Activity for Olin Lathropâ€
| Type | On... | Excerpt | Status | Date |
|---|---|---|---|---|
| Comment | Post #290690 |
Aerogel is structurally weak. Keep in mind that if you want simulate an Earth biosphere that humans don't need spacesuits to walk around in, then the pressure will be much higher than outside. Even at 10 PSI (about 2/3 of Earth atmospheric pressure at sea level), you still have enormous forces on t... (more) |
— | 3 months ago |
| Comment | Post #289665 |
<i>"That's not what downvotes are for"</i> they are on meta. Here votes indicate agreement or disagreement, although I suppose downvotes for poorly written posts wouldn't be out of line.
<i>"what proposal is there to disagree ? It needs a name change"</i> In your opinion. It seems at least some ... (more) |
— | 8 months ago |
| Comment | Post #289665 |
<i>Why the downvote ?</i> Most likely because people disagree with your proposal. (more) |
— | 8 months ago |
| Comment | Post #289641 |
This site isn't just about world building. If it were, it would be named that. This might be a good place for people trying to build somewhat plausible fictional worlds, but the site is certainly not limited to that, nor does it or should it have a particular focus on that. As the help you linked ... (more) |
— | 8 months ago |
| Comment | Post #289639 |
No, that's not what I said at all. (more) |
— | 8 months ago |
| Comment | Post #287486 |
The system I described inherently produces DC at a high voltage. That would most likely need to be converted to something else for actual use, but that also seems out of scope of the question. The question is about extracting electrical power from a radioactive lump directly, not what to do with th... (more) |
— | over 1 year ago |
| Comment | Post #287486 |
That's one way, but I thought the OP was asking about capturing the current directly. Each proton that gets emitted represents a current flowing from the radioactive lump to whatever conductor the proton lands on. Your 4.3 MeV figure gives you some idea how much of a voltage gradient these protons ... (more) |
— | over 1 year ago |
| Comment | Post #287351 |
The whole idea is rather silly in the first place. What services would a ring of aerogel provide either? It's not like you can dock ships at it, store materials in it, have people live it it, etc. (more) |
— | over 1 year ago |
| Comment | Post #287351 |
If you make the ring spin, then it will support itself. When the ring spins to match the orbital velocity at that altitude, it is neither in tension nor compression. Not tethers required. (more) |
— | over 1 year ago |
| Comment | Post #287348 |
<blockquote>Utility fog is a swarm robotics concept in which a mesh of robots barely larger than a grain of pollen (5 micrometer ( m ) bodies and 50 micrometer arms) are dodecahedrons (12 sided polygons) ending in telescoping arms (12 of them) ending in grabbers.</blockquote>
No, it's not. <i>Ut... (more) |
— | over 1 year ago |
| Comment | Post #286826 |
This is a comment because it's only a knee-jerk reaction and not based on any real knowledge. How exactly is "output" defined. If a company of 100 people makes widgets, then only those that actually physically make the widgets count? What about those that designed the widgets? Those that get the w... (more) |
— | almost 2 years ago |
| Comment | Post #285964 |
Kinetic energy is mV<sup>2</sup>/2. Each second your engine is putting out (1 kg)(1 Mm/s)<sup>2</sup>/2 Joules, or 500 GJ, which is a power of 500 GW, not 1 TW. Also your exhaust speed is 1 Mm/s. The speed of light is about 300 Mm/s, so you're at 1/300 the speed of light. There aren't going to be... (more) |
— | about 2 years ago |
| Comment | Post #283283 |
From your avatar, it's clear you are interested in electronics in some form. You may like the <a href="https://electrical.codidact.com">Electrical Engineering</a> site here at Codidact. This site is fairly new and needs people posting content, particularly asking good questions. Tell everyone else... (more) |
— | over 2 years ago |
| Comment | Post #283763 |
This question needs to be closed. It's not clear what you are asking. The first two bullet points seem to be irrelevant, and aren't necessarily right anyway. You talk about bureaucracy, but in the end it appears you just want a science-base way to identify humans. If that's really the case, then ... (more) |
— | over 2 years ago |
| Comment | Post #280677 |
Hmm. That sounds rather dangerous for the command center. It may move fast, but it's location would be highly predictable. Tossing a rock at the right time and angle from the canyon rim would make quite a mess, I expect. (more) |
— | over 2 years ago |
| Comment | Post #283359 |
Winter wheat doesn't grow during the winter. It's called that because it is planted in the fall, so the seeds are in the ground during the winter. That way they are ready to sprout just as soon as conditions allow. All growing still happens during the growing season, and requires light other than ... (more) |
— | over 2 years ago |
| Comment | Post #283382 |
Oops. Fixed. (more) |
— | over 2 years ago |
| Comment | Post #282490 |
How is digging a depression supposed to create an island? What mechanisms are you imaging at work? There is a lot of context missing here. Sustainable how? All real islands eventually erode away, once whatever forces formed them stop. (more) |
— | almost 3 years ago |
| Comment | Post #282177 |
