What is the fastest that any amount of verifiable matter has been observed to travel either in space or in experiments. Distance of travel doesn’t matter.
Technically, speed is always measured relative to something else. But let’s stipulate that we’re asking about the fastest speed relative to earth.
In 1991, an extremely high-energy particle was detected hitting the upper atmosphere. It’s not exactly clear what the particle was, but it was almost certainly no bigger than an atom, and most likely an iron nucleus. If that’s what it was, then its speed (relative to the earth) was 99.9999999999999999985% the speed of light.
I thought these were interesting on a human scale:
And the hypersonic manhole cover!
http://savvyparanoia.com/the-fastest-man-made-object-ever-a-nuclear-powered-manhole-cover-true/
Before coming back to the topic within physics, I wonder if anyone (scientist or not) senses something unsatisfying about more “knowable” real world analogies used in physics.
From the wiki on ultra high energy cosmic rays: (Ultra-high-energy cosmic ray - Wikipedia), on the event cited above:
Normally these kinds of analogies can be shockingly illuminating (if they’re good ones), but this one, interestingly, I think, falls flat. When you put it like that, to me it seems “meh.” Why? This is what I think: “Well, hell, any Major League pitcher does that every pitch–and a nucleus must be a zillion times lighter than a baseball. A bowling bowl is hard for me to throw; a baseball is lighter and takes less effort, so for anything lighter it would take even less effort–so don’t get what the big deal is.”
I know where that reasoning goes off. But why does f=ma seem counterintuitive in this case?
Because it’s about energy, not force.
Let’s run with your bowling ball comparison. A bowling ball weighs perhaps 7 kg and I’m sure you have no trouble throwing one at 6 m/s (~13 mph). That’s 126 joules of energy.
To put the same energy in a 142 gram baseball requires throwing it at 42 m/s, or 94 mph. Despite being the same amount of energy, it’s far more difficult for a human to accomplish.
How about a whiffle ball? They weigh about 20 grams. You would have to throw one at 250 mph for the same energy as the bowling ball. No human can do that.
So it’s the very fact that atoms are tiny that makes it astonishing. It’s easy to see at a human scale that it gets more difficult to pack a certain amount of energy into an object, the smaller you go. The Large Hadron Collider is a massive thing that cost billions, and can still only push particles to about a 50 millionth of the energy of the OMG particle.
While it doesn’t break the record for highest energy, given that neutrinos have a much smaller rest mass than protons, the high-energy neutrinos detected by the IceCube array probably hold the record for highest velocity/greatest time dilation.
If such a particle was hitting my head, how would it feel? Would it feel similar to having an actual baseball hitting my head? Worse because the impact would be concentrated on a tiny point? Would I feel nothing because it would pass in between the atoms of my body? Would it cause any damage?
If the OMG particle itself hit you, it would probably pass right through, depositing only a small amount of its energy, and doing you little or no harm. If, however, it hit atmospheric particles in front of you, that interaction could result in a bunch more particles with not-quite-so-much energy, and those particles could in turn interact with more, and so on (this is called an atmospheric cascade). Get hit by the cascade, and you might get a burn.
Indeed. Just like another strangeness from the atomic world is the strength of the strong nuclear force – the force that holds protons together in the atomic nucleus despite their mutual repulsion. Despite the fact that an atom is inconceivably tiny beyond any possible bounds of human comprehension, the repulsive force of the protons in a typical nucleus is of the order of several pounds. IOW, there’s enough energy in the nucleus of a single atom to knock your cup full of coffee right off your desk. It’s an interesting perspective on the nature of nuclear energy.
Much like the question of what would happen if you created a microscopic black hole with a relatively small mass, like that of a mountain. As long as it was moving fast enough, it was pass right through the earth’s center and disappear out the other side and no one would ever know it was here. To such a particle, the earth would look no more substantive than the vacuum of empty space.
That’s another good one.
An underappreciated fact is that what we call nuclear bombs are perhaps more accurately called electromagnetic bombs. It’s largely the stored electromagnetic energy in the nucleus (from the protons pushing on each other) that is released in an explosion. The nuclear force is just the string that holds the nucleus together–the electromagnetic force is the spring that actually holds most of the energy.
Which leads to an interesting fictional weapon: A strong-force neutralizer beam. The matter hit by the beam of PFM suddenly loses its strong force. So the electromagnetic forces have free reign. Each proton in each nucleus repels all the others violently.
I don’t know enough nuclear physics to say how much energy gets released, and I’m too lazy to wiki it up, but it’d be a very impressive number. Not quite like a matter/anti-matter annihilation, but impressive nevertheless.
If you get close enough to a magnatar (star) the magnetic field apparently is strong enough to disrupt bonds enough that you’ll dissolve into your basic atoms.
Why aren’t Our Best Men working on this at Livermore?
Although you are conceptually correct that the kinetic energy of the resulting products comes from the release the strong nuclear (or color) force and are repelled by electromagnetic repulsion, it isn’t quite right to call the stored energy “electromagnetic energy”. The energy exists is shared between the balance of the fields, not withstanding the energy released by conversion of a neutron or proton from beta decay. The resulting release of decay products (nuclei, beta particles, and neutrinos) is kinetic (inertial) energy; the x-rays and gamma-rays are electromagnetic fields. Energy, as a measurement, is really a state that can only be defined by the interaction between to fields or activity above a baseline.
Stranger
I hate when that happens.
I was being slightly tongue in cheek of course–it’s a complicated system and it’s tough to really pin down where all the energy really comes from.
To be slightly more accurate, it’s actually the residual strong force that we’re talking about here. As a whole, the strong force is responsible for most of the mass-energy of the nucleons, and hence the atom. The residual strong force–i.e., the fact that nucleons are not point particles–is what keeps the nucleons together at close range, but when a large atom is perturbed sufficiently, the EM forces can take over and split the atom.
It’s in this sense that I mean the EM field is where most of the energy comes from. Energy is force times distance, and although the residual strong force is quite powerful, it operates over only a short range, and so contains a (relatively) small amount of energy compared to the EM field (which operates over a longer range).
Interesting. It would also appear that English is not their first language.
You know, I hear the Mythbusters guys are looking for something big for their last episode.