Topic: Ask me anything about Earth Sciences - tips appreciated (Read 2254 times)

Interesting concept, while it's probably cheaper to just install more cameras on the streets. BUT.. as a civil rights activist I'd rather see more well-trained policemen in the streets instead of ubiquitous surveillance. The policemen could actually stop crime instead of just having a nice movie of it. Of course it leads to more criminals caught, but it can't prevent anything. Okay, this is an entirely different topic..^^

OK, I'm sorry if I insulted you. There's too many services popping up that say "sign up here for paid services" and many of those are a little on the questionable side, so I've become very wary of any such service being offered to me.

Tip received, thank you!

First of all thank you for your reply.

I googled a bit and looks like we had to have an enormous lens (about half the size of earth) to see it, but the maths were done to many many light years away.

Doing this on the moon we could see aprox 2s in the past, two moons away 4s and so on

Maybe nasa could launch a gigantic mirror into space, this could help solving some street crimes since you have a "past whole world camera".

Regarding bitip.io, thank you for your feedback but dont call it a scam since im behind it .

Tipped you anyway.
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I'm not an astronomer, but the basics of this should be easy: you're probably referring to the limited speed of light, so when we're looking out into the universe, we also look back into the past. So.. yes, in theory, if we could look at a mirror-like surface far away with a telescope, we would see the Earth of the past. But..
a) I don't think mirror-like objects, natural or otherwise, have been found far enough away (or at all).
b) If they were far enough away for us to look significantly into the past, they would need to be incredibly huge to reflect enough light from tiny Earth for our telescope to see. It is very hard to look at even a big planet directly when it's orbiting a faraway star, imagine how hard it would be to see an asteroid-sized mirror. If you only wanted to see Earth as it was 100 years ago, you would already need a mirror that's 50 lightyears away. Finding such a mirror should be virtually impossible. But let's assume we found one. Through the mirror, Earth would appear to be 100 lightyears away. I don't think a telescope exists that would sufficiently resolve anything on our planet at that distance. If you even saw a tiny blue dot that would be Earth, you'd be extremely lucky.


Huh. A service that subtracts fees from a tip purely for forwarding it? That's at best useless and at worst a scam. I'm not going to sign up for that. If you think my reply is worth a tip, please just use Bitcoin.. otherwise I'm sure I'll survive without it.

wow, that sounds cool, but... how far into the past would we actually be able to see?  I think it would depend on the material as well as the distance away from Earth, correct (light travel)?

Hi,
Are there any "mirrored" like asteroids/material out there that reflect light just like in a mirror?

If the above is true, can we use a giant telescope, look back at earth and see its past?

Ill tip you using bitip.io

Thanks

I found an estimation for the total volume of water frozen as ice on Earth excluding sea ice: about 12,7*10¹⁵m³ (equating to 12,7 million gigatons, calculated from these findings).

Yes, movement is caused by this. At the end of the last ice age Scandinavia was buried under several thousand meters of ice. The weight caused the Earth's crust to sink deeper into the mantle that behaves plastically on geological timescales. After the ice melted, the land started "popping up" like a swimming mattress on water when you get off it. Because of the huge masses involved, that "popping up" process takes a very long time, in fact Scandinavia is still rising today at a rate of about one centimeter per year. Like the two sides of a scale, the coast of northern Germany is sinking at the same time, but only at about one centimeter per decade. You can see nice pictures explaining the process at http://de.wikipedia.org/wiki/Postglaziale_Landhebung (German, the pics are missing from the English page).

Earthquakes? I don't think so. This might be the case if fault lines / subduction zones would experience a pressure release due to melting ice, but as far as I know there are no such zones near any large ice caps. In theory, yes, of course - when large amounts of mass move, stress on the crust changes, and in unlucky cases that might destabilise fault lines, causing them to move (that would be the cause of an earthquake). But I'd say that's very unlikely. The masses of glaciers in geologically active mountain ranges are too small to really make a difference (the Earth has a high inertia), and those glaciers and ice caps that are large enough to cause movement (see above) are all in geologically inactive areas (Antarctica and Greenland, mostly).


