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If the Earth were revolving around the Sun much faster than it does, let's say 100 or 1000 times faster or whatever big-enough multiple of its actual speed, would we feel it? What sensation would we feel? How could I estimate how big the revolution speed would be for us to feel it? Would it be possible to speed up the Earth motion around the Sun? How? What basic physics concepts can be used to explain what would happen?

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You don't feel velocity, only changes in velocity. – ja72 Nov 26 '13 at 15:49

Well, it depends... If you just made the sun much heavier, so the earth would have to move faster in it's orbit, you wouldn't feel any different. It's just that the year would be shorter and the tides higher.

If you just put a rocket behind the earth and somehow put it on rails so it couldn't go to a different orbit, then you'd feel it. You'd be heavier in the daytime and lighter at night. If it was faster enough, you'd fly off into space at night, along with the air, the ocean, your room, a few new volcanoes, and everything else :)

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The acceleration needed to maintain circular motion is $v^2/r$, for $v$ the velocity of the body and $r$ the radius of the circular orbit. Earth's orbit isn't exactly circular, but this is good enough for napkin math. Clearly, increasing the velocity of the orbit increases the acceleration needed, but if the Earth is being accelerated this way, we trust that we'll be accelerated this way, too. That's how gravity works. Because of this, you would never "feel" like you're being pushed into or yanked off the surface of the Earth because of Earth's rotational velocity about the sun. In essence, you are orbiting the sun as much as the Earth is, so the sun's influence on the Earth is also its influence on you.

It's not possible to speed up the Earth's orbit in such a drastic way, and never mind how a planet's orbital radius must change based on its velocity for the orbit to be stable.

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As Dunlavey said, It depends upon several factors... But, once the size of the sun got bigger, our lifetime here would be definitely less. Neglecting temperature, there are several other factors which contribute to the issue. I think, the rising tides (tidal forces) would be powerful enough to crush or cause some serious damage to the landscapes.

Ok. Let's just assume that you've sped up Earth somehow. There are several observed things like the 8.9 Earthquake which sped up Earth by several microseconds and tilted its axis by several inches. These slight changes of microseconds and inches might not be as insignificant as they seem..! Even if humans on one side of Earth jumped almost instantly, they wouldn't create such a marvelous Richter to speed up Earth by several microseconds (at least)...

Currently, Our Earth rotates at a velocity of about 1673 km/h and its circumference along the equator (because it varies with latitude) is 40,031 km. Its rotational period is $t=\frac{c}{v}=$ 23.9277 h. Now, Earth has sped up 1000 times its initial value. It gives the rotational period - 0.0239277 h (OR) 1.4 min. I couldn't imagine something like that.

First of all, This causes a drastic change in the duration of a day, Weather, Climate, Wind, etc. Gravity won't change. But, the weight (I would be too fatty) measured at equators and poles would differ much than it is present now..!

Perhaps, You may have a look over these links for Slowing down and Stopping it.

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The faster the earths orbit, the further it would go form the sun until it reached "escape velocity". The speed itself would make no difference to you anything you can feel. However, the distance from the sun, you would feel. The sun rotates around our galaxy core at one tremendous speed (and us with it), and you don't feel that.

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The Earth orbital speed could be increased by bringing the Earth closer to the Sun. That would require orbital maneuvering of the whole planet (planetary retrograde burn to go into a transfer orbit and another retrograde burn to circularize the orbit) which would be felt by the Earth population as acceleration. After the final orbit would be achieved, the increased Earth orbital speed would not be felt. It would be the same as before. But we would be closer to the Sun, so we would feel more heat. If we would go closer than Mercury, we would feel a lot of heat...

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protected by Qmechanic Jan 7 '15 at 0:01

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