@John: This is the *scientific* speculation site. Some minimum level of science is required to ask good questions and understand answers here. I'm not saying your understanding of gravity is below that level, but is nonetheless rather basic as Newtonian mechanics goes. This might make a better que... (more) |
— | almost 3 years ago |
| Comment | Post #282175 |
There seem to be two separate questions here. While you're at it, fix the *"is ... must be"* too. I had to read that a few times before getting past it to see the apparent questions. (more) |
— | almost 3 years ago |
| Comment | Post #281984 |
This still leaves open what the intensity of the resulting radiation is. If even after shifting the CMB to 570 nm you only get a few Watts per square meter, you still don't have anything remotely like Earth. (more) |
— | almost 3 years ago |
| Comment | Post #280633 |
It's been over two weeks since there was any activity here. Where is this at? (more) |
— | about 3 years ago |
| Comment | Post #280633 |
That's 47,330 no-brainers. Go for it. (more) |
— | about 3 years ago |
| Comment | Post #279498 |
@Peter: Good point. And the large animal that kills the most people in North America is the moose. (more) |
— | over 3 years ago |
| Comment | Post #279499 |
This depends a lot on what the device actually *does*. Is it a really fast computer you can run arbitrary code on? A communications device? A really fast computer that runs specific apps only? If so, what apps? Does it provide a view of some remote location? Able to spy on anyone anywhere in re... (more) |
— | over 3 years ago |
| Comment | Post #278155 |
That explains why I didn't get pinged. However, the removal of the comment prevented me from seeing what I had asked the OP to do. To use your words, the comment wasn't really deprecated since I still needed to see it despite the original problem having been fixed. The moderation was a bit too agg... (more) |
— | over 3 years ago |
| Comment | Post #277102 |
@aCVn: Yes, I should have been more clear. Obviously stars can be that close if they will eventually merge. However, that will decay quickly. That means conditions were drastically different recently, and will be different again shortly. Such rapid changes are not good for starting life. (more) |
— | over 3 years ago |
| Comment | Post #276352 |
@Pasty: I was also including the efficiency of using the result, not just producing the high-energy chemical with photosynthesis. In other words, overall efficiency of running the metabolism and working the muscles, divided by the total incident sunlight required to achieve that. (more) |
— | over 3 years ago |
| Comment | Post #277084 |
*" If I remove any specifics, that would confuse everything and stray everyone from the question."* Exactly the opposite. Discussion is already straying from the question due to all the irrelevant information, and because it's not obeying physics. Stating something with high precision implies that... (more) |
— | over 3 years ago |
| Comment | Post #277124 |
Actually, they have been tested. I've seen a video of a frog being held in a magnetic field strong enough to keep it suspended in air without touching any object. (more) |
— | over 3 years ago |
| Comment | Post #277102 |
@Enf: If any planet orbits two stars at 109 million miles, then the two stars must be absurdly close together. The distance between the stars must be a small fraction of this orbit radius, else a single orbit radius is meaningless. Let's say 10% to pick something. So the two stars are 11 million m... (more) |
— | over 3 years ago |
| Comment | Post #277084 |
What makes you say cyanobacteria can't live there now? You've got liquid water on the surface, so there must be places with appropriate temperatures. And there must be rain, so fresh water somewhere, making the acidity of the oceans irrelevant. (more) |
— | over 3 years ago |
| Comment | Post #276696 |
This seems to be missing the point. It's not about pressure felt by the second ship, but about colliding with all those particles at relativistic speeds. A good ion drive would send very small amounts of material out the back at very high speeds, the closer to the speed of light, the better. (more) |
— | almost 4 years ago |
| Comment | Post #276503 |
You don't need this to be a full sphere to determine efficiency. The same would be true of a 1 square meter thermal panel in space receiving about 1.3 kW from the sun on one side and facing cold space on the other. (more) |
— | almost 4 years ago |
| Comment | Post #262927 |
This question really should be closed until it is cleaned up. Currently it is too confusing and annoying to read. (more) |
— | almost 4 years ago |
| Comment | Post #261471 |
I'm only now actually thinking about the numbers. Light travels 30 km in 100 µs in vacuum. Certainly sound propagation in any medium can't be faster than that. Are neutron stars really that small, and the speed of sound a reasonable fraction of the speed of light? (more) |
— | almost 4 years ago |
| Comment | Post #261471 |
*for most people, milliseconds are a more familiar quantity than microseconds*. I find that hard to believe. (more) |
— | almost 4 years ago |
| Comment | Post #261471 |
Note that a "tenth of a millisecond" is 100 µs. So why not just write that? (more) |
— | almost 4 years ago |
| Comment | Post #273256 |
Your numbers are inconsistent. You estimate the required surface area is achieved by a sphere 22 meters in diameter. Then you say seawater contains 20% less oxygen, but requires a sphere 49 meters in diameter. That's 2.23 times the diameter, and 5.0 times the surface area to compensate for 80% of ... (more) |
— | almost 4 years ago |