That would make sense, yes. (Just goes to show that I know a great many things, but not everything.)Slenn said:
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Your initial presumption is correct. The energy left over by moving your arm will most likely be lost by internal friction in your joints and muscles. Otherwise your arm would keep moving without friction or something to stop it. The energy may be absorbed mechanically in your skeleton until it transfers into the ground.TheSlothOverlord said:
That's the case for most of science, really. In paleontology, the fossil record is analogous to the physicists's standard model of particle physics. The fossil record lets us predict and model the time scale of how the evolution of species went down. When the idea of science came out in the Ionian Greeks, people were not liking the idea that their gods had to obey rules. The Ionians were proposing that the universe is knowable and testable. For the time period, this was considered heresy for some and revolutionary for others. I'm not familiar with the Kant quote, but I think I understand what you're implying. What I think it's saying is that you'll never completely know everything in perfection. But it doesn't really hinder science's motives in any way. Science is limited based on what tools we're using and the human imagination. No doubt there will be some point where we might have to evolve our minds to create new concepts. But we, as humans, have a natural drive to be curious about things. As Carl Sagan said "We make our world significant by the courage of our questions and the depth of our answers." And for many people that's a huge deal; they want to feel significant. And for scientists, significance may be part of the goal, if any. But really the end goal of any scientific endeavor is to know the truth through hard evidence and experimentation. I guess the short version of this is "Yes, we know we can't know everything, but this universe is meaningful to us. So we'll keep searching for answers until the end of time."
How accurate, physics-wise, is School Days?
Is it easier to corrupt light or dark?
Is bad physics still better than no physics?
Which part of the personified body should we really grab "life" from?
Are there any good physics-based raps?
Is it easier to corrupt light or dark?
Is bad physics still better than no physics?
Which part of the personified body should we really grab "life" from?
Are there any good physics-based raps?
I have not watched that series.FPLOON said:
Yin and Yang, bro. The dot in the center of its symbol means that neither side is completely pure.
You mean physics in the real world, or people studying physics?
I have no idea what you're talking about. *shrug* Could you elaborate on what you mean by "personified body"?
You have the basic understanding of it. The idea comes from the fact that if you had an electron orbital with two electrons, one has to point up and the other has to point down in terms of spin. (If you want to know more details, I'd be happy to explain the details of fermions and why they must have asymmetric wave functions.) If the electrons across the universe are really that sensitive when it comes to spin, then quantum entanglement proposes you could flip the orientation of one electron and that flips an electron miles away instantaneously. Not at the speed of light. Some people don't particularly like this idea because the electric field that's felt by an electron around one atom is going to be negligible for an electron around another atom. Some other people don't like this for the reason that the information transfer might be instantaneous, which is understandable. That's why it's somewhat of a big deal. Although I haven't heard much in the way of news about it.The Almighty Aardvark said:
QM has had a complex history, and has had many parents that fostered its growth. In the realm of QM, we're still looking at new things to this day. We calculate based on our original model that comes from our current concepts of QM. And when we find deviations from our predictions, then that's when things get interesting.Ouroboros said:
I hope that answers what you're talking about.
What do you think of the feasibility of the high beta fusion reactor being developed by Lockheed-Martin?
(reference link: http://www.lockheedmartin.com/us/products/compact-fusion.html)
How about Alcubierre Drive? And if it's achievable, would it takes more like decades, or centuries?
(https://en.wikipedia.org/wiki/Alcubierre_drive)
I understand the answers would be mostly guesswork, but you clearly have better basis for such guesses than I do
.
(reference link: http://www.lockheedmartin.com/us/products/compact-fusion.html)
How about Alcubierre Drive? And if it's achievable, would it takes more like decades, or centuries?
(https://en.wikipedia.org/wiki/Alcubierre_drive)
I understand the answers would be mostly guesswork, but you clearly have better basis for such guesses than I do
.
