How Fast Are We Travelling and How Can We Prove It ?

I was having a conversation with a friend of mine and we were discussing current events and I said quite blaise that "We are on a rock travelling through space" at which point he said to me that we are not traveling through space and in fact we are standing still. I tried to tell him that science says we are and his retort was "You can't believe everything on the internet" (which is fair but slightly flawed) basically to say that everything on the internet has no factual scientific basis is a bit of a sweeping comment, but he does actually say this for anything he doesn't agree with.

So basically my question is: How fast are we traveling through space if at all? and how can science prove this? I need an answer that will stop him from saying "well how do you know its true just because its on the internet"?

Many thanks

Good point Fans,

Down to one thing only.

How fast are we traveling in relation to What?

What is the point of measurement from to?

Relativity proves it, however not easy eh to get your head around it properly not just on a surface level.

Encahnted Learning Spped of Earth

AstroSociety How fast are we moving when sitting still?

Kind Regards,

Elf

And it's funny that you come on the internet to find an intelligent answer to your problem.

Perhaps time to re-evaluate the people you hang with?
Not being rude. Change is good.

Originally posted by franspeakfree
So basically my question is: How fast are we traveling through space if at all? and how can science prove this?

As others have asked... "in relation to what"?
But we can start out at a simple level by assuming your friend has the brains to understand we are orbiting the sun. To do so, we are travelling at a speed which lets us do this in 365 days.

If your friend does NOT believe we are orbiting the sun, then just walk away and do something more productive with your time.

monty python already answered it

Ask him if we are not moving, why are there seasons. Does he think the sun orbits the earth? old school.
Obviously the sun is moving. I see the problem though, seems common sense that we are traveling through space but if someone won't accept the internet as a reliable source then where do you tell them to go? books I suppose...

I think what he means is that while we orbit the sun, obviously, our whole solar system is moving at a certain speed through the galaxy. Our galaxy is moving at a certain speed through the universe. (In theory, our universe is moving at a certain speed among other universes).

So while we know how fast we orbit the sun, do we know how fast our solar system is going through the galaxy? Do we know how fast our galaxy is travelling through the universe? If so, and our planet, solar system, and galaxy were all moving in the same direction across our universe - what would be the actual speed?

Originally posted by deadline527
So while we know how fast we orbit the sun, do we know how fast our solar system is going through the galaxy?

I suspect it gets more difficult for your average citizen to measure such a thing. Probably need equipment capable of measuring red shift of objects "in front" and "behind" our position.

But as a general concept, perhaps that friend can understand that if we were NOT in orbit around the sun, then we'd just fall straight in and die.
In the same way, if we were NOT orbiting around the galaxy, then we'd just fall straight in and die.
Thus, we cant be stationary. (Which was the point of the discussion).

Originally posted by franspeakfree
So basically my question is: How fast are we traveling through space if at all? and how can science prove this? I need an answer that will stop him from saying "well how do you know its true just because its on the internet"?

Many thanks

This is a good Video that explains the calculation.

reply to post by franspeakfree


OK, if you are standing on Planet Earth, as I assume you are, the planet is revolving around and around, it never stops. The planet is also orbiting around the Sun, and the Sun and it's planets are also moving in a much wider and older orbit around a Central Sun some say is Alcycon in the Pleiadies System. I would say at any given time, you have to be moving at some 10,000 miles an hour. Stand still, is your friend living under a rock?

If we were to time travel back to a certain year, would we have to figure out where the Earth was located in that year? And relative to what?

The Earth is approx : 24,000 miles around the equator, it takes 24 hours for 1 revolution so at the equator everything on the earth is moving at approx: 1000 mph.

The earth also travels around the sun at approx: 666,000 mph.

On a calm sunny day it is hard to believe the speeds we travel at so who knows.

Speed is really a relative term. Basically its how fast you're moving away from a point of measurement. Since all things are moving, even the point of measurement itself, true speed is impossible to measure.

