Wednesday, 9 November 2011

Anti-matter

The latest xkcd comic led me to read about the Kardashev scale on Wikipedia, which is one of these wonderfully pointless ideas (such as the Drake equation) dreamt up by people who I'm sure, like me, read a lot of science fiction as children, and are consequently fascinated by the idea of extra-terrestrial life and ultra-advanced civilisations. But that's not what I want to discuss here. The article mentions anti-matter, and this is a concept which is often misunderstood by non-physicists.

So what is anti-matter? Our world is made up of particles — the stuff around you is made of atoms, which in turn are made up of electrons and atomic nuclei. Electrons seem to be pointlike, while the nuclei are ultimately made up of other seemingly pointlike particles called quarks and gluons. Quantum field theory, which represents our current best understanding of how the universe works on the fundamental level, tells us that for every type of particle, there is also an anti-particle. It has exactly the same mass as its corresponding particle, and the same spin (a number which measures how fast a particle rotates, in a technical, quantum mechanics sense!), but the opposite charge. For example an anti-electron, which is usally called a 'positron', is identical to an electron in every respect, but has a positive electric charge instead of a negative one. A similar statement holds for all anti-particles — they are exactly the same as the corresponding particle, except for their charge. Note that we actually know about more types of charge than just ordinary electric charge, such as the 'charge' carried by quarks which holds them together to form protons and neutrons. All of these charges are reversed for an anti-particle.

In fact, since what we call 'positive' and 'negative' charge is just a convention, the only real difference between matter and anti-matter is that our universe contains a lot of matter, but almost no anti-matter. Why is that, you ask? That's a good question. In fact, it's such a good question that nobody knows the answer!

In newspaper articles and other places, one sometimes reads that when matter and anti-matter meet, they "turn into pure energy", or some similar nonsense. I say nonsense, because there is no such thing as 'pure energy' (see below for a caveat to this statement). So what does happen when, say, an electron and a positron annihilate? Their energy is typically carried away by photons — particles of light. Photons are somewhat special — because they don't have any charge at all, an anti-photon is exactly the same as a photon. Sometimes we say the photon is its own anti-particle. But although they don't have charge, photons do carry momentum and angular momentum, and if you carefully measure this, it can tell you about the momentum and spin of the original electron and positron. You certainly wouldn't know anything about those quantities if I just told you the total energy of the pair of particles! The lesson is that energy is always carried by something; there is no such thing as 'energy' in the absence of any particle to carry it. A related issue is the apparent widespread misunderstanding of what Einstein's famous equation E = m c^2 actually means, but I might write about this another time.

For now, I want to leave you with some exciting semi-recent news about anti-matter. Because anti-matter behaves exactly the same way as ordinary matter, it can also form atoms, the simplest of which is anti-hydrogen. Until recently, scientists could produce anti-hydrogen, but only keep it trapped for a fraction of a second before it annihilated with some ordinary matter. Earlier this year, however, the ALPHA experiment at CERN (where the LHC is currently doing its stuff, but that's not all that happens there) released a paper in which they announced that they had successfully trapped atoms of anti-hydrogen for up to fifteen minutes or so. This will allow them to study, for the first time, detailed properties like the energy levels, to test whether these really are exactly the same as for ordinary hydrogen, as theory predicts. For the cognescenti among you, this is a consequence of CPT invariance, which holds in any Lorentz-invariant quantum field theory.

(I said earlier that there was a caveat to my statement that there is no such thing as pure energy. In fact, Einstein's theory of general relativity allows space itself to have a non-zero energy density — this is often referred to as the 'cosmological constant' for historical reasons. This energy is uniformly spread throughout space, and does not have any associated momentum. A constant energy density like this certainly cannot arise from the annihilation of two particles of matter and anti-matter, which is why it was not relevant above.)