Could you explain how we are able to see so close to the Big Bang with better telescopes? I understand that light takes time to travel, but since all the matter in the universe was concentrated in a single point, including the matter that makes up the earth, wouldn't the light coming from the first moments of the universe be long gone, farther ahead of us?
How many elementary particles do we know exist? I know there's electrons (up and down)quarks and neutrino's(i'm not sure what neutrinos are and where we find them though)
Also, do you have an idea why some things in quantum theory just sort of randomly happen(according to a probability distribution), such as light choosing to manifest itself wherever it pleases?
I've had a few introductory courses in quantum theory and watched many youtube videos, so I'll understand some vocabulary.
Also, do you have an idea why some things in quantum theory just sort of randomly happen(according to a probability distribution), such as light choosing to manifest itself wherever it pleases?
I've had a few introductory courses in quantum theory and watched many youtube videos, so I'll understand some vocabulary.
Well, I would say that I only stick to one interpretation. But during the course of research, I'm not taking a blind approach to calculating anything. Everything has to be methodically pinned down before being executed. And the interpretations of QM don't come up in any part of the research. Maybe if my thesis would be about philosophy then I would be considering the different interpretations. But maybe there's going to be a conclusion where I do such a thing.Ouroboros said:
I admit, this took some research to do, because I wasn't familiar with the theory. I'll try to condense what I've found out.Myrios said:
The idea behind the hidden variable stuff that Bell addresses is that quantum mechanics does not have a deterministic nature. This means that answers to questions like "where is the particle?" are going to be given as probabilities rather than absolutes. Classical mechanics on the other hand, if you did your math right, you can figure out the position and momentum simultaneously and accurately without any repercussions.
Hidden variable theories think that there might be variables that are unknown at this point that allow for quantum mechanics to be deterministic. Bell's theorem states that if there are hidden variables for smaller cases, they will not account for all of quantum mechanics' predictability.
The short answer is "Even if there was a deterministic value to be found from quantum mech', it won't account for everything within quantum mechanics' power."
As for planes flying upside down, it has to do with how the plane's wings are tilted with respect to the flow of air. Take a sheet of paper and tape the short end together so that the paper has a teardrop shape. Most planes have their wings shaped like this. When you blow across the top, the paper will lift up because the flow of air on the top is creating a lower pressure than the pressure on the bottom.
If the wings were level with the flow of air, then no lift would happen on the plane because there's equal air flow going over both halves. But if you tilted the wings with respect to the air flow, then you create an unequal flow across both sides. The plane being upside down doesn't make a difference as long as the wings have a symmetric cross section. All you need to do is to tilt the wings at the same angle with respect to the air flow and you'll get lift again.
OK some specifici question
Do you understand de Yang-MIlls theorems and hypothesis? can you explain the to me? (As some one into Math, that theoretical physics question rises my eyebrow)
Can you please explain how does Dirac's Delta Zero work? How can a function be 0 almost everywhere, infinity in one point an the integral still be one? Is that related to Lebesgue integrals?
DO you know of any timedependant solutions to the Schrödinger equation? What implications do those have?
Can you explain to em a little a baout the math behind Einstein's Equations of relativity?
THat to star. Interesting thread
Do you understand de Yang-MIlls theorems and hypothesis? can you explain the to me? (As some one into Math, that theoretical physics question rises my eyebrow)
Can you please explain how does Dirac's Delta Zero work? How can a function be 0 almost everywhere, infinity in one point an the integral still be one? Is that related to Lebesgue integrals?
DO you know of any timedependant solutions to the Schrödinger equation? What implications do those have?
Can you explain to em a little a baout the math behind Einstein's Equations of relativity?
