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Blazing Speed: The Fastest Stuff In The Universe
Unfallversicherung writes "'If you're light, it's fairly easy to travel at your own speed -- that is to say 186,282 miles per second or 299,800 kilometers per second. But if you are matter, then it's another matter altogether.' Astronomers are now measuring matter that moves at 99.9 percent of light-speed. Jupiter-sized blobs of hot gas embedded in streams of material ejected from hyperactive galaxies known as blazars."
To get first post? ...probably not :(
This stuff is at rest. It's we who are moving at 99.9% the speed of light.
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How about linking to the original Space.com article?
Blazing Speed: The Fastest Stuff in the Universe.
I'm interested in how we can measure the speed of things that far away at that level of precision. Any measurement would rely on light from those gas balls reaching us at different times -- and as such, how can we tell that nothing is interfering with the light between there and here?
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Maybe its possible to travel faster then light then
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Thats impossible nothing can go faster than the speed of light.
Of Course Not! Thats why scientists increased the speed of light in 2208.
From TFA: "For us, the speed limit makes strange sense: Go faster than light, and you could return before you've left, become your own grandpa, or other perform other leaps of cosmic logic."
Someone's been watching too much Futurama.
Ah, how I love hillbilly journalists. Though the facts of the article itself are not incorrect, the way they are presented reeks of naiveté.
Gamma, the factor that in general relates quantities (time, mass, energy, momentum) in two reference frames in Special Relativity, is non-linear. Being within 0.1% of the speed of light does not place you any 'closer' to breaking it than being within 50% of it.
This is why instead of speaking of the speed of particles and objects travelling close to that of light, we refer to the kinetic energy they have, which gives a much more practical way of understanding these speeds.
My motorbike travels in Chile.
"Nothing we know of zips along more quickly than light. Einstein, nearly 100 years ago, said it's not possible."
Erm did'nt he say nothing(matter) can accelerate to the speed of light?
moo
1) Under the current physics, light-speed travel is impossible. As you approach the speed of light, the energy required to accelerate you further approaches infinity.
2) As you accelerate to 99.9% the speed of light, time slows down very significantly. Theoretically, at the speed of light, the passage of time stops, but since you cannot accelerate to the speed of light, that's a moot point.
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Dude, screw the asteroid detection. One of those things will only take out most of the world's costal area.
Whereas one of those blazar things could take out the whole solar system. Imagine the fireworks there, as a mass the size of Jupiter smacks into the sun.
Gentlemen... we cannot allow... a blazar detection gap!
www.eissq.com/BandP.html Ball and Plate System. Amuse your friends. Crush your enemies.
My buddy had a blazar and that piece of shit would be lucky to do 0 to 60 in 10 minutes.
AH HA get it? chevye blazar kekekekekeke kthxbye
I don't need no instructions to know how to rock!!!!
Theoretically. It would just go backwards in time. Nothing with mass can travel AT the speed of light.
I ain't a physics geek, but I did learn that much in college.
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In modern accelerators electrons routinely have energies of a few GeV, meaning that their velocity differs from c by probably less than one part in a billion (I can't be bothered to do the calculation, but the rest mass of the electron is about 0.5 MeV).
But what exactly is the speed of light? If I stand here and shine a laser, sure, it has a speed, but think about it: This planet is hurtling through space at breakneck speeds. Now add the speed of light from my laser to the speed the Earth is moving, and voila! You have a speed faster than the speed of light
First rule of relativity club is the speed of light is the same for all observers. Which means your laser will appear to be travelling the same speed for somebody travelling through space at "Breakneck speeds" as it would for somebody just leaning back in a chair sipping a Corona watching you.
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I don't have to think about it, Einstein already did it for me: the speed of light does not "add" to other speeds. Time warps instead. That's (very very basically) what the Theory of Relativity is all about.
