one interpretation is that it requires observation by a conscious mind to cause decoherence, meaning that the measuring equipment is itself in a state of superposition up until the moment that Alice and Bob check the readouts. This interpretation has been largely relegated to cocktail conversations by scientists because it appears impossible to test,
More to the point: We can test that it isn't true. We can measure when superposition occurs, and when it ceases to occur, and this is verifiably occurring without human intervention. In fact one of the biggest problems in quantum computers was getting the superpositions to last through the entire 'circuit', and this was measurably occurring on time scales small enough no human could have interfered.
Since the only argument for the interpretation is a fucking pun and taking advantage of Common English connotations of words (measurement -> observation -> observer -> sentient life form observer), there's a reason only mystics and New Agers hold onto it.
No problem, I had to have it explained to me once too. They say newborns have an intuitive understanding of some basic physics, but nobody is born understanding quantum mechanics.
Frankly I don't think anyone dies understanding quantum mechanics.:)
Assuming you know enough information to determine that a particle has been disentangled (and I think that this is the case), then you have faster-than-light transmission of information.
Nope. The only way you'd know that the particles had been disentangled is when the person on Mars sent you, via normal communication channels, the information they had measured and you saw that it was not correlated with what you had measured.
That's what was going on in this experiment -- Alice and Bob could not tell just by looking at their individual particles whether or not they were entangled. Even comparing their measurements doesn't tell them, since they could have gotten the same results as they would have in the case of entanglement through chance alone. Only when Victor told them which particles were entangled could they sort their data sets into entangled and non- and see that in fact the entangled set showed the expected correlation.
BTW, this is at a high level how Quantum Encryption works -- along with regular data, you send information about your entangled particle. If the information was snooped, then the entanglement is broken, and what you measure will have no correlation with the measurements you were sent. That's the only way to tell. You can't just look at the particle and say "yep, it's entangled".
I have a pretty bad grasp/understanding of this stuff, but if two atoms are entangled, changing the state in one affects the other, right?
No. All that happens is that when the particles are entangled they will have a correlated state when measured. e.g. if one has positive spin the other will have negative. Measuring -- or changing -- the state breaks the entanglement, so you can't simply use it like an FTL telegraph.
Besides, they are working on this now, so it hardly seems futile?
They are not working on FTL communication. The "quantum communication" they are talking about is like the GP said, in a sense a new form of encryption. You can't use entanglement to communicate FTL. However you can use it to determine if your communications have been intercepted -- due to the property that measuring the entangled particles breaks the entanglement. This is awesome because it means you could transmit a shared encryption key, and detect if anyone snooped it, and either send a new one if it was, or use the shared key if it wasn't.
I have wondered whether causality is an assumption rather than an actual property of the universe.
Causality is absolutely an assumption, one that physicists have understood that they are making -- among others -- for a long time. It might be an invalid assumption that only appears to be correct most of the time.
And what a fucking weird world would that be? Could we even reason about such a universe? It might be impossible.
I know I'm not going to let go of this assumption until there is some very, very convincing evidence.
So a key part of the experiment was that the pair of photons sent to "Victor" went through a 104 meter cable to ensure that whatever Victor did, Alice and Bob measured their polarizations first.
Presumably, one could extend this cable to increase the amount of time between Alice and Bob's measurement and Victor's decision to entangle or not.
Presumably long enough for Alice and Bob to send the result of their measurement to Victor.
And then instead of an RNG, Victor chooses to entangle based on whatever would contradict Alice and Bob's measurement.
Come on, we have to try...
P.S. the paper says they aren't violating causality, and it only looks like they are if you're looking at it wrong.
This is high school physics, more specifically Newton's laws of motion. It's not as if this is really that hard to understand:
Acceleration is defined as the rate of change of velocity, dv/dt, so, each of these "accelerations" will result in "velocities" (again plural), and using the definition for velocity, i.e., rate of change of position, or dp/dt, we get multiple positions. So, a direct consequence of your "accelerations" is "positions" (plural!), all for the same mass! I've never observed anything like that, nor have I ever heard of anybody observing it. If you have any evidence of this, I'd very much like to see it.
