Its not really due to a speed requirement, but the curvature of spacetime. Black holes bend spacetime so much that any path sort of wraps around back to the singularity.

What do you think of a of telepathy being possible via dreams?

[deleted]

1. is the human population explosion over the last 300 years responsible for climate change?

2. is it true that if a population explosion occurs in nature, such as the rabbits in Australia, there is a natural regulation response that leads to population collapse such as a virus of starvation?

[deleted]

For the thrust part : yes, the artificial gravity created in the ship would just be the floor pushing you towards the ship's up. This is why the designs of spaceships with artificial gravity all have a rotating part usually around the axis of the ship. There is a permanent centrifugal acceleration (as long as the rotation exists) in the part that is moving. The artificial gravity would be in this moving part there are some specificities to this type of artificial gravity because of the inertia and momentum in circular motion. There is a great Tom Scott video on this subject I'll try to find it.

It's not something that's been suggested to my knowledge and geochemically it's missing some of the hallmarks. There are suggestions of isolated slab window related magmatism in the Tahoe region (e.g., Cousens et al., 2011), but not Long Valley. Long Valley is generally associated with other magmatic systems in that part of the western Greater Basin. Their exact origins are a bit enigmatic but are largely inconsistent with slab window volcanism seen elsewhere.

Yeah, inside the event horizon, no matter which direction you look, you are looking at the singularity (whatever that looks like, which no one knows). That has always tripped me out.

Physics - would a ship have to be under constant thrust to have gravity? As there's no friction in space surely a lack of thrust would just mean the momentum would carry on?

Biology - If humans were exposed to less gravity - lets say on mars and grew up in this condition, what would happen to their bones? How would they feel on a planet of different gravity? Would their skeleton be able to grow accustom to it?

Why does the microscopic singularity theory exist with the Big Bang. Isn’t it possible that the Big Bang started with a gigantic, infinitely dense chunk?

Our current understanding would technically allow something that goes faster than the speed of light to get out of the event horizon, as that exists due to the speed of light. However a lot of things will be broken in physics if such an object exists and we don't think they do.

Is it theoretically possible to live outside in the atmosphere of a gas giant if it was breathable and you had some sort of floating platform, and if so, what kind of properties would such a planet need to have?

I’m thinking wind speeds and radiation would be a problem, but I’m curious if there are any other considerations and what a plausible scenario could look like, if there is one.

IANAP, but the way I heard it explained is that a black hole bends space-time so much that a straight line curves back into itself as a circle. Thus light fails to escape not because it lacks enough speed, but because there is no straight line it can follow that exits the black hole.

A relatively simple way scientists date things is by using carbon dating. Now, this is only accurate a few hundred years either side, due to the nature of carbon dating. However, by any more than ~200 years is not really going to happen. We just have too much evidence.

The stonework has been proven to be actually pretty easy with the simple tools they built, it just took a lot of slaves to build it.

And it's unlikely, just due to the sheer amount of evidence we have, from a fossil record if you mean that much older, to built structures, or lack thereof.

Theoretically, maybe? The biggest problem with that is that you can't physically get faster than that, even theoretically

Somewhere on Reddit today, I saw a photo of some very lovely whole crinoid fossils. They feathery parts look very delicate—how did crinoids come to be buried under heavy mud and still look as beautifully 3-dimensional as they do?

In the northern hemisphere, the shortest days of the year are around the 21 of december, but the coldest month is usually february, when days are already getting longer and the sun reaching higher in the sky as it nears spring. Does this delay between amount of sunlight and amount of heat mean that there is a cumulative effect of sun radiation on the atmosphere over the span of many weeks, as opposed to it being warmed or cooled instantly by the amount of sun radiation coming from the space? Why doesn't that acummulated radiation/heat disperse through the globe, considering it's summer at the same time at the opposite hemisphere?

As a follow up, could slab window volcanism be responsible for the volcanoes in southern and eastern California such as Long Valley since it is too far south to be driven by the Cascade Subduction zone?

If QED says light travels in the path that minimizes the time of travel, shouldn't all the light from an object become part of the mirage image in situations involving mirages?

(I.e., why would there be a "real" image as well since that light takes longer to arrive at the observer.)

There are a couple of different potential outcomes, and there are examples of pretty much all of them in some places. If the ridge is roughly parallel to the subduction zone:

1. Option 1 is that the ridge doesn't actually subduct because subduction stops before the ridge gets there. Effectively the idea is that subduction is driven by the negative buoyancy of the subducted slab, which is a function of the age/temperature of the slab. The piece of lithosphere adjacent to an active ridge is pretty warm, young, and positively buoyant so it will resist subducting. Depending on the relative competition of forces what may happen is that subduction slows down as this young lithosphere approaches the ridge (resisting subduction) and then the slab rips off (i.e., it detaches) because the slab pull force overcomes the strength of the slab nearer the surface. This can effectively terminate subduction (no slab pull = no subduction). As to what happens from there, it will depend on the specific forces, but most likely the ridge might die and there will be a general reorganization. That reorganization might see a wholly different set of plate boundary kinematics or the subduction zone might "jump", keeping effectively similar broad scale kinematics but with the subduction zone in a different place. It might also jump and reverse polarity.
2. Option 2 is the ridge subducts and the slab detaches because there's nothing really connecting the other side of the ridge to the slab. The end result of this proceeds largely the same as above.

In terms of these geometries, the basic assumption was effectively option 2, but in detail, it's actually hard to get a ridge to subduct and option 1 is more favorable (e.g., Burkett & Billen, 2009). Semi-parallel ridge subduction does happen though, and for it to happen, usually some amount of complicated geometries and "3D effects" are required (e.g., Burkett & Billen, 2010).

If instead the ridge is very oblique or orthogonal to the subduction zone, the ridge will subduct and in many cases a "slab window" will open along the subducted segment of the ridge. You can picture the ridge effectively unzippering down the length of the subduction zone, kind of like this. This makes some specific predictions about what you would see in the upper plate, specifically a gap in normal arc volcanism and instead magmatism that is more indicative of direct mantle interaction with the upper plate rocks.

I know this is kinda beaten to death here but here goes...

2 ships traveling near c from opposite directions equidistant from Earth. Each would not see the other traveling near c due to relativity. From each's perspective they should arrive at Earth first as the other would appear to not be moving at all right?

[deleted]

Physics: could something escape a black hole if that object would somehow reach a speed higher than current limit(c)? Or it is a nature of a black hole that nothing can escape, no matter the speed?

[removed]

Historians and archaeologists work hard to make sure their dating methods are as accurate as possible.