A relative ran a trucking operation for a few years and now says he’s significantly more wary of any trucks on the road.
At the same time, he says that it’s a miserable business because you’re constantly getting sued (at a level markedly higher than the admittedly poor driver performance)
It’s 4 years old; I don’t know if this JWST finding changes anything. I do know we have finally found some (one?) intermediate-mass black holes in the interim, but I don’t know if that changes it either.
The possibility it leaves open for “Planck relics” is interestingly exotic
Yeah the mass ranges these primordial black holes would need to be mean that it cannot possibly be those little red dots. While the early universe magnifies things, the mass of those little red dots still needs to be close to a small galaxy worth of mass. Tens to hundreds of thousands of star masses absolute minimum. And that's just far, far, incredibly far to high.
I wonder if my slop radar is oversensitive to em dashes and the construction: “it’s not just about foo, it’s about bar” because this post seems human written but the indicators are flashing
There are also many non sequiturs. The sentences only read fine if you don't think about what the author might be trying to say. I also think that this reads like the "author" was an LLM and, therefore, isn't trying to say anything.
À propos of nothing – I'm human and I like using special characters, including en dashes. ;)
I think you have it backwards. From the POV of someone near the Event Horizon, other space speeds up. Galaxies begin to spin at noticeable speeds.... But the black holes would appear to be approaching each other at "normal" speeds.
I suppose nothing but gravitational waves can escape the even horizon — or, rather, gravitational waves are born near / around it, because the black holes bend the space enormously.
OTOH whatever else may be outside the black holes near the merger and count towards their mass for astronomical purposes, such as accretion discs, should be much lighter weight than what's inside the event horizon.
Gravity does action at a distance. That's its thing.
The reason these waves are not generated from inside the black hole is that, to us, time stops there. For example these black hole mergers aren't actually merging, they are getting closer, and then they time dilate out of existence.
> Gravity does action at a distance. That's its thing.
Why does it need to travel in waves at the speed of light? If one mass moves, a distant mass is unaffected until the information reaches it. That's the opposite of action at a distance.
Your question is confusing. Action at a distance does not imply going faster than light, it means there is some sort of field connecting the two things.
Action at a distance means there is nothing connecting the two things. That's the "distance" part of action at a distance. Modern physics rejects the concept, saying instead that forces are carried by particles from a source to a destination, and the effect of the force is the result of local [opposite of "distant"] interaction with the particles carrying the force.
Compare wikipedia:
> Under our modern understanding, the four fundamental interactions (gravity, electromagnetism, the strong interaction and the weak interaction) in all of physics are not described by action at a distance.
> This is an alternative to the concept of instantaneous, or "non-local" action at a distance.
> The idea is that for a cause at one point to have an effect at another point, something in the space between those points must mediate the action. To exert an influence, something, such as a wave or particle, must travel through the space between the two points, carrying the influence.
You'll note that "action at a distance" does in fact specifically mean that information travels faster than light!
But this understanding would seem to be incompatible with the idea that the mass inside a black hole can interact gravitationally with anything outside the black hole.
I'm not seeing where any of this requires faster than light travel.
But here's something that might help: We'll use gravity for our example, and I'll be non-technical for ease of typing.
The gravitational force that leaves an object is constant and continuous, it never stops, and it never starts. It exists from before the beginning of time, and it will never stop. The only thing you can do with that force is move it. This is because it's impossible to destroy energy. If you move the mass (the energy actually if you want to be exact) then you have changed the location (but not the strength) of the gravitational force, and that CHANGE travels at the speed of light.
So the gravitational attraction of my hand has, right now, already reached the end of universe, out to infinity. When I move my hand, it sends a tiny gravitational wave that travels at the speed of light, indicating a change in where the force is.
So the gravity inside the black hole has already reached the end of the universe, when that matter starts to clump, a change in the location of the gravity is sent out saying "this gravity is now moving over here".
This is why it feels like it's moving faster than light - it's not, it's already there at the end of the universe.
This is also why the orbit of Mercury is different in relativity, the sun pulls on Mercury where it WAS in the orbit, not where it is (which would require faster than light travel). In Newtonian gravity it's instant (i.e. faster than light).
What part of your comment says something about gravity that is different from what I've already said about it?