Heh, well, you certainly have a high-school physics understanding. Such as not realizing that you have observed this in every experiment you've ever conducted; or conversely that if your conception was correct that every 'acceleration' you've ever claimed to measure was wrong and you should have failed high school physics. After all, how often when calculating the force on an object did you add in the force of gravity from the sun, or the center of the galaxy, the Andromeda galaxy, etc. Never I'd wager. You're always selecting a sub-set of forces and calculating the acceleration due to them, completely ignoring your own incorrect declaration that this is invalid!
You see, things can have multiple accelerations, velocities, and positions. Say you're on a train moving at a constant velocity. You then begin riding your unicycle down the aisle at a constant velocity. Relative to the train you have one velocity and position, and relative to the tracks you have another velocity and position, and of course relative to the sun you have yet a third. You could view your track-relative velocity as simply your velocity, or you could view it as the sum of your velocity relative to the reference frame of the train and the velocity of the train reference frame to the tracks. Or your velocity is simply that relative to the train, and the tracks too have a velocity relative to the train. According to the Galilean principle of relativity, these are all, really, physically equivalent ways of viewing it and there isn't one answer that is "true" and the others false. Measuring the velocity of your unicycle from the train, or from the track, gives different answers yet both are correct.
Similarly, relative to something that is accelerating towards the center of the earth at 9.8m/s^2, you are being accelerated upward at 9.8m/s^2 by your chair. The general principle of relativity is trickier to formulate in all cases, yet still applies.
Because you can always view the situation from a perfectly equal viewpoint where only a subset -- or exactly one -- force or velocity vector applies, you can always refer to each component of the net acceleration as the sum of accelerations of each of the component reference frames.
And what's more, you take advantage of this fact yourself all the time, and yet were unaware that you were doing it.
Hopefully now you'll see it next time you think your car's acceleration due to its engine is something meaningful despite being an insignificant rounding error on its acceleration towards the sun.
(o) So those trapped gases must have been in the air at some point, millions of years ago, and then planet did just fine. So what's there to worry about? Uh.....
Nothing if you're a Gaea-worshiping hippie. Mother Earth will be just fine.
Most of us have concerns a lot more specific than just "the planet" doing fine.
Though on the other hand it's been nearly a decade since I've heard the solar neutrino problem brought up as an obvious reason why everything mainstream physics thinks is wrong and [kooky theory] is totally obvious if you aren't a member of the Scientific Clergy.
I think a lot of them will just move on using whatever other "anomalies" they please and ignore the times where they said "this means I'm right!" and they turn out to be wrong. Classic selection bias.
It's rather easy to infer the acceleration from the resulting force (and mass).
And rather easy to infer the net force from the net acceleration (and mass), which is how you actually measure force.
But why do you keep talking about "accelerations" (plural)? A ridgid body can only have one acceleration. (As the grandparent previously correctly stated.)
It can only have one net acceleration and also only one net force. Yet you can break that acceleration up into components which add up to the net acceleration, and those are the accelerations, plural.
It's like you think F=ma only applies to the net force and not to individual forces acting on a body. But that's wrong. A force is the acceleration of a mass. If you have multiple force components, then you have multiple acceleration components.
If I have Ftot = F1 + F2, then I can say that atot = Ftot/m, or I can say that a1 = F1/m and a2 = F2/m and atot = a1 + a2.
a1 and a2 are accelerations the body experiences. Like forces, they add as vectors to get a net result. It's as valid as talking about the forces adding. If you think there's no component acceleration, then that's equivalent to saying that there's no component force, only a net force. Well, in a sense you could say that a rigid body can only experience one net force. But to then go "what do you mean forces, plural?" would be to miss the broader perspective.
The forces cannot be inferred by the acceleration, thus disproving your point.
