Can you check mine please? Say we have N photons and the mass of a photon is 0. Then N times 0 equals 0, making a total mass of 0? Is that right?
If the photons were confined in some kind of box, then they'd add to the mass of the box though, so you could do it that way with an imaginary box in a thought experiment, and use this e=mc^2 formula you've picked up from somewhere.
Well it had a silly name anyway. Eve wasn't the matrilineal most recent common ancestor in the bible. That was Noah's wife, Naamah, so she would be the appropriate biblical analogue.
Last I checked, the tides still come in and out every day, regardless of how much energy we extract from the process.
That energy is coming from somewhere and that's the spinning of the earth. It's barely noticeable over one human lifespan but the days are getting longer, which means there's less tidal power available over time.
That fusion reactor may be 150 gigameters away, but it's still a safety hazard! You can't even look at it directly without putting your eyes at risk, not to mention the cancer it causes.
It might be more useful to point out that 'gut feeling = cognitive bias' whenever someone mentions they feel something to be true.
Cognitive biases reveal the problems with relying on gut feelings. They're not synonyms. It seems some people in this thread have taken the '=' sign literally here and it's led to some strange comments about cognitive bias, when they actually mean 'gut feeling'.
Gut feelings allow decisions to be made quickly with minimal use of energy. This is important in the animal kingdom. Human beings have an abundance of energy and often have the luxury of time to make their decisions. As a result, human beings have put a great deal of effort into studying how the human brain systematically underperforms with regards to rational decision making. I would recommend reading up on all the cognitive biases listed here to anyone who takes pride in being correct.
Earth will most likely fix itself, but in the short run it can go through all kind of unpleasant changes. Historically humanity develops best in the quiet phases of climate changes, we live in such a quiet time.
What does it mean for earth to fix itself? That the environment remained conducive to life and for ecosystems to remain sufficiently stable in the past is guaranteed by the anthropic principle. That is we could not have evolved to observe it unless the conditions in the past facilitated our evolution. The anthropic principle says nothing about the future however. In the long run (~billion years) the sun will get hot enough to vapourise the oceans. Currently, temperature rise is unusually rapid. It would be nice to believe that everything will be hunky dory in between, because fate will throw at us some cooling mechanism. How is this anything more than wishful thinking though?
That doesn't sound like ultimate power to me. That sounds like a scenario in which the geeky engineers can overthrow you. They do run the military after all.
Why does it upset you so much? If I said zero was its own additive inverse, would this anger you? When we talk about particle-antiparticle pairs generally do you think it's more convenient or less convenient to include photons pairs?
I'm pretty sure we're using different definitions of falling. I'm not claiming light experiences anything at all, let alone acceleration. We do not regard a free fall frame as an accelerating frame, so I don't define falling in terms of acceleration.
A major result of GR is that spacetime is curved around massive objects, so there are no straight lines to follow. Light follows a geodesic like any other body not acted on by a force. Perhaps you're confusing it with special relativity? Light's path is bent toward the earth in GR. Obviously it travels way above the earth's escape velocity, so you won't see the beam of a torch flop onto the ground following a similar path to a slow moving tennis ball. If you were to instead consider a black hole, then light can be much more severely bent and fall into the black hole.
I hope this all comes in handy in 100 million years time when the dominant species at the time tries to make a park full of animals from the quaternary period. Of course the marketing team will call it Neogene Park, even though most of the species come from the quaternary period, not the neogene period, but Neogene Park sounds way cooler. They'll probably not give birds feathers either, not realising that was a thing until its too late.
Try typing "light falls" into google and see what comes up. For me first on the list, it's Professor Brian Greene's website explaining how light falls in GR. It even has "light falls" in the title so you don't have to read very far. Why didn't you do at least this before posting?
Gravity doesn't come into special relativity anywhere. General relativity is the most accurate model for gravity we have. If we're modelling the path of a small particle (which antimatter is in our experience) in free fall then its mass isn't really important in GR. It follows the same geodesic through curved spacetime regardless. Massive objects like the sun and earth significantly curve spacetime, but the mass of the antiparticle will have negligible effect whatever sign you choose to put on it if it is small in magnitude. If the sign of the mass mattered then photons and photons have zero mass, then which way would they fall? In practice they fall down, following the geodesic GR describes.
Photons fall down. Their antiparticle (photons) falls down. It would confuse the crap out of people if we started seeing anything fall up, and GR would need rethinking.
