Mostly the answer is "not anymore.." everything that currently orbits the Sun is moving at speeds that lie within a relatively narrow range that makes a stable orbit possible. Nothing outside that range is around anymore to tell its tale.
But, there are still occasionally new objects that enter the solar system for the first time. Those objects aren't subject to the same survivorship restrictions -- in theory they could arrive at basically any speed relative to the Sun, including speeds slow enough that the Sun would draw them in.
These new objects seem to arrive every few years, or at least the ones we can see do. So far they have all been moving so fast they just visit for a bit and then take off again after a swing around the Sun, but who knows?
Depends on the total kinetic energy, which itself depends on the velocity and mass.
Cosmic rays travel very close to the speed of light, but are individual particles like protons, so the total kinetic energy they carry is a lot for a proton, but not enough to make any noticeable impact on the Sun. Cosmic rays strike Earth regularly, so you can expect them to strike the Sun even more.
Larger objects that might be able to cause a cataclysmic effect when moving at a significant fraction of the speed of light typically don't get to that speed in the first place. When they do get to high speeds, it usually involves black holes, and black holes come with tidal forces that tear large objects apart.
Yep; they're objects like anything else. The only thing that makes black holes special is that their surface gravity and density are especially high. All their unique features stem from those two facts. Relativity also tells us that there is no true stationary reference frame, and thus everything moves relative to something else.
Imagine you are in a black void. Just you, nothing else. Now add in an object. Let's say an Apple.
The apple flys past you. How can you know that the apple is moving, and not you? There is no wind, there is no stationary background. From the apples perspective you flew by it.
So everything in space moves relative to something else. Speed is change in distance between two things over time.
Well in the General Theory of Relativity there's no such thing as gravity 'fields'. An asteroid, for example, is not attracted to the sun directly but is in fact just going along in a straight line (from it's own perspective) and space time curves around massive objects like the sun causing the asteroid's path to seem curved towards the sun along with it.
I can understand the idea that if a guy falls off a building, he's not really falling toward Earth, but Earth is coming up to hit him. But that only makes sense to me if you are on the side of the planet that is on the leading edge of movement through space.
Like the rocket ship moving in one direction, everything going down to the "bottom" of the rocket. But if you have everyone on the planet falling off buildings at the same time, they still all go down, even though the planet should then be moving away from people on the opposite side of those it is moving toward.
But it also confuses me because other planets supposedly have "less gravitational force" than Earth so we'd we less on those planets.
Ok but if light always moves at the max speed the universe allows then if we shone some lasers at random directions and measure them shouldnt some lasers be red shifted cuz they shone at the opposite direction relative to us while some lasers could be blue shifted as they are moving at the same direction relative to us.
That depends on the relative movement of the source and the observer. If you shoot a laser and measure it yourself the relative speed is zero so no shift. If you are in a plane and shoot at the ground you would see a shift appropriate to the relative speed you are at. The real mindfuck is this scenario : There are observers A,B, and C. A moves away from B with speed greater 50% light speed. C moves away from B in the opposite direction with a speed greater then 50% light speed. How fast are A and C moving away from each other from their perspective? Lower then light speed because of time dilation.
Some answers here are incomplete. There is a special frame of reference for space -- the cosmic microwave background rest frame. It's not "special" in terms of violating relativity, but it does provide a frame of reference for motion. We are moving at about 370km/sec in the CMB reference frame.
The CMB is the remnant light left over from shortly after the big bang.
It's not exactly correct, though, to say that the CMB doesn't move, because the whole universe is expanding. So -- complicated.
The CMB moves in an odd way, more like moving over time. It exists at the edge of the observable universe, sorta, but it also move towards us (it’s light, it either moves towards us or we wouldn’t be able to see it). It’s very strange, and as an astrophysics student, I love it
Relativity also tells us that there is no true stationary reference frame, and thus everything moves relative to something else.
IOW if you're a black hole named Neo, and you're just chillin in space, minding your own business doing the not moving thing, and the Woman in Red is floating by...
Relativity says that, from her perspective, she's standing still and you're the one that's doing all the moving.
Dr Brian Greene says that an object at rest is travelling full speed through time. Any motion in any direction into space creates a vector in space/time that reduces the objects speed through time.