You can't infer the forces from the net acceleration, you can't infer the accelerations from the net force, what is your point? Physically, the "force" keeping you from falling through your chair is being transmitted via discreet transfers of momentum and the 'force' field is just a consequence. But you can still talk about forces. You're not wrong about that, you're just wrong that it's wrong to talk about accelerations or changes in momentum adding to produce a net force. F = dp/dt. It's not a one-way thing. It's an equivalence.
I thought that E=mc^2 meant that E could me converted to M not that all it was both energy and mass at the same time.
So did I! But it's not a conversion, it's an equivalence! Energy and mass -- relativistic mass, the quantity that informs our notions of gravity, weight, and inertia -- are really, always, the same thing just in different units. If there's more energy in a system, then it weighs more on a scale. Water weighs less than two hydrogen and one oxygen because it's at a lower energy state. This of course includes the energy that is in the form of rest mass.
Rest mass is a form of energy. It can be converted into other forms of energy at a rate equal to m0*c^2. Energy and relativistic mass are always related by the equation E=mc^2.
Re:This was already solved by a portuguese in 2009
on
Pioneer Anomaly Solved
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· Score: 1
Ah, that was the Phong shading one! Only in 2009? Seemed like longer ago...
At the time people were saying "Oh, why Phong shading? What's so perfect about that?" and, well, the answer is it isn't, it's an approximation. Not a bad one, either, but still. So's the finite element analysis these folk did. Just a much better one.
Not really as long as you realize that some things seem obvious once you know they're true... Or as long as you just mean "obvious possibility".
It's not like they didn't know that if there was a favored direction for the emission of radiation that this would affect the velocity of an object. The concept of a photon drive existed for decades before the Voyagers were launched. It's just that it was though that whatever net force there was would be essentially zero. Assume a uniform, spherical Voyager craft...
This has been a long-standing possible, and then probable, explanation for the anomaly. Seems to have taken quite a bit of effort to figure out what the actual value of the force would be with sufficient precision. I remember what seems like a long time ago an article posted to/. about someone calculating the effect of heat radiation using Phong shading, the 3D graphics technique, as an approximation and got pretty good agreement.
Going all the way to a complete finite element analysis, using multiple methods to come up with the coefficients for the model, and getting a result that leaves only a noise-level signal is pretty impressive. And not what I'd call obvious.
So despite maybe feeling like it, it's not exactly a case of research by the Maximegalon Institute of Slowly and Painfully Working Out the Surprisingly Obvious.
That's what I was going to say at first but I wanted to lead into the cooling thing -- anticipating the follow-on that they craft could have been designed differently to both radiate heat and radio in the same direction. Somehow.
In a sense yes. Radiation and all other forms of energy have relativistic mass, as in the m in E=mc^2, as in things that have more energy (moving objects, high-energy states of atoms and molecules, systems in general) have more mass as it applies to inertia and gravity.
Heat radiation as in (mostly infrared) photons don't have rest mass. That's the m0 in E = root(pc^2 + m0^2*c^4). So they don't have mass in the sense of matter as you usually think of it. But it turns out the way you usually think of mass is not equivalent to matter. Even though the usual way you think about it is that they are.
There's an acceleration vector for every force vector and a net acceleration and a net force vector. They're mathematically equivalent. You could also look at it as a sum of momentum delta vectors. How is the electromagnetic force conveyed? By a photon exchanging momentum. So is force something that only exists as an effect of adding up all the changes in momentum, or vice versa? Neither, both are correct viewpoints. Have a nice day.
Well actually, if they'd anticipated this and pointed the heat dissipating surfaces to the rear, Pioneer would be going faster.
I'm not sure they'd have done anything... the effect is so small, completely irrelevant for the main part of the missions, and they might have other reasons for orienting the craft a certain way -- maybe to maximize cooling. As a rule the side that emits the most photons would also be absorbing the most from the sun. I realize the situation could be more complicated than this; if it was simple the result would have been calculated a long time ago.
What I'm wondering is how many people will remove this from their "these handful of unexplained results in not fully understood circumstances mean all of physics are wrong (and my pet theory is right)" lists?
