Why did they need an algorithm to take a picture of the black hole and what did the algorithm even do? |
- Why did they need an algorithm to take a picture of the black hole and what did the algorithm even do?
- AskScience AMA Series: I'm Robbert Dijkgraaf, mathematical physicist, author, and director of the Institute for Advanced Study, here to answer your questions about the math and physics of the universe and Big Bang. Ask me anything!
- Storing Nuclear Waste: Why not dilute and put it back where it came from?
- Could you move a lot of water to a mountain by boiling it at the bottom and then directing the steam up and cooling it there back in to a liquid?
- What is the state of a particle that has collapsed its wavefunction to one observer, but not another?
- When animals leave their parents to establish their own lives, if they encounter the parents again in the wild, do they recognise each other and does this influence their behaviour?
- When a blue whale gulps to catch prey, does it also swallow all that saltwater?
- How do conservationists decide what trees and plants are local or non-local?
- How could scientists prove that the placebo effect works even when someone is aware that they’re taking a placebo?
- Recently, a group of astronomers discovered the universe's first molecule in a dying star, the helium hydrate ion (HeH+). How could they tell it was the universe's first molecule?
- Neutrons last ~15 minutes on their own. How can Neutron stars, which are mostly or only Neutrons, exist?
- Ferrets are classified as being unrelated to mongoose and fossa, which in turn are not closely related to civets. Why do these unrelated animals look so similar?
- What is the difference between the subclass 'Theria' and the subclass 'haplorhini'?
- Why is everyone so worried about a measles outbreak of they're already vaccinated?
- Why did they need so much code to take the black hole picture?
- Why is the speed of light slower in a non-vacuum? What slows it down?
- How does the molecular weight of a polymer affect it's ability to produce electrical charge?
- Is there a limit to how large a single living organism can be?
- Why are leading zeroes in a decimal number not considered significant figures?
- How do scientists determine the age of organisms?
- Does instantaneous wavefunction collapse imply an infinite derivative?
- Could someone help clarify the testing methodology for the M87 image construction algorithm?
| Posted: 17 Apr 2019 10:11 PM PDT |
| Posted: 18 Apr 2019 04:00 AM PDT This is Robbert Dijkgraaf, Director and Leon Levy Professor at the Institute for Advanced Study, one of the world's foremost centers for curiosity-driven basic research, located in Princeton, New Jersey. I'm a mathematical physicist specializing in string theory, and my research focuses on the interface between mathematics and particle physics, as well as the advancement of science education. Ask me anything about fundamental questions in physics like the Big Bang, black holes, or the mathematics of the universe! In light of recent news, here is an article I wrote last week about the first black hole photograph. You can also view a talk I gave at the 2017 National Math Festival on The End of Space and Time: The Mathematics of Black Holes and the Big Bang. This AMA is in partnership with the Mathematical Sciences Research Institute in Berkeley, California, as we are the co-organizers of the National Math Festival taking place on May 4th in Washington, DC. I'll start answering questions at 11:30 a.m. Eastern (15:30 UT), and end around 1:00 p.m. AMA! [link] [comments]  |
| Storing Nuclear Waste: Why not dilute and put it back where it came from? Posted: 17 Apr 2019 08:44 AM PDT Backstory: One of my bosses, let's call him Andy, is an extremely opinionated electrical engineer who has the answers for everything. Admittedly, he is actually really smart and can solve almost any work related issue we may have(we specialize in flow measurement) but is rarely challenged on some of his 'opinions' because it is a lot more work than it is worth. Anyway, we have lots of random discussions at work and his new latest and greatest thought regarding nuclear waste disposal is: Andy: "Well, it was radioactive and found in the ground before. Why not put it back when we are done with it?" Moonlapsed: "Probably because it's a lot more concentrated after its refined" Andy: "So just dilute it and spread it out like before" Moonlapsed: "..." I did some google searching and I could not find any easy answers. My initial thought is the simple answer: he cannot be correct because if this were that simple it would likely be applied in the real world... right? Though I do not know 100% why, lol sigh. Thank you in advance! [link] [comments]  |
| Posted: 18 Apr 2019 06:19 AM PDT |
| Posted: 18 Apr 2019 04:34 AM PDT Possibly, I may be thinking of a problem already addressed by quantum entanglement, but my idea was more me thinking about how an instantaneous collapse of a particle's wavefunction works with special relativity. I'm aware that the information that the wavefunction has collapsed cannot reach a distant observer faster than the speed of light. However, what I do not understand is that if the wavefunction is distributed throughout all of spacetime, how a complete and instantaneous collapse would apply to all of spacetime in that instant, such as to a distant observer. I understand that special relativity postulates that all inertial reference frames much agree, but am unsure as to how this resolves the observations of observers positioned at different points in space. [link] [comments]  |
| Posted: 18 Apr 2019 07:08 AM PDT I'm thinking of, for example, eagles that have been nurtured by their parents for many months before finally leave the nest to establish their own territory. Surely a bond has been created there, that could influence future interactions between these animals? [link] [comments]  |
| When a blue whale gulps to catch prey, does it also swallow all that saltwater? Posted: 18 Apr 2019 02:21 AM PDT |
| How do conservationists decide what trees and plants are local or non-local? Posted: 18 Apr 2019 06:46 AM PDT Does the species have to be in an area for a certain period of time? Decorative trees in urban areas are likely non-local, but what about seeds naturally moved to other areas via animals or humans? I know colonists brought new species when they arrived. Are those counted as local by this time? [link] [comments]  |
