I humbly disagree. For those readers unfamiliar with Popper, he said that a scientific conjecture must be falsifiable. That is, a test must exist in which a possible proves the initial position to be false. If the initial conjecture is: "There is no life on Mars", this is proven false if is a single instance of life is found. If the conjecture is: "There _is_ life on Mars", that's not falsifiable at all. Unless maybe the planet is destroyed. Absence of evidence is not evidence of absence, so the fact that we haven't detected life doesn't mean it's not there. You cannot prove there is no life on Mars unless you examine every point on and in the planet simultaneously and find nothing. And even then it might just mean your detection methods were insufficient. So I say that it's up to those who believe there is life on Mars to offer evidence in support of that position. Personally, I'm neutral.
Farnsworth: I'm sorry, Fry, but astronomers changed the name of that planet in 2260 to end that stupid joke once and for all.
Fry: What's it called now?
Farnsworth: Urrectum! Here, let me find it for you!
Tidal heating is only effective on Enceladus if a) the ice is already warm to start out with and b) the ice shell is decoupled from the core by a subsurface ocean. It turns out it's really hard to keep the ocean from freezing even with tidal heating. Once you freeze solid, the tidal dissipation rate plummets and you can never get out of it (without some additional heat source). So you've got to either form hot and stay hot from Solar System formation until now, or have some additional heat source. A giant impact might do it, but impacts are the last refuge of the scoundrel since the impact must have happened relatively recently for us to be seeing the thermal effects.
Not particularly. Perseus is pretty far north and and Eridanus is in the south. O-Per is at RA: 3h44m, Dec: +32. amd 300-500 pc away from Earth. O-Eri is at RA: 4h12m, Dec: -7 and only about 40 pc away. There's 40 degrees of arc adn 1000 light years between them.
Door locks just tell theives you have something worth locking up. Really you should leave your doors unlocked and open to show you have nothing worth securing. Better yet, just remove the doors entirely. If you do have valuables, put them in a big pile by the front door. Theives will be so suspicious of a hoard of unguarded treasure, they'll be sure you're watching them.
Anything could be used as a terrorist tool. The ONLY possible solution therefore is the complete destruction of the entire Universe and everything in it. Anyone who disagrees is obviously in league with the terrorists.
One time my father-in-law kept them on the phone for quite some time. When they asked "How are you doing tonight?", a question to which most people expect a one-word answer, he went and narrated everything that happened that day without pausing to give the other party a chance to speak. Must have been half an hour. And as I understand it, it's actually illegal for the caller to hang up on the callee. That's more effort than the alternative options that other posters have provided, but it was very entertaining.
Yeah, a line in my particle physics textbook said "We have made so many approximations we have lost all fear of making more." It was at that point I dropped the class. (It was my last semester and I didn't actually need the class to graduate. I was taking it for "fun". I still sat in on it.)
That's right, despite always being cited to be the first to discover America, Columbus was the last person to discover America (even that's not true, since he never went to the mainland). Heck, he wasn't even the first European to do so.
Why didn't I think of that! With a negative debt, we're effectively rolling in cash. Next we just need to switch our currency to the negabuck, 1 Nb = -$1.
I agree those kind of fees are ridiculous. With a bit more effort, you can often work around that. Most scientists will post their own papers to a personal website for free (The copyright agreement with the publisher typically allows this). If the author has no such site, they will still provide the paper in response to an email request. The authors want you to read their work, and don't care if you pay for it or not, since they see none of the money in any case. What I think is truly wretched is that most publishers charge the authors AND the readers for the publication.
He was just some dumb cowboy that came across as more likable to people dumb enough to vote for President based on who they'd rather sit down and have a beer with.
If it was easy, they would have done it before now. We managed flybys of Merc 30 years ago, but those are much easier since you don't have to slow down.
I occasionally teach undergraduate level astronomy/planetary science.
I'll typically drop the lowest homework grade. But I don't want anyone to deliberately skip out on an assignment, so I don't announce that until after the last assignment has been handed in. This announcement at that point also takes a little pressure off the students right before the final.
I've been known to allow students to redo earlier assignments to recover points. That allows people to recover from an early failure. Whether I do this depends on the nature of the assignment, but the opportunity is offered to everyone, regardless of how well they did originally. I typically only do this for homework assginments, not for exams. My experience is that the ones who take advantage of it are the ones who don't need it, who got a 90 the first time round and push it up to a 98, while the ones who got a 40 don't even bother.