13 comments:

  1. 3d bioprinting = Immortality = go to stars ((typewrite: interstellar travel constant acceleration))

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  2. ...interstellar travel not acceleration constant (laser)... L=2*3.14*r... that beam of a laser pointer that turn 180º, from horizon to horizon, in 1 second and 4 imaginary semicircular screens located, for example, to the distances from Earth... 1: 95493 kms... 2: Moon (384403 kms)... 3: Sun (150 Million kms, 1.5*10^8)... 4: Andromeda (2 million light years...19 Trillion kms, 1.9*10^19), Universal Large Scale: 1 billion=1 million of millions, 10¹²)... The mark of laser pointer to reach, would move alongside each screen to an angular speed of 180º/sec and a linear speed, based on the light, of...(3.14*r)/c... km 95493=1c... Moon=4c... Sun=1570c... Andromeda galaxy= 198 Billion*c, (1.98*10^14)*c... If turn laser pointer to the right, why is going to bend each laser beam to the left, not to exceed c, from km 95493, radius "frontier" in which the speed of laser mark on the screen = c ?... Decreasing magnitudes have a close limit, but growing...have an "infinite" limit to our knowledge, understood here as "infinite", at least, an exorbitant figure... As with the TEMPERATURE (-273 ºC → "infinite")... MATTER (quark → "infinite")... TIME (0 → "infinite")... SPACE (0 → "infinite")... why it would be SPEED different?...(0 kms/sec → "infinite")...

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  3. (2)...interstellar travel not acceleration constant (laser)... the question is to ask oneself whether we should consider as a real or fictitious speed the apparent displacement of laser mark on the scrren. Because (apart from the different photon´s wave trains that make up the light beam are "almost" parallels, that is divergent, increasing the cross-sectional area of light beam with distance, and becoming thus increasingly tenuous) it´s really not the same light beam that rotates, but an "unlimited" number of light rays with limited length, leaving together from light source but, on turning this, grow apart laterally from each other, as the ribs of a fan, with increasing travel distance; as we see in harbor lighthouse that rotates and the look towards us, seeing 1 beam of light instantly. So, as go turning laser pointer, each laser beam that go out in direction going straight and to reach screen leaves its mark a moment, the next beam leaves its mark a moment, etc...separate two adjacent marks for a dark space, bigger in each farther semicircular screeen, proportional to the radius. What we would see, as in frame of a movie, how the continuous displacement of 1 single mark apparent... Of course at an Andromeda´s radius, without obstacles, the photons of each waves train would arrive...but the others photon´s wave trains of laser beam would be so far...that would not see the mark.

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  4. (2b)...interstellar travel not acceleration constant (laser)... But, if someday could make a laser-ray with its photon´s wave trains auto-correcting the divergence...how if they go away inside of a fiber-optic tube reflecting on the walls without can go out, although the ray would travel millions of light years, to the end would arrive the beam cross-section with the same area that beam departed from the light source... Laser/Antilaser? Trajectories: photons divergent, perhaps antiphotons convergent?, then would go 2 concenter "tubes of light" ◙, normal photons interior-tube divergent/antiphotons exterior-tube convergent, perhaps repulsion photon/antiphoton...the exterior-antilaser prevents go out outside the interior-laser; and the interior-laser prevents go in inside the exterior-antilaser...maintaining always the same diameter... What would happen to arrive those intact laser marks to the distant semicircular screens?...hyperluminal-speed.

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  5. (2c)...interstellar travel not acceleration constant (laser)... Light from Andromeda, photons divergent (on Earth there are reflection on dust´s particles, but in space...radiation-pressure inside of the light´s beam to the beginning of go out from its source and the beam still has high density of photons?)...although...if all they diverge, or not it would be sighted, or Andromeda would be sighted without details how a diffused spot amalgam of photons from different stars, the fact that in telescope its stars can be sighted how ░░light´s dots░░, indicates that Some Photons, perhaps into the center of the light´s beam stabilized by the exterior layers, they do not diverge and go away in straight line those central photons always from the beginning, permitting thus to see that star how a clearly defined • light´s dot...

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  6. ...interstellar travel constant acceleration (without religion "feasts": Inquisition)... when until goes to continue the world the "feasts" of religion enduring?... What a beautiful is the "Christ"mas!, but...that still only has the splendid showcase and after with the back-room of religious gloomy darkness, horror and crime. No more wiles to innocents, make already the authentic Birthmas, the Nativity from the wonderful real women, and not from the inhuman-religious tales. Have to transform already ALL the "feasts" of religion into TRUE HUMAN FESTIVITIES, that not "pagans", nor do "mundane". Have that send already once and for all the religion, what religion, mine, yours, or of those?, all religions: the religion...to the trash. Without delinquency, a New World based on Truth and Justice. No more religion for to continue "forever and ever" the religious infecting global media, enterprises, governments, schools, high schools and universities with their ancestral system buys-wills, if you want have a job, home and a car on the door, already you know put the neck in the priests, with their thousands of millions of "believers": Bought, or Innocents, or Ignorant... A Planetary Convention to select the True Starting of the History...if from beginning of the Bronze Ages: on Earth Planet, century 66... Merry Birthmas and Happy New Year 6519.

