svarogteuse

svarogteuse t1_je22qxr wrote

Pictures of other objects in space, say astronauts, are taken in the daylight so said foreground objects are lit. You don't see stars in the daylight on Earth (or large cities with lots of light pollution) either because they are to faint. Same thing applies to space.

The sky is black because the bright sun light is not scattered producing blue not because its dark.

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svarogteuse t1_jbaeb4f wrote

No where near the same scale as plate tectonics. On the local level tides will cause erosion but when we do modeling of tectonics with something like gplates you aren't modeling the small time scale erosionable bits (like the coastline) anyway you are modeling masses of rock. The fine details that would be effected by tidal erosion are just left to artistic interpretation once you make more detailed maps.

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svarogteuse t1_jba9uin wrote

There is a forum for this /r/worldbuilding. Many of these questions are asked there in the context you are looking for.

The short answers are:

We don't usually consider a satellite to have any influence on geography, geology or climate other than tides. A satellite and the tides are usually considered necessary for the evolution of life.

>Also, what would happen if a natural satellite suddenly appears around a planet that did not had one ?

Largely depends on the mass and distance.

>creating a new Mars-like (like red desert planet) satellite directly from the crust of the original Earth-like planet they lived on

Ripping that much mass from the planet is much more devastating than the moon itself.

>it destroys Pangea and reshapes the lands.

It reshapes the planet. Gravity isn't going to tolerate a missing chunk and gravity is going to force the planet back into round or nearly so. Massive devastation as in earthquakes beyond imagination until its settled.

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svarogteuse t1_j8sfd3o wrote

So hypothetically do we have the knowledge? Yes. Orbital mechanics and the force need to apply to each object are pretty easy math to calculate once we know their mass and current orbit.

However its not a practical exercise.

The entire mass of the asteroid belt is only 3% the mass of the moon. And some 40% of that is Ceres alone with 62% being in the largest 4 asteroids. So you need a lot more mass to make anything approaching a planet. The larger the object the a harder it is for us to move.

It also takes a lot of energy to redirect masses like that, and time for the orbits to coincide and come together in a manner thats not gong to cause catastrophic break ups sending rock where we dont want it. Yes we can minimize the collision force, but that takes more energy. We dont have the technology to manipulate hundreds of thousands of rocks and get them into a single area in any kind of reasonable time scale. Hundreds of years if not longer. Its not just the shear volume its finding a way to apply enough energy to the larger objects to change their orbits significantly in a life time.

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svarogteuse t1_j8nqj9h wrote

>so a long haired orange cat would suck at blending into a jungle, get eaten or starve to death.

Tigers would beg to differ.

Many prey animals don't see orange/red as anything different that green. Green is a hard pigment for mammals to produce, but red isn't. Foxes are red, tigers are orange, and neither seem to suck at blending in vs their selected prey.

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svarogteuse t1_j7ljxgl wrote

As of the Casablanca Conference Jan 1943 the Allies via Roosevelt publicly announced they would not accept anything other than unconditional surrender. There were several reasons for this and possible dissention over the decision, but it would have been pretty hard to back down from it afterwards.

One of the main reasons for it was to preempt a WWI situation where Germany surrenders before Germany itself gets damaged and the resultant "stabbed in the back" mentality of the German people. It was also done to keep the Soviets in the war because if the Soviets negotiated a separate peace the U.S. and U.K. would not have been able to finish defeating Germany.

>have led to a truce being called during the war before axis lost

  • Before Casablana, Hitlers death or overthrow by his own generals. * A defeat of the Soviets, like the capture of Moscow, Leningrad and the Baku oil fields and their withdraw from the war prompting the rest of the war into a stalemate and eventual peace.

>Would there have ever been any reality in which axis just decided they had conquered enough land and people and that point in time was a good time to quit?

Hitler didnt want to be at war with the U.K. Yes taking the entire Eastern portion of the Soviet Union would have been enough... for a while but eventually a new war would start. The Nazi economy was reliant on new conquests and not set up for a peace.

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svarogteuse t1_j6npt7i wrote

What you are looking for is explicitly spelled out in the Space gun article that I already linked and you couldn't find in the section Technical Issues.

>the acceleration would theoretically be more than 1,000 m/s2 (3,300 ft/s2), which is more than 100 g-forces, which is about 3 times the human tolerance to g-forces of maximum 20 to 35 g[5]

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svarogteuse t1_j6nn0xt wrote

No the g-forces wont exclude humans. A proper Orion craft has a payload section and a pusher plate. The pusher plate and the payload are separated by massive shock absorbers to minimize the forces exerted on the payload.

>Two shock absorber designs were explored. The first consisted of three donut-shaped gas-filled cushions, each one meter high, looking like a stack of tires. Six-meter high aluminum pistons rose from these absorbers. This system would limit peak G forces to 3 to 4 G's. But it would be a bumpy ride for the passengers. Therefore the second design was more complex but allowed the shock absorbers to operate in synchronization in order to further even out the G-forces. This would limit peak forces to 1.5 to 2.0 G's.

1.5 -2.0 Gs is less than the 6Gs of early rockets and the 3 of the shuttle.

$200k and radiation over an area, downwind from the fallout and environmental damage noticeable across the world. We didnt stop Orion strictly because of the treaty. If it had been viable (ie worth the environmental damage) we would have negotiated it into the treaty.