TWW
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Not really, see this is exactly what special relativity explained. The speed of light is constant. If you're moving at 50% of the speed of light, and some light wizzes past you, it looks to you as if it were going at 100% of the speed of light (not 50%). And to an outside observer seeing you go past, it also looks like the light is going at 100% of the speed of light (not 150%). What has happened is that because you are going at 50% of the speed of light, time for you has slowed down, so the if the light goes past at what would apparently be 50% of c if time were not slowed, it still looks to you as if it were going at c.
So what would it feel like to get hit by matter traveling at 99.9% of light speed? It would probably slice thru the body like a hot knife thru butter and you would not feel a thing, if it's not too big that is. :)
LOL. Talk about misinformation and hype. It's trivial to transmit an interference wave with a phase velocity faster than the speed of light. That doesn't imply that you can send a signal with information content faster than light - the group velocity (the information carrier or signal you actually control) can't go faster than light.
That argumant is SO 1700's. You simply can't add speeds that way, unless the speeds involved are so low that there are only negligable relativistic effects. Read a little Einstein, the speed of light is constant, no matter who measures it or who produces the light.
It's easy to create signals with "phase velocities" faster than the speed of light, for example set up a series of identical oscillators such that the phase of oscillation is perfectly in sync (within a stationary observers frame). Such a system will have an infinite phase velocity, (or within the limits of experimental error it can easily be made greater than c). This phase velocity merely means the phase of the "wave" of the oscillation appears to travel infinitely fast from one oscillator to the next.
But the key point is that no information is transferred faster than the speed of light, and thus everything still adheres to the confines of special relativity. So the parent AC is correct that one can create an effective velocity larger than c, but one cannot do anything useful with it.
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how to add relativistic speeds
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If you're travelling at a very high speed (close to the speed of light) your time would, from an outsider's point of view, be slower (i.e. a second would last longer in your spaceship/whatever than on the outsider's watch,) given that the outsider moves slower than you. This means that if you flew off into space at a very high speed and turned around and flew back to earth after, let's say, 5 minutes (on a watch in your ship,) earth would have aged several thousand years (i.e. you would have travelled forth in time.)
If you wanted to go back in time you would have to move faster than the speed of light, which is impossible unless you use some sort of wormhole (which is completely theoretical.)
"If you're light, it's easy to travel..."
Did anyone else read this and think, "Well, I'm not overweight... so I can go really fast?"
-- I prefer the term "karma escort."
As I recall from a late 1990s lecture by Hawking, some matter can exceed "the speed of light" and in doing so, escape a black hole. At an event horizon exactly, that border at which matter including light either escapes a black hole or not, the position of particles is known with complete precision. As such, Heisenberg's Uncertainty Principle dictates that the speed of the particles cannot be known as precisely. Photons at the event horizon of a black hole are allowed, by a tiny quantity, some Scotty Factor in their speed because their position is certain. In plain words, these are the mathematics of the matter :) Some leptonic matter, in only such a particular position, can be slightly faster than "the speed of light."
As theorized, Hawking's predictions that black holes might leak have, I understand, been observed as radiation from what are as-yet assumed to be black holes. Anyone knowing more than I do about this particular phenomenon is (un?)certainly welcome to add more. The explanation Hawking made was directed at interested and able nonprofessionals; he put forward some mathematics around but not specifically deriving the surprising conclusions. Made sense to me, anyhow. I believe the matter discussed here, blasers measured at .999999... of light's speed, is the fastest measured "directly." But I do not believe this is the fastest known matter, if you allow that "knowing" the speed of the matter Hawking discussed (observed as radiation) was theoretical and later indirectly measured.
BG
Observing particles moving at 99.9% c is not so amazing as it sounds. First of all we routinely accelerate matter to great speeds for use in particle physics experiments (in places such as CERN, SLAC, FermiLab, Brookhaven, etc.).
As an example, the LEP accelerator at CERN which was used in the period 1989-2000, acceleratod electrons to about 99.9999999977% c.