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  7. (2)...interstellar travel constant acceleration (without suffering)... in that Brazil of the miserable ones, they say that for "to clean" the streets for the World Football Championship,,,the polic,,,assassi,,,childr,,, (someone of those majors children is capable of to kill for robbing the shoes, but the vermin are who governs and convert them in that). And FIFA "get to knew nothing", they would must to have done suspend the damned World Champioship and to observe 1 minute of silence for those innocents "swept away" from the streets and from the life... Can watch in photographs to two little girls begging alms, the tender creatures are joined for mutual helping to carry their solitude and abandonment... When the night goes down, to where they go?...they have searched instinctively, such as all living beings, a place for take refuge...the place of the darkness, the place of the distance, the place of the fear, the place of the rats present over there too...one day another day, one night another night... Where is that "God"?, in the homovices ceilings of the Vatic ano. Where the hope?, where the tenderness?, where the education?...at none part. Others ones, carry glue to them for inhaling and forgetting and for dying.

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  8. ...interstellar travel constant acceleration (without suffering)... in the Brazil of the "Ordem e Progresso" the "children of the street" abandoned such as if they were dogs...in countries of Orient as Lebanon, children almost babies thrown away on the ground together with an adult begging alms, already from their more tender infancy they get accustomed to look the World from down and suffering...children dying of cold into refugee camps in countries with endless religion´s wars...and meanwhile shameless multireligious-pontifices in their golden palaces eating partridges, and well sheltered with the best wool in the best blankets made in England, the best boots...and not fall down their faces of shame when they look to themselves in the mirror... How they can have $50,000 million in the Bank, living on a golden skyscraper and to be dedicated to want build a barrier-wall, instead of to be dedicated to saving to all those who they can?... THE WORLD CAN NOT CONTINUE INDIFERENT TO THAT HORROR AGAINST THE INFANCY... ALL those children who are suffering must be rescued and be in ward by the State and be delivered in ADOPTION to all adequate FAMILIES OF THE WORLD who want adopt them... Children 8,500 die of hunger everyday on the World... Off with religion, off with monarchies and off with politicians shameless.

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  9. ...interstellar travel constant acceleration (times to reach light-speed)... 1g (9.8 mts/sec²)=354 days ...↓... 0.5g (4.9 mts/sec²)=1.94 years ...↓... 0.25g (2.45 mts/sec²)=3.88 years ...↓... 0.1g (98 cms/sec²)=9.7 years ...↓... 0.01g (9.8 cms/sec²)=97 years ...↓... 0.001g (9.8 mms/sec²)=970 years ______ Huge constant acceleration the ship, living areas to 1g: inside the living areas..."the same as going submerged in water"...↓↓↓↓g (motors)...less...↑↑↑g (gravitational transformers)=↓g... ...↨... 2g (19.6 mts/sec²)=177 days ...↨... 10g (98 mts/sec²)=35.4 days ...↨... 100g (980 mts/sec²)=3.54 days ...↨... 1000g (9.8 kms/sec²)=8.5 hours ...↨... 10000g (98 kms/sec²)=51 minutes ...↨... 50000g (490 kms/sec²)=10.2 minutes ...↨... 100000g (980 kms/sec²)=5.1 minutes ...↨... 1 million G (9800 kms/sec²)=30.6 seconds... ((typewrite: interstellar travel constant acceleration))