If you're referring to radiation coming from the accretion disk around the black hole, then it's not within the event horizon, so it can escape. If you're referring to Hawking radiation, then good luck understanding that.
If you're referring to his incompleteness theorem, then the same limitations it imposed on machines, it also imposes on humans. In much the same way a machine can't mindlessly rattle off closed tableaus of the negations of propositions until everything we want proved is proved, nor can a person. A human mathematician doesn't normally take this approach and is guided by intuition but there is nothing in his theorem to say a machine can't follow an algorithm indistinguishable from intuition.
Of course, whether or not you want to call a human being a machine depends on the definitions you're using and these definitions vary from context to context and from dictionary to dictionary.
That's not a very useful definition of the word "good" for most of us. We want a definition for which "good" actions are actions we should take. For example, flooding the earth, wiping out almost every human and almost every land animal is not something we want to encourage people to do, so we don't want to label it "good". Even if you could find a way to argue that it was the lesser of two evils, we would still want to label it an evil. It sets a really bad example otherwise.
Ever seen what caged rats will do to each other when they hit their critical point of overcrowding?
Is it engage in intelligent discourse to arrive at a solution which alleviates the problem for future generations, with each rat selflessly playing its part? Yes, it's probably this. Let's learn from caged rats, everybody!
Because nobody knows how a child learns language. Chomsky famously called it a "black box inside their heads."
This means if we had a robot learning the way a child does, we would not be able to verify it was learning in the same way. It doesn't mean it's impossible to independently arrive at the same solution. It just means we wouldn't know it was the same method but why would we care? If the inputs and outputs are the same and the machine is efficient, then problem solved.
Pushing it into a spiral means pushing it continuously. If you stop pushing it, then all you've done is changed its orbit. To make it spiral into the sun, it needs to be decelerated until its orbital speed hits zero. It's travelling at 30km/s and weighs a tonne, so it's not an easy feat to pull off.
Slashdot Mirror
Can you check mine please? Say we have N photons and the mass of a photon is 0. Then N times 0 equals 0, making a total mass of 0? Is that right?
If the photons were confined in some kind of box, then they'd add to the mass of the box though, so you could do it that way with an imaginary box in a thought experiment, and use this e=mc^2 formula you've picked up from somewhere.
Well it had a silly name anyway. Eve wasn't the matrilineal most recent common ancestor in the bible. That was Noah's wife, Naamah, so she would be the appropriate biblical analogue.
Dust particle? Insignificant? My home, this is!
Last I checked, the tides still come in and out every day, regardless of how much energy we extract from the process.
That energy is coming from somewhere and that's the spinning of the earth. It's barely noticeable over one human lifespan but the days are getting longer, which means there's less tidal power available over time.
That fusion reactor may be 150 gigameters away, but it's still a safety hazard! You can't even look at it directly without putting your eyes at risk, not to mention the cancer it causes.
It might be more useful to point out that 'gut feeling = cognitive bias' whenever someone mentions they feel something to be true.
Cognitive biases reveal the problems with relying on gut feelings. They're not synonyms. It seems some people in this thread have taken the '=' sign literally here and it's led to some strange comments about cognitive bias, when they actually mean 'gut feeling'.
Gut feelings allow decisions to be made quickly with minimal use of energy. This is important in the animal kingdom. Human beings have an abundance of energy and often have the luxury of time to make their decisions. As a result, human beings have put a great deal of effort into studying how the human brain systematically underperforms with regards to rational decision making. I would recommend reading up on all the cognitive biases listed here to anyone who takes pride in being correct.
Astronomers have discovered a dwarf galaxy
How do we know it's populated by dwarves?
Unless you are modelling every single animal on the planet,
Even the butterflies? What effect does a butterfly have, I wonder?
Earth will most likely fix itself, but in the short run it can go through all kind of unpleasant changes. Historically humanity develops best in the quiet phases of climate changes, we live in such a quiet time.
What does it mean for earth to fix itself? That the environment remained conducive to life and for ecosystems to remain sufficiently stable in the past is guaranteed by the anthropic principle. That is we could not have evolved to observe it unless the conditions in the past facilitated our evolution. The anthropic principle says nothing about the future however. In the long run (~billion years) the sun will get hot enough to vapourise the oceans. Currently, temperature rise is unusually rapid. It would be nice to believe that everything will be hunky dory in between, because fate will throw at us some cooling mechanism. How is this anything more than wishful thinking though?
