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Proposed Space Telescope Uses Huge Opaque Disk To Surpass Hubble

ceoyoyo Re:This is fine in theory (109 comments)

I don't think it's an interferometer. It's a standard diffraction lens, just like the Canon one you linked, that produces a real image, not an interference pattern. You could stand at the focal point and see an image.

It would be an interferometer if you put a ring of telescopes on the rim instead of at the focus.

5 hours ago
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Proposed Space Telescope Uses Huge Opaque Disk To Surpass Hubble

ceoyoyo Re:Bless you. (109 comments)

So long as you're not looking at something really close, the little bit of parallax you get by going around the planet isn't going to cause too many problems. And if you're looking at something where it does matter, you just take shorter exposures and stack them. As a bonus you get 3D measurements.

5 hours ago
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At Oxford, a Battery That's Lasted 175 Years -- So Far

ceoyoyo Re:Bullshit (210 comments)

Action potentials are a bit funny. They're not actually movements of electrons down a wire like we're used to thinking about, but rather propagating waves of changes in the way cellular pumps move heavy ions through the cell membrane. Action potentials provide essentially no long-distance current, for example.

If you applied 15 mV across the SA node (the heart's built in pacemaker) at just the right time in the cardiac sequence you might be able to interfere enough to stop the organized contraction. There's a lab at my university that's been looking at analyzing chaotic heart contractions in order to use very small, very well-timed pacemaker signals, to correct them.

You would absolutely have to do it internally though ("applied directly to the heart"). The human body is basically a bag of salt water, which conducts quite well (about 300 Ohm from head to toe IIRC) surrounded by skin, which is a pretty good insulator. So if you want to electrocute someone, stab the electrodes in first.

3 days ago
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At Oxford, a Battery That's Lasted 175 Years -- So Far

ceoyoyo Re:Hold your horses (210 comments)

You missed his point. 1 nA per ring, second, hour, whatever, makes no sense. An amp is already of measurement of charge per unit time. If the current measurement is correct, which I believe it is, then the GP's formula is correct. Multiplying a current (charge / unit time) by a time gives you a measure of total charge. Multiplying by the voltage then gives you total energy.

3 days ago
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At Oxford, a Battery That's Lasted 175 Years -- So Far

ceoyoyo Re:Interstellar missions... (210 comments)

The previous posters are correct - the clear, low humidity air over deserts is more transparent to infrared light and radiative loss is the major reason for fast cooling at night. I've spent the night out in the Sahara. When the air cools off and you dig into the sand you realize that not only is the sand a decent insulator, just below the surface it's also much warmer than the air.

3 days ago
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At Oxford, a Battery That's Lasted 175 Years -- So Far

ceoyoyo Re:Interstellar missions... (210 comments)

Dry batteries don't work well in the cold because chemical reactions slow down the colder it gets. Wet batteries don't *survive* the cold because things freeze. I say this both as someone whose camera batteries often needed to be hand warmed, and as someone who's had to change a car battery at -40 because it discharged, froze and cracked it's case.

3 days ago
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At Oxford, a Battery That's Lasted 175 Years -- So Far

ceoyoyo Re:Bullshit (210 comments)

You probably could stop someone's heart with 15 mV. But it would have to be applied directly to the heart, and at just the right time.

For external application (i.e. without the open heart surgery) it's going to take rather more than that. You generally need a current of around 100 mA through the heart to stop it. If you're not standing in a puddle of salt water or gripping a water pipe, it's going to take quite a bit more voltage to achieve that.

110 V household current can kill, if you manage to get a good connection hand to hand. I think the lowest voltages observed to kill someone were around 40 V, but that requires some fairly exceptional circumstances.

3 days ago
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Government Recommends Cars With Smarter Brakes

ceoyoyo Re:Not a fan (303 comments)

I'm pretty sure pre-emptive braking systems are designed to use the ABS system, not lock the brakes. So go ahead and swerve with controlled braking.

3 days ago
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Government Recommends Cars With Smarter Brakes

ceoyoyo Re:Airplanes handle it better (303 comments)

Airline pilots are rather better trained than the average driver. Things also tend to happen more slowly in the air. If you're ever in a collision situation that requires action as quick as you're probably used to on a daily basis in your car, you've screwed up royally.

3 days ago
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Government Recommends Cars With Smarter Brakes

ceoyoyo Re:The "what?!" is reaction time (303 comments)

Crashes have been getting much more survivable, but the number of collisions per car-kilometre has also been flat or dropping. Texting in North America took off in a fairly short period of time. If it were actually responsible for as many crashes as it gets blamed for there would have been a big spike in the collision rate. There wasn't. That supports the idea that the ultimate cause is bad drivers, and texting is just the latest thing they can be distracted by. Texting while driving is undoubtedly dangerous, but so are a lot of other things people do in cars.

