thermodynamics did it.

https://arxiv.org/abs/1203.3271

Most people won't like this answer, because it's too impersonal. Thus the search for a more inspiring origin story continues. There is no drama in thermodynamics, no love, no revenge, although there are explosions.

Re: Scientists discover the highest energy gamma-rays ever from a pulsar

#22

Post by Eddy_Viscosity2 »

c4mpute wrote: post #18
nullandvoid wrote: post #17

I have a question - what would happen if you were to drop one of these spoons of matter that weigh 5 billion tonnes onto the floor right now, where would it stop?

It would sink into the center of the earth and then oscillate around the center until friction stops it dead center. Materials in the earth's crust and mantle are not strong enough to stop that mass from sinking ever deeper. But that assumes that this spoon of matter were stable in that state, which it isn't. That kind of density can only be held up with some force like gravity keeping up the pressure. The gravity of…

I've heard that black hole matter is stable at any size, so how much difference in density is there between neutron star matter and black hole matter where it crosses the threshold of stability from its own gravity?

Re: Scientists discover the highest energy gamma-rays ever from a pulsar

#23

Post by rad_gruchalski »

tomohelix wrote: post #4
asicsp wrote: post #2

> These dead stars are almost entirely made up of neutrons and are incredibly dense: a teaspoon of their material has a mass of more than five billion tons, or about 900 times the mass of the Great Pyramid of Giza Five billion tons packed within a teaspoon volume!? Incredible.

When it comes to cosmic scales, it is literally unimaginable by the puny human mind. I don't know about others but I frankly can't really comprehend what does the mass of an entire mountain condensed into a single pebble mean. And there are stars full of this stuff. And there are stars spinning so fast its magnetic waves would rip the iron out of my blood and destroy the physics that hold my atoms together just becau…

Paraphrasing: There are 100 billion galaxies in the observable universe, each galaxy contains approximately 100 billion of stars. It takes 100s of thousands years travelling at the speed of light to get from one end of the galaxy to the other. It takes 100s of millions to billions of years to get from one galaxy to another. And all those galaxies are moving away from each other at mind boggling speeds 73 kilometres per second.

It’s humbling. And we kill each other for silly reasons. We are so significant, yet so insignificant.

Re: Scientists discover the highest energy gamma-rays ever from a pulsar

#24

Post by [deleted] »

Eddy_Viscosity2 wrote: post #22
c4mpute wrote: post #18

Earlier quoted context omitted.

It would sink into the center of the earth and then oscillate around the center until friction stops it dead center. Materials in the earth's crust and mantle are not strong enough to stop that mass from sinking ever deeper. But that assumes that this spoon of matter were stable in that state, which it isn't. That kind of density can only be held up with some force like gravity keeping up the pressure. The gravity of…

I've heard that black hole matter is stable at any size, so how much difference in density is there between neutron star matter and black hole matter where it crosses the threshold of stability from its own gravity?

[deleted]

Re: Scientists discover the highest energy gamma-rays ever from a pulsar

#25

Post by JackFr »

tomohelix wrote: post #12
JackFr wrote: post #5

Earlier quoted context omitted.

[flagged]

[flagged]

Apologies. My response was too snarky and too clever by half.

My point was that it’s easy to miss our own hubris when measuring our present ideas against the past, and that a bit of circumspection is well taken.

Re: Scientists discover the highest energy gamma-rays ever from a pulsar

#26

Post by op00to »

asicsp wrote: post #2

> These dead stars are almost entirely made up of neutrons and are incredibly dense: a teaspoon of their material has a mass of more than five billion tons, or about 900 times the mass of the Great Pyramid of Giza Five billion tons packed within a teaspoon volume!? Incredible.

It is now that I recommend you read Dragons Egg, a hard sci-fi book about a species that evolved on the surface of a neutron star. I am contractually obligated to mention this any time I hear neutron stars mentioned.

Re: Scientists discover the highest energy gamma-rays ever from a pulsar

#27

Post by johndunne »

Eddy_Viscosity2 wrote: post #22
c4mpute wrote: post #18

Earlier quoted context omitted.