It's Sir David Attenborough! He may be too old for jousting, but he's still a knight!
That doesn't sound like ultimate power to me. That sounds like a scenario in which the geeky engineers can overthrow you. They do run the military after all.
Why does it upset you so much? If I said zero was its own additive inverse, would this anger you? When we talk about particle-antiparticle pairs generally do you think it's more convenient or less convenient to include photons pairs?
I'm pretty sure we're using different definitions of falling. I'm not claiming light experiences anything at all, let alone acceleration. We do not regard a free fall frame as an accelerating frame, so I don't define falling in terms of acceleration.
A major result of GR is that spacetime is curved around massive objects, so there are no straight lines to follow. Light follows a geodesic like any other body not acted on by a force. Perhaps you're confusing it with special relativity? Light's path is bent toward the earth in GR. Obviously it travels way above the earth's escape velocity, so you won't see the beam of a torch flop onto the ground following a similar path to a slow moving tennis ball. If you were to instead consider a black hole, then light can be much more severely bent and fall into the black hole.
I hope this all comes in handy in 100 million years time when the dominant species at the time tries to make a park full of animals from the quaternary period. Of course the marketing team will call it Neogene Park, even though most of the species come from the quaternary period, not the neogene period, but Neogene Park sounds way cooler. They'll probably not give birds feathers either, not realising that was a thing until its too late.
Try typing "light falls" into google and see what comes up. For me first on the list, it's Professor Brian Greene's website explaining how light falls in GR. It even has "light falls" in the title so you don't have to read very far. Why didn't you do at least this before posting?
Gravity doesn't come into special relativity anywhere. General relativity is the most accurate model for gravity we have. If we're modelling the path of a small particle (which antimatter is in our experience) in free fall then its mass isn't really important in GR. It follows the same geodesic through curved spacetime regardless. Massive objects like the sun and earth significantly curve spacetime, but the mass of the antiparticle will have negligible effect whatever sign you choose to put on it if it is small in magnitude. If the sign of the mass mattered then photons and photons have zero mass, then which way would they fall? In practice they fall down, following the geodesic GR describes.
Photons fall down. Their antiparticle (photons) falls down. It would confuse the crap out of people if we started seeing anything fall up, and GR would need rethinking.
If you're referring to radiation coming from the accretion disk around the black hole, then it's not within the event horizon, so it can escape. If you're referring to Hawking radiation, then good luck understanding that.
The sun probably isn't big enough to go nova, so if we can't die until after it goes nova, then i guess that makes us immortal. Yay!
If you're referring to his incompleteness theorem, then the same limitations it imposed on machines, it also imposes on humans. In much the same way a machine can't mindlessly rattle off closed tableaus of the negations of propositions until everything we want proved is proved, nor can a person. A human mathematician doesn't normally take this approach and is guided by intuition but there is nothing in his theorem to say a machine can't follow an algorithm indistinguishable from intuition.
Of course, whether or not you want to call a human being a machine depends on the definitions you're using and these definitions vary from context to context and from dictionary to dictionary.
That's not a very useful definition of the word "good" for most of us. We want a definition for which "good" actions are actions we should take. For example, flooding the earth, wiping out almost every human and almost every land animal is not something we want to encourage people to do, so we don't want to label it "good". Even if you could find a way to argue that it was the lesser of two evils, we would still want to label it an evil. It sets a really bad example otherwise.
Ever seen what caged rats will do to each other when they hit their critical point of overcrowding?
Is it engage in intelligent discourse to arrive at a solution which alleviates the problem for future generations, with each rat selflessly playing its part? Yes, it's probably this. Let's learn from caged rats, everybody!
Because nobody knows how a child learns language. Chomsky famously called it a "black box inside their heads."
This means if we had a robot learning the way a child does, we would not be able to verify it was learning in the same way. It doesn't mean it's impossible to independently arrive at the same solution. It just means we wouldn't know it was the same method but why would we care? If the inputs and outputs are the same and the machine is efficient, then problem solved.
Pushing it into a spiral means pushing it continuously. If you stop pushing it, then all you've done is changed its orbit. To make it spiral into the sun, it needs to be decelerated until its orbital speed hits zero. It's travelling at 30km/s and weighs a tonne, so it's not an easy feat to pull off.