I have a question about the Big Bang?

Question

If the Big Bang was an explosion and everything in the universe is accelerating outward from that original point, then how do planets orbit? For one half of the orbit the planet is moving in the direction that it was projected at in the explosion, however, the other half of the orbit is moving in the direction of the explosion which obviously violates the laws of physics.

I didnt do a good job of verbalizing my question: Basically I'm saying that for half of earth's orbit to move in the direction of the big bang would appear to violate the laws of inertia.

Answer 1

Hello. Planets aren't just orbiting a single point in outerspace. Galaxies move through the universe as a whole and are, for the most part, spreading away from each other. Planets orbit around stars, stars orbit the galactic center of a galaxy, and galaxies are heading away from each other. The universe is an estimated 15 billion years old and since then stars have been born, have died, and sent asteroid, comets, dust, and matter in many different directions. The law of physics state that things will tend to travel in a straight line until someother force affects this. This is what happens to planets and other objects such as comets. When a comet approaches a star it will cause it to pull inward while at the same time maintaining its current speed. Gravity from the sun will cause the comet to circle around the sun until it's flung out in to space in another direction. Our planets would normally travel in a straight line but the suns gravity combined with the speed of the rotation of the planets causes the planets to orbit the sun. Hope this helps.

Answer 2

Actually, it is not violating the law of inertia. The law states that an object in motion will stay in motion unless acted upon by some resisting force. that is exactly what is happening. The planet is moving forward all the time, but gravity from the sun and other objects in space is preventing it from moving in a straight line. So basically, if the sun was not there, the planet would just be moving in one straight line until another object in space's gravity affected the planet.

And for the sun, its also orbiting the center of the galaxy. A theory states that at every center of every galaxy lies a super massive black hole. So the sun is orbiting around that, still under the same circumstances as a planet. And if there was no supermassive black hole, then the sun would just move in a straight line.

Answer 3

"...If the Big Bang was an explosion and everything in the universe is accelerating outward from that original point..."

I'm sorry, but you're understanding of the Big Bang needs some adjustment. First of all it wasn't an 'explosion.' An explosion happens inside something else, and to the very best of our knowledge there was no 'thing' before the Big Bang...no energy, no space, no time, no mass. It was only at the very first instant of the Big Bang that space-time itself was created. Then some time later sub-atomic particles formed, and then atoms, molecules, clouds of gas, stars, planets, and so on.

With all that in mind then your question about the orbit of planets in relation to the 'center' of the Big Bang has no true meaning. Nothing orbits the 'center' of the universe because there is no center. The universe is what's known as 'isotropic,' meaning that no matter where in it your are that point appears to be the center because all other major structures are receding from it.

Answer 4

There are several problems here in your understanding.

First, the Big Bang was not an explosion in the usual sense. Instead of things moving away froma center and through space, the Big Bang is actually space itself expanding. The amount of motion through space is actually pretty small.

Second, the earth and planets were not formed from the Big Bang. The Big Bang was about 13.7 billion years ago. Between that and the formation of our solar system, there was at least one generation of stars that went through a complete life cycle. Then, the dust and gas from those dead stars collapsed to form our sun and the planets about 4.5 billion years ago. The earth has been around about 1/3 of the time of the universe.

Third, objects moving in straight lines do have angular momentum with respect to each other. All that gravity does is take that angular momentum and convert it into actual orbital motion.

Fourth, the scale of our solar system is TINY compared to even our galaxy (which is tiny compared to the overall expansion of the universe). Eddy currents are certainly not a violation of the laws of physics.

Answer 5

Think of passing another car on the interstate (or any other road). You and the other car are both moving in the same direction, but since you're moving faster, the other car apears to be moving in the opposite direction. It's the same with the Earth, Solar System, galaxies, etc. Everything is still moving outward...it's just moving around a bit relative to other objects that are also moving outward.

Answer 6

It seems to me that part of your problem lies with the fact that none of this happened yesterday. It happened (if at all) some five billion years ago plus say 4 Billion years for the mass of the Earth to become accumulated into one unit from all of the various debris out there.

Now for all that time, the object now known as Earth has been moving, and at some point it moved past a gigantic ball of gases that was the Sun. The Earth was moving very fast, but it became ensnared by the gravitational pull of the Sun which made the Earth swing around in a circle around the Sun. Earth has been doing that ever since because there is nothing to stop it from doing so.

Answer 7

Violates the laws of physics?!

It's called gravity. You know, the same force that keeps you glued to the ground. Space is expanding, but gravity draws all matter together. Galaxies, stars, planets and asteroids all form because of the force of gravity.

See the Wikipedia page on Isaac Newton. He proved mathematically that a moving object under the influence of gravity has a path like a conic section: a circle, ellipse, parabola or hyperbola. His equations support the observations made by Kepler a century before him.

Answer 8

It would only violate physics in an environment where there was atmosphere to cause a slowdown of the orbit...

Space is void of matter so there would be nothing that prevents a planet from orbiting it's sun.

Answer 9

imagine you drink your coffee in your car, driving down the highway. Your hand is like the gravity of the sun, it moves the coffee around in the car, despite you moving 80 miles an hour over hte Highway. (At the same time, you move rotational with the earth around itself once in 24 hours, once around the sun in 365,25 days, around the milky way and the milky way, our galaxy, is racing since 15 Billion years away from the center of the explosion, how about that. Don't forget the tires on you car rotating, the cylinders going up and down and Bush still trying to convince himself, that he is for real.

Answer 10

Turbulence. The flows are initially supersonic and highly turbulent; any slight irregularity in the flow (due to an attraction between two particles, for example) will be magnified chaotically. Work out the Reynolds numbers with suitable assumptions and see for yourself.