5 ms·
30 billion solar masses, numbers kind of loose the meaning at this scale.
by rwaksmunski 4y ago
30 billion solar masses, numbers kind of loose the meaning at this scale.
- unnouinceput 4y agoNot masses, size. The article says size.
- nathan_compton 4y agoIn the case of a black hole mass and size (radius) are inextricably and linearly linked. All black holes with a given mass have the same radius (modulo a small effect of angular momentum).
- davorak 4y agoI did a rough calc in: https://news.ycombinator.com/item?id=35361280 https://news.ycombinator.com/item?id=35361280 When it was pointed out TON618 has ~66 billion solar masses. But if it is 30 billion times the size of the sun then I think that means it is ~2354000 billion solar masses.
- runnerup 4y agoI believe for black holes the volumetric size is a known function of mass. If you exclude the rest of any Lyman-alpha blob present around the black hole.
- trilbyglens 4y agoMass is the only really meaningful measure of a blackhole, as they occupy a spacial singularity, which is to say, the have no measurable size. The event horizon has a diameter, but that's not the object itself.
- ioblomov 4y agoGuessing that "size" for black holes can mean mass, volume, or radius. But I'm pretty sure the relationship between those three quantities is well defined and directly proportional, so any way you look at it, this thing is incomprehensibly huge.
- croes 4y ago30B time the mass of the sun is already huge but 30B times the size of the sun would be much much bigger.
- javajosh 4y agoIt is not possible to have an intuition about 1 solar mass, by easily 10 OOM. Adding OOM can't make it less comprehensible.
- seanhunter 4y agoIf they want people to relate to their numbers, they have to use units people understand, and also they need to be accurate about which dimension they are talking about. If it's mass the correct popular science dumb reporting unit is the blue whale. Ie "The mass of this black hole is almost 3 x 10^35 blue whales" If it's size, the correct popular science dumb reporting unit is the football field unless it's specifically length, in which case it's acceptable to either go with football field or switch to double-decker bus or blue whale.
- galaxytachyon 4y agoWell, most people can't properly understand the scientific notation, as in getting a proper scale of how big one order of magnitude is supposed to be. They may see ^35 and say "oh, so it is like less than 100 of something, meh". If you doubt that, remember the quarter pounder ads where they made people think 1/4 is kinda more than 1/2 because 4>2...
- seanhunter 4y agoThe point is how are people ever going to get intuition about the numbers if they don't report them in blue whales/football pitches/double decker busses?
- samus 4y agoAt these scales, it really doesn't make much of a difference, as a sibling commenter pointed out.
- seanhunter 4y agoI was being sarcastic. Pretty sure it's impossible for the vast majority of people (myself definitely included) to gain any kind of intuition for numbers of this scale. I also don't gain any intuition for things by comparing them to a blue whale etc (and I'm not really sure anyone else does either) and find it pretty weird that it seems to be a go-to comparison for science articles in the press.
- jws 4y agoA billion is three groups of three zeroes. So for visualizing I would think of a cubic meter compared to a cubic millimeter. A grain of sand serves for a cubic millimeter. For the cubic meter you can either visualize a cube that size, or four oil drums, or a small hot tub. Now for the 30 out front, That’s about 27 which is 3^3 so let’s just size a smaller grain of sand which is only 1/3mm on a side. Maybe table salt would be good. So a grain of table salt in a small hot tub. If you perform this thought experiment with actual solar masses, use sufficiently long tongs and wear eye protection.
- lttlrck 4y agoThat's really neat. Thank you.