Recent comments in /f/askscience

noirxgrace t1_jdu9ilh wrote

Reply to comment by wazoheat in Around 550 million years ago the earth's magnetic field almost collapsed, but then strengthened a few million years later. Scientists say this may have been due to the formation of the inner core. But why exactly would that cause the magnetic field to get stronger? by somethingX

I remember reading about the same. Since lava's temperature is well above above the Curie temperature of magnetite(800^(o)C), and it cools down, the orientation of the magnetite particles are all aligned and proportional to the ambient magnetic field, which makes it ferromagnetic.

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mfb- t1_jdu8hgd wrote

Reply to comment by the_fungible_man in Can you entangle more than two particles? Can entanglement be produced on a macroscopic scale to observe new physical interactions? by and-no-and-then

The state itself should be easy to understand after a course on quantum mechanics, so hopefully for most with a BSc in physics. The state is a superposition of these two options "all particles are in state 1" and "all particles are in state 0" (for some systems that have these two options for each particle). It's pretty similar to the typical example of two entangled particles where you have one particle in one state and the other in the other, or both in the same state. Just with a third particle.

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TrumpetOfDeath t1_jdu888e wrote

Reply to comment by zanderkerbal in Around 550 million years ago the earth's magnetic field almost collapsed, but then strengthened a few million years later. Scientists say this may have been due to the formation of the inner core. But why exactly would that cause the magnetic field to get stronger? by somethingX

I’ve heard this theory before, but there’s no real evidence to support it besides it being a coincidence.

As mentioned elsewhere, life was aquatic back then and water is a pretty good radiation shield. Even most planktonic algae are mixed throughout the surface layer, which can be hundreds of meters deep, they don’t float at the surface for long

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the_fungible_man t1_jdu7skt wrote

Reply to comment by mfb- in Can you entangle more than two particles? Can entanglement be produced on a macroscopic scale to observe new physical interactions? by and-no-and-then

I read the article you linked, and achieved 0% comprehension, which made me wonder, how esoteric is the information it presented? Pretty basic for physics post-grad students? Or only those with advanced degrees specifically in more narrow physics specialties?

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itssallgoodman t1_jdu6k70 wrote

Reply to Why does mild compression lead to paresthesia but not paralysis? by Hola3008

It’s my understanding it’s due to the anatomy of a peripheral nerve. To keep this simple, the anatomy of sensory v motor fibers are akin to a coaxial cable. The sensory fibers are the outside of the nerve(insulative portion of the cable) and the motor fibers are the inside(copper wire).

Thus when compressing the nerve the outer layers are effected first and the inner fibers require more compression and time to be effected compared to the outer. This leads to sensory deficits superseding motor deficits.

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