But even outside the laboratories we have previously observed even larger speeds. The UHECR (ultra high energy cosmic rays) whose origin is still a mystery seems to consist of protons moving at speeds of 1-1^(-22) = 0.9999999999999999999999 c.
Furthermore, it might seem like we need absurd accuracies in our measurements to discern the numbers from each other. But we don't really - the speed of the particle is practically the same when 0.99c and 0.99999c are compared, but things like the momentum of the particle will still differ wildly. For the curious, the formula is: momentum = m*v/sqrt(1-(v/c)^2).
I've always been intrigued by Feynmann's conjecture that there's only one electron, which moves so fast that it appears in all the times/places in the universe that appear to be individual electrons. That accounts for "every" electron having identical properties - it's the same electron. But I suppose that setting different quantum properties, like spin, to different states, without seeing that state "propagated" to "other" electrons, defies that model. Or does it? Maybe we just haven't tested enough electrons, or maybe our technique for setting state actually sets the state of the (moving) space in which we measure that persistent electron state. Or maybe Feynmann had even more clever subtleties in his model. Or maybe it was all just a bad idea.
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Wouldn't such large, fast masses thereby account for the majority of "stuff" (matter/energy) in the Universe? If they were previously unaccounted, wouldn't that reduce the amount of "dark matter/energy" postulated to be bending the observable universe, by showing another gravity sink instead?
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"If you're light, it's fairly easy to travel at your own speed -- that is to say 186,282 miles per second or 299,800 kilometers per second."
:)
Light is faster with the metric system...
Doh!
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You should also read about the Oh My God particle (it's real and not a joke). This proton particle travels almost as fast as light. After traveling one light year, the particle would be only 0.15 femtoseconds--46 nanometres--behind a photon that left at the same time.
Banu
I suppose it must mean these gases travel at (nearly) the speed of light with reference to stationary objects. But of course, light itself still moves as fast compared to this stuff as it does compared to us.
The speed of light can be given in terms of other fundamental electromagnetic constants (1/sqrt(permeability of vacuum * permittivity of vacuum)), but I suspect that this doesn't really answer your question.
Now, the question does have a less profound answer that is not what you have in mind. A meter is DEFINED as the amount of time that light moves in 1/299792458 seconds, so light moves exactly at 299792458 meters per second. The miles per hour speed is just a conversion factor away.
E = m c^3 Don't drink and derive E = m c^3
You are right, unless you have particles like tachyons, which have imaginary rest mass. Such particles could travel only faster than light and will never slow down under the light speed.
Wikipedia has something about that: http://en.wikipedia.org/wiki/Tachyon
Not a bit. Relativity shows why it's not possible for anything with mass to move as fast as light, but doesn't prevent matter from moving at any lesser speed. As long as the blobs of gas aren't actually moving at the speed of light, there's no problem with relativity, general or special.
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God had to lower it to 186,000 miles per hour, or lose out on quadrillions of dollars worth of highway funds from congress. There are all sorts of studies proving that it conserves entropy or saves lives, but they're all bunk.
As you rightly point out, the speed depends on the frame of reference (i.e. the speed is always relative to the position of the observer).
However, adding the velocities the way you did is only possible with slow-moving objects (slow in comparison with the speed of light, that is). When dealing with fast objects, the Lorentz transformations creep in.
That means, for example, that shooting a cannonball at the speed 0.75 c from a spaceship that is moving at the speed 0.5 c in the same direction, you would get a cannonball travelling at some 0.8 c (my guesstimate, I'm too lazy to calculate it), rather than at 1.25 c. At low speeds, these differences are negligible and Galilean ("normal") transformations apply.
As for your other comment, when you really think about it ;-), speed does exist - not as an absolute number, but as a speed relative to something.
