How fast is Earth traveling through space? That depends. | Michelle Thaller

How fast is Earth traveling through space? That depends. | Michelle Thaller

Eugene, you’ve asked one of my favorite questions
and a surprisingly deep one. The essence of it is: How fast are we really
moving? We are a solar system; we are planets going
around the Sun. But the Sun has its own motion around the
galaxy, the Milky Way. And there are larger motions still because
the Milky Way galaxy is also moving through space. So I’m going to try to break this down because
there are a number of different ways to think about motion because when you get to these
scales, one of the most important questions you have to ask is: Motion compared to what? And I’ll explain that as I go along. So one of the most easy to understand motions,
but a kind of mind-blowing one is that the Sun is orbiting around the center of the Milky
Way galaxy. Now, the Milky Way galaxy is a huge collection
of about half a trillion stars, and it’s about 100,000 light years across end-to-end. Now, we actually orbit around the center of
the galaxy — the center of the galaxy is about 30,000 light years away from us — and
we orbit around about once every 230 million years. OK, that sounds like a long time. So 230 million years to make one orbit around
the galaxy. So how fast are we going? It turns out that the Sun, and us with it,
it’s going at about 560,000 miles an hour. That’s over half a million miles an hour just
around the center of our galaxy. So right now, you are moving at over half
a million miles an hour around the center of the galaxy. And if you want to think about it in kind
of a dramatic way, the center of the galaxy has a massive black hole at the middle, and
it’s about 4 million times the mass of the Sun. So right now, you are orbiting a massive black
hole at half a million miles an hour. That’s kind of fun. But there are larger velocities as well. And here’s where things start to get a little
bit complicated because the universe is expanding. And what that really means is that space itself
is expanding. It’s not really correct to say the galaxies
are flying through the universe with the expansion of the universe. That’s actually not how it works at all. The galaxies in that sense are standing still,
but the space in between them is getting bigger. It’s a very strange thing to think about,
but the expansion of the universe is not galaxies moving through empty space. And one of the reasons that this is important
is because the farther away you look into space, the more expanding space you look through. And it’s not that galaxies very far away are
actually moving through space very, very fast, but they appear that way to us. There’s something called the Hubble Constant,
and what that means is how fast the universe is expanding for every amount of space that
you look through. The Hubble constant right now is about 75
kilometers per second per megaparsec, and a megaparsec is about 3 million light years. So that means that every 3 million light years
you go out, things are receding from you at an additional 75 kilometers per second. So when you’re 3 million light years away,
a galaxy would naturally recede away from you at 75 kilometers per second. Now double that. Say that you’re now 6 million light years
away, double 75: 150 kilometers per second. So for every 3 million light years you go
out, you put an additional 75 kilometers per second onto the speed. Now, that means the galaxies nearer to us
are not moving very quickly at all in the natural expansion of the universe. But if you look at something billions of light
years away, you’re looking through that much expanding space, and it can be receding away
from us, appearing to recede away from us, at a very fast velocity indeed. In fact, when you actually look at the very,
very edges of the universe, things are receding away from us close to the speed of light. So that’s not anything moving at the speed
of light. That’s just the fact that you’re looking through
that much expanding space that it appears to be going that fast away from you, and this
is called the Hubble Law. It took a long time for people to realize
that there might be other motions besides just this expansion of the universe. And we have to tease them out because galaxies,
as big as they are and as fast as they’re moving, the distances they’re moving across
are so vast it’s very difficult to detect. Over time we realized that yes indeed there
were other motions besides this, what we call Hubble flow, this expansion of the universe. So we began to realize that the Milky Way
galaxy was part of larger clusters of galaxies. And in some cases, clusters of galaxies were
bound together by gravity, sort of orbiting around big groups of galaxies. And in other cases, these concentrations of
galaxies are probably going to disperse over time as the universe expands. So starting from relatively close to us, the
closest large galaxy to us is Andromeda. And Andromeda is so big and so close that
in fact, we are falling towards each other faster than the universe expanding us away. Right now the Andromeda galaxy is coming at
us at a speed of about 300,000 miles an hour. And that means that’s going to collide with
us in a couple billion years so I wouldn’t worry about that, that’s not a problem for
us at all. And in fact, we think the Milky Way has collided
with other galaxies in the past as well. But the reason Andromeda is coming toward
us is the force of gravity is accelerating us together faster than the expansion is taking
it away. Other galaxies even closer to us are orbiting
the Milky Way, like the Magellanic Clouds. So now, let’s go out a little bit further
and think about how the Milky Way is moving through space compared to larger things. Well, the largest motion we know of right
now is that we are falling in towards something called the Great Attractor. And this is a concentration of mass, a giant
cluster of galaxies. And right now, we’re moving at a little over
one and a half million miles an hour towards that part of the sky. For a long time, we really didn’t know what
was there. We called it the Great Attractor because it
seemed kind of mysterious. But now, we realize that it’s actually the
center of gravity of a huge cluster of galaxies, something called a super cluster. And this cluster probably contains over 100,000
galaxies, and it’s probably on the order of about half a billion light years across. And this has been discovered only in the last
few years, and it’s been called the Laniakea Supercluster. Laniakea is the Hawaiian language word for
the highest heaven. And this is the largest group of galaxies
that we think that we are actually gravitationally associated with. We are actually falling in towards the center
of this giant collection of galaxies. So where’s the Sun going? How are we moving? It depends on with respect to what. We’re moving around the galaxy at half a million
miles an hour. We’re falling into the center of a supercluster
of galaxies at one and a half million miles an hour. And all of that is superimposed on top of
the expansion of the universe, which isn’t really a speed, it’s just that you have to
look through a lot of expanding space. So there’s no one answer as to how fast you’re
moving right now. And I think that’s one of the most wonderful
things is how complex these simple answers can get.