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  10. ...interstellar travel constant acceleration (Sun-Deneb: 1000g)... Earth...the 2 ships that will go formation flying for mutual assisting if there are problems...indestructible structures made of Hexapentas material, awaiting in airport the arrival of passengers... Day 1: zero-speed... THE SHIPS TAKEOFF►... navigation computer places on screen the spacecraft in the center of sphere...spherical\tridimensional\spatial\Heading: Deneb... Antimatter rocket engines...ON... Here we go...goooooo!...1g...10g...100g...constant acceleration cruise: 1000g (9.8 kms/sec²)... Inside the living areas (the same as going submerged in water: constant acceleration downwards...less...constant thrust, constant acceleration, from water upwards)...the gravitational transformers, perfectly synchronized with the acceleration, running: 1000g constant acceleration toward the floor ↓↓(motors)↓↓...less...999g constant acceleration toward the ceiling ↑↑(gravitational transformers)↑ = 1g constant acceleration toward the floor↓... 8.5 hours: light-speed = 1c...the fusion reactor as an artificial sun illuminating the immense Vital Support Gardens to lowering, from their comfortable apartments, cheerful passage to the pool...the electromagnetic shield anti-radiation...antigravity fields generator run forward, working: light objects away from the path of the ship...and trajectory ship away from the heavy objects...superluminal-speed > 1c... 42.5 hours: reaches hyperluminal-speed = 5c... Day 508: Half Journey...1000 light years...high hyperluminal-speed = 1435.39c... OFF engines...a few minutes of weightlessness during maneuver...the ship rotates 180º around its axis...motors ON again and... ◄STARTS TO BRAKE... Day 1017 (2.79 years): End Path party...2000 light years...zero-speed... The forever young passage of the 1st Immortal Generation (3D Bioprinting...Telomerase...modified Biological Timers...) disembarks at destination: an extra-stellar planet which came errant to orbit of Deneb giant.

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  11. ...space-elevator (orbital station bike wheel-1g)... geostationary orbit, a huge "bike-wheel" is gyrating around its own axis for have 1g-centrifugal. Wheel held in place with 4 CABLES (each cable with a track for Train, for both trains crossing ↓↑) FORMING THE STRUCTURE OF A RHOMBUS♦ (minor diagonal of rhombus is the gyration-axis of the Station-Wheel)...rhombus below, the carbon nanotubes Track towards Earth...rhombus above, Cable towards a higher counterweight... if...WHEEL´s RADIUS = 250 mts... Wheel gyration´s Axis length = rhombus´s minor diagonal = ½ Wheel´s radius = 125 mts (axis could be a resistant hollow tube, e.g. 20 mts in diameter, with an adequate wall´s thickness, hollow which could serving how tank of anything, e.g. air, or tank of frozen water storage no totally full, for volume expansion from liquid to ice without tank, Axis, breaking, thawing using solar-heat)... Cable´s length of the rhombus´s side = Wheel diameter = 500 mts... Wheel´s ZONE-1g: habitable-length = 1571 mts*50 mts wide (separation at both sides between Cable and Circumference of the gyratory Wheel, approx.= 5 mts, adjusting this separation installing an Axis with major or minor length, as much as shorter Axis, stronger and, for easy train´s passing, an angle nearer to 180º value in both rhombus´s-vertex, minor diagonal, where are the Big Soundless-♫-Bearings of Axis´s-insertion...a few Electrical Motors fed with Solar Energy maintain automatically the gyration-speed counteracting the slow braking by friction from the Bearings...besides of Bearings: main Maglev system also for the gyration and Axis´s supporting, leaving the Bearings only how secondary security system...with a slight roominess between each Bearing and its exterior subjection, into the roominess all around...little solid Pistons radial extensible and retractable... Axis´s subjection: extensible ON, with Bearings; extensible OFF, with Maglev. With a sufficient cables tension coming from the counterweight, if Axis resists: the rhombus structure is undeformable)*10 Floors, 9 with 25 mts in height each one; top with 25 - axis radius = 15 mts; gyrating 360º each 31 second, angular-speed = 11.61º/sec, linear-speed (tangential) = 182 kms/h... Station-Wheel GYRATION: AXIS IN PERPENDICULAR (90º) ORIENTATION TO THE ORBITAL TRAJECTORY...and so, while Station-Wheel follows its geostationary orbit, the Wheel does Not changes the spatial-orientation of its axis, and thus there are Not Precession forces actuating (and thus there is Not torsion´s force against Track)...