Yes, it is often said "the speed is 65 mph," but this is mostly a shorthand for saying "65 mph relative to the Earth." Two cars travelling against each other, each at a speed of 65 mph relative to the Earth, travel at a speed of 130 mph relative to each other. Both of the speeds do objectively exist, but it takes two to play the game - the object and the reference frame:-).
(Feel free to correct me, IANAP)
In math, something is said to approach infinity when its value increases endlessly, without bound. It may always have a finite value, but that value will increase past any arbitrary limit you care to name, not matter how high.
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IT doens't work that way. The speed of that laser will appear the same to any observer anywhere. The only thing that will changes is the observed wavelength.
Speed does exist, just not absolutely, it will always be percieved differently by different observers (except for the speed of light.)
The universe is stranger than you think.
I remember a SciAm article about cosmic matter (protons) actually going FASTER than light. The trick was that nothing goes faster than light in a vaccuum, but what about in air? When cosmic rays going .99c hit the interface of the upper atmosphere there are conditions where the refracted speed of light is less than the speed of those particles.
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First off, IAAAP (and I don't even play one on TV).
I understand this is true if the energy or gravity providing the acceleration is in a different frame of reference than the mass being accelerated (think particle accelerator or plasma blob).
But my layman's question is .. what about a rocket?
In a rocket, the energy to accelerate the rocket is in the same frame of reference as the rocket itself. The rocket converts mass into energy which accelerates mass and sends it out the nozzle to provide thrust. As the rocket approaches the speed of light (from Earth's reference, for instance) it becomes heavier and harder to accelerate, but so does the mass upon which it relies to convert into energy to provide thrust. The propellent is also heavier. My guess is that this would all cancel out in such a way that an astronaut travelling inside the rocket would have no way of knowing how close to c he is travelling at without looking out the window.
Now my understanding is that from Earth's perspective the rocket could only reach c at the end of time, but my question is this: given a sufficiently efficient rocket engine, is this the case for the rocket and the astronaut? If the rocket were capable of constant acceleration (for the comfort of the astronaut, lets say an acceleration of G) how long, from the astronauts perspective, would it take for him to reach c?
And once he got there (and he could only know if he looked out the window or kept track of time) what's to stop him from going further? It may be the end of time on earth, but how old is the astronaut?
Error:
The speed of light can be given in terms of other fundamental electromagnetic constants (1/sqrt(permeability of vacuum * permittivity of vacuum)), but I suspect that this doesn't really answer your question.
On the contrary, I think that answers the question perfectly. The speed of light is directly derivable from other fundamental constants which are inherent properties of our Universe.
And, of course, the way to answer the question "Why are those constants inherent properties of our universe?" is to invoke the anthropic principal: these constants are what they are because those are the values necessary to produce us, thus allowing us to ask the question in the first place.
"Jupiter-sized blobs of hot gas embedded in streams of material ejected ..."
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Actually, light does have mass, depending on how you define mass.
There is inertial mass, defined by Newton's second law (F=ma) as the proportionality constant between force and acceleration of an object) Since light doesn't accelerate, this definition doesn't apply.
What does apply is gravitational mass. We know newtons law of gravity, and we can measure how much light is affected by gravity, as in a black hole. This gives us a mass for light, since objects need mass to be affected by gravity. If use this "mass" for the light in other equations to calculate things like the energy of the light (E=mc^2) or the momentum of the light (p=mv), it all works out.
All material objects in the universe have both inertial mass and gravitational mass that are equal within an accuracy of any experiment ever devised. Light is strange in that it only has gravitational mass.
E = m c^3 Don't drink and derive E = m c^3
As an example, the LEP accelerator at CERN which was used in the period 1989-2000, acceleratod electrons to about 99.9999999977% c.
right, sure, but, an electron is one thing, a ball of gas the size of jupiter is another... on earth we accellerate tiny little masses to high speed... what they're measuring is something more massive than our own planet
Dude, even if you go from 0 miles/hour to the speed of light you're still accelerating
Unless the particle was created with an initial speed of greater than the speed of light. The relativity equations are mirrored, in that a particle travelling slower than light cannot accelerate past C, and a particle travelling faster than light cannot decelerate past C.
