Couldn't you orbit the earth at any altitude greater than the highest peak? Say 29,029 feet?
Sure you can. You can orbit below that altitude too, as long as you choose an orbit which never intersects anything too hard. A near equatorial orbit lets you go round at a height just a bit higher than Kilimanjaro (you gotta have a safety margin, after all).
The big problem is that the air is rather thick down there. This has two consequences. First the drag means you slow down so fast that you either hit something pretty hard pretty quickly unless your engines are working hard enough to counteract the drag. Second, the drag dissipates so much energy in such a small volume that it gets pretty damned hot very close to your vehicle. The shuttle was much higher when it burned up, and travelling significantly slower than orbital speed at 10km to boot.
Assuming birds are the ancestors of dinosaurs, does anyone here know why the would have been better able to survive the extinction event 65m years ago? I don't imagine they would be able to fly high enough to avoid the dust cover that enveloped the earth.
Nope. They would have been char-grilled if they had been flying. The re-entering material thrown up by the initial impact would have turned the entire sky red hot for a few hours over the entire world.
The survivors would have been those well-insulated, perhaps by living in caves, under water or buried (as eggs, for example).
I set up my 15x80 binoculars this morning so some of the folk at MS Research in Cambridge could see the transit. A core-searcher brought along his eclipse viewer spectacles from the 1999 solar eclipse and another cow-orker took the photos
Not at all a professional looking site, but it was created within an hour of the photos being taken and without any pre-planning. I hope that some people, at least, find it interesting.
The transit is still in progress here. A bunch of us observed it by various means and a few photos are now available.
Enjoy.
Paul
Re:No! I use CapsLock as my "ESC" key
on
Is Caps Lock Dead?
·
· Score: 1
... where the hash key was mapped to
Try Shift-3 which is probably labelled with the sign, aka GPB, aka Pound Sterling, aka £ aka £ on your keyboard.
I bet the symbol goes astray here...
I occasionally have to use a system which is set up a physical UK keyboard and a logical US keyboard. A bit of experimentation soon turns up most things.
By definition, open source includes the right to make incompatible modifications. Open source which requires compatability is impossible; it is a contradiction in terms.
With respect, I think you completely missed the point. Sure an incompatible fork could take place under the GPL. However if a lump of software is given a trademarked name, the owner of the trademark could insist that the product be given a different name if that product were incompatible with the one released by the trademark owner.
IANAL, but last time I looked the GPL was about copyright and, in the jurisdictions with which I am familiar, copyright issues and trademark issues fall under different rules.
How long will this last. The BBC supplying to the world with only the Brits paying for it. I would guess they would give it to the Brits at no cost but charge everyone else.
It works both ways. I'm a Brit, living in Britain (or Britland as Dubya would say). Some years ago I wrote to NASA's public relations people asking for some information. By return of post, at no cost to me and sent by airmail, came a large envelope full of stuff.
AFAICT, both NASA and the BBC take the view that the material has already been paid for by tax payers and so, by and large, they are willing to send out copies to non-commercial entities.
I drive two vehicles. The first is a Honda ST1100 and I'm averaging 52mpg, with a high of 57 and a low of 49. That's imperial gallons, so the US equivalent is 42mpg with high of 46 and low of 39. It runs on petrol (gas) and is, of course, a high-power touring motorcycle (1100cc engine, circa 100 horsepower, circa 1/3 ton dry weight).
The other vehicle is a Peugot 307 diesel hatchback, mostly driven by my wife who is not a biker. She gets around 43mpg in town and up to 58mpg when touring gently on uncluttered fast roads. In US measures, these figures correspond to 34mpg and 46mpg respectively. Not bad for a workhorse with a 1900cc engine, top speed well over 100mph and weighing about a ton.
Both vehicles seem to have milage figures which are well in excess of what I see claimed for the vast majority of US vehicles.
Here in the UK, the Tesco and Waitrose supermarket chains have been taking orders over the net and delivering the goods by truck for several years. It's no longer remarked upon as being anything special.
Tesco were the first to realise that using their regular staff picking goods off the shelves of their regular supermarkets was a low-investment and very cost-effective way of linking orders to delivery trucks.
