Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Nasa’s Roman Mission Will Hunt for Primordial Black Holes

nasa.gov

Post reply on HN
Print view View original

11–20 of 79 posts

Re: Nasa’s Roman Mission Will Hunt for Primordial Black Holes

#11

Post by Loughla »

api wrote: post #2

Primordial black holes are a fascinating topic. One of my favorite hypotheses is that "planet nine," a large possibly 1-5 Earth mass planet suggested by some orbital models to exist beyond Neptune and Pluto in the far outer solar system, may be a primordial black hole. If such a thing existed it'd be a black hole about the size of a billiard ball and would be extremely hard to detect. It would not emit Hawking radiat…

I feel like if you were close enough for a gravity assist, wouldn't the tidal forces just tear the probe apart?

Re: Nasa’s Roman Mission Will Hunt for Primordial Black Holes

#12

Post by Tostino »

Loughla wrote: post #11
api wrote: post #2

Primordial black holes are a fascinating topic. One of my favorite hypotheses is that "planet nine," a large possibly 1-5 Earth mass planet suggested by some orbital models to exist beyond Neptune and Pluto in the far outer solar system, may be a primordial black hole. If such a thing existed it'd be a black hole about the size of a billiard ball and would be extremely hard to detect. It would not emit Hawking radiat…

I feel like if you were close enough for a gravity assist, wouldn't the tidal forces just tear the probe apart?

Not necessarily. If you replaced the sun with an equivalent mass black hole, none of the orbits of the planets would change.

Re: Nasa’s Roman Mission Will Hunt for Primordial Black Holes

#13

Post by sandworm101 »

api wrote: post #2

Primordial black holes are a fascinating topic. One of my favorite hypotheses is that "planet nine," a large possibly 1-5 Earth mass planet suggested by some orbital models to exist beyond Neptune and Pluto in the far outer solar system, may be a primordial black hole. If such a thing existed it'd be a black hole about the size of a billiard ball and would be extremely hard to detect. It would not emit Hawking radiat…

At that size, very few things would ever get close enough to be torn apart, let alone fall in. We should look for objects suddenly changing course ivo the potential black hole.

Re: Nasa’s Roman Mission Will Hunt for Primordial Black Holes

#14

Post by sandworm101 »

Loughla wrote: post #11
api wrote: post #2

Primordial black holes are a fascinating topic. One of my favorite hypotheses is that "planet nine," a large possibly 1-5 Earth mass planet suggested by some orbital models to exist beyond Neptune and Pluto in the far outer solar system, may be a primordial black hole. If such a thing existed it'd be a black hole about the size of a billiard ball and would be extremely hard to detect. It would not emit Hawking radiat…

I feel like if you were close enough for a gravity assist, wouldn't the tidal forces just tear the probe apart?

The tidal forces would be no different than using jupiter for an assist. You would still have the probe pass by at several thousand, several tens of thousands of kilometers. A close-in gravity assist may look better on paper, but the practicalities and speeds of such a thing are risky. One small error and the mission would be over quick, launched out at a radically incorrect trajectory.

Re: Nasa’s Roman Mission Will Hunt for Primordial Black Holes

#15

Post by woopsn »

Fascinating mission. I don't understand how microlensing events resulting from primordial black holes can be differentiated even statistically, given that they "can't be formed by any known physical process", but in any case it's exciting to discover there's much more of something up there than we knew. Even if they are "just" rogue planets.

Re: Nasa’s Roman Mission Will Hunt for Primordial Black Holes

#16

Post by ccgreg »

stainablesteel wrote: post #7
breckenedge wrote: post #3

I really want primordial black holes to turn out to be the missing antimatter from the Big Bang, but I don’t think that could ever be tested. And of course a mechanism for this would probably need new physics since antimatter interacts the same as normal matter wrt gravity.

it sounds a lot like it now that i read this, large dispersed amounts of antimatter that apparently doesn't give off light yet has massive gravitational pull

Antimatter has the same electrodynamic properties as matter.

Re: Nasa’s Roman Mission Will Hunt for Primordial Black Holes

#17

Post by gus_massa »

bigyikes wrote: post #6
ryandrake wrote: post #4

Earlier quoted context omitted.

> It could also be used in tight gravity assist flybys to accelerate probes to incredible velocities, maybe making interstellar probes a lot more practical. Would 1-5 earth masses really provide enough of a yeet to appreciably affect the speed of a probe? Jupiter is about 300+ earth masses and we're not flinging probes out to stars using him.

You can get a lot closer to the center of mass of the black hole, which should drastically increase acceleration since it falls off with distance squared.

The satelite acelerates when it aproach the planet, but most of it is compensated when it goes away. There is a nice graphic in https://en.wikipedia.org/wiki/Gravity_assist#/media/File:Voy...

Re: Nasa’s Roman Mission Will Hunt for Primordial Black Holes

#18

Post by pixl97 »

gus_massa wrote: post #17
bigyikes wrote: post #6

Earlier quoted context omitted.

You can get a lot closer to the center of mass of the black hole, which should drastically increase acceleration since it falls off with distance squared.

The satelite acelerates when it aproach the planet, but most of it is compensated when it goes away. There is a nice graphic in https://en.wikipedia.org/wiki/Gravity_assist#/media/File:Voy...

You toss off some mass as you pass the black hole and it gives a powerful boost.

Re: Nasa’s Roman Mission Will Hunt for Primordial Black Holes

#19

Post by gus_massa »

pixl97 wrote: post #18
gus_massa wrote: post #17

Earlier quoted context omitted.

The satelite acelerates when it aproach the planet, but most of it is compensated when it goes away. There is a nice graphic in https://en.wikipedia.org/wiki/Gravity_assist#/media/File:Voy...

You toss off some mass as you pass the black hole and it gives a powerful boost.

Do you have a source for that?
Post reply on HN