For exams, I weight the final much more heavily than the midterm, and replace the midterm grade with the final exam grade if it would go up. However, I do require students to pass the final in order to pass the class. What you know at the end is important. If you don't show up to the final, you fail, even if you aced everything before. I find that encourages people to study hard for the final. (Note that I'm deliberately ambiguous as to what constitutes "passing" the final exam. I'm not going to fail someone with a passing average just because they make a 59 on the final exam. But that situation has never come up. I've never failed a student on the final that wasn't failing already)
Clearly, then. I did not recall correctly. And now that you mention it, I clearly remember having known there were flowers in the Cretaceous. I was sure about the Eocene and the grass though. Oh, well.
By that logic, then the Moon was even closer to the Earth before 85 mya. Dinos seemed to do ok then.
But of course, as another poster pointed out, it was never that close. The Moon formed at about 12 Earth radii and is now at about 60. It's rate of recession is not constant, but depends upon the time-varying dissipation function of the Earth. Since most of the tidal dissipation on the Earth is in the oceans, this function depends on the configuration of continents and oceans.
IIRC, flowering plants evolved during the Eocene, ~10 My after the K-T impact. This includes grasses. Kind of eerie if you think about it. Grass is so ubiquitous now, but back in the day it would just be patches of bare dirt between the trees and shrubs, and I guess vast open stretches of nothing.
It's more an issue of oxygen than gravity. Insects have a very primitive respiratory system. They basically just diffuse gases through their exoskeleton, so their size is limited by the oxygen content of the atmosphere. This was high during the Devonian, hence the 70 cm dragonflies mentioned by another poster. I also recall hearing about spiders that predated on those dragonflies, but I don't have any sources to back that up.
That only happens if you're in a resonance, and an object pulls on you at the same point in the orbit each time. Example, Europa orbits once every time Io orbits twice. Their closest approach occurs at the same point, and Io's eccentricity is constantly pumped up. If the two were not in a resonance, Europa (and everything) would pull in varying directions more or less cancelling each other out, and Io's orbit would circularize. (This particular example is more complicated because Ganymede is also in resonance with them.)
That's right. In the Santa Cruz area, there are signs everywhere that say: "Warning! This facility may contain chemicals known to be harmful to pregnant women," or something to that effect.
Locations of these signs include the entrance to the Sutter Maternity Center. Brilliant.
Slashdot Mirror
I humbly disagree. For those readers unfamiliar with Popper, he said that a scientific conjecture must be falsifiable. That is, a test must exist in which a possible proves the initial position to be false. If the initial conjecture is: "There is no life on Mars", this is proven false if is a single instance of life is found. If the conjecture is: "There _is_ life on Mars", that's not falsifiable at all. Unless maybe the planet is destroyed. Absence of evidence is not evidence of absence, so the fact that we haven't detected life doesn't mean it's not there. You cannot prove there is no life on Mars unless you examine every point on and in the planet simultaneously and find nothing. And even then it might just mean your detection methods were insufficient. So I say that it's up to those who believe there is life on Mars to offer evidence in support of that position. Personally, I'm neutral.
Farnsworth: I'm sorry, Fry, but astronomers changed the name of that planet in 2260 to end that stupid joke once and for all. Fry: What's it called now? Farnsworth: Urrectum! Here, let me find it for you!
Sadly, most coffee makers fail to achieve a sufficiently high temperature to make a respectable brew.
Tidal heating is only effective on Enceladus if a) the ice is already warm to start out with and b) the ice shell is decoupled from the core by a subsurface ocean. It turns out it's really hard to keep the ocean from freezing even with tidal heating. Once you freeze solid, the tidal dissipation rate plummets and you can never get out of it (without some additional heat source). So you've got to either form hot and stay hot from Solar System formation until now, or have some additional heat source. A giant impact might do it, but impacts are the last refuge of the scoundrel since the impact must have happened relatively recently for us to be seeing the thermal effects.
Not particularly. Perseus is pretty far north and and Eridanus is in the south. O-Per is at RA: 3h44m, Dec: +32. amd 300-500 pc away from Earth. O-Eri is at RA: 4h12m, Dec: -7 and only about 40 pc away. There's 40 degrees of arc adn 1000 light years between them.
Door locks just tell theives you have something worth locking up. Really you should leave your doors unlocked and open to show you have nothing worth securing. Better yet, just remove the doors entirely. If you do have valuables, put them in a big pile by the front door. Theives will be so suspicious of a hoard of unguarded treasure, they'll be sure you're watching them.
If your medication actually has a finite half-life, then it's probably not something you want to be ingesting regularly.
Anything could be used as a terrorist tool. The ONLY possible solution therefore is the complete destruction of the entire Universe and everything in it. Anyone who disagrees is obviously in league with the terrorists.
Don't you think you're being a bit soft on this issue?