Unfortunately for your model, the Sun has orbited the galaxy about 20 times since its formation. During that period, the combination of inital random velocities and perturbation by other stars has well scrambled its initial neighborhood. The stars which are local now are quite likely to have been remote a billion years ago, and vice versa.
On the other hand, stars which are not more than a few billion years old and which were formed in the disk of the galaxy (as opposed to the bulge or the outlying globular clusters) are quite likely to have heavy elements no matter where in the disk they were formed.
I happen to know him a little, as one of my friends is his student, and another one was. If you think mathematicians are crazy, Franke is more than that. When you talk to him, he will usually just continue to stare at the piece of paper he has directly in front of his eyes (Nobody knows why he isn't wearing glasses.) and think of that as a normal way of communicating.
I also know Jens quite well (we are on first-name terms) and he seems sane enough to me. Perhaps I have hung around with mathematicians too much!
But if you manage to get along with him, he is actually quite nice and extremely helpful.
Seconded. Thorsten Kleinjung is also one of the good guys and very helpful.
Actually, the chance is negligible if you try that algorithm. Guesswork just doesn't cut it, unless you like betting at odds of 10^170 to one against.
Responding to the parent post: rather a lot of hackers have easy access to 100 node farms. It's not difficult any more to find 100 cpus, especially for an algorithm such as GNFS which doesn't need especially fast communications between them. The final stages are more of a bottleneck than the sieving, but far from impossible for reasonably clueful people.
such a calculation would be meaningless. whereas the space inside an instrument horn is filled with air and is where the sound comes from, the "space" in the model-universe horn is completely unaccessible.
Not entirely. The universe may be empty to a good approximation, that doesn't mean that it can't support standing waves.
Spacetime itself is elastic (assuming that you believe in General Relativity or something similar to GR) and so can distort in a periodic manner. These distortions are called gravity waves and there's some indirect evidence that they exist. Searches for direct evidence are underway.
Similarly, any other long-range field can support standing waves. I see no a priori reason why electromagnetic waves can not exist which have wavelengths which are integral fractions of twice the universal scale.
Likewise, I can see no a priori reason why any of the possible standing waves should not have observable consequences.
The Discovery article says that New Scientist magazine reported it Saturday, making it sound like a new discovery. But then it goes on to say it's been around since 1996. So how is this news?
Mathematics and physics applied to observations.
It may well have been discovered recently, but if enough of its orbit has been observed, it's possible to calculate where it has been in the past. In particular, it's possible to see where it's been since 1996 or so.
You will find that so-called amorphous carbon is really just graphite, but in very small particles. It's not really an allotrope in its own, more microcrystalline form of another.
Slashdot Mirror
A lot of plants can't hack 2-week long nights, whereas the nights on Mars are only slightly longer than they are here.
Paul
Brasilia?
Paul
Sure you can. You can orbit below that altitude too, as long as you choose an orbit which never intersects anything too hard. A near equatorial orbit lets you go round at a height just a bit higher than Kilimanjaro (you gotta have a safety margin, after all).
The big problem is that the air is rather thick down there. This has two consequences. First the drag means you slow down so fast that you either hit something pretty hard pretty quickly unless your engines are working hard enough to counteract the drag. Second, the drag dissipates so much energy in such a small volume that it gets pretty damned hot very close to your vehicle. The shuttle was much higher when it burned up, and travelling significantly slower than orbital speed at 10km to boot.
Paul
Nope. They would have been char-grilled if they had been flying. The re-entering material thrown up by the initial impact would have turned the entire sky red hot for a few hours over the entire world.
The survivors would have been those well-insulated, perhaps by living in caves, under water or buried (as eggs, for example).
Paul
Not at all a professional looking site, but it was created within an hour of the photos being taken and without any pre-planning. I hope that some people, at least, find it interesting.
Paul
Enjoy.
Paul
Try Shift-3 which is probably labelled with the sign, aka GPB, aka Pound Sterling, aka £ aka £ on your keyboard.
I bet the symbol goes astray here ...
