I am inviting answers to these questions. They have troubled me, and perhaps they trouble a few other people.
Each of these questions describes a problem I have with the description of the science I read in the standard text books. I would be very grateful if you could send me an email with the answer; if you can also point me to a book or article which provides the solution, I would be even more grateful.
I will post the answers I receive on the Answers page as soon as I am able.
|•||Why are there two tides a day?|
|•||How long is a quantum leap?|
|•||How does gravity work?|
|•||Questions about multiple universes|
|•||Can antimatter annihilation fail to conserve spin?|
|•||How does the colour wheel work, since light has a frequency?|
|•||How does the universe expand?|
|The universe and everything in it is expanding|
|The universe is expanding but not everything in it|
The books all say that we have tides because the moon (and, to a lesser extent, the sun) exert a gravitational pull on the water in our oceans. And one high tide tracks the moon's movement. But we have two tides each day: if the water facing the moon is being pulled by the moons's gravity, is the water on the other side of the Earth being pushed away by that same gravity?
A quantum leap is the shortest distance an electron can move. It travels from one quantum level to the other without passing through the space in between.
There are two possibilities: either the leap is instantaneous, or it takes a finite time. In the first case, we have faster than light travel. In the second, conservation of matter no longer works as we were told: the electron ceases to exist for a while.
Of course, the electron does not actually orbit the atom's nucleus as a planet orbits a star: it exists as a wave, or a probability distribution. But however you describe it, the same problem exists. Does the probability of the electron being found in the higher state start to increase at the same time as it starts to decrease in the lower level? Whether you think of it as a particle, a wave or a probability distribution makes no difference to the question.
The standard picture asks us to imagine three dimensional space as a two dimensional rubber sheet. Place a marble on the sheet, and it creates a slight indent; place an iron ball on the sheet, and it creates a much larger indent. The amount of the distortion of the fabric depends on the mass of the object. Given this model, you can see that the marble can orbit the iron ball, given the corrrect distance and velocity - just as in the real world.
But this model does not explain gravity at all: in fact, it depends on gravity to make it work. The ball and the marble sink into the sheet because of gravity, and the marble orbits the ball because the gravitational attraction pulling it down exactly balances the inertial tendency to travel in a straight line. Without gravity, you have neither the distortion of space-time nor the movement of objects affected by the distortion.
This model does explain the way in which light is bent by a massive object: the light travels in a straight line, but the straight line in a distorted fabric is not the same as the straight line in the undistorted fabric.
But the distortion of space-time does not explain why one mass is attracted towards another mass. The Earth beneath my feet may distort space-time, so that the vertical dimension differs from the two horizontal dimensions. But this would have the effect of making it harder for me to travel vertically than to travel horizontally; and it would be harder for me to travel vertically, either up or down. Space-time is distorted in that dimension, not only in one direction. For me to be pulled in one direction requires a force, not just a distortion of space-time.
We can reasonably extend the image: think of the rubber sheet as a carpet with a pile. In this case, the distortion caused by a mass has not only a dimension but also a directon. After a mass is placed on the rubber sheet, a small square becomes, roughly speaking, a rectangle: one direction is stretched, while the other direction is not. Thus, it is easier to travel in one dimension than in the other. With a carpet being stretched, the pile may point 'downhill', so that it becomes easier to travel in one direction in the stretched dimension than in the other direction - towards the mass becomes downhill, and away from the mass becomes uphill. But this still only has any effect when somthing causes the marble to move. The fabric being stretched may make it easier to move in one direction than another, but it still does not explain why there is an acceleration in the downwards direction.
Things only roll downhill because of gravity, but it makes no sense to invoke gravity in a model which is trying to explain gravity.
I have three basic issues with the interpretation of quantum events which suggests that reality splits into two for each event: in one, one possible event happens, and in the other reality the other possible event happens. In one universe, Schrödinger's cat is alive, and in the other, it is dead.
This first point seems to be trivial to some people. possibly because it is so obvious. Before the quantum event, we have one universe, mass: 1 universe. After the quantum event, we have two universes, mass: 2 universe. The quantum event seems to have created one universe worth of matter and other energy. Nobody is saying where all this energy has come from.