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svarogteuse t1_j6nirtb wrote

Super guns have been attempted. Space guns comes up fine on google.

What you are missing is the shock of initial launch. In a gun the projectile goes from 0 to its orbital speed virtually instantaneously. Very little other than solid objects survive the massive g forces involved. Certainly not people.

Project Orion lifted of slowly, each bomb pushing the craft (with a massive pusher plate to absorb shock for the payload) just a little higher and faster. That why it took many bombs not just one. A single bomb can launch something pretty high but that wasn't the Orion design because they wanted the payload to be less robust than a solid object.

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svarogteuse t1_j5u45an wrote

Newton's law: A body in motion stays in motion unless acted upon by on outside force.

This largely depends on where you are in space but there is always an outside force which is some body with gravity.

If you are near a significant body of some kind (moon, planet, star) the frisbee is going to be influenced by the gravity of that object. Technically its going to influenced by your own gravity but you can through it hard enough to overcome that. The frisbee is largely going to inherit your status since the energy you impart to it isn't enough to significantly change where it goes. On that large body, even an airless one its going to land maybe a long way away, but be pulled downward until it impacts because you cant toss it with enough velocity to orbit, or reach escape velocity.

If you are in orbit it will likely also remain in orbit around the same body. It retains the momentum you had plus whatever change in velocity you give it, which isn't likely enough to cause it to leave that orbit either to impact or to escape.

If you are in/near a small body like say a 1km asteroid you might be able to toss it with enough force to escape the body, but its going to go into orbit around the sun with roughly the same orbit as the body you started in/near.

If you are in deep space, lightyears from any body yes its going to go in a straight line as far as you can tell but you are likely in orbit around the center of the galaxy so it will be too. Its just going to be in a big circle one that takes 226 million years to complete.

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svarogteuse t1_j0i0jkq wrote

The early Earth has a closer, and hence larger and brighter Moon. The Moon drifts away at about 3.8cm/year. Given that the Moon itself is the second brightest object in the sky even a nearby passing star would likely be fainter than the Moon. So the brightest regular night skies would be a night with a full Moon when it was at perigee soon after formation.

Studies on the formation of the Moon also suggest the Earth may have had a ring system shortly after the collision with Theia, a ring system would also have made the sky brighter while it existed.

And of course shortly before the collision a massive Theia (Mars size) reflecting sunlight in the night sky would have been even brighter than the non yet existent Moon, but that wasn't a longer term or repeatable event.

And all this would have drowned out starlight.

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svarogteuse t1_iwpx97q wrote

Google maps said just short of 8 hours.

372 miles is much closer when you have well built roads like interstates. Even taking American state roads can add significant times to a trip. My trip to see the family is about 2:15 by interstate, yet almost 4 hours by state road that parallels and continuously crosses the interstate. I've drive both routes as many as 6 times a year for nearly three decades, the times are pretty consistent.

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svarogteuse t1_iwmpkad wrote

The famous pyramids and the Valley of the Kings yes. Pyramids were built in several eras of Egyptian history from the 3rd dynasty (2600 B.C.) to the last being built in the 18th Dynasty (1150 B.C.) which was the same era as Tutankhamun (1341-1323 BC). I don't know what era the one in question came from.

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svarogteuse t1_iwmghhf wrote

Proper English grammar on "and pyramid of an unknown queen unearthed near King Tut's tomb" in says that either both the mummies and the pyramids are near Tut's tomb or the pyramid is near his tomb but not just the mummies. Phrases like that do not refer to only the first element of a list, its either all or the last.

So no the title still doesn't make sense if the mummies are near his tomb.

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svarogteuse t1_iu46rae wrote

>I don’t think we can say yet whether it’s probable that any life is out there, or even close by.

The problem with this is its never ending. A hundred years from now with colonies on Mars someone is going to say the same thing about that little niche over there on Mars that hasn't been explored to their satisfaction.

Life on Earth has left no doubts its here. It has produced rocks in volume (limestones), its changed the atmosphere and entire chemical makeup of the surface and oceans. If life isn't thriving across the surface of a world it wont last in geologic terms. Life isn't going to hold on under some rock for any length of time, being localized like that is to fragile. And there is no evidence that anything on Mars or Titan isn't the result of normal non-life initiated chemical reactions. As much as we want it to be life isn't common.

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svarogteuse t1_iu1je2z wrote

And at this point it look quite improbable that there is anything out there, much less nearby. That could change, the numbers of planets known has gone from 9 to thousands in only half my lifetime, but even with 5,197 known exoplanets as of today we have 1 known with life.

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svarogteuse t1_iu1c1pq wrote

Thousands of years.

The laws of physics wont change. We aren't going to send probes and get back data any faster than light and in all likelihood much slower. Even at our best "hey we might be able to do this in our lifetime" we are looking at a probe taking 20-30 years to reach Alpha Centauri, then 4 more years for the data to get back. A Cent is only 4 light years away so even visiting a reasonable close star of 100 light years is a 750 year journey and another 100 to get back data.

Now couple that with the small likelihood of life (so far we have a sample of 1 in infinite), the number that will be sent to habitable but uninhabited worlds, the expanded size probes need to be to send back data from ever increasing distances, the costs and political realities of funding and it will be thousands of years before we see that data if ever.

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