100 thoughts on “How fast is Earth traveling through space? That depends. | Michelle Thaller

  1. how can you say these things and be taken seriously, you know perfectly well there is no such thing as 'outer space'

  2. I'm not sure if this is valid, but using the 75 km/s space expansion rate for every 3,000,000 light years, I calculate that the amount of space between the earth and sun increases by half a millimeter every 24 hours, or about 1,000,000 km in the lifetime of earth. That doesn't sound possible.

  3. by the way, the reason why "the great attractor" is giving astronomers such a hard time is actually because the center of our milkyway is right inbetween.

  4. With out getting to scientific I'll say this they earth is spinning fast, but that speed is counteracted by the speed earth is orbiting the sun,as well as gravity

  5. I always get stuck on the idea that space is Something that can be bent, and is something that can be bent by some mass, or another located in that nothingness of empty space before mass came into being . It seems that Space is like an Escher drawing of some impossible, geometrical reality – an expanding, bending something which is not defined, and constantly distorted by the motion of all mass that is in that "Pudding" of a "Universe" having the massive lumps stirred into "Smoothness" by the hand of "Science," and using gigantic, Black Hole spoons of various sizes …

    I get sea-sick just trying to imagine the curving, expanding Space on the light year, parsec and higher level of objectivity, then I have to bring myself back to being small, minute, insignificant in the scheme of "Things." Now, I'm caught in a tilt-a-whirl expanding, bending space and disturbed, even nauseated by the thought that I am constantly growing apart spatially from all the rest of humanity, the world and the rest of the universe … smaller and smaller … father and farther apart … The Great Attract(or) has got us in its coils … or does it?

    Birkeland Currents of the Universe and on that apparently infinite level – not gravity at all …

  6. The Milky way, our Galaxy. If the only man made object is just leaving our solar system, witch is in the Galaxy. how can we have pictures of the Galaxy? If we just got out of bed , how can we have a picture of the house.

  7. you didn't give an answer what speed are we rotating what speed are we traveling around the Sun what speed is the sun traveling around the Milky Way and what speed is the Milky Way moving toward the great attractor and please inform me on how we could be moving at all these speeds tour different things around different orbits and never change direction a carnival ride if there is more than one Pivot Point there are times that the second Pivot Point of something spinning either speeds up or slows down the procession of the first Pivot Point why is it that we feel none of that

  8. I think too much thought was brought into this question. I think the question was meant as how fast is earth orbiting the sun.