But, of course, it is much worse than this. We are not just dealing with one quantum event, but an almost infinite number of them: at each instant, the atom can decay or not; so each instant generates another universe. And this is true not only for the single atom we are tracking in the sealed chamber, but also for every other atom in the universe capable of a quantum event. The numbers rise so fast, they start to become meaningless.
Before the quantum event, we have one universe; after it, we have two distinct universes, each going their different ways. If the cat is alive in our universe, we have no way to peer into the other universe in which it is dead.
But, somehow, we do. A single photon, which might go through one of two slits, produces an interference pattern because it interferes with itself. So here we have a quantum event, and the universe splits into two universes; in one, it goes through the first slit, and in the other, it goes through the second slit. But these two universes are not quite distinct, because somehow the photon which split knows about the other version of itself which went through the other slit; and on the basis of that knowledge produces an interference pattern. The photon is somehow detecting a photon (albeit itself) in another universe.
If we can detect what is going on, this does not sound like a parallel universe to me. It sounds more like something strange happening in my own universe. Possibly associated with one of those extra, 'rolled-up' dimensions that string-theorists like to tell us about.
If we return to the cat, and only consider two universes - one of the infinite universes in which the cat is alive, and one of the infinite universes in which the cat is dead, we have another problem.
At the start of the experiment, we have one universe with a box and a cat and bits of equipment. At the end of the experiment, we have two universes with a cat (one alive, one dead) and various bits of equipment. Not just two boxes and two cats, but two whole universes.
Somehow, this quantum event inside a box in a laboratory (just like every quantum event, everywhere, at all points in time...) has managed to duplicate an entire universe. This event, at one point in space-time, has managed to produce a new universe identical to the first, other than the one detail of the quantum event.
Ignoring the question of how a quantum event can achieve such an impressive feat, I would like to know how it can know about the state of the universe billions of light years away, in order to reproduce this state. Parts of the universe may be beyond our event horizon, but they are not beyond the reach of this quantum event.
If you duplicate a universe, you do not only duplicate all the matter: you duplicate all the information. Even the information it is impossible for you to access. Information is being transmitted, via the quantum event, at infinite speed. I think Einstein should be told.
We are told that every measurable quantity is conserved in all atomic interactions: not only energy, but charge, spin, and anything else relevant to the particles in question. We are also told that matter and antimatter will annihilate each other if they come into contact.
So let us take a lot of energy and create a couple of particles - for the sake of argument, an electron and a positron. Do it twice (or more, as necessary, but again let us assume only one more is required). You have the same energy at the end, much of it now in the form of electrons and positrons, the same charge (they add up to no charge) and the same spin (they also cancel out). Everything balances.
Now put an electron and positron with the same spin together. They must annihilate each other, releasing energy. Now we have one remaining electron and one remaining positron, but they have the same spin. Now we have the same energy as before, the same charge, but somehow we have created spin out of nothing.
Of course, you can turn a line into a circle fairly easily: you simply join the two ends together. Which would work if:
I think I understand how the last point can be true, but I really struggle with the first two: they seem so unlikely. Without a precise cut-off, there must be a point on the colour wheel where I am only partly seeing the colour - or maybe partly seeing two colours; this does not seem to be the case. And if two people are not identical in the range of wavelengths they can see, then the colour wheel must be larger for some people than for others.
It seems to me there are two possible scenarios.
I can tell how far apart things are by measuring them. I generally use a ruler, but other methods are available. It doesn't make any difference how you measure: in the end, every measurement is simply a comparison of the length of one thing as compared to the length of another.
The textbooks say that the universe is uniformly expanding everywhere. If everything is expanding, then my ruler is expanding with the universe. If the universe doubles in size, so does my ruler: my measurement of the universe is unchanged.
On the other hand, if the universe is expanding but some things in it are not, what exactly is expanding? The galaxies are moving further apart, but are the stars in the galaxies also moving further apart? If not, what is telling the universe to expand there but not here?
Is the Earth moving further away from the sun? The moon away from the Earth? Is my keyboard moving further away from my computer? Are the atoms in my chair moving further apart from each other? Are the electrons in those atoms moving further from the nuclei?
If the expansion of the universe is happening in some places and not in others, how does the universe know where to expand? Or what protects some things and prevents them from being expanded?