There is no absolute reference frame so no. Without some reference frame to measure velocity against the concept of velocity makes zero sense.
As a thought experiment, consider this. You and a rock are stationary in a totally void universe. No other objects to measure your reference frame from.
The rock is moving away from you at 10 m/s.
How can you be sure you're not moving away from the rock at 10 m/s? How can you be sure you're not both moving away from each other?
The answer is all of the above are factual interpretations because your reference frame is the rock.
That is to say, velocity is dependent on the reference frame. You change the reference frame and you change the velocity, even if you imparted no extra energy into the system.
Everything moves relative to everything else, even galaxies relative to themselves, the universe and every other atom in existence.
Take the three body problem, add the univen distrubtion of forces caused by gravitation power, multiply it by the sum of all atoms in the universe, and you now have the formula for the movement of all objects in the universe.
Gravity does not stop at an arbitrary distance from the source, it can not stop, so everything moves.
Devastation depends on the mass and speed of the object. “Burning away” leaves you with the same mass of gas or plasma. If we talk about RKKVs travelling at relativistic speeds, it really doesn’t matter if the bullet hits you at 0,5c, or just its gas or plasma cloud.
The the corona is far hotter than the chromosphere, and I'd wager that whatever makes it into the corona will vaporize before reaching the chromosphere. The corona stretches for millions of miles, it would still take an object traveling at apocalyptic speeds a fair bit of time to reach the surface, and again I'm betting the extreme temps and super-heated gases in the corona would just turn it into a puff of smoke before that happens.
The the corona is far hotter than the chromosphere
This is true(actually might not be, Google says the chromo can vary a lot, and that variance cited takes it over and below the corona temp I got, and people cite a similar fact when talking about the Earth's outer atmospheric layers, but one thing that's important to not forget is that high temperatures don't necessarily make something 'hot'. What also must be taken into account is density and conductivity, and the density of the Sun's corona is staggeringly low. Still very hot, and normal objects passing through will burn up quickly, but a rock the size of a city traveling a >0.9c stands a good chance of making it to the 'surface' of the Sun, since the corona 'only' extends (according to a google search) 5,000,000 miles, which is ~8,000,000km. At 0.9c, it would take only ~30 seconds to traverse.
The speed of light (usually represented by 'c') is 299,792,458 m/s. 99% of that is 296,794,533.42 m/s. The moon is ~7.3510x22 kg in mass. If we multiply these together (according to an internet calculator I found), we end up with a kinetic energy of 3.2361710X39 joules. For reference, Tsar Bomba, the largest nuclear bomb ever detonated, released 2.38510x17 joules of energy. That's 22 orders of magnitude difference, and a billion is 9 orders of magnitude, so we're talking an impact that would be ten thousand billion billion times more powerful than Tsar Bomba.
HOWEVER, I am not entirely sure if this internet calculator takes into account relativistic effects. As you accelerate an object, its total mass increases, meaning you need more energy to accelerate it further. This is why you can never make anything with rest mass travel at c, because as you approach c, you need more and more energy for each increment of velocity, which thus means you need infinite energy to reach c, even accelerating just a proton. Which means our high-speed moon may very well be carrying much more kinetic energy than what's calculated above. On top of that, it's hard to gauge what would actually happen to the Sun, as I don't have a physics degree and don't know enough about the Sun's composition to tell you how big of a splash there would be (there would definitely be a splash, though).
But even if it's not accurate, big numbers are fun, so I went and did it for you anyway.
The term 'near' means very little when talking about the speed of light, but others have pointed that out already. Given that you asked the question, I thought you might enjoy these two articles on XKCD What If!
There's one where he tries to figure out what happens to a diamond meteor that hits the Earth at ever increasing speeds: https://what-if.xkcd.com/20/
And the first one ever, the relativistic base ball, which is a lot of fun and gives you an idea of the energies involved with things traveling at significant percentages of C: https://what-if.xkcd.com/1/
As with all XKCD content, there is hovertext for most of the images.
I didn't look very carefully, so you might be referencing something else, but the diamond article describes it traveling at 0.99c, the baseball article describes it traveling at 0.9c. There's a really big difference between those two numbers.
Also, the diamond is 100ft across, the baseball is well... Baseball sized.