  9. I wonder, hypothetically of course… Would we be able to detect absolute zero motion by measuring its effect on the speed of time, relative to Earth time?

    I mean, since time progresses slower on board a really fast space ship, could we attempt to build a space craft whose only purpose was to do the complete opposite, decelerate down to a point where it truly stood completely still in relation to everything, using its effect on time as our reference guide?

  10. The funny thing is that all these discoveries we've made with our ever increasing technology were not there until we observed that they were there. The job (if you will) of the universe is to appear endless until we develop new tech to see further only to realize that it's bigger than we thought.
    "The universe is a jigsaw puzzle that gets infinitely larger in size every time we're about to put in the last piece of the puzzle"
    -HarpuaSlutBag June 12th 2019

  11. We are part a helical waveform traveling at the speed of light. The universe appears to be expanding because of time delay.

  12. ive realised something nobody addresses. The shuttle,space station and space suits all have windows that the astronaut see out. Wouldnt the windows let radiation in and make the so called radiation shield redundant?There would be no point putting shielding for radiation on a space craft if the radiation gets threw the window they can look out.Ask what the windows are made out of that prevents the radiation from slipping in.

  13. Interesting.
    Those are facts that I learned in my 6th grade "Science Class"! It's amazing just how many kids just refused to listen/learn ANYTHING!

  14. This is only theoretical.
    No proof of earth "traveling" anywhere. Don't be fooled by NASA deceptions they just want your $$$.

  15. Wow…all this distance and speed and time expansion, and YET, all the constellations in the sky are in the EXACT same location/configuration today as they were thousands of years ago.
    Hmm…gotta love this propagation of the patently false narrative of the Heliocentric THEORY Model of the Universe. Shameful.

  16. How fast are we moving through an un-expanding space-time?
    Spin speed of earth = sE
    Orbit speed of earth = oE
    Orbit speed of solar system = oS
    Orbit speed of galaxy around great attracter = oA
    Assume all orbits and spins align to add its maximum possible speed
    C – sE+oE+oS+oA
    Would this represent the actual speed of the earth moving through space-time?
    I am sure there are probably more orbits higher than the great attracter.
    At what speed does time dilation begin to be substantial?

  17. Truth is, that her information is completely wrong! Heres why,,,, the earth, our galaxy, our own selves, even the void of space we are within, are in actuality nothing more than a swirl of atoms or more specifically sub atomic particles. Nothing is a solid. No such thing! Time itself is a man made concept utilized to desperately grasp onto a branch to use as a crude measuring system. Calculating speed requires time to be placed within the equation. It s just an illusion since its a man made concept. In the same way a pair of scissors does not actually cut thru paper or fabric. Scissors, only separate, not cut, the attraction bond of molecules joined side by side at the point of the outer partially vacant electron shell?

  18. The biggest question I always had about this is, the faster you move, the more time dilates, so since we're moving really fast, how much is time getting dilated for us?

    In other words, the old, "If a set of twins is separated, one travels to one light year away in 5 years, relative to the twin doing the travel, then comes back, to that twin, they've only gotten ten years older, yet the twin that stayed on Earth is something like eighty years old."

    If we've only been "traveling" for a couple thousand years, could alien races have already progressed through millions of years of time because they're moving at a significantly slower rate of velocity, thereby being long dead to our frame of reference? I know that's probably badly worded, but hopefully I got the main idea of my question across

  19. There are some people with the gift, MT has it, grabs your attention and stuffs knowledge between your ears!

  20. [The Milky Way Galaxy is about] "a hundred thousand lightyears end to end." That's "a hundred thousand light years *side to side*."

  21. The funny thing is a normal person doesn’t even care about this nonsense.. only geeks who are still virgins even care about this stuff. You people seriously need to get laid. LOL

  22. A more relevant Q: Where on the Earth can I travel to and see the curve of the globe? Michelle accepts the orbital mechanics she describes to others, but where can the average 'JOE' go to see the curve?