THat to star. Interesting thread
I have high hopes for fusion reactors. I think it will be achievable one day in 2 centuries or so if the research is unhindered. Perhaps when condensed matter physics creates superconductors that work near or around room temperature, we might be able to create better and more efficient circuitry for the reactor. The only catch is that nuclear reactors have not had a good reputation. There's only a few hundred of them, and 2 of them came from human error if I recall correctly. It's going to not only take a lot of inginuity to pull it off, but also a lot of discipline. If that makes any sense.Ugicywapih said:
I would imagine that such a thing would require more than the human imagination could achieve. Perhaps in the future, we'll have setups where man and machine are thinking in unison. Or perhaps 10 human minds are hooked up in unison to multiply the thinking power by a factor of 10. And those setups could think of a theoretical basis for the machine. But I think such a thing would require deeper study into particles that have yet to be examined. The wiki article you're talking about points to "negative energy", which comes from "exotic particles" such as dark matter. What does all that jargon mean exactly? Dark matter can only interact gravitationally. So detecting it with particle detectors is going to require more precise instrumentation and higher energies. I would estimate in a thousand years that we'll have a solid yes or no answer to this question.How about Alcubierre Drive? And if it's achievable, would it takes more like decades, or centuries?
(https://en.wikipedia.org/wiki/Alcubierre_drive)
I understand the answers would be mostly guesswork, but you clearly have better basis for such guesses than I do
What we're seeing is the cosmic microwave background that came from the Big Bang. I need to explain blackbody radiation to make this sound clearer. Depending on the temperature of the object, it will give off different wavelengths of EM radiation. Hot objects (from hotter to cooler) will give off blue, white, yellow, orange, and red light. Warm objects, like our bodies, will give off mostly infrared light. And much colder objects will give off microwaves.ShyGuy said:
What you're saying about visible light from the moment of the explosion is correct. We would not be able to pick up any thermal radiation in the form of visible light because it would've already passed away. However, the microwaves that are detected by our microwave telescopes are from the universe when it was presumably hundreds of thousands of years old. By that point the universe has already substantially expanded and reached a temperature around 2 to 4 Kelvin. So objects at roughly 300,000 years after the Big Bang would be giving off microwaves. And that's what we're picking up.
So what we're picking up from our instruments isn't exactly at the moment of birth. It is sometime after, but it is the closest that we can get to the Big Bang with telescopes. I do hope that helps!
Ok, first things first, there are three major types of elementary particles.bauke67 said:
Leptons; which are Electrons and other 1/2 spin particles with charge. They are also not affected by the Strong Nuclear force.
Quarks; of which there are 6 with -1/3 or +2/3 charges depending on which familly they are a part of.
Bosons; these are going to seem odd, these are the particles that carry the effects of forces between other particles.
As to how many they are, well, my old physics classroom had this exact sheet which gives a pretty good explanation I think:
CAPTCHA: Cutting Edge. That definitely seems appropriate for a physics thread doesn't it Captcha?
I think I can help you with that question. The Dirac delta function is not actually a function. However, you can see it as a measure on the real line that assigns measure zero to every set that does not contain 0 and measure 1 to every set that contains 1.kurokotetsu said:
Then, integrating (in the sense of Lebesgue) a function f with this measure gives you f(0). Indeed, the only value where the pre-image by f is a set of non-zero measure is f(0), since every set that does not contain 0 has measure zero.
I hope that was clear. It's also possible to see the Dirac delta function as a distribution, but since you asked about Lebesgue integrals, I assumed that this is what you refered to.
We typically define elementary particles as particles that cannot be divided up any further. As far we know we have 6 quarks: up, down, charm, strange, top, and bottom. There's 3 leptons, and they each have their own respective neutrino that goes with them: electron, muon, and tauon. And all of those have their own antiparticle.bauke67 said:
Then we get into the realm of the mediating particles. There's the photon, which mediates the EM force. The gluon for the strong nuclear force. And the Z0, W+, and W- mediates the weak nuclear force. And most recently we uncovered the Higgs Boson, which helps describe how objects without mass, like the photon, can interact with objects that do have mass.