| Posted: 17 Apr 2019 07:01 PM PDT I generally understand how the placebo effect can work when a person is unaware that they're taking a placebo treatment. However, when a person knows that they're taking something as a placebo, but they still exhibit a measurable response to the "treatment" how can scientists confirm that the person's improvement was still just because of the placebo effect? Totally made up example that is intentionally unrealistic with the sole intent of clarifying the question I'm getting at: Scientific research studying 100,000 people confirms that taking garlic supplements does not improve the condition of bad breath. One individual with bad breath decides to start taking garlic supplements anyways, even though he fully understands that it will not improve his bad breath. However, the day after he starts taking the garlic supplements, he notices his bad breath is completely gone. He also notices that if he forgets to take garlic one day, his bad breath comes back. He knows with 100% certainty that he did not make any other changes besides the garlic. In this scenario, garlic has been "proven" to not cure bad breath, but how could scientists say with confidence that this individual's bad breath improved due to the placebo effect instead of some other cause that could have caused the garlic to actually work for him (like maybe he has slightly different stomach acid than 99.8% of the population that was causing his bad breath, and the garlic neutralized it but no one thought to test for that because it's super random)? Basically, if something is considered to be a placebo treatment, that means that it didn't show consistent/measurable improvement when studied in a clinical trial, right? But if a placebo appears to work for patients sporadically or inconsistently, is it really more likely that it's just the placebo effect, as opposed to the 'treatment' actually working in specific situations/ways that weren't just weren't shown in the population studied? TLDR: is the placebo effect, specifically in people who know they're taking a placebo, basically just a fancy way of saying "this treatment shouldn't work and we don't know any legitimate mechanisms for how it could work, so we're going to say it's just the placebo effect even though we don't know the true root cause of why the patient's condition improved"? [link] [comments]  |
| Posted: 18 Apr 2019 07:13 AM PDT |
| Posted: 18 Apr 2019 12:06 AM PDT |
| Posted: 17 Apr 2019 08:32 PM PDT I get that they most likely evolved to fill the same niche, but they have the same long body, short limbs, and arched spine. Why would they share all of these traits if they evolved independently? [link] [comments]  |
| What is the difference between the subclass 'Theria' and the subclass 'haplorhini'? Posted: 18 Apr 2019 06:19 AM PDT |
| Why is everyone so worried about a measles outbreak of they're already vaccinated? Posted: 18 Apr 2019 05:14 AM PDT |
| Why did they need so much code to take the black hole picture? Posted: 17 Apr 2019 03:54 PM PDT Why couldn't they have just used a telescope, pointed it at the black hole and just took a photo of it? [link] [comments]  |
| Why is the speed of light slower in a non-vacuum? What slows it down? Posted: 17 Apr 2019 09:54 AM PDT |
| How does the molecular weight of a polymer affect it's ability to produce electrical charge? Posted: 18 Apr 2019 04:08 AM PDT Today in class my polymers professor mentioned this and I thought it seemed interesting. Upon looking it up, there doesn't appear to be a cohesive correlation between the two. Does anyone know anything about how electrical charges may depend on molecular weight? Any help would be appreciated, thanks! [link] [comments]  |
| Is there a limit to how large a single living organism can be? Posted: 18 Apr 2019 03:28 AM PDT |
| Why are leading zeroes in a decimal number not considered significant figures? Posted: 17 Apr 2019 05:22 PM PDT It seems like a 0 in an initial post-decimal position is just as relevant to the precision of a calculation as a zero on the end of a decimal. For example, 0.08 (1 sig fig) vs 0.60 (2 sig figs). Both are exhibiting precision to the hundredths place - why the difference? [link] [comments]  |
| How do scientists determine the age of organisms? Posted: 17 Apr 2019 08:34 PM PDT Unless the animal/plant was brought up by humans and has it's age recorded, how do we know about its age? A similar question is how do we determine the average/maximum age of organisms of a given species? [link] [comments]  |
| Does instantaneous wavefunction collapse imply an infinite derivative? Posted: 17 Apr 2019 04:49 PM PDT Hello, I am an engineering student taking a quantum computing class. Getting straight to the question, my professor said that when a measurement is made of a particle the wavefunction instantaneously collapses into a Dirac delta at the measurement of interest and zero elsewhere. Coming from a signals background, this is counterfactual to everything I have been taught. Firstly, a Dirac delta should not be a physical phenomenon; the signals analogue is an impulse, which cannot be physically realizable as it would require an infinite derivative. Secondly, the idea that a continuous distribution (the squared wavefunction) instantaneously shifting to anything would imply a time derivative of infinity, which again should be physically impossible. The only solution that I can imagine is that the wavefunction actually converges extremely rapidly (but not infinitely) as the particle "approaches measurement" (i.e., as it approaches interaction with another particle), but this is 100% intuitive conjecture and in no way backed by theory. Am I incorrect about the impossibility of physical infinite derivatives, or is there a more subtle interpretation afoot? [link] [comments]  |
| Could someone help clarify the testing methodology for the M87 image construction algorithm? Posted: 17 Apr 2019 07:23 PM PDT Let me premise this by saying thousands of the best minds on the planet have looked at this, and haven't echoed these sentiments, so the main purpose of this post is to clarify what I'm misunderstanding. I'm trying to clarify how the algorithm was tested, as it's explained in this video from around 8:38 - 11:47. My question is: If the purpose of the tests is to ensure that the software generates a composite image of what exists, rather than simply reiterating we expect to see, then how exactly would a software that takes in any set of data, and returns a similar end result (regardless of if the images are black holes, planets, stars, or facebook photos) prove that the algorithm is functioning correctly? Wouldn't that actually indicate that the software isn't functioning as intended? [link] [comments]  |
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