These faster-than-light particles are called tachyons, and though they are theoretically possible, no-one has ever detected them. Apparently, they'd be fairly easy to detect as well; since Tachyons travel backwards in time, one would have to look for an "effect-and-cause", rather than a "cause-and-effect", or so I've been told.
excuse my ignorance in physics, but i always wondered: if light has no mass then it has no speed or energy because E=MC^2, right ? if you insert a 0 in M, then 0 times C^2 is 0, thus E = 0
assuming that photons have mass ( or we would live in a very strange universe ) than at least is possible for some kind of mass to travel at the speed of light ( because light have mass and is mass because has energy and velocity )
so why would be impossible for other kinds of mass to travel at the speed of light ?
When people say that light is massless, they are referring to its invariant mass (sometimes incorrectly referred to as its "rest mass"); the full relativistic equation is,
E^2 = (mc^2)^2 + (pc)^2
where p is relativistic momentum. For light, m=0, and this reduces to E=pc (the energy of a photon is directly proportional to its momentum).
Likewise, when people say that objects with mass can't travel at the speed of light, they are referring to objects with nonzero invariant mass.
no, relativity teaches us there are no rigid objects. Consider a 12 inch ruler sliding along a long table with a 10 inch hole in it. If the ruler moves fast enough it will shrink (in the table's frame) enough to fall through the hole. But now consider the ruler's frame of reference. It is still 12 inches long and the diameter of the hole has shrunk. So how does it go through. By bending as it goes over the lip of the hole. (this can be worked out precisely and it *all works*)
There is a lot of talk and a lot of debate going on here with regards to the effects of near-light speed travel. A theory that seems to fit General Relativity and recent expeditions to measure a phenomenon called "Frame Grabbing" should provide some insight:
1- Any object that travels through space-time has an effect on space time. Think, for a second, of space-time as a gas. When you accelerate an object through this gas, much of the surrounding gas is pulled along with the craft due to drag. Any object/material traveling through space-time will pull along with it "Frames" of space-time. This, in theory, is the cause of Time Dilation, as predicted by General Relativity.
2- As you approach c, you are dragging more "Frames" with you. Hence the reason Time Dilation is more evident and further exagerated the closer you get to c.
3- To achieve speeds faster than that of c, the material must be "invisible" to space-time itself. Any drag on space-time, produced by a craft or any sort of matter will render any attempt to break the limit c impossible. Current linear motion produces an almost cavitational effect, where frames are, in essence, skipped while older frames are continually dragged by the mass causing clock skew and a need for even more energy to achieve acceleration. This is not dissimilar to the effect of breaking the sound barrier, only we are describing a completely different medium, space-time, not gas.
4- By skipping over current frames and dragging older ones with you, the time lapse occuring on or within that particular body will appear slower to the observer than said observer's time lapse. It is because of this that it is theoretically impossible to travel backwards in time and only possible to travel forward at different rates.
If anyone has any objections to this, let me know. IANAP (I am not a physicist) so I could be dead wrong. It is just that, this makes the most sense to me and seems to fit the facts best.
No. That equation has nothing to do with the speed or energy of a photon. It's only used to calculate the energy equivalent of mass, or the mass equivalent of energy. Just because a photon has no mass doesn't mean it can't have energy or velocity.
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nobody thought it was physically impossible for any body to move supersonically; not only did no law of physics forbid it, but there were well-known examples of supersonic motion.
That's basically all I'm saying. If we start to see examples of bodies (be that particles or planets) that seem to be traveling faster than c, then we really need to reexamine whether it is a fundamental limitation.
Some recent experiments already might indicate that it isn't.
So if I'm zipping through space at this speed, and you're passing by me traveling at the same speed but in the opposite direction, will I perceive your speed as nearly twice the speed of light?
bort.