How do you look at a quote stating explicitly that action at a distance is, by definition, instantaneous, and say "I'm not seeing where any of this requires faster than light travel"?
> So the gravitational attraction of my hand has, right now, already reached the end of universe, out to infinity.
And how has the gravitational attraction of your hand gone more than 200 light years from Earth?
> How do you look at a quote stating explicitly that action at a distance is, by definition, instantaneous,
I clicked to the Wikipedia article, I did not see this quote.
> And how has the gravitational attraction of your hand gone more than 200 light years from Earth?
My hand is made of mass collected on earth. Those atoms have been rearranged into the shape of my hand, but their gravity has existed since the beginning of the universe, just in difference shapes.
> I clicked to the Wikipedia article, I did not see this quote.
No need to go to that much effort; I pulled that quote in my comment.
>> This is an alternative to the concept of instantaneous, or "non-local" action at a distance.
> My hand is made of mass collected on earth. Those atoms have been rearranged into the shape of my hand, but their gravity has existed since the beginning of the universe, just in difference shapes.
So, as you acknowledge, zero information about your hand has gone much distance from the earth. Someone 1000 light years away who could resolve gravitational information into an image with perfect detail wouldn't be able to perceive your hand, you, or anything related.
>> This is an alternative to the concept of instantaneous, or "non-local" action at a distance.
Notice the word "alternative", instantaneous action at a distance is a concept that was suggested at one point in the development of physics and discarded once relativity was figured out. Action at a distance these days is always at the speed of light.
> So, as you acknowledge, zero information about your hand has gone much distance from the earth.
No, not zero. All the gravity from the atoms in my hand is already out there.
> Someone 1000 light years away who could resolve gravitational information into an image with perfect detail wouldn't be able to perceive your hand, you, or anything related.
Correct, they would see the location of the atoms that make up my hand today, as those atoms looked 1000 years ago. (Probably in plants, and water.)
But remember: They do see the gravity from those atoms!!! Meaning the gravitational force my hand exerts, already exists 1000 years away, just in a different shape.
> Because gravity isn't a non-local force.
Are you saying gravity is a local force? Because that's not true.
the backstroke rule change was circa 1988. They changed butterfly (and I suppose freestyle) after the 96 Olympics when Dennis Pankratov won both butterflies with this technique. Interestingly, the backstroke innovator who probably triggered the earlier rule change got beat in the final by someone not using it (Berkhoff in 88, silver)
The latest rule change in this area was banning dolphin kicks on your back on the breast-to-free exchange in IM. Ryan Lochte triggered that one.
"That all changed in 1998, when FINA, the world governing body of competitive swimming, ruled that swimmers performing the backstroke had to surface after 15 meters."
... which aligns with my recollection of the '96 Olympics and being gobsmacked at how long the swimmers were holding their breath.
They would swim the entire 50m underwater, if given the chance. I've seen them do so in practice, very lazy-looking dolphin kicks, but still faster than most swimmers on the surface.
The benefit of AI as a feature in calorie counting apps is great. But you have to track stuff manually for a while to realize the benefit. Specifically: using AI for restaurant meals is a convenient starting point, from which you use your hard-won feel for weight & caloric density of things to tweak the first pass to something closer to the mark.
As of now I would not at all trust a fully AI calorie counting app
This is exactly correct. I find AI in my food tracking app (FoodNoms) to be really useful, but no, you cannot rely on it on its own. You always have to tweak the results to match what you feel in your gut (no pun intended) the counts should be. Interestingly, very similar situation to using AI for code: you shouldn't just blindly trust what it puts out, but if you know what you're doing, it can save you a lot of time.
100%. You should not trust photo based calorie tracking and should only use it when there is no other realistic choice (e.g. eating out).
You especially should not trust an app that does not do any research on the accuracy of it's algorithm or claims to be "consistently accurate" as many of them do currently. The truth is these algorithms have the potential to be accurate when values are averaged out over the long term, but dish to dish they will have occasionally wildly inaccurate results.
> You especially should not trust an app that does not do any research on the accuracy of it's algorithm or claims to be "consistently accurate" as many of them do currently.
Your website says:
> SnapCalorie is the first app where you can take a picture of any meal and get an accurate calorie count and nutrition in seconds.
So which is it? Can you get an accurate calorie count of a meal from a picture or not?
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