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For Questions That Don't Merit Their Own Thread


Skyler4856

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11 hours ago, MaverickSawyer said:

Had a bit of a crazy idea last night while driving home from class...

We're all pretty familiar with the energetic nature of antimatter, correct? It's hard to find something with more bang per unit of mass. This, however, raises some interesting questions...

-I am familiar with the anti-hydrogen atom (one antiproton, one positron), and that would react violently with, well, anything. Does anti-deuterium have a regular neutron, or an antineutron?

-If it's an antineutron, does it also mutually annihilate when it contacts a "regular" neutron?

-If the answer to the above is "yes", then does that make antideuterium a better choice for use as a reactant in antimatter reactions, density wise?

Under certain circumstances, I am told, antiprotons and neutrons can annihilate. So you would probably have a Bad Time™ trying to put the one and the other in the same nucleus.

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24 minutes ago, 0111narwhalz said:

Under certain circumstances, I am told, antiprotons and neutrons can annihilate. So you would probably have a Bad Time™ trying to put the one and the other in the same nucleus.

Okay, that's a fair point... but that's also mixing matter and antimatter. A quick search has revealed that there is apparently an antineutron, but I'm not sure what reaction they have with regular neutrons...

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Just now, MaverickSawyer said:

Okay, that's a fair point... but that's also mixing matter and antimatter. A quick search has revealed that there is apparently an antineutron, but I'm not sure what reaction they have with regular neutrons...

Antineutron and neutron would annihilate as readily as antiproton and proton.

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1 hour ago, 0111narwhalz said:

Antineutron and neutron would annihilate as readily as antiproton and proton.

Ah. So, reacting deuterium and antideuterium would be possible. Sweet.

So, side discussion time. I remember reading in one of John Ringo's books about trapping antimatter ions inside of a C60 buckyball. They'd never touch the buckyball because of the repulsion from the electrons in the buckyball creating a stable spot in the center of the ball. The trick was actually cracking open the buckyball at the right time to release the antimatter. In the story, it's used to make a cluster nuke that fit inside of an artillery shell. I'm curious about it being used as a high-yield filler material for a small artillery shell, say, 57mm or 75mm, to give it the punch of a 1-ton bomb. I've done the math, and it would take 46.55 nanograms of antimatter to actually equal that energy release. I'm... not entirely sure that the correlation is accurate, though, as there's not really much more than theoretical research into the subject. shifty.gif

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1 hour ago, MaverickSawyer said:

Ah. So, reacting deuterium and antideuterium would be possible. Sweet.

So, side discussion time. I remember reading in one of John Ringo's books about trapping antimatter ions inside of a C60 buckyball. They'd never touch the buckyball because of the repulsion from the electrons in the buckyball creating a stable spot in the center of the ball. The trick was actually cracking open the buckyball at the right time to release the antimatter. In the story, it's used to make a cluster nuke that fit inside of an artillery shell. I'm curious about it being used as a high-yield filler material for a small artillery shell, say, 57mm or 75mm, to give it the punch of a 1-ton bomb. I've done the math, and it would take 46.55 nanograms of antimatter to actually equal that energy release. I'm... not entirely sure that the correlation is accurate, though, as there's not really much more than theoretical research into the subject. shifty.gif

Well, if antimatter and matter meet, kaboom. End of story. So antimatter can still go kaboom with electrons, through quantumn tunneling.

This is a fairly stupid question, so it does not deserve its own thread.

What language do deaf people hear when they talk in their hearts? Or do they see sign language?

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An antiBH would be indistinguishable from a BH.

A antiBH+BH merger would be indistinguishable from a BH+BH merger.

No energy from the annihilation can escape the event horizon.

Behind an event horizon, energy and mass is indistinguishable. A BH can be created (hypothetically) from EM radiation alone.

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2 hours ago, Xd the great said:

What language do deaf people hear when they talk in their hearts? Or do they see sign language?

It is an interesting question. But one can ask these people and they may describe their thoughts.

 

Is a language even necessary for an internal dialogue ? Or is there a complexity threshold, maybe individually different, that sets a limit to these reflections ? Does complexity of thoughts develop parallel to language ?

For basic thoughts like "hungry", "want to play", "angry", ... a language is not necessary. Many species of higher animals do this.

Trained animals can make basic decisions, like choose a way, wait at a red traffic sign, return home from a task. Do they have an internal dialogue for this ? Is it more than running "firmware" ? I heavily doubt it think so.

Edited by Green Baron
Nonsense corrected. Internal dialogue went wrong way :-)
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1 hour ago, RealKerbal3x said:

OK, I have a question which I've been wondering about for a while:

Say a comet entered Earth's atmosphere. What would happen? Would it melt or something, because it's mostly ice?

No, not much. It wouldnt have time to melt significantly and would act like a solid body of low mechanical strength.

I mean yes, some outer layers would be vaporised, but that is the same for rocky bodies too, just with an icy body a bit more.

Generally, when a large body enters the atmosphere it goes something like this:

 

Due to extremely high speeds and drag, entering the atmosphere is like hitting a brick wall, but continuously.

This puts extreme stress on the body.

Its slowing down all the time, but due to very high initial speed (10-70km/s) it doesnt slow down all that much.

As the atmosphere thickens with decreasing altitude, drag forces ramp up very quickly.

At some point, the body will break/crack/shatter.

This vastly increases drag as parts split apart (by vastly increasing aerodynamic cross-section, especially if it breaks into a great many pieces) dumping a great deal of kinetic energy into the air as heat.

This can happen so rapidly and completely, that it resembles an explosion, often of multi-megaton proportion.

