Showing posts with label physics. Show all posts
Showing posts with label physics. Show all posts
Saturday, November 10, 2012
Wednesday, September 26, 2012
Stephen Hawking: Look at Me Hector
What kind of man writes a book about Physics? Not even a man -- a rata.
Supernova!
I love Breaking Bad.
Supernova!
I love Breaking Bad.
Thursday, October 20, 2011
Quantum Levitation -- Very Cool Science
I found this video on Youtube a few days ago, and I thought that I would share it on my blog. Here, we have a super cool video of a superconductor levitating over a magnetic field.
The physics behind superconductors is pretty amazing. One of the interesting things though is that the circulation of the superconductor around the magnetic track is NOT without friction (if we define friction as the loss of energy to heat). Actually, inhomogeneity in the magnetic field of the track will create voltages as the superconductor passes through it, which will cause eddy currents to flow. These eddy currents will eventually dissipate themselves as heat, meaning that the orbit of the superconductor around the track will not last indefinitely (although it will last for a long time).
The physics behind superconductors is pretty amazing. One of the interesting things though is that the circulation of the superconductor around the magnetic track is NOT without friction (if we define friction as the loss of energy to heat). Actually, inhomogeneity in the magnetic field of the track will create voltages as the superconductor passes through it, which will cause eddy currents to flow. These eddy currents will eventually dissipate themselves as heat, meaning that the orbit of the superconductor around the track will not last indefinitely (although it will last for a long time).
Thursday, September 29, 2011
Thoughts on Living Forever
Image via WikipediaIf you were talking about a universe of infinite size or an infinite multi-verse, then you still would have spent an infinite amount of time in some or all parts of the universe/multi-verse in many cases. The only exception that I can think of to this happening is if the sizes (i.e. Lebesgue measure) of the infinite time dimension versus the size of the infinite space dimension were different (with the size of the time dimension have a smaller Lebesgue measure) and you were constantly moving to new parts of the universe (with or without repeated visits to old parts of the universe). In this case, you would actually technically spend zero percent of your time in any one part of the universe, which I find equally disturbing.
Second, the idea of always learning new things has troubled me too. According to Physics, information is ultimately stored as a state of a subsystem or subsystems in the Physical universe and is transmitted via energy (i.e. photons). Therefore, as the amount of information stored in a given subsystem of the universe (let's say God's head) tends to increase, then shouldn't the energy density and the energy expenditure of that system also increase to a point where it's no longer physically possible to pack more energy into the subsystem? In other words, shouldn't there be an upper limit on the amount of things that you can learn, even given an infinite amount of time to learn them?
Let me put this another way. Let's suppose that we have a system composed of N particles in a quantum state defined by the variables a_1, a_2, ... a_n. According to my intuition (which may be off because we are talking about quantum mechanics here), the number of possible quantum states attainable by a particle in the ensemble should be finite. In other words, any one particle in the system should only be able to contain a finite amount of information. With that assumption in place then, as the information contained in the system increases, the number of particles in the system (the ensemble) should also ultimately have to increase as well. Therefore, since the size of the system is finite (i.e. God's head is contained in a finite space), the energy density of the system must also either a) reach a limit where there can be no more information contained in the system or b) continue to increase as more information is pushed into the system.
So, to make a long story short, if you kept trying to learn new things forever, wouldn't you either a) run out of room or b) have your head eventually explode (due to too high of energy density)?
Also note that there is demonstrably an infinite amount of information in the universe, so you can't make the argument that there is an upper limit to the amount of information.
Has anyone else ever thought about this?
Tuesday, September 6, 2011
Quantum Mechanics and The Supernatural
Image via WikipediaAn example would be from the appearance of the angel. A person with a naturalistic interpretation could say that the event was staged by a huckster , an extremely improbable event, or a shared illusion -- all using well understood natural laws. In turn, a supernaturalist could conclude that, at each stage, some supernatural intercession was necessary to invoke each natural event. Then, the naturalist could conclude that each of these supernatural stimuli -- if present -- was the result of some sort of natural laws governing the stimuli. And so on.