So that's (6 + 3 + 3)*2 + 1 + 1 + 3 + 1 = 30.
As for the randomness, there's still restrictions. It can't do whatever it pleases, if that's what you're talking about. Light manifesting by itself cannot happen unless there's some interaction that mediates it, otherwise we'd be breaking energy conservation. There's specific rules that are set in place for quantum mechanics. What Schrödinger's equation allows you to do is to figure out the probability distribution as a function of space and time. This lets us estimate the shape of the electron clouds around atoms. With enough math and powerful computers, one can figure out the distribution for a whole molecule like water.
I hope that does answer what you're referring to.
I think it's because some people like to think that whatever is unexplained is magic. And here we get into the definition of unexplained. As for all the math, jargon, and reasoning that goes with it, quantum mechanics is pretty well explained. So that might be why they get upset. But as to why the universe behaves that way, no one knows for sure.MiskWisk said:
Negative Kelvin would mean that it is hotter than any object with a positive temperature. I'm afraid I don't know too much on that subject.
Could you elaborate where you found this postulation? I might be able to help if you gave me a bit more context.TheRaider said:
I realized before he posted that chart that I made a mistake: I meant to say that electrons can only exist within the energy levels of atoms, not that atoms can only exist there.
What I meant about the Higgs Boson is that seems odd that a type of particle would create the effects associated with individual perception, given the discoveries I mentioned--or is the idea that perception influences the behavior of the particle like it seems to affect electrons?
I think the idea of alternate realities is improbable and irrefutable. I meant literally the boundaries of the universe, the universe being defined as everything that exists.
I also wonder: if such artificial gravity is possible, is a diameter of 100 feet sufficient? I know that if the rotating spaceship is too small, the astronauts will feel like they are being pulled in two directions at once. Arthur C.Clarke made that mistake in 2001: A Space Oddyssey--I usually prefer my fantasy, sci fi, cartoons, etc. stories to be unrealistic, but Clarke and Mike Judge are exception.
What does there being an equal amount of matter and antimatter in the universe mean: Are there structures like planets and stars made of antimatter, or are they just random floating particles? Were a lot of sudden cataclysmic events like supernovae, black holes opening, gamma ray bursts, or something like those to destroy a large portion of the matter universe, could the decreased gravity of the matter cause it to be pulled in by the gravity of the antimatter?
Are we on the verge of the heat death of the universe? I remember an Arthur C. Clarke story from the '60s or '70s saying that space was at 3 Kelvin, a science class telling me that it was 2.75 Kelvin, and I think I heard someone say recently that it was at 2.5 Kelvin.
What I meant about the Higgs Boson is that seems odd that a type of particle would create the effects associated with individual perception, given the discoveries I mentioned--or is the idea that perception influences the behavior of the particle like it seems to affect electrons?
I think the idea of alternate realities is improbable and irrefutable. I meant literally the boundaries of the universe, the universe being defined as everything that exists.
I also wonder: if such artificial gravity is possible, is a diameter of 100 feet sufficient? I know that if the rotating spaceship is too small, the astronauts will feel like they are being pulled in two directions at once. Arthur C.Clarke made that mistake in 2001: A Space Oddyssey--I usually prefer my fantasy, sci fi, cartoons, etc. stories to be unrealistic, but Clarke and Mike Judge are exception.
What does there being an equal amount of matter and antimatter in the universe mean: Are there structures like planets and stars made of antimatter, or are they just random floating particles? Were a lot of sudden cataclysmic events like supernovae, black holes opening, gamma ray bursts, or something like those to destroy a large portion of the matter universe, could the decreased gravity of the matter cause it to be pulled in by the gravity of the antimatter?
Are we on the verge of the heat death of the universe? I remember an Arthur C. Clarke story from the '60s or '70s saying that space was at 3 Kelvin, a science class telling me that it was 2.75 Kelvin, and I think I heard someone say recently that it was at 2.5 Kelvin.