| I always thought that all dirt is the result of fungus slowly breaking apart bedrock over millions of years but I do not know if this is actually true. Is it? Posted: 04 Oct 2020 05:53 AM PDT Assuming that is true does it mean most every rocky planet in our galaxy is just bedrock and oceans? Ive never considered the fact that all rocky planets might look incredibly similar to one another. submitted by /u/weird_foreign_odor [link] [comments] |
| Is the density of black holes constant, since adding or removing mass only affects the size of the black hole? Posted: 03 Oct 2020 08:34 PM PDT |
| What is the difference between gravitational mass and inertial mass? Posted: 03 Oct 2020 01:08 PM PDT |
| How long can anosmia persist after a covid-19 infection? Posted: 04 Oct 2020 03:52 AM PDT As I read on papers and articles, one of the distinct symptoms of an infection from covid-19 is anosmia (i.e. loss of smell), that seem to appear soon after infection. My question is: how long does anosmia persist in covid-19 patients? Has there been any instances where patients that healed from the infection showed symptoms of anosmia even months after the recovery? Thanks a lot! submitted by /u/_white_jesus [link] [comments] |
| How did the black death of the 14th century spread? Posted: 04 Oct 2020 01:54 AM PDT If the plague was caused by the bacterium Yersinia Pestis, which was carried by fleas - how did it spread from human to human? Was it flea transmission? And as far as I'm aware there were 3 forms of the plague in 14thC Europe, was it all spread the same way? submitted by /u/liquidtension [link] [comments] |
| Do two observers agree on the position of a beam of light? Posted: 03 Oct 2020 07:17 PM PDT Suppose you have an observer on earth, a traveler in a rocketship, and a beam of light. The rocketship leaves earth and travels at the speed of 0.5c. The same time the rocketship launched, a beam of light was emitted in the same direction as the ship. After one year: The earthbound observer observes the rocketship to be 0.5 light years away, and the light beam to be 1 light year away. Because the beam of light always appears to be traveling at c no matter what speed an observer is travelling at, the rocketship traveler also observes that the light beam to be 1 light year away, even though he has travelled 0.5 light years during this time. So the rocketship traveler believes that the light beam is around 1.5 light years from the earth, but the earthbound observer believes that the light beam is 1 light year from earth. earth------>*[spaceship] earth-------------------------------->*[light beam position from earth observer] earth---------------------------------------------------------------->*[light beam position from spaceship observer] earth--------0.5 light year --------1.0 light year-------------1.5 light year I realize that time and length will vary between observers. In my example at the speed of 0.5c the time dilation factor is 86%. So close to normal time, dilated a reasonable bit, but not extreme. Nothing accounts for the 50% difference in observations, where is this light beam at? submitted by /u/jeffial_relativity [link] [comments] |
| Which cells in the human body contain the 23 chromosomes that were sequenced for the first time in 2001? Posted: 03 Oct 2020 10:52 PM PDT I have heard many, many times how incredible a feat it is to have sequenced the human genome. However, I can't wrap my head around how it is done. Bacteria are single-celled organisms, so for me it is quite straightforward to understand the sequencing process. But when we talk about incredibly intricate multi-cellular organisms, I can't understand what is actually being sequenced. Where is the DNA coming from and where is it located? How does one isolate this DNA? Which cells in our body actually contain "the human genome" and why do they? submitted by /u/PhiloQib [link] [comments] |
| Does the color of the tapetum lucidum correlate with the types of rhodopsins for that animal? Posted: 03 Oct 2020 06:26 PM PDT I was just thinking how the color of the tapetum lucidum varies from species to species, and I imagine the suite of cones and rods also vary. Crocodilians have an orange tapetum lucidum. Is that the color of light their eyes are most sensitive to? submitted by /u/teach5ci [link] [comments] |
| What causes the "printer ran out of ink" effect on litters of cats with black-and-white coloring? Posted: 03 Oct 2020 08:24 AM PDT You know how when a tuxedo cat has a litter of kittens, they can range in coloring with each one progressing from black and white, to dark gray, light gray, and mostly white? Biologically why does this happen instead of all the kittens having the same black and white? submitted by /u/Marshall_Lawson [link] [comments] |
| does metal decay or rust on mars? Posted: 03 Oct 2020 10:10 AM PDT |
| Could a giant world-size heat sink to outer space technically work? Posted: 03 Oct 2020 08:30 AM PDT I was thinking how computers transfer lots of heat to specific places on the computer go keep it cool, theoretically could we build something like that but that goes between through the atmosphere, transferring away some of the heat we've created? Outside of the obvious, 'we cant build something that big' reasons? submitted by /u/scdirtdragon [link] [comments] |
| Would spacecraft in perfect two body problem maintain attitude because the gravitational field has a zero curl vector? Posted: 03 Oct 2020 11:25 AM PDT Ignoring perturbations, assuming a perfect 2-body problem with M1>>M2, where M2 is the spacecraft's mass, and assuming the spacecraft is in circular orbit for simplicity, would a spacecraft maintain attitude as it goes around its orbit? I'm learning about torques on spacecraft due to atmospheric drag, solar radiation, electromagnetic forces, and gravity gradient effects. But because the gravitational field has a curl of zero (vector), shouldn't the spacecraft maintain whatever attitude it has? I'm also thinking about irrotational vortices, where a twig floating in water would maintain its attitude as it travels around in a circular path. So what would happen if it was a perfect 2 body problem and I guess the only torque would be due to the gravity gradient? Also, if it would, why would it rotate the spacecraft since there's zero curl? Does the idea of a twig floating in water rotating only apply to paths that travel along the streamlines of the vector field? submitted by /u/Armang211 [link] [comments] |
| How viable are GaN processors and solar panels? Posted: 03 Oct 2020 08:55 AM PDT I've seen in a ton of tech videos and products from things like phone/laptop chargers that Gallium Nitrite can replace Silicon because of its higher efficiency, etc. I also noticed that solar panels use Silicon as its semiconductor. Do you think GaN could replace silicon in solar panels and processors? As far as I know, no one's been working on big (important) GaN chips other than chargers. Is this because it's not fit for every task Silicon is used for, or just because we haven't tried/succeeded/reported on it yet? submitted by /u/marvil_txt [link] [comments] |
| Why are some fats not shown on the back label of food? Posted: 03 Oct 2020 06:30 AM PDT I was eating some almonds and it said it has 16.9 grams of fat in 1 serving and it said in the 16.9gs of fat it has there is 1.3 grams of saturated fat and nothing else. So how will we know what are the other types of fats present in the almonds that I was eating? submitted by /u/yomomma935 [link] [comments] |
| Are the orbits of the planets in our solar system flat, or largely on a similar plane? Why? If so, are planets in other solar systems the same? Posted: 03 Oct 2020 04:41 AM PDT |
| Why do halons have methane in their chemical name? Posted: 02 Oct 2020 11:58 AM PDT Like halon 121 (bromochlorodifluoromethane) CF2ClBr. Why does it have methane in the name of it doesn't have methane? submitted by /u/AmumuPro [link] [comments] |