Also, we can consider quantum mechanics. At it's basis, the fundamental laws of quantum mechanics describe the behavior of of a particle at low energies, with one of the fundamental aspects of QM (depending on your philosophical interpretation of what's happening) being the evolution of the wave function according to the Schrodinger equation: H *\psi = E *\psi for the time independent version of the equation, which could be understood at the Hamiltonian operator acting on the wave equation being equal to a constant times the wave equation. As a fundamental part of that, the wave function is said to collapse into an observable state under observation, with the probability of the particle being located at a given point in space being equal to the wave equation times by it's complex conjugate integrated over all of space (if I remember my elementary quantum mechanics correctly).
However, what is actually happening when the wave function "collapses"? If you look at different interpretation of QM (many of which are summarized nicely) on Wikipedia, you will find everything from the idea that the universe splits off into different branches with each split to the idea that a collapse is caused by the consciousness of the observer and has no meaning outside of that reality. So, even among the "naturalistic" worldviews, there are large variations in what people think is happening behind the scenes in something like wave function collapse.
By the same token, a supernatural worldview could imagine a smart little elf sitting at a magical keyboard each time an observable event takes place and "allowing" that event to occur each time by hitting a button. Then, a naturalist viewpoint could say that, if the elf exists, science can explain it away as the result of some previously unknown natural laws, which a supernaturalist can explain away as the result of an even more powerful elf at an even more complex keyboard, and so on.
With the flood of Noah, a naturalist can point to scientific evidence that the flood never occurred by pointing to evidence that the ark would have been to small, there isn't enough water in the world, the geological record doesn't support a world wide flood, etc. A supernaturalist could then come up with a series of miracles or improbable explanations to explain away these problems, including the power of God to control the animals, the introduction and retraction of water from heaven by angels, and the altering of the geological record by the devil. Then, a naturalist could find additional objections to these new theories, which the supernaturalist could then explain away by further invoking miracles, and so on. There really is no way to distinguish between these possibilities in this case or in any other scenario.
At this point, physics usually throws up its collective hands and uses what is called a "black box" model for events in nature. In other words, physicists can observe a system with possibly complex internal component only in terms of the available inputs and outputs of the system and not on the basis of possibly extremely complex interactions occurring inside of the system itself. There are many situation in science when there exist several experimentally consistent models of what is happening inside of the black box that can only be compared scientifically once experimental tools have been discovered to penetrate the black box and discover more about the working parts of that box.
Also, it should be noted that, even in QM itself, there are room for extremely unlikely events to occur. One such event is called "quantum tunneling", where a particle ensemble has a finite probability to penetrate a potential energy barrier and emerge on the other side of that barrier. Mathematically, this can be understood from the wave equation existing at all points in space with an finite (nonzero) value, even though the probability is bounded by an exponentially decreasing envelope. The probability of a tunneling even to occur is inversely proportional to the mass of the particle ensemble, meaning that it happens quite often for small subatomic particles and much less often for more massive particles. However, the gist of this argument is that there is a nonzero probability that, according to the laws of QM, [b]you could be standing next to a wall and suddenly appear on the opposite side of the wall[/b]. Numerically, the probability of this happening is so small that we would not expect it in the lifetime of the universe; however, the probability is still nonzero.
Ah, the joys of quantum mechanics.
Monday, July 11, 2011
Amazing Strength of Air -- Breaks a Ruler!!!
Watch the amazing strength of simple air as it helps to break a ruler that has been hit on the side of a table. It's an amazing video you have to watch!
Tuesday, May 31, 2011
Cool Physics -- Amazing waterspout 'tornado'
Check out this amazing video from Australia showing the effect of a "tornado" traveling over a body of water off the coast of Australia. Courtesy of the RussiaToday channel on Youtube.
I think the awesomeness of the video speaks for itself.
I think the awesomeness of the video speaks for itself.
Cool Physics -- Fun with Magnets
Check out this super cool video from Youtube where a guy does some amazing things with ball magnets. If you like science, geometry, magnets, or just cool things, you really need to check out this video.
Probably the coolest thing about this video for me is just all of the shapes that the guy manages to make in rapid succession. Whoever was making this video really has spent a lot of time playing with magnets to make all of the geometric shapes that you see in the video.