That's funny, just last night I was looking at the stars. And admiring these choice shots from the Spitzer space telescope.
I don't think getting rid of what was supposed to be like a pickup truck but ended up with the cost structure of a fighter jet represents ceasing to look towards the stars.
No, instead we get multiple companies giving us more frequent space travel, for humans and cargo alike.
We humans land on Mars, it will not be a government that sends them there.
I think that's unlikely, for the first people anyway.
I think it will be a government that sends people to Mars, but a private rocket that gets them from earth to their LEO rendezvous with their Mars vessel which was similarly brought up piecemeal by commercial rockets.
It's the commoditization of LEO access that is going to bring about a new dawn. It'll be a long time after that before the next leaps in space are conquered by private ventures, and it'll probably be well after governments already paved the way.
So at first there would still be a lot of small babies of big (dead) dinosaurs to compete with the smaller dinosaurs (that evolved into birds?) from the short grasses that would emerge post fireball.
Birds evolved well before the KT event. The dinosaurs that were still dinosaurs at the time simply died out.
T-Rex had tiny arms to compensate for the increased weight of its gigantic murder-maw.
It had arms at all because they helped it stand up (and maybe other uses). Skeletons show both many more muscle attachment points than would be needed for vestigial arms, and stress marks from bearing the weight of its body. Its arms were tiny, but very strong.
There was an oncoming aircraft on the same flight path 1000ft below. The FO was visually searching for that aircraft, saw venus, panicked, and put the aircraft nose-down.
Go figure, a groggy pilot's panicked reaction put the plane closer to danger.
I'd be more suspicious of Venus... clearly it was trying to take down a passenger aircraft, the classic cowardly maneuver of a terrorist. And it is a known hoarder of deadly chemicals used in the manufacture of WMD. Who knows how far along it's program already is, since it has never allowed IAEA inspectors beneath it's all-concealing clouds?!
Slashdot Mirror
one interpretation is that it requires observation by a conscious mind to cause decoherence, meaning that the measuring equipment is itself in a state of superposition up until the moment that Alice and Bob check the readouts. This interpretation has been largely relegated to cocktail conversations by scientists because it appears impossible to test,
More to the point: We can test that it isn't true. We can measure when superposition occurs, and when it ceases to occur, and this is verifiably occurring without human intervention. In fact one of the biggest problems in quantum computers was getting the superpositions to last through the entire 'circuit', and this was measurably occurring on time scales small enough no human could have interfered.
Since the only argument for the interpretation is a fucking pun and taking advantage of Common English connotations of words (measurement -> observation -> observer -> sentient life form observer), there's a reason only mystics and New Agers hold onto it.
No problem, I had to have it explained to me once too. They say newborns have an intuitive understanding of some basic physics, but nobody is born understanding quantum mechanics.
Frankly I don't think anyone dies understanding quantum mechanics. :)
Assuming you know enough information to determine that a particle has been disentangled (and I think that this is the case), then you have faster-than-light transmission of information.
Nope. The only way you'd know that the particles had been disentangled is when the person on Mars sent you, via normal communication channels, the information they had measured and you saw that it was not correlated with what you had measured.
That's what was going on in this experiment -- Alice and Bob could not tell just by looking at their individual particles whether or not they were entangled. Even comparing their measurements doesn't tell them, since they could have gotten the same results as they would have in the case of entanglement through chance alone. Only when Victor told them which particles were entangled could they sort their data sets into entangled and non- and see that in fact the entangled set showed the expected correlation.
BTW, this is at a high level how Quantum Encryption works -- along with regular data, you send information about your entangled particle. If the information was snooped, then the entanglement is broken, and what you measure will have no correlation with the measurements you were sent. That's the only way to tell. You can't just look at the particle and say "yep, it's entangled".
I have a pretty bad grasp/understanding of this stuff, but if two atoms are entangled, changing the state in one affects the other, right?
No. All that happens is that when the particles are entangled they will have a correlated state when measured. e.g. if one has positive spin the other will have negative. Measuring -- or changing -- the state breaks the entanglement, so you can't simply use it like an FTL telegraph.
