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I knew that energy is a scalar quantity, so I wonder can a character move and alter direction of an object at distance by giving it kinetic energy? Thanks.

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  • $\begingroup$ Welcome to worldbuilding. Please take the tour and visit the help center to get familiar with the type of questions we answer here, then rework your question to fit those standards. $\endgroup$ – L.Dutch Nov 22 '18 at 13:56
  • $\begingroup$ You can't cancel gravitational potential energy. That is the capacity to do work present in an object due to its height. If you add kinetic energy to an object, whether it moves depends on its inertia. Providing KE to an object from a distance is easy: just shoot it with something. $\endgroup$ – nzaman Nov 22 '18 at 14:04
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    $\begingroup$ "can a character move and alter direction of an object at distance by giving it kinetic energy?" Yes, hit it with a projectile. $\endgroup$ – Renan Nov 22 '18 at 15:39
  • $\begingroup$ This is in the VTC queue for a lot of different reasons. I'm not convinced that it deserves to be closed. Please remember that voting to close is not meant to be used as a super downvote. Vergil, welcome to Worldbuilding. Please be patient with us. Cheers. $\endgroup$ – JBH Nov 23 '18 at 0:41
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Can a character perform telekinesis with energy manipulation?

Perhaps. The answer could be yes, but only conditionally upon the character being able to manipulate:

Dark Energy

dark energy is an unknown form of energy which is hypothesized to permeate all of space, tending to accelerate the expansion of the universe. Dark energy is the most accepted hypothesis to explain the observations since the 1990s indicating that the universe is expanding at an accelerating rate.....

Dark energy's status as a hypothetical force with unknown properties makes it a very active target of research.

It is described in several hypothetical models:

Cosmological constant The simplest explanation for dark energy is that it is an intrinsic, fundamental energy of space.

Quintessence In quintessence models of dark energy, the observed acceleration of the scale factor is caused by the potential energy of a dynamical field, referred to as quintessence field. Quintessence differs from the cosmological constant in that it can vary in space and time.

Interacting dark energy This class of theories attempts to come up with an all-encompassing theory of both dark matter and dark energy as a single phenomenon that modifies the laws of gravity at various scales. This could, for example, treat dark energy and dark matter as different facets of the same unknown substance, or postulate that cold dark matter decays into dark energy.

Plus a number of others. The mechanism by which your character might manipulate matter is not something that Physics can say very much about at present, however there are many examples in fiction of how unusual powers have been written about and explained before Dark Energy was even thought of:

A character able to create gravitational fields at will is of course familiar from "Marvel's Agents of Shield" - episode 107 titled "Option Two" Talbot absorbs a rare substance called Gravitonium and is then able to manipulate gravity at will.

Asimov's "The Gods Themselves" is another example:

Beings are divided into three different types with slightly varying abilities:

is set in the parallel universe where, because the nuclear force is stronger, stars are smaller and burn out faster than in our universe.....

Because atoms behave differently in this universe, substances can move through each other and appear to occupy the same space. This gives the intelligent beings unique abilities.

No specific telekinesis, but the idea of beings or technology either more advanced than us, or imbued with the ability to interact with matter in unusual ways is a familiar trope.

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Not really

There are two fundamental forces that work at a distance, gravitational and electromagnetic. Either of these forces could be used to generate a potential energy field. An object in that field would be able to move along the potential gradient in the negative direction and convert some of its potential energy to kinetic energy. Some of the potential energy would be lost as friction.

If you were able to establish some sort of gravity potential field, the problem is that it would act on all objects nearby proportional to the mass of the nearby objects and inversely proportional to the square of the distance. So, there is no 'scientific' way to use gravity to target a specific object. Also, gravity is only known to be attractive, so there is only one direction you could move an object with gravity.

The electromagnetic force could be expressed in several ways. Electrostatic force is attraction or repulsion based on charge. Again, this works in all directions, so there is no real way to target a single object. Furthermore, the object needs a positive or negative net charge for electrostatic force to work, so most objects will not be affected. Magnetic force is the other half of Lorentz force, and could potentially be used to move an object. However, there are more limitations. The object needs to be electrically charged, or needs to have some sort of conduction loop. Depending on how you could generate magnetic fields lines, there are geometric restrictions on which way you could move an object.

Finally, you could just hit the object with a lot of photons to transfer momentum to it and move it, but the problem with that is you transfer a lot of energy too, and by the time you can transfer a lot of momentum to a target, you've probably incinerated it with a death ray.

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It's a bit more complicated, but the general answer is "yes, using rocketry!"

Mass and velocity are entwined by two major equations. One is the energy equations, like $E=1/2m|v|^2$. The other is momentum, $p=mv$. If you simply want to make the object go faster, you have to not only increase its energy, you also have to increase it's momentum. They have to go hand in hand.

Of course, you can absolutely play games. let's say you want to increase the energy by a factor of 2, but you want to keep the momentum the same. Well, if you also decrease the mass at the same time, you can make this happen. We usually treat mass as a constant because our objects can't break apart. However, in rocketry, we have masses that change all the time. A substantial portion of a rocket's mass on the ground is its fuel.

And rockets also show how you would go about changing an object's velocity with only energy manipulation. After all, that's exactly what rockets do. They get hot. Really hot. Really really hot. Really fast. And they cause some of the mass of the rocket (the exhaust) to streak out backwards, providing the momentum needed to go faster.

So your telekenetic should basically excite a small chamber of "reaction mass" on the object which then propels itself out in one direction, driving the object the other way.

The higher velocity you achieve, the more efficient you use your propellant. This is called Specific Impulse (ISP), and is highly related to "effective exhaust speed." Some thrusters, like ion thrusters, are particularly efficient with their mass -- they accelerate their exhaust to very high speeds and energies, so that they get the most bang for their buck. Once a rocket is out of mass to fling, it's dead in the water (vacuum?)

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