I would imagine the best way to find our speed would be to monitor other galaxy's speed relative to us. If you can identify and monitor galaxies moving away from us and galaxies moving towards us, you should be able to find a relative rate of speed you and your friend can agree upon.

reply to post by franspeakfree


The only way to truly know how fast the Earth is moving with respect to space, itself, is to measure the amount of linear frame dragging caused by the Earth's momentum as it moves through space.
When people refer to "frame dragging," they're most often talking about rotational frame dragging, where angular momentum (rotation of a mass) causes space-time to bend around an object. This, though, isn't the only kind of frame dragging - another is linear frame dragging, which is caused by linear momentum (linear motion of a mass).
The problem here is that, while rotational frame dragging has been measured and confirmed as predicted by General Relativity, linear frame dragging is much harder to measure, and, in fact, it has never been measured.

So, that's the answer: the only way to know how fast Earth is truly moving through space is to measure the linear frame dragging caused by its motion. The problem is, such a measurement is currently beyond our abilities.

Originally posted by deadline527
I think what he means is that while we orbit the sun, obviously, our whole solar system is moving at a certain speed through the galaxy. Our galaxy is moving at a certain speed through the universe. (In theory, our universe is moving at a certain speed among other universes).

So while we know how fast we orbit the sun, do we know how fast our solar system is going through the galaxy? Do we know how fast our galaxy is travelling through the universe? If so, and our planet, solar system, and galaxy were all moving in the same direction across our universe - what would be the actual speed?

Nicely defined question, and one that I asked myself just the other day. Specifically, is it cumulative? How do we know how close we are to approaching the speed of light. (Oh, additionally, when you ride on a jet... you're going faster than the spin of the Earth.)

reply to post by CLPrime


Interesting. I've never heard of this Earth frame drag before.
Is frame in reference to video frame? How would the expansion, of space itself, play into the equation?

reply to post by Bleeeeep


The expansion of space is (measurably) equal throughout the universe, and it is locally negligible. So, the expansion of space would have no impact on Earth's measured linear frame dragging.

The "frame" in frame dragging is from "reference frame," which is the name for a closed system in Relativity.

And, for anyone concerned with measuring frame dragging in a relativistic universe:
In terms of rotational frame dragging, we have to ask "rotating relative to what?" Is the Earth rotating relative to the Sun? The galaxy? What we find, though, is that it doesn't really matter... because we are on the Earth, and what matters is how we measure the Earth to be rotating (which is the same whether we measure it with respect to the Sun or anything else).
It's a bit different for linear frame dragging, but the basic idea is the same. We're on the Earth, which is travelling through space... so, if we measure Earth's linear frame dragging with respect to that space, we then find how fast the Earth is moving through the space.

reply to post by CLPrime


It sounds like, in its simplest definition, frame dragging is somethings' speed measured by using reference points. That to me, is already how we find somethings speed, so basically it's a new term for an old equation. Is this an old term that I just wasn't aware of or am I missing something - something that make's frame dragging revolutionary in its definition?

reply to post by Bleeeeep


Rotational frame dragging is the bending of space around a rotating mass (like the Earth). Technically, it's the tendency for an object to co-rotate within the gravitational potential of a mass with angular momentum. It's mathematically described by the Kerr metric, and it has nothing to do with relative velocities.
It might be best visualized by pushing your fist into a bed and turning it, twisting the bed sheet around your hand.

Linear frame dragging is the pulling of space along with a moving mass (again, like the Earth). Technically, it's the tendency for an object to co-move within the gravitational potential of a mass with linear momentum.
Using the previous example, it would be best visualized by pushing your fist into a bed and sliding it, pulling the bed sheet along with your hand.

We can observe and feel gravity. We can observe the motion of planetary bodies and see that they obey the effects of gravity. In order to not plummet into the sun, we have to have a certain velocity around it. Similarly, in order for our solar system to not plummet into the center of the galaxy, we have to have a certain velocity around it. That velocity is sqrt(a*r) where a is the local gravitational acceleration and r the distance between the objects.

In terms of clinging to ignorance, there's very little as irritating as earth-centrism.