Besides, they are working on this now, so it hardly seems futile?
They are not working on FTL communication. The "quantum communication" they are talking about is like the GP said, in a sense a new form of encryption. You can't use entanglement to communicate FTL. However you can use it to determine if your communications have been intercepted -- due to the property that measuring the entangled particles breaks the entanglement. This is awesome because it means you could transmit a shared encryption key, and detect if anyone snooped it, and either send a new one if it was, or use the shared key if it wasn't.
I have wondered whether causality is an assumption rather than an actual property of the universe.
Causality is absolutely an assumption, one that physicists have understood that they are making -- among others -- for a long time. It might be an invalid assumption that only appears to be correct most of the time.
And what a fucking weird world would that be? Could we even reason about such a universe? It might be impossible.
I know I'm not going to let go of this assumption until there is some very, very convincing evidence.
Or at least try...
So a key part of the experiment was that the pair of photons sent to "Victor" went through a 104 meter cable to ensure that whatever Victor did, Alice and Bob measured their polarizations first.
Presumably, one could extend this cable to increase the amount of time between Alice and Bob's measurement and Victor's decision to entangle or not.
Presumably long enough for Alice and Bob to send the result of their measurement to Victor.
And then instead of an RNG, Victor chooses to entangle based on whatever would contradict Alice and Bob's measurement.
Come on, we have to try...
P.S. the paper says they aren't violating causality, and it only looks like they are if you're looking at it wrong.
This is high school physics, more specifically Newton's laws of motion. It's not as if this is really that hard to understand:
Acceleration is defined as the rate of change of velocity, dv/dt, so, each of these "accelerations" will result in "velocities" (again plural), and using the definition for velocity, i.e., rate of change of position, or dp/dt, we get multiple positions. So, a direct consequence of your "accelerations" is "positions" (plural!), all for the same mass! I've never observed anything like that, nor have I ever heard of anybody observing it. If you have any evidence of this, I'd very much like to see it.
Heh, well, you certainly have a high-school physics understanding. Such as not realizing that you have observed this in every experiment you've ever conducted; or conversely that if your conception was correct that every 'acceleration' you've ever claimed to measure was wrong and you should have failed high school physics. After all, how often when calculating the force on an object did you add in the force of gravity from the sun, or the center of the galaxy, the Andromeda galaxy, etc. Never I'd wager. You're always selecting a sub-set of forces and calculating the acceleration due to them, completely ignoring your own incorrect declaration that this is invalid!
You see, things can have multiple accelerations, velocities, and positions. Say you're on a train moving at a constant velocity. You then begin riding your unicycle down the aisle at a constant velocity. Relative to the train you have one velocity and position, and relative to the tracks you have another velocity and position, and of course relative to the sun you have yet a third. You could view your track-relative velocity as simply your velocity, or you could view it as the sum of your velocity relative to the reference frame of the train and the velocity of the train reference frame to the tracks. Or your velocity is simply that relative to the train, and the tracks too have a velocity relative to the train. According to the Galilean principle of relativity, these are all, really, physically equivalent ways of viewing it and there isn't one answer that is "true" and the others false. Measuring the velocity of your unicycle from the train, or from the track, gives different answers yet both are correct.
Similarly, relative to something that is accelerating towards the center of the earth at 9.8m/s^2, you are being accelerated upward at 9.8m/s^2 by your chair. The general principle of relativity is trickier to formulate in all cases, yet still applies.
Because you can always view the situation from a perfectly equal viewpoint where only a subset -- or exactly one -- force or velocity vector applies, you can always refer to each component of the net acceleration as the sum of accelerations of each of the component reference frames.
And what's more, you take advantage of this fact yourself all the time, and yet were unaware that you were doing it.
Hopefully now you'll see it next time you think your car's acceleration due to its engine is something meaningful despite being an insignificant rounding error on its acceleration towards the sun.