Maybe I've found a new hobby :)
Probably the coolest thing about this video for me is just all of the shapes that the guy manages to make in rapid succession. Whoever was making this video really has spent a lot of time playing with magnets to make all of the geometric shapes that you see in the video.
Maybe I've found a new hobby :)
Thursday, March 31, 2011
12 Year Old Physics Wonder Kid -- NOT!!!
As a scientist (specifically a Physicist), nothing bugs me quite so much as Pseudoscience. In many ways, it is literally the bane of society's existence and one of the reasons people find it so hard to understand real science. So, imagine my horror when I found the viral video of this "wonder kid" who is supposedly going to take on Einstein and change the world's understanding of Relativity. Yeah, right. Give me a break. Watch the video and scroll down for my comments as to why this brat doesn't know what he is talking about.
A few points.
1. There is no "forwards", "backwards", and "sideways" in the universe. Think about it: you're sitting out in the middle of a vacuum, no stars around you. Which way is up? Which way is down? Thus, when the little brat says "light doesn't accelerate forwards or backwards but exactly to the side", it is a statement that doesn't have any meaning. Light DOESN'T accelerate. As far as all experimental evidence I have ever seen has said, photons are created instantaneously traveling at c. If light accelerated, physicist would be able to (routinely) measure light in a vacuum at speeds far below c. This doesn't happen, at least as far as I am aware. If someone has a paper showing this, please send me the citation.
*Btw, just to clarify, light can travel slower inside of a non-vacuum, say in water. The photons of the light still travel at c, but they are being continuously absorbed and recreated by the electrons in the medium, making the effective propagation velocity of the light less than c.
2. Tachyons and massive photons have never been shown to exist, ever, at least that I am aware. If this kid has evidence of their existence, he needs to publish in a journal and claim his Nobel Prize. So, when the brat mumbles something towards the end of the clip about "Tachyons and massive photons exist . . .", he is just talking out of his ass.
3. I am not sure where this kid is getting a figure of a speed of light existing, perhaps in another universe," that is "0.9 faster than the speed of light in our universe", or whatever he said. This is a figure that, in my opinion, the kid has once again pulled from his ass. Why not 0.8? 0.7? 0.4? 3.141925? times faster/slower than our universe? Why did you choose 0.9, other than you were trying to look smart for the cameras?
If this kid wants to show off for his mom's ignorant friends at dinner parties, fine. Let him. But,please, don't stick this idiot on Youtube. It's bad for the legitimate scientists of the world.
A few points.
1. There is no "forwards", "backwards", and "sideways" in the universe. Think about it: you're sitting out in the middle of a vacuum, no stars around you. Which way is up? Which way is down? Thus, when the little brat says "light doesn't accelerate forwards or backwards but exactly to the side", it is a statement that doesn't have any meaning. Light DOESN'T accelerate. As far as all experimental evidence I have ever seen has said, photons are created instantaneously traveling at c. If light accelerated, physicist would be able to (routinely) measure light in a vacuum at speeds far below c. This doesn't happen, at least as far as I am aware. If someone has a paper showing this, please send me the citation.
*Btw, just to clarify, light can travel slower inside of a non-vacuum, say in water. The photons of the light still travel at c, but they are being continuously absorbed and recreated by the electrons in the medium, making the effective propagation velocity of the light less than c.
2. Tachyons and massive photons have never been shown to exist, ever, at least that I am aware. If this kid has evidence of their existence, he needs to publish in a journal and claim his Nobel Prize. So, when the brat mumbles something towards the end of the clip about "Tachyons and massive photons exist . . .", he is just talking out of his ass.
3. I am not sure where this kid is getting a figure of a speed of light existing, perhaps in another universe," that is "0.9 faster than the speed of light in our universe", or whatever he said. This is a figure that, in my opinion, the kid has once again pulled from his ass. Why not 0.8? 0.7? 0.4? 3.141925? times faster/slower than our universe? Why did you choose 0.9, other than you were trying to look smart for the cameras?
If this kid wants to show off for his mom's ignorant friends at dinner parties, fine. Let him. But,please, don't stick this idiot on Youtube. It's bad for the legitimate scientists of the world.
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