One time my father-in-law kept them on the phone for quite some time. When they asked "How are you doing tonight?", a question to which most people expect a one-word answer, he went and narrated everything that happened that day without pausing to give the other party a chance to speak. Must have been half an hour. And as I understand it, it's actually illegal for the caller to hang up on the callee. That's more effort than the alternative options that other posters have provided, but it was very entertaining.
Yeah, a line in my particle physics textbook said "We have made so many approximations we have lost all fear of making more." It was at that point I dropped the class. (It was my last semester and I didn't actually need the class to graduate. I was taking it for "fun". I still sat in on it.)
That's right, despite always being cited to be the first to discover America, Columbus was the last person to discover America (even that's not true, since he never went to the mainland). Heck, he wasn't even the first European to do so.
Why didn't I think of that! With a negative debt, we're effectively rolling in cash. Next we just need to switch our currency to the negabuck, 1 Nb = -$1.
I agree those kind of fees are ridiculous. With a bit more effort, you can often work around that. Most scientists will post their own papers to a personal website for free (The copyright agreement with the publisher typically allows this). If the author has no such site, they will still provide the paper in response to an email request. The authors want you to read their work, and don't care if you pay for it or not, since they see none of the money in any case. What I think is truly wretched is that most publishers charge the authors AND the readers for the publication.
He was just some dumb cowboy that came across as more likable to people dumb enough to vote for President based on who they'd rather sit down and have a beer with.
And the irony? He doesn't even drink.
The newsletter of the Virginia Tech chapter of the Society of Physics Students is (or was) called "The Naked Singularity."
If it was easy, they would have done it before now. We managed flybys of Merc 30 years ago, but those are much easier since you don't have to slow down.
I occasionally teach undergraduate level astronomy/planetary science. I'll typically drop the lowest homework grade. But I don't want anyone to deliberately skip out on an assignment, so I don't announce that until after the last assignment has been handed in. This announcement at that point also takes a little pressure off the students right before the final.
I've been known to allow students to redo earlier assignments to recover points. That allows people to recover from an early failure. Whether I do this depends on the nature of the assignment, but the opportunity is offered to everyone, regardless of how well they did originally. I typically only do this for homework assginments, not for exams. My experience is that the ones who take advantage of it are the ones who don't need it, who got a 90 the first time round and push it up to a 98, while the ones who got a 40 don't even bother.
For exams, I weight the final much more heavily than the midterm, and replace the midterm grade with the final exam grade if it would go up. However, I do require students to pass the final in order to pass the class. What you know at the end is important. If you don't show up to the final, you fail, even if you aced everything before. I find that encourages people to study hard for the final. (Note that I'm deliberately ambiguous as to what constitutes "passing" the final exam. I'm not going to fail someone with a passing average just because they make a 59 on the final exam. But that situation has never come up. I've never failed a student on the final that wasn't failing already)
Clearly, then. I did not recall correctly. And now that you mention it, I clearly remember having known there were flowers in the Cretaceous. I was sure about the Eocene and the grass though. Oh, well.
By that logic, then the Moon was even closer to the Earth before 85 mya. Dinos seemed to do ok then.
But of course, as another poster pointed out, it was never that close. The Moon formed at about 12 Earth radii and is now at about 60. It's rate of recession is not constant, but depends upon the time-varying dissipation function of the Earth. Since most of the tidal dissipation on the Earth is in the oceans, this function depends on the configuration of continents and oceans.
IIRC, flowering plants evolved during the Eocene, ~10 My after the K-T impact. This includes grasses. Kind of eerie if you think about it. Grass is so ubiquitous now, but back in the day it would just be patches of bare dirt between the trees and shrubs, and I guess vast open stretches of nothing.
It's more an issue of oxygen than gravity. Insects have a very primitive respiratory system. They basically just diffuse gases through their exoskeleton, so their size is limited by the oxygen content of the atmosphere. This was high during the Devonian, hence the 70 cm dragonflies mentioned by another poster. I also recall hearing about spiders that predated on those dragonflies, but I don't have any sources to back that up.
That only happens if you're in a resonance, and an object pulls on you at the same point in the orbit each time. Example, Europa orbits once every time Io orbits twice. Their closest approach occurs at the same point, and Io's eccentricity is constantly pumped up. If the two were not in a resonance, Europa (and everything) would pull in varying directions more or less cancelling each other out, and Io's orbit would circularize. (This particular example is more complicated because Ganymede is also in resonance with them.)
That's right. In the Santa Cruz area, there are signs everywhere that say: "Warning! This facility may contain chemicals known to be harmful to pregnant women," or something to that effect.
Locations of these signs include the entrance to the Sutter Maternity Center. Brilliant.
Riggall? Rig all? Are you fscking kidding me?