    Michelle's fairy tale is beautifully described.

  23. Fascinating and very informative video.  Thank you Ms Thaller for uploading for the rest of us to enjoy.  Certainly food for thought !

  24. This lady makes my major life problems look like crap. Astronomy is a religion with facts that brings you at peace, yet gets you curious, happy n mellow together with huge humbleness.

  25. Conversion to kilometers for my fellow humans not in the USA:
    Sun orbiting around Milky Way – 901,233 km/h
    The speed at which Andromeda is moving towards the Milky Way – 482,803 km/h
    Our movement towards the Great Attractor (Laniakea Supercluster) – 2414016km/h

  26. 5:10 — “it’s going to collide with us in a couple of billion years, so I wouldn’t worry about that at all”

    Subtext: humans will have fucked over the planet Earth longggggggg before then.

  27. I like how you explained that the expansion of space isn't galaxies "moving" away from one another, but the space between them expanding.
    I'm gonna use that. We all should.

    You also touched somewhat on the critically important point that asking what speed/velocity something is going, is a meaningless question without at least an implied reference frame.


  28. Still not as fast as Michelle stuffs her pie hole, with her oblate spheroid belly and jumbo pear shaped bottom ?

  29. Thanks, Michelle. I've recently stumbled upon your videos and now I'm a big fan. As a physics enthusiast, I really appreciate these videos! 🙂

  30. Why is it that astronauts in space or just after they leave our atmosphere they can look back and see earth just sitting there? If the earth is traveling at these speeds around the sun and and galaxy it seems that once the rocket leaves the atmosphere the earth should speed away, but it doesnt it is still where it was when the looked at it last.

  31. Fuck I love Michelle. She's so genuine and loves what she's talking about. She shares my awe of everything space. If only she would marry me… we'd have so many great talks.

  32. If you would like to ask her a question, here is the page:

  33. If everything is moving away from everything else; That would indicate that everything did not start at a singular point. Objects are moving towards us, and away from us. If the Singularity theory is correct, this can not happen. Every item would be moving away from a central point.

    There would have to be multiple " starting points " for each Galaxy. That becomes an argument against the Big Bang. Maybe " Big Bangs ? "

  34. I love your explanations to questions raised. Too bad I began to appreciate and love the cosmos at age 62, but now that we have such brilliant scientists as yourself I can't get enough. Have you authored any books, I'd love to learn more. Thank you.

  35. Gene Bowdish asks Fermilab on YouTube :
    What if, the earth is moving and the sun is moving and the Galaxy is moving which might be that one twin is moving through space on the earth at 1,500,000 Miles an hour and the other twin is in a spaceship with a thrust of 1,500,00 miles an hour the other way which might mean that this twin is not moving at all in the spaceship … Who would get older as they move apart … ??? Gene Bowdish

  36. Just remember that you standing on a planet that's evolving revolving at 900 miles an hour
    It's orbiting at 19 miles a second so it's reckon an the sun is the source of all our power now the sun an you an me and all the stars that we can see are moving at a million miles a day
    In a outer spiraling arm at 40.000 miles and hour in galaxy we call the milky way
    Our galaxy its self contains a hundred billion stars.
    It's hundred thousand light years side by side
    It bolges in the middle 16.000 ligh years thick… But out by us its just 3.000 ligh years wide
    We 30.000 light years from galactic central point
    We go around every 200 million years our galaxy its self is only one of millions and billions in this amazing an expanding universe
    The universe its self keep in expanding and expanding
    In all of the directions it can wizz.
    AS fast as we can go the speed of light you know is 12 million miles a minute and that's the fastest speed there is

    SO remember when your feeling very small and insecure how amazing an unlikely is your birth.. An prey that there's intelligence life somewhere out in space
    BECAUSE I see fuck all of it down here on the way s earth…

  37. Imagine how much knowledge this lady has in that beautiful mind to be able to explain such complex things in such an easy way

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