(o) So those trapped gases must have been in the air at some point, millions of years ago, and then planet did just fine. So what's there to worry about? Uh.....
Nothing if you're a Gaea-worshiping hippie. Mother Earth will be just fine.
Most of us have concerns a lot more specific than just "the planet" doing fine.
Ain't it the truth. :(
Though on the other hand it's been nearly a decade since I've heard the solar neutrino problem brought up as an obvious reason why everything mainstream physics thinks is wrong and [kooky theory] is totally obvious if you aren't a member of the Scientific Clergy.
I think a lot of them will just move on using whatever other "anomalies" they please and ignore the times where they said "this means I'm right!" and they turn out to be wrong. Classic selection bias.
It's rather easy to infer the acceleration from the resulting force (and mass).
And rather easy to infer the net force from the net acceleration (and mass), which is how you actually measure force.
But why do you keep talking about "accelerations" (plural)? A ridgid body can only have one acceleration. (As the grandparent previously correctly stated.)
It can only have one net acceleration and also only one net force. Yet you can break that acceleration up into components which add up to the net acceleration, and those are the accelerations, plural.
It's like you think F=ma only applies to the net force and not to individual forces acting on a body. But that's wrong. A force is the acceleration of a mass. If you have multiple force components, then you have multiple acceleration components.
If I have Ftot = F1 + F2, then I can say that atot = Ftot/m, or I can say that a1 = F1/m and a2 = F2/m and atot = a1 + a2.
a1 and a2 are accelerations the body experiences. Like forces, they add as vectors to get a net result. It's as valid as talking about the forces adding. If you think there's no component acceleration, then that's equivalent to saying that there's no component force, only a net force. Well, in a sense you could say that a rigid body can only experience one net force. But to then go "what do you mean forces, plural?" would be to miss the broader perspective.
The forces cannot be inferred by the acceleration, thus disproving your point.
You can't infer the forces from the net acceleration, you can't infer the accelerations from the net force, what is your point? Physically, the "force" keeping you from falling through your chair is being transmitted via discreet transfers of momentum and the 'force' field is just a consequence. But you can still talk about forces. You're not wrong about that, you're just wrong that it's wrong to talk about accelerations or changes in momentum adding to produce a net force. F = dp/dt. It's not a one-way thing. It's an equivalence.
I thought that E=mc^2 meant that E could me converted to M not that all it was both energy and mass at the same time.
So did I! But it's not a conversion, it's an equivalence! Energy and mass -- relativistic mass, the quantity that informs our notions of gravity, weight, and inertia -- are really, always, the same thing just in different units. If there's more energy in a system, then it weighs more on a scale. Water weighs less than two hydrogen and one oxygen because it's at a lower energy state. This of course includes the energy that is in the form of rest mass.
Rest mass is a form of energy. It can be converted into other forms of energy at a rate equal to m0*c^2. Energy and relativistic mass are always related by the equation E=mc^2.
A portuguese aeronautics engineering student from Instituto Superior Técnico already figured this out way back in 2009 in his masters thesis, available here.
Ah, that was the Phong shading one! Only in 2009? Seemed like longer ago...
At the time people were saying "Oh, why Phong shading? What's so perfect about that?" and, well, the answer is it isn't, it's an approximation. Not a bad one, either, but still. So's the finite element analysis these folk did. Just a much better one.
Am I arrogant for saying "wasn't this obvious?"
Not really as long as you realize that some things seem obvious once you know they're true... Or as long as you just mean "obvious possibility".
It's not like they didn't know that if there was a favored direction for the emission of radiation that this would affect the velocity of an object. The concept of a photon drive existed for decades before the Voyagers were launched. It's just that it was though that whatever net force there was would be essentially zero. Assume a uniform, spherical Voyager craft...
This has been a long-standing possible, and then probable, explanation for the anomaly. Seems to have taken quite a bit of effort to figure out what the actual value of the force would be with sufficient precision. I remember what seems like a long time ago an article posted to /. about someone calculating the effect of heat radiation using Phong shading, the 3D graphics technique, as an approximation and got pretty good agreement.