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Okay, basic rocket physics:
:)
dV = Ve * Me / Mr, where dV is the change in velocity of the rocket, Ve is the velocity of the exhaust, and Mr is the mass of the rocket.
Now, basic relativity:
S = sqrt(1 - V^2/C^2) -> A scaling factor
M' = M / S -> Mass increases as V increases.
T' = T / S -> Time slows down as V increases.
L' = L * S -> Lengths decrease as V increases.
Now, if you just consider M, you're right. Me' / Mr' = (Me / S) / (Mr / S) = Me / Mr. Thus, dV remains constant, because the increases cancel out.
However, you have to consider that Ve is measured relative to an observer. Further, you have to remember that lengths and times measured by the observer are not the same as those measured on the rocket. Consider that a rocket is moving at Vr relative to a stationary observer. The observer can measure the velocity of the exhaust, Ve, by measuring how far the exhaust travels in a given unit of time.
Ve = L / T.
However, that "L" and "T" are actually L' and T', because the rocket (and it's exhaust) are moving relative to the observer. So:
Ve = L' / T' = S^2 * L / T.
Since S is always less than one (eg: S at 0.99c is about 1/7), Ve measured by the observer will be less than Ve measured by the rocket by a factor of S^2. That means, as the rocket accelerates closer to the speed of light, Ve measured relative to the observer approaches zero. As a result, the rocket cannot ever accelerate to the speed of light.
My numbers could be completely wrong, but hopefully I remember my rocket physics well enough from class that the results are correct
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...the idea that if the astronomers had simply got the distance to the host galaxy wrong? Say the gas is moving towards us a little, thus appearing hotter/faster in addition to the putative distance error, and the host galaxy is exhibiting a genuine doppler redshift in reaction to this, thus appearing further away?
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Interesting theory, but whouldn't its transferance from atom to atom create some sort of electric 'jetstream' as it takes the path of least resitance over and over again in order to be everythings electron? Still, nice to learn a new theory on /. that doesnt have anything to do with computers.
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excuse my ignorance in physics, but i always wondered: if light has no mass then it has no speed or energy because E=MC^2, right ? if you insert a 0 in M, then 0 times C^2 is 0, thus E = 0
That's a good question, and the answer is very simple. The equation E=MC^2 is a simplification. The actual equation is E^2=M^2*C^4 + P^2*C^2, where P is momentum. For particles at rest, momentum P is zero, so the equation simplifies to E=MC^2. For photons, rest mass M is zero, but they are always in motion, and the equation is E=PC. (Photons do have momentum even though their rest mass is zero.)
Faster than light travel simply introduces i...
Introduces i? You must be imagining things.
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No, it can't have any mass or it wouldn't be able to travel at c. It has energy, of course, and that energy can be considered to be equivalent to a certain mass, but that's different.
There are two ways you can think about gravity affecting light. One way is to think of it affecting the mass-equivalence of the photon's energy. The other way is to think of gravity as bending space so that the light travels in the straightest line possible in warped space.
Remember that any effect you can get from gravity you can duplicate with acceleration and the other way around. It's easy to show that if you accelerate at right angles to the path of a light beam the beam will appear to bend, so the same thing must happen when the light passes through a gravity well.
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Ok, I'm game. Here's some bullshit which I do not believe is at all likely to be true but argues by analogy with another system where an "impossible" barrier is broken.
An old exercise in quantum mechanics is to show that a particle can pass a barrier which is too high for its (classical) energy to get over. The process is called tunelling, and relies critically on Heisenberg's uncertainty principle. In particular, a particle's energy is uncertain if it is measured for a short time. There is a probability that the energy may be sufficiently greater than the barrier's height ...
The analogy should now be obvious. A better understanding of physics may enable us to work out how something can tunnel through the speed of light barrier without actually going over the top of it.
As I said, the above argument has no physical justification, AFAIK.
Paul
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