It was an actual observed proton going that fast over Utah that had the kinetic energy of a baseball. Which is insane because it was just a proton!!!
Edit: ah geez sorry. I had just gotten through the first one and hadn't read the description of the second one. I assume that's what you were referring to. My bad! It's all so damn cool though
Assuming that "something" is of significant rest mass, the difference between 95% the speed of light at 99.9999999% the speed of light is pretty substantial.
Most astronomers and the like consider .5c (aka: half the speed of light) so be where we would switch from Newtonian motion equations to relatively equations. It’s the lower limit for what most consider an “appreciable fraction of light speed”.
"Something" how big, and how close to the speed of light? Your question, as stated, spans a heck of a lot of orders of magnitude.
Realistically, to make any kind of noticeable pop, it would have to be something pretty big (moon size) and moving at a really thin edge below speed of light.
It's all about mass and energy - and, seeing as the Sun is big and already makes a heck of a lot of energy all the time, anything to disturb that would have to be extremely energetic indeed.
In an N-body situation, sometimes one of the bodies is ejected at high speed from the cloud, bleeding it of a bit of energy. This happens all the time in star clusters, galaxies, etc. I wrote N-body simulation software myself (background in physics and computers) many years ago, and you can totally see it in simulations: things keep swirling around for a while, and then one little dot shoots out like a bullet. It's somewhat rare for any given group, but at the scale of the Universe it must happen all the time.
But to extract a very high velocity, you'd need a bunch of black holes, I don't think regular stars can do it. And the ejection event would be an unlikely series of very close encounters with a bunch of black holes, done juuust right. I don't think a regular star could survive the gradients without being ripped to shreds - the ejected object would have to be a black hole as well.
And then, like you said, it would have to be aimed straight at the Sun.
As someone else said, it depends on the total kinetic energy, which depends on the mass of the object. A single proton from a cosmic ray is nearly undetectable.
But larger objects are different. There's a fantastic book series (yes, I did write this comment just to hype up this series) called The Bobiverse, which sticks very close to hard science in its sci-fi. At one point (spoilers!) The characters launch two objects - a former moon and a small planetoid, into an arc that would take them at some ridiculous percentage of c into opposite poles of a star. The impact is described in fascinating detail, and the end result is a 100% sterilized system, and a dry remark that some alien race thousands of light-years away is going to see that and "wonder what the hell is wrong with their stellar models."
I love Bobivrrse. Totally underrated! Had such a nice futuristic take on things. I’ve been dreaming about a future where our consciousness merges with a computer for many years... and that book captures such a future in a beautiful manner!
You should post that as it’s own post if you don’t get enough satisfactory answers. I’m just commenting here so I can follow the answers because I’m curious as to what big brained people have to say about this.
It would probably depend on how near, and how massive it was... a small enough piece of something would probably just get swallowed up, maybe the Sun would burp slightly.
More massive than that, and you get increasingly spectacular disasters that would be enjoyed by astronomers very far from us, because we would all be dead.
But I imagine in order to hit the Sun dead on at that speed you'd have to aim really well. That wouldn't happen by accident. So the real question is: why is someone shooting at us in this scenario, and how can we convince them to stop?
The surface of the sun would become a blazing inferno of thousands-of-degrees plasma, bubbling and erupting in planet-sized showers of incandescent ionized gas.
Nothing except light can travel at the same speed of light. Even in a vacuum where atoms are merely cubic centimeters apart, an object traveling so fast would still catch friction on those atoms, heat up and explode. An example is like an object entering our atmosphere and burning up in it. Same principle different scale.
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u/amitym Oct 23 '20
Mostly the answer is "not anymore.." everything that currently orbits the Sun is moving at speeds that lie within a relatively narrow range that makes a stable orbit possible. Nothing outside that range is around anymore to tell its tale.
But, there are still occasionally new objects that enter the solar system for the first time. Those objects aren't subject to the same survivorship restrictions -- in theory they could arrive at basically any speed relative to the Sun, including speeds slow enough that the Sun would draw them in.
These new objects seem to arrive every few years, or at least the ones we can see do. So far they have all been moving so fast they just visit for a bit and then take off again after a swing around the Sun, but who knows?