I searched for scientific publications, but couldn't find anything. I would also say that these masses are too small to cause any significant movement. They do change the isotopic composition of atmosphere and oceans, though, but that's only interesting because you can measure it, it doesn't have any impact on life, even less on tectonics. Until now, about 300 gigatons of carbon (from all fossil sources combined) have been burned and about 5000 gigatons are thought to exist in total (source). Compare to the amount of ice mentioned above, and you'll see that this mass can be disregarded when talking about tectonic balances.
Of course local mishaps can happen, when you extract fluids from the pores of a rock. Tiny earthquakes associated with oil and gas exploration are known to happen, and collapsing coal mines can also destroy buildings above ground.

I have a Question:
It melts a lot of ice from glaciers.
Can you calculate the weight?
The weight of all glaciers spread new to the earth's surface.
In some places pressure is released and in other places of the earth pressure is increased.
Can be generated by the displacement of the weight, a new movement of the continental plates?
1. Can produce an acceleration of earthquakes?

Added to this is the total amount of coal and oil in the last 200 years. This total weight is partially in air and partially in the sea. Also causes a certain pressure redistribution on the tectonic plates.
2. Is there geological investigations that take into account the weight distribution?

It's funny that of all movies you ask about "The Core". It's known as the scientifically worst movie of all time.

But let's answer your question properly anyway: To drill down to the Earth's core, the guys from the movie built a kind of "sub-earth ship" from a metal that can withstand extreme pressures and protect everyone inside from the intense heat of the Earth's innards. The problem is that such a material is not known to exist, that's why they even call it "unobtainium" in the movie - it can't be obtained.
People need air, so we'd need to build something that encloses air at not much more than 2 atmospheres of pressure, because else you'll die from diver's paralysis, and it needs to stay in shape even with an excess of 250000 atmospheres on its outside.
Okay, let's assume we could build such a vehicle. The Earth is, for the most part, solid (due to the aforementioned pressure, rock doesn't melt even when it gets extremely hot), so we'll need to drill our way through. In the movie they use lasers for that - when you put enough heat in, you'll be able to melt rock even when it's pressurized. The amount of energy required would however be hard to produce in a mobile contraption, plus I'm not even sure if lasers powerful enough have been built. Using a mechanical drill would not work. The heat would destroy it (it becomes dull and gets stuck), this is why all scientific deep drilling projects have failed at 7 to 12,2 kilometers deep. The center of the Earth is more than 6000km down.

What's more: down there you won't even find anything especially rare! The core is made from iron and nickel. The mantle is made from olivine. Olivine is indeed rarely found above ground (usually only when volcanoes barf up some mantle pieces), but due to a relatively rare geological process called the formation of an ophiolite there are actually some huge deposits of olivine that we can just easily dig up, for example in Oman.
On the other hand, there might be diamonds. But we still have no idea how exactly they form and where to look for them. They do come from somewhere down there in the mantle. In the movie they showed huge diamonds the size of city blocks. While they aren't technically impossible (there are even entire stars theorized to be made up of diamond!), I can't imagine how that much carbon (which is what diamonds are) should get into one place at the same time.

If you have any more questions, let me know.

Is that possible that human can travel into the centre of earth ?
Like this movie The Core

If this can happen,
I Imagine that I can collect a huge amount of rare material on earth and bring back to surface to sell it on auction 

Hi everyone. I am a geologist. I have studied Earth Sciences (geology, soil science, mineralogy and the like) for five years and am now working as Engineering Geologist for a civil engineering company.
If there's anything you always wanted to know about rocks, mountains, volcanoes, earthquakes, soil, minerals.. Go ahead and ask me.
Found a weird rock and wonder what it is? Post a pic (preferrably after cracking it open or at least cleaning it), if possible share where you found it.
If you're content with my reply, I'd be content with a BTC tip at your discretion.

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