Going all the way to a complete finite element analysis, using multiple methods to come up with the coefficients for the model, and getting a result that leaves only a noise-level signal is pretty impressive. And not what I'd call obvious.
So despite maybe feeling like it, it's not exactly a case of research by the Maximegalon Institute of Slowly and Painfully Working Out the Surprisingly Obvious.
That's what I was going to say at first but I wanted to lead into the cooling thing -- anticipating the follow-on that they craft could have been designed differently to both radiate heat and radio in the same direction. Somehow.
Does it have mass?
In a sense yes. Radiation and all other forms of energy have relativistic mass, as in the m in E=mc^2, as in things that have more energy (moving objects, high-energy states of atoms and molecules, systems in general) have more mass as it applies to inertia and gravity.
Heat radiation as in (mostly infrared) photons don't have rest mass. That's the m0 in E = root(pc^2 + m0^2*c^4). So they don't have mass in the sense of matter as you usually think of it. But it turns out the way you usually think of mass is not equivalent to matter. Even though the usual way you think about it is that they are.
Hope that clears things up. :)
There's an acceleration vector for every force vector and a net acceleration and a net force vector. They're mathematically equivalent. You could also look at it as a sum of momentum delta vectors. How is the electromagnetic force conveyed? By a photon exchanging momentum. So is force something that only exists as an effect of adding up all the changes in momentum, or vice versa? Neither, both are correct viewpoints. Have a nice day.
Well actually, if they'd anticipated this and pointed the heat dissipating surfaces to the rear, Pioneer would be going faster.
I'm not sure they'd have done anything... the effect is so small, completely irrelevant for the main part of the missions, and they might have other reasons for orienting the craft a certain way -- maybe to maximize cooling. As a rule the side that emits the most photons would also be absorbing the most from the sun. I realize the situation could be more complicated than this; if it was simple the result would have been calculated a long time ago.
What I'm wondering is how many people will remove this from their "these handful of unexplained results in not fully understood circumstances mean all of physics are wrong (and my pet theory is right)" lists?
That's funny, just last night I was looking at the stars. And admiring these choice shots from the Spitzer space telescope.
I don't think getting rid of what was supposed to be like a pickup truck but ended up with the cost structure of a fighter jet represents ceasing to look towards the stars.
No, instead we get multiple companies giving us more frequent space travel, for humans and cargo alike.
We humans land on Mars, it will not be a government that sends them there.
I think that's unlikely, for the first people anyway.
I think it will be a government that sends people to Mars, but a private rocket that gets them from earth to their LEO rendezvous with their Mars vessel which was similarly brought up piecemeal by commercial rockets.
It's the commoditization of LEO access that is going to bring about a new dawn. It'll be a long time after that before the next leaps in space are conquered by private ventures, and it'll probably be well after governments already paved the way.
Google "Terror Bird". :)
So at first there would still be a lot of small babies of big (dead) dinosaurs to compete with the smaller dinosaurs (that evolved into birds?) from the short grasses that would emerge post fireball.
Birds evolved well before the KT event. The dinosaurs that were still dinosaurs at the time simply died out.
Good points btw.
T-Rex had tiny arms to compensate for the increased weight of its gigantic murder-maw.
It had arms at all because they helped it stand up (and maybe other uses). Skeletons show both many more muscle attachment points than would be needed for vestigial arms, and stress marks from bearing the weight of its body. Its arms were tiny, but very strong.
There was an oncoming aircraft on the same flight path 1000ft below. The FO was visually searching for that aircraft, saw venus, panicked, and put the aircraft nose-down.
Go figure, a groggy pilot's panicked reaction put the plane closer to danger.
I'd be more suspicious of Venus... clearly it was trying to take down a passenger aircraft, the classic cowardly maneuver of a terrorist. And it is a known hoarder of deadly chemicals used in the manufacture of WMD. Who knows how far along it's program already is, since it has never allowed IAEA inspectors beneath it's all-concealing clouds?!