It would sink into the center of the earth and then oscillate around the center until friction stops it dead center. Materials in the earth's crust and mantle are not strong enough to stop that mass from sinking ever deeper. But that assumes that this spoon of matter were stable in that state, which it isn't. That kind of density can only be held up with some force like gravity keeping up the pressure. The gravity of…

I've heard that black hole matter is stable at any size, so how much difference in density is there between neutron star matter and black hole matter where it crosses the threshold of stability from its own gravity?

Black hole's aren't matter, they're pure gravitational binding energy. A neutron star becomes a black hole when the neutrons pushing against each other can't push back at the gravitational forces (neutron degeneracy pressure) and the neutrons do something we're not sure of... but whatever happens, they're crushed down into something smaller than a neutron star; into a singuality and we see the result.. a black hole. Eternal darkness for the poor neutrons; this bit gives me chills.

Re: Scientists discover the highest energy gamma-rays ever from a pulsar

#28

Post by automatic6131 »

op00to wrote: post #26
asicsp wrote: post #2

> These dead stars are almost entirely made up of neutrons and are incredibly dense: a teaspoon of their material has a mass of more than five billion tons, or about 900 times the mass of the Great Pyramid of Giza Five billion tons packed within a teaspoon volume!? Incredible.

It is now that I recommend you read Dragons Egg, a hard sci-fi book about a species that evolved on the surface of a neutron star. I am contractually obligated to mention this any time I hear neutron stars mentioned.

That must have inspired Stephen Baxter's Flux, which is about artificial humans, living just inside the skin of a neutron star.

Re: Scientists discover the highest energy gamma-rays ever from a pulsar

#29

Post by Cyphase »

mikub wrote: post #8
tomohelix wrote: post #4

Earlier quoted context omitted.

When it comes to cosmic scales, it is literally unimaginable by the puny human mind. I don't know about others but I frankly can't really comprehend what does the mass of an entire mountain condensed into a single pebble mean. And there are stars full of this stuff. And there are stars spinning so fast its magnetic waves would rip the iron out of my blood and destroy the physics that hold my atoms together just becau…

I find all this really incredible as well. But at the same time I also find it really 'mindblowing' that I am able to think about why and how all of this stuff was made, and while thinking about it, there will always come a point where you have to at least 'think' about an creator. Not that I think it was made especially for us, but it's still very strange. Somewhere I read when you think about the universe it is lik…

> Somewhere I read when you think about the universe it is like "The Universe thinking about itself.".

This reminds me of this quote from Jill Tarter of SETI, particularly the last sentence:

“Might it be the discovery of a distant civilization and our common cosmic origins that finally drives home the message of the bond among all humans? Whether we’re born in San Francisco or Sudan or close to the heart of the Milky Way Galaxy, we are the products of a billion-year lineage of wandering stardust. We, all of us, are what happens when a primordial mixture of hydrogen and helium evolves for so long that it begins to ask where it came from.”

source: https://www.ted.com/talks/jill_tarter_join_the_seti_search (@ 3:02)

(I copied this nearly verbatim from another comment of mine: https://news.ycombinator.com/item?id=37061363)

Re: Scientists discover the highest energy gamma-rays ever from a pulsar

#30

Post by ourmandave »

hollander wrote: post #15
tomohelix wrote: post #4

Earlier quoted context omitted.

When it comes to cosmic scales, it is literally unimaginable by the puny human mind. I don't know about others but I frankly can't really comprehend what does the mass of an entire mountain condensed into a single pebble mean. And there are stars full of this stuff. And there are stars spinning so fast its magnetic waves would rip the iron out of my blood and destroy the physics that hold my atoms together just becau…

> I frankly can't really comprehend what does the mass of an entire mountain condensed into a single pebble mean. Maybe turn it around. On a cosmic level, that mountain is nothing but a fluff of cottonwool, the earth a hot air balloon.

Or turn around again. Zoom out far enough and maybe there's a view where the pulsar is comparably no more that a lit sparkler.

Note: This isn't an argument for god or whatever. Just thinking on scales where our "laughing in the rain" is a nightmare for ants.

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