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Serious Scientific Answers to Absurd Hypothetical questions


DAL59

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3 minutes ago, kerbiloid said:

Not to start politics, but I believe that Fulda gap story irl would finish with a general truce (but ruined and rebuilt again Germany).

Too many factors to make a reliable prediction but that was the hope...

...but as we all [should] know, war doesnt always work out the way you think. Just off the top of my head, the weather could completely change the outcome either way in that scenario.

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13 hours ago, Green Baron said:
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The Romans would of course use their cloaking device.

... err ... no ... wrong movie. Those were the Romulans ... nevermind.

Btw., the Romulan Roman Empire finally (phew) ended 1453 ;-) Renaissance is dawning ...

Well you have the holy roman empire.

Not holy, roman or an empire as the joke went. Kind like the democratic people republic meme

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Problems with deep drilling, besides the near impossibility to get the heat away, is pressure and keeping the borer from veering off. Kind of the opposite we want our contraptions to point :-) Boring deeper than a few km is really hard. The ocean crust has only ~8-10 km but temp gradient is high and one can as well dive to the middle ocean ridges or visit one of the ophiolites and have a direct look.

Continental crust is something different, besides mechanical stress on a km-long borer, changing sedimentary and metamorphic stuff, the time needed, pressure and temp., the figures 12.000psi and 1200°C are a cool day in thin air once you're in the middle of the crust (let's say 30km). In some places where it is really thick and temp. gradient low it was tried before, but i think the deepest hole has 12km or so ?

Besides that, i'd expect other more dense materials than any steel alloy to be much more suited for such an enterprise. Requirements for a borer are rather different from that for a rocket ;-)

Edited by Green Baron
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7 minutes ago, Green Baron said:

In some places where it is really thick and temp. gradient low it was tried before, but i think the deepest hole has 12km or so ?

The Kola hole stopped when it hit 180 °C in the Baltic Shield, approximately a third of the way to the mantle. A different project in Bavaria hit 260 °C merely at 9 km.

Edited by DDE
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32 minutes ago, DDE said:

The Kola hole stopped when it hit 180 °C in the Baltic Shield, approximately a third of the way to the mantle. A different project in Bavaria hit 260 °C merely at 9 km.

Yep, conditions can be very different locally, much more than that actually.

There are other sources than a drill core, cheaper to obtain, though more indirect.

Edited by Green Baron
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Funny.
Humans more or less see how to reach the stars and even can do this if really want.
But I still haven't heard about any plausible idea how to reach the core just several thousand kilometers below.

They suggested to melt the way down with a big radioactive drop, but nothing about a working probe.

Edited by kerbiloid
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Conditions are really hard down below, no material can stand this without being phase transformed.

1 hour ago, kerbiloid said:

They suggested to melt the way down with a big radioactive drop, but nothing about a working probe.

But what for ? There'll be a radioactive hole then and a warning sign (hopefully). Usually, such a project would aim to obtain some information, a drill core, temp./pressure readings, elemental phase transitions, exact position of boundary layers like the moho, etc. ... But we can get this information otherwise, just not with the accuracy of measured hole. What hasn't been replicated yet in a laboratory are the p/t conditions in the lower mantle and core. A pulsed machine can achieve this, but nothing that keeps the conditions long enough for minerals to form. So we actually do not know exactly what the material in the core is like.

Yep, it is easier to send a probe to the outer solar system than to obtain a sample from the earth's mantle, if not tectonic processes lift it up high enough.

Edited by Green Baron
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8 hours ago, kerbiloid said:

Funny.
Humans more or less see how to reach the stars and even can do this if really want.
But I still haven't heard about any plausible idea how to reach the core just several thousand kilometers below.

They suggested to melt the way down with a big radioactive drop, but nothing about a working probe.

 

I think it might be arguable that it should not be surprising that the core is a harder place to reach.

Is there more mass between a person on the Earth's surface and the core? Or between them and a nearish star?

 

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12 hours ago, p1t1o said:

Is there more mass between a person on the Earth's surface and the core? Or between them and a nearish star?

+1
The first thing which came into my head when I had realized that.

1. Wiki says, Alpha Centauri is inside "G-Cloud"...
https://en.wikipedia.org/wiki/Alpha_Centauri#View_from_this_system

2. ... which is inside a "Local Interstellar Cloud" (LIC), as well as we.
https://en.wikipedia.org/wiki/G-Cloud
Although it's not clear if we are inside the G-Cloud, too., but both of us are definitely inside LIC, and G anyway occupies almost everything between us, we are right near it's wall.
220px-The_Local_Interstellar_Cloud_and_n

3 And LIC is 30 ly wide.
We have enetered it 40..150 ky ago (look! when the humans became clever!) and will leave it 10..20 ky later.
220px-Local_Interstellar_Clouds_with_mot

And it's hot. As hot as Sun, 7000 K. We live in oven,

Quote

The cloud has a temperature of about 7,000 K (6,730 °C; 12,140 °F),[4] about the same temperature as the surface of the Sun. However, its specific heat capacity is very low because it is not very dense, with 0.3 atoms per cubic centimetre (4.9/cu in). This is less dense than the average for the interstellar medium in the Milky Way (0.5/cm3 or 8.2/cu in), though six times denser than the gas in the hot, low-density Local Bubble (0.05/cm3 or 0.82/cu in) which surrounds the local cloud.[3][5] In comparison, Earth's atmosphere at the edge of space has around 1.2×1013 molecules per cubic centimeter, dropping to around 50 million (5.0×107) at 450 km (280 mi).[6]

So, we can take 0.3 atoms (probably, H) per cm3. = 3*105 at./m3 = 3*105 * 1*10-3 / 6.022*1023 ~= 5*10-22 kg/m3.

density * distance:

Earth ~= 3000 km * 3000 kg/m3 = 3*106 * 3000 ~= 1*1010 kg/m2.

To aCen ~= 4.3 * 9.5*1015 * 5*10-22 ~=2*10-5 kg/m2.

So, it's 5*1014 times more matter between us and the Earth core than between us and closest stars.

A funny thing: the Sun surface, the Earth core, the gas cloud around us are ~6500..7000 K hot.
And we are between them and so cool.

Upd.
I haven't counted the gas inside the Solar system itself, so maybe not 5*1014 times, but just 1014.

Edited by kerbiloid
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1 hour ago, kerbiloid said:

+1
The first thing which came into my head when I had realized that.

1. Wiki says, Alpha Centauri is inside "G-Cloud"...
https://en.wikipedia.org/wiki/Alpha_Centauri#View_from_this_system

2. ... which is inside a "Local Interstellar Cloud" (LIC), as well as we.
https://en.wikipedia.org/wiki/G-Cloud
Although it's not clear if we are inside the G-Cloud, too., but both of us are definitely inside LIC, and G anyway occupies almost everything between us, we are right near it's wall.

Amusingly, the two clouds are inside a low-density Local Bubble, so the LIC is below average Milky Way density.

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It is actually even worse, earth's crustal density is ~2.7 (continental) to ~3.0 (oceanic), mantle density increasing to ~5.8 with depth. Then a juicy discontinuity at the core/mantle boundary to ~10, increasing to just below 13 in the inner core. Since the mantle makes by far for the most volume, it is safe to assume a medium density of 4 or even 4.5 for the calculation.

Edited by Green Baron
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  • 3 weeks later...
1 hour ago, Xd the great said:

What if we are an experiment of an alien race to understand the development of life forms?

It’s the same epitome of solipsism as the Simulation Theory, where the absense of evodemce is justified by raising the bar for the other side’s evidence-hiding ability.

The two are ultimate conspiracy theories.

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