 

All of this can be observed in all that great footage of the Chelyabinsk meteor.

A comet has much less structural strength than a rocky body, so those phases will occur at higher altitudes.

 

The larger the body and the stronger the body, the lower down into the atmosphere it will penetrate before exploding, and bodies of sufficient size/strength can impact the surface.

Small bodies have much better strength/size/drag force ratio and can slow down to terminal velocity (so-called "dark flight" as it is now moving too slowly to glow or leave a trail) at altitude before drag forces get high enough to destroy it, making it to the ground intact, this will be slow enough that there will be no significant explosive effects at impact, like a rock dropped from a skyscraper.

 

 

Newtons approximation for impact depth (https://en.wikipedia.org/wiki/Impact_depth) can be used to estimate depth of penetration into the atmosphere. Just knowing the size and density of the body can give you a decent idea. This approximation is very useful for any impact where kinetic energy >>> chemical bond energy (Im not sure of the exact numbers, but this starts around Mach 3-5)

Penetrating our atmosphere to the ground at very high speed has been compared to piercing approx 6 feet of steel (if that helps to understand why some bodies explode) based on depth and density, per the above.

Edited by p1t1o
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11 hours ago, p1t1o said:

FunFact: A lone, free neutron will spit out an electron leaving behind a proton, with a half-life of about ten minutes.

Is it ten minutes now? I thought it was fifteen.

9 hours ago, p1t1o said:

An antiBH would be indistinguishable from a BH.

A antiBH+BH merger would be indistinguishable from a BH+BH merger.

No energy from the annihilation can escape the event horizon.

Behind an event horizon, energy and mass is indistinguishable. A BH can be created (hypothetically) from EM radiation alone.

Interestingly, this means that black holes do not conserve baryon number. Hawking radiation is half-and-half matter and antimatter, even though whatever goes into the hole is probably mostly matter.

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On 11/8/2018 at 1:28 AM, p1t1o said:

Im going to unashamedly fanboy on something.

It sounds ike you would get a kick out of playing "Command: Modern Air/Naval Combat" ["CMANO"].

[...]

I've seen this before, but the price tag has turned me away. Would someone who liked Aurora 4X like this?

I don't know if that's me, since I haven't yet put in the time to learn it.

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8 hours ago, Mad Rocket Scientist said:

I've seen this before, but the price tag has turned me away. Would someone who liked Aurora 4X like this?

I don't know if that's me, since I haven't yet put in the time to learn it.

Something similar, but older, is Fleet Command.   I just picked it up off Steam during the summer sale for a few bucks.   Worth it. 

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1 hour ago, kerbiloid said:

That's what makes me still thinking that a BH+anti-BH would be a cool thing.

There is no such thing as an anti-black hole. Baryon number information is lost. A black hole made from baryonic matter is indistinguishable from one made of antibaryonic matter and from one made of non-baryonic mass-energy like photons.

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7 minutes ago, 0111narwhalz said:

There is no such thing as an anti-black hole. Baryon number information is lost. A black hole made from baryonic matter is indistinguishable from one made of antibaryonic matter and from one made of non-baryonic mass-energy like photons.

Until they discover a proton decay (it's prevented by the baryon number conservation), the hope stays alive.

(I mean, BH is still a mathematical model describing some observed phenomena, so its properties depend on the theoretical assumptions)

Edited by kerbiloid
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1 minute ago, kerbiloid said:

Until they discover a proton decay (it's prevented by the baryon number conservation), the hope stays alive.

Assume baryon number is conserved during black hole formation and interactions.
When a positive baryon black hole and a negative baryon black hole collide, they will annihilate. The energy released, however, is still densely packed enough that it is a black hole. Now you have one black hole with mass-energy equal to the sum of the mass-energies of the original two. Which is exactly the same as if you combined a positive baryon black hole and a negative baryon black hole.

The only information preserved by black holes, as far as I know, is mass-energy, momenta, and charge. Everything else is either lost or entrapped in a way which equates to being lost.

This has made my lack of understanding of Hawking radiation rather clear, though. Maybe a real physicist could speak on this.

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21 hours ago, 0111narwhalz said:

Is it ten minutes now? I thought it was fifteen.

Average lifetime is 15minutes, half life is 10mins.

 

20 hours ago, Mad Rocket Scientist said:

I've seen this before, but the price tag has turned me away. Would someone who liked Aurora 4X like this?

True, but the price tag reflects the hi-fidelity nature IMO, its a bit more serious than a "game". I was nervous about buying it too but got 60hours out of it in the first week!

I believe it is the successor to the "Harpoon" series of sims.

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On 11/9/2018 at 4:12 PM, Xd the great said:

What language do deaf people hear when they talk in their hearts? Or do they see sign language?

I guess they don't have such hearing memory thing. Quite possibly it'd be a visual one instead (they can read normal letters as well you know).

Unless the person in question has had a memory of sound (ie. people who go deaf after being able to talk or understand conversation).

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Probably the deaf people with dyslexia are the key to the understanding of the inner dialog and the thinking.

I believe the human thinking is the inner dialog, and that's the threshold separating humans from other animals.

Edited by kerbiloid
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I got some weird thinking lately, so I think I'm gonna ask something. If for some reason (don't ask how) every military vehicles (from the smallest humvee to the strategic bomber to the largest battleship) only needs 1 crew, and it performs at 100% efficiency using only a single crew (aka no delayed order, clarification of status, perfect situational awareness, or any problems in multi-crewed vehicle), how the warfare will change? Less casualties means "safer" war? 

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