3 days ago
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Uber Suspends Australian Transport Inspector Accounts To Block Stings

ceoyoyo Re:Extradition? (299 comments)

If you're in any kind of commercial transport and you're seriously injured by fault of the driver, owner, maintenance, etc., covering your health care is likely to be the least of what the insurance does. Particularly in the US.

about two weeks ago
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Uber Suspends Australian Transport Inspector Accounts To Block Stings

ceoyoyo Re:Extradition? (299 comments)

I imagine the laws governing cars are much like those for boats, but less enforced for individuals. If you're the skipper of a boat you can share costs with guests/crew/passengers but those costs cannot be more than the consumables used on the trip and they cannot pay you for your time. As soon as you accept payment for your services you need commercial permits, your boat has to meet more stringent standards, etc.

about two weeks ago
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Lawrence Krauss On Scientists As Celebrities: Good For Science?

ceoyoyo Re:Of course it's good for society (227 comments)

If publishing a paper is the requirement to be a scientist, it's not surprising that stuff like what Wakefield pulled gets by. Wakefield was trained as a physician, not a scientist. His "research" was conducted unethically, on children, without approval. It's generally believed now that the whole thing was a fraud perpetrated to boost his interest in a competing vaccine company.

Wakefield was trained as a physician and operated as a con man. He wasn't a scientist. I agree with you that scientist-celebrities aren't necessarily the best scientists. Especially the "scientist"-celebrities. Part of the problem is that many of them aren't scientists at all, but are perceived that way because people have the strangest criteria for dubbing someone a scientist.

about two weeks ago
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Lawrence Krauss On Scientists As Celebrities: Good For Science?

ceoyoyo Re:Just another form of scientific contribution (227 comments)

A list of the most highly cited papers was released recently. All the top papers were tools and techniques. Discoveries like the structure of DNA were well down the list.

The tool builders get recognized pretty well where it counts.

about two weeks ago
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Lawrence Krauss On Scientists As Celebrities: Good For Science?

ceoyoyo Re:Of course it's good for society (227 comments)

You mean the physician (not a scientist) who started the anti-vax movement?

Other than the bad example, your point is good.

about two weeks ago
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Lawrence Krauss On Scientists As Celebrities: Good For Science?

ceoyoyo Re:Scientists are human beings too (227 comments)

It is wrong to say science seeks truth, because it gives a false impression of what science is. Science looks for theories that make the most accurate predictions. If a particular theory tuns out to have problems, that's part of the process of finding one that does.

Too many people, including a lot of not-so-good scientists, regard "scientific truth" as something that actually exists. Some experiment, or a journal article, or a hundred years of experience seems to show something, therefore it's true. Way too many people also insist that science is just another kind of religion.

about two weeks ago
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The Strange Story of the First Quantum Art Exhibition In Space

ceoyoyo Re:Infiniteness of infinity ... (69 comments)

He (or more likely his scientific advisor) has it right. You've mixed up the explanation of it a bit.

The idea with a superposition is that something, usually something small, can be in more than one state at once. If I take your unpowered cell phone camera and expose it to some weak radiation, such as the CMB, some of the molecules in the photo sensitive layer will donate an electron and some won't. Before you look, you can say that each of those molecules is in a superposition of electron-yes and electron-no. That means that each of the electron wells technically contains every possible combination of electrons, which means that the ccd itself is simultaneously in a superposition of representing every single image it can, at the same time. Naturally if you actually measure the image the superposition will collapse into one of the more likely states, with overwhelming probability, a black image with some sparse noise.

You can also say that the photo-sensitive layer is encoding every book that has ever been or ever will be written, in the handwriting of every person who has ever lived.

While it's technically true-ish, at least if you believe certain interpretations of quantum mechanics, it's also pretty meaningless.

about two weeks ago
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The Strange Story of the First Quantum Art Exhibition In Space

ceoyoyo Re:Crap Science (69 comments)

Certainly. I beat him to producing this art last time I turned my phone off.

about two weeks ago

Submissions

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Martian Volcanoes May Not Be Extinct

ceoyoyo ceoyoyo writes  |  more than 7 years ago

ceoyoyo writes "The Tharsis volcanoes on Mars show evidence they may have erupted within the last two million years and may still be dormant, not extinct. The three volcanoes also show evidence of erupting in a chain, much like the Hawaiian islands, with the southernmost showing the oldest lava flows and the northernmost the youngest. On Earth chains of volcanoes are produced when the crust moves over a magma plume in the mantle. On Mars, since there is no tectonic activity, the researchers theorized that the magma plumes themselves move under the fixed crust."
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