Planets were also mentioned.
As for the Sun maybe the rocket would just melt?
But you've got the cart before the horse. In order for the spacecraft to hit the planet it requires a change in energy.But just because the Space Shuttle has to loose energy to land on Earth, that doesnt mean that everything has to loose energy before it can come down. With no atmosphere a rocket would not have to loose energy before it gets to that planet with no atmosphere. It could loose that energy when it hits the planet, so it would loose lots of energy alright but not until it hits.
This is the exact same thing, just you're thinking in absolute terms and not in relative terms.You're somehow trying to say that a bullet cant hit a target unless it looses all it's energy FIRST.
But you've got the cart before the horse. In order for the spacecraft to hit the planet it requires a change in energy.
Netwons first law. An object that is in motion will not change its velocity unless an unbalanced force acts upon it.
This is the exact same thing, just you're thinking in absolute terms and not in relative terms.
The bullet needs energy to move. This is a STATIC model in newtonian physics. Your target is at relative rest with respect to the bullet.
What I'm saying is that you're holding the gun and you're moving at the speed a bullet would be travelling. NOW try and hit the target ! How much energy do you need to make the bullet hit the target ?
In space, the sun is moving, your rocket is moving. This is basic relativity. EVERYTHING in the universe is ALWAYS moving. They are never at rest (unless it is with respect to each other).
Remember that this is about material falling into black holes, matter has kinetic energy that it must lose in order to fall in.
Lets bring it back to a marble rolling down a funnel. You roll the ball around the rim of the funnel. This represents it's initial velocity.
Now the ball starts to roll and roll into or fall into the funnel. But it does this because it loses energy. If it did not lose kinetic energy then the ball would roll around the rim forever.
The ball falls down the funnel by losing energy as sound and heat through friction.
It's just a simple example of Netwon's first law.
Now replace the funnel with a black hole and the marble with something like an asteroid. How does the asteroid lose energy to fall in ?
There is no air, no friction, no sound .... How does it lose the kinetic energy of it's orbit ?
This isn't a trick question. It's a real world problem and one which highlights how the universe works.
Or - How fast is the moon falling towards the earth ?
Shhh ! It was a trick question.The Moon is not falling towards the Earth, its in fact moving away at approx 2cms/year
The Earth's rotational energy.But since the cat is out of the bag, the question now becomes. The moon is falling up ! This means that it's gaining energy.
More conservation of energy.
Where does it get this energy from ?
@ MrAl
"The Moon is falling toward the Earth, it's just that it falls less over time"
But doesn't everything fall at the same rate ? How can something fall 'less' ?
" If you could make it rotate faster, it would move away from the Earth in a spiral pattern."
This IS what the moon is doing. So it's rotating faster. Where is this orbital energy coming from ?
That wins my award for the worse attempt at back pedalling I've ever seen. You have a promising careerer in Australian politics if you ever immigrate.The word 'less' means that some quantity has decreased. That's why i said do a diagram. You'd see the distance become greater over the same time period. But since we used the word 'fall' and the distance was increasing, that means it's falling 'less'
I think you're missing the point of this entire thread then. Because it is about the properties of black holes.
A diagram ... why ? Ok.. since your incapable of answering the question I'll give you the answer.
That wins my award for the worse attempt at back pedalling I've ever seen. You have a promising careerer in Australian politics if you ever immigrate.
The Moon's orbit is increasing because it is gaining energy.
It gets this energy from the earth's rotation and tidal effects with the moon.
This means the earth's rotation is slowing and the energy transferred to the moons orbital velocity.
As the Earth rotates there is a small gravitational tug between the moon and the earth.
No double negatives, no diagrams. Just a simple explanation of a gravitational interaction.
Which brings as back to the objects in orbit falling.
How do they lose energy. It's a simple question which needs nothing but a simple answer.
In examples of satellites in low earth orbit, atmospheric friction de-orbits satellites.
But a large single object like an asteroid cannot do this. A black hole doesn't have an atmosphere, so atmospheric drag can't bring it down.
What can cause it to de-orbit ?
In the case of the earth-moon interaction, the earth's uneven shape influences the moon.
These are simple newtonian answers to common observations.
But black holes are aren't so easily observed so we need to run models in order to better explain them.
In the case of a black hole, it would be safe to assume that the surface (or event horizon) is smooth or a black hole down not have any gravitational anomalies to cause a similar effect in large bodies orbiting them.
I've already explained why microscopic particles in orbit close to the event horizon can fall in. They lose their energy by emitting bremsstrahlung in the form of X-rays. Black holes are observed emitting X-rays.
I've also explained how binary objects can gravitationally sling shot each other so that one object is ejected while the other falls.
https://en.wikipedia.org/wiki/Stellar_kinematics#Production_methods
In the case of very massive objects like a neutron star or another black hole, the theory is that they emit gravitational waves. https://en.wikipedia.org/wiki/Gravitational_wave#Power_radiated_by_orbiting_bodies
This is a reasonable enough theory. We haven't yet detected gravity waves so if they don't exist then there is a problem with our model of gravity.
If they do exist, then we should be able to use them to make other accurate measurements or the universe.
It's not a trick question. It's a simple question. How do macro objects lose orbital energy and fall into a black hole ?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?