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  12. (2)...space-elevator (orbital station bike wheel-1g)... Wheel with maneuver´s tangential-rockets for gyration´s start, or...gyration emergency stop...and maneuver´s axial-rockets for reorientation of Wheel´s axis, if it is necessary: because the Earth´s axis slightly and very slowly goes oscillating cyclically due to nutation and precession...that oscillation evidently produces transversal traction pulling of the Track towards aside from its anchoring on equator, thus would have and also slight pendular movement side to side and it would produce precession´s movements of the Wheel´s axis and thus a not wished torsion of the Track...but the system must supporting lateral charges, in the same orbital plane and thus without precession´s problems on the Wheel´s axis, of acceleration against W→Track←E produced by the Coriolis effect when movement´s direction is perpendicular to the gyration´s axis, that lateral charge is maximun on equatør (there, a vertical movement is perpendicular to Earth´s axis) and zero on poles (there, a vertical movement is parallel to Earth´s axis); upwards charge to West, downwards charge to East; the gyroscopic-rigidity contributes for maintaining the gyration-axis perpendicular to the orbital trajectory... When the Maglev Train slowly arrives (Train with one opened ╚╝ side in its technical maglev-zone train´s all along over Track for can passing for both tracks: main-Track/rhombus-track/again main-Track), using now cogwheels on Zipper-Track (zippers installed on the same Maglev-Track), Train stops in Geo 0g-Station placed over one Extreme of the Gyration-Axis, next to «Port for Spacecrafts»... Passengers disembark and entering into gyratory circular corridor, they take now the interior-elevator of one of the Wheel´s hollow-radius (also could be an exterior-elevator running for a simple zipper-radius), and tunnel "descending" till Hotel into the final Zone-1g...where while Station-Wheel goes turning, the immense O2 producer Hydroponics Garden receives a filtered Sun light...and there are Earth´s awesome views.

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  13. (1)...space-elevator (orbital station ramp: fresh air)... CO2 + UV laser → C + O2... RENOVATOR AIR UNIT: Powerful-Compressør³ continuously extracting the air Only from bathrooms ((((air passes condenser metallic grid which has a cold extreme ship´s wall through at outer space, water drops distilled go out centrifuged...air´s pipe goes to outer space sufficient for air cooling only till CO2 freezing point, their already solid ice particles go away into the air current centrifuged impacting against the wall of *U-Tube* of the air which *has exit in the U zone* to a perpendicular at 90º *Cylinder-Tube* that has a, with axis at both sides, ←▬▬|PISTON|▬▬→ *shoving the ice pieces at both ways goes↔comes*, for isolate air current the same PISTON *at both sides* opens↔closes Cylinder extremes on both *intersections* with U-Tube, and shoves/releases a *Circular Cap* which has on the back side a spring against the wall of *another perpendicular Tube forming "T" at both sides, 2 branch-lines, of the Cylinder-Tube*, from that another Tube *arrives from one side* hot CO2 current, this *drags towards the another side* and thaws the ice...from both branch-lines which outlet into 1 only tube, gas CO2 passes now by a thin and long tube with mirror interior walls ╩╩╩╩╩╩ with inclined multiples UV laser rays discharges...finally C and separation of O2 which passes to ■Tank reservoir O2 liquid)))) → compressed dirty air through anti-return retention´s ÷valve goes to 2 ©Deposits at outer space...besides punctually reinforcing, when sensor detects presence into bathroom connects extractor ~Ventilator of Pressure (220 v.ac/50 W) that carries the dirty air, already without water nor CO2, to a graphene´s inflatable ºBalloon at outer space, another Compressør² extracts the air of the ºBalloon and injects it compressed through another anti-return retention´s ÷valve to circuit of the ©Deposits which have the dirty air already liquid at cryogenic temperature → #DISTILLER Linde mini → N and O2 ((someday will be obtained also Oxygen from...CO2 + UV laser → C + O2...electrons of CO2 molecule are in covalent bond, shared, they acquire energy from photons of the UV laser jumping thus to higher orbits and breaking thus the molecule)), the dirty remains that can´t be used is thrown to space...the 2 ©Deposits alternatively working, one closed exit mode distilling, another open exit mode throwing; both have at entrance a solenoid┴valve, and exit´s hinged door slightly open/close with 1 motorized gyratory screw outside the ©Deposit → █Tank Reservoir Air Liquid that receives, if it is necessary, also O2 from ■Tank reservoir O2 liquid... From █Tank Reservoir Air Liquid (N+O2) arrives more/less new air for maintaining the ambient pressure: »»» breeze of clean fresh air 1 bar »»»░... Finally shall smell to roses in a Spacecraft.

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