41–50 of 89 posts
"A search for the X-ray signatures of low-mass black hole binaries in the Chandra data turned up 12 within three light-years of Sgr A*."
Three light years is not that big of a distance in the grand scheme of things. For reference, the nearest star to Earth is Proxima Centauri, which is 4.2 light years away. Having 12 binaries within 3 ly sounds really dense. Having several hundred sounds crazy.
To be honest, in reading this and considering the vastness of space, my initial impression was "what, only twelve?!"
Every object in the universe attracts any other object. My initial impression was : not only one ?
only one and so many we can't possible try to count them all
Earlier quoted context omitted.
People have been saying "we might have invented everything" for hundreds of years. I like the "invention wavefront" analogy, but I unfortunately can't remember where I learnt it. Imagine the high-dimensional space of all possible things that can be invented. In the "centre" of the space is a hypersphere containing everything that has been invented to date. Every new invention is invented by "poking outwards" in one s…
> People have been saying "we might have invented everything" for hundreds of years. No, they really haven't. In fact for a good chunk of centuries (from 16th century onwards), the optimism for the eventual future developments was endless. At some point there was a few scholars saying that during the end of 19th century, but still not some widespread belief. That said, discovery probably also follows an 80/20 rule, a…
To be honest, in reading this and considering the vastness of space, my initial impression was "what, only twelve?!"
Let me try an optimistic thought experiment. Roughly around the end of the Napoleonic era, call it 1815, 9/10ths of humans lives in what we would call abject poverty. today it is reversed and only 1/10th does. (This is still a travesty, but it is objectively better) In that period we have seen incredible technological, political and economic improvements. But it's not clear if we will continue to see them "we might h…
> with no other information we can only plump for "in the middle". This is because the derivative of e^x is e^x, so when undergoing exponential growth the rate of change tells us nothing about where we are on that curve. And this is also why people (not GP, of course) who talk about the 'knee' in an exponential graph really annoy me...!
Of course, there's no reason to think invention should follow an exponential over the long term...
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You are describing evolution without an utility function. That won't work. We may be able to come up with an alternative utility function but, given past history, I'm afraid we won't and will be aimlessly exploring the solution space. A good parallel can be draw to evolution in painting. Up until the invention of photography, painting evolved to be photo-realistic. It made amazing strides, with breathtaking results.…
New utility function seems to be consensus-based monetary value as modern art becomes a store for value and/or an investment.
Let me try an optimistic thought experiment. Roughly around the end of the Napoleonic era, call it 1815, 9/10ths of humans lives in what we would call abject poverty. today it is reversed and only 1/10th does. (This is still a travesty, but it is objectively better) In that period we have seen incredible technological, political and economic improvements. But it's not clear if we will continue to see them "we might h…
It talks about far future civilizations, hypothesizes they would live in or near the surface of (possibly manufactured) blackholes, and that black holes are actually all over the place.
It also takes the stance that intelligent civilizations (including ours) would be more likely to minitiarize and grow inwards, rather than exploring and spreading throughout the galaxy as per Star Trek.
http://brighterbrains.org/articles/entry/the-transcension-hy...
Earlier quoted context omitted.
People have been saying "we might have invented everything" for hundreds of years. I like the "invention wavefront" analogy, but I unfortunately can't remember where I learnt it. Imagine the high-dimensional space of all possible things that can be invented. In the "centre" of the space is a hypersphere containing everything that has been invented to date. Every new invention is invented by "poking outwards" in one s…
For all practical purposes, I agree with the analogy, but would like to point out that the box might not be infinite so there could be limits to invention. Take a chess game as an example. No one would say there weren't creative inventions regarding tactics and strategies to win, but the bottom line is that the number of possible chess games, no matter how staggeringly huge, is still finite. In the end, no matter how…
Are discoveries about black holes legit? Isn't it still the case that they have not been experimentally confirmed to exist, and all talk of discoveries is just conceptual?
They are actually quite visible - their accretion disks (matter falling into the black hole) are very hot and radiate on a broad range of frequencies.
There is also some lack of precision on the LIGO experiment that does not invalidate all reasonable alternative explanations.
As people already said, the evident is overwhelming on the side of black holes existing. But we don't have any definitive measurement of them.