I occasionally have to use a system which is set up a physical UK keyboard and a logical US keyboard. A bit of experimentation soon turns up most things.
Paul
With respect, I think you completely missed the point. Sure an incompatible fork could take place under the GPL. However if a lump of software is given a trademarked name, the owner of the trademark could insist that the product be given a different name if that product were incompatible with the one released by the trademark owner.
IANAL, but last time I looked the GPL was about copyright and, in the jurisdictions with which I am familiar, copyright issues and trademark issues fall under different rules.
Paul
Swanage is a pleasant little seaside resort. I know it well and stayed there a few nights when on my honeymoon.
Finding Swanwick and Swanage on a map of southern England is left as a exercise. Hint: Mapquest may be a good place to start.
Paul
Paul
Indeed. These are truly amazing beasts. I have a HPIII at home, still working as well as when it was bought, god knows how many years later.
Paul
It had rings last time I looked at it through a telescope.
Guess I may have been hallucinating or perhaps my memory is not what it was.
How do we know anything?
Paul
It works both ways. I'm a Brit, living in Britain (or Britland as Dubya would say). Some years ago I wrote to NASA's public relations people asking for some information. By return of post, at no cost to me and sent by airmail, came a large envelope full of stuff.
AFAICT, both NASA and the BBC take the view that the material has already been paid for by tax payers and so, by and large, they are willing to send out copies to non-commercial entities.
Paul
The other vehicle is a Peugot 307 diesel hatchback, mostly driven by my wife who is not a biker. She gets around 43mpg in town and up to 58mpg when touring gently on uncluttered fast roads. In US measures, these figures correspond to 34mpg and 46mpg respectively. Not bad for a workhorse with a 1900cc engine, top speed well over 100mph and weighing about a ton.
Both vehicles seem to have milage figures which are well in excess of what I see claimed for the vast majority of US vehicles.
Paul
Here in the UK, the Tesco and Waitrose supermarket chains have been taking orders over the net and delivering the goods by truck for several years. It's no longer remarked upon as being anything special.
Tesco were the first to realise that using their regular staff picking goods off the shelves of their regular supermarkets was a low-investment and very cost-effective way of linking orders to delivery trucks.
Paul
But then, I'm a pragmatist and like to get as big a bang for my buck as possible.
Paul
On the other hand, stars which are not more than a few billion years old and which were formed in the disk of the galaxy (as opposed to the bulge or the outlying globular clusters) are quite likely to have heavy elements no matter where in the disk they were formed.
Paul
I also know Jens quite well (we are on first-name terms) and he seems sane enough to me. Perhaps I have hung around with mathematicians too much!
But if you manage to get along with him, he is actually quite nice and extremely helpful.
Seconded. Thorsten Kleinjung is also one of the good guys and very helpful.
Paul
Responding to the parent post: rather a lot of hackers have easy access to 100 node farms. It's not difficult any more to find 100 cpus, especially for an algorithm such as GNFS which doesn't need especially fast communications between them. The final stages are more of a bottleneck than the sieving, but far from impossible for reasonably clueful people.
Paul
Not entirely true. The article states that three of the contributors were part of NFSNET which does have a distributed client.
Paul
Not entirely. The universe may be empty to a good approximation, that doesn't mean that it can't support standing waves.
Spacetime itself is elastic (assuming that you believe in General Relativity or something similar to GR) and so can distort in a periodic manner. These distortions are called gravity waves and there's some indirect evidence that they exist. Searches for direct evidence are underway.
Similarly, any other long-range field can support standing waves. I see no a priori reason why electromagnetic waves can not exist which have wavelengths which are integral fractions of twice the universal scale.
Likewise, I can see no a priori reason why any of the possible standing waves should not have observable consequences.
Paul
It has had temporary (and artificial) ones in orbit around it at various times in the last few decades.
Paul
Surely that's "Charon"?
And don't call me Shirly
Paul
Mathematics and physics applied to observations.
It may well have been discovered recently, but if enough of its orbit has been observed, it's possible to calculate where it has been in the past. In particular, it's possible to see where it's been since 1996 or so.
Paul
Paul