Science desk
< June 1	<< May \| June \| Jul >>	June 3 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is a transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

June 2[edit]

How radio waves can travel space without any medium?[edit]

Unlike sound waves, radio waves can travel space which doesn't any medium. How is that possible? Rizosome (talk) 07:15, 2 June 2021 (UTC)[reply]

Just because they're both called waves doesn't mean they have anything else in common. Sound waves are longitudinal waves, but radio waves are electromagnetic waves. I suggest you read both of those articles.--Shantavira|^{feed me} 07:30, 2 June 2021 (UTC)[reply]

There is a medium – the Electromagnetic field, which combines the Electrical field and Magnetic field: see also Classical field theory. The same applies to Gravitational waves and the Gravitational field (which is also interpreted as Space-time curvature). Note that all of these concepts are imperfect models that describe things we don't fully understand yet, since, for example, electromagnetic 'waves' can also be detected as particles called photons, and the General theory of relativity that explains gravity as space-time curvature gives highly accurate answers, but is incompatible with Quantum mechanics that also gives highly accurate answers. We await a Theory of everything that will explain all this (maybe). {The poster formerly known as 87.81.230.195} 2.121.163.176 (talk) 09:57, 2 June 2021 (UTC)[reply]

Normally, the term "medium" in the sense of "transmission medium" is understood to refer to a material substance, which does not include physical fields. Historically, physicists thought that light waves required a medium for propagation, for which they posited the "luminiferous aether" – see especially the section End of aether. We know that light propagates through space; we can very accurately describe the process in terms of physical laws; but what makes these little photons, or the electromagnetic field, behave in accordance with these laws is as mysterious as anything. Ultimately, the question "how can ...?" is as unanswerable as the question why there is anything at all. Listen to Richard Feynman about the "why" at the end of everything; this is quite similar. --Lambiam 10:21, 2 June 2021 (UTC)[reply]

Just to correct 2.121.163.176 said, the modern models of light behavior are NOT "imperfect models", they are actually fantastically accurate and well-behaved models that, to levels of accuracy that far exceed our ability to measure, completely describe the behavior of light. The problems are not with the models, which work very well, but with people who get hung up on trying to fit the model with some philosophical concept about what they "mean" or some such thing. Once you stop doing that, the models work fine. --Jayron 32 14:40, 2 June 2021 (UTC)[reply]

But shut up and calculate is a philosophical concept about meaning itself. A rather thin and unsatisfying - and ultimately infertile one imho. Dirac [I sat in front of him at a lecture some years ago] and others tried to repopularize the aether thought-style without success; one recenter Nobelist says just the word has become taboo [like talking about sex in many cultures], but the concept omnipresent or something like that.John Z (talk) 17:39, 2 June 2021 (UTC)[reply]

It may be thin and infertile, but even if it were fat and fecund, it is not falsifiable and thus not relevant to discussions about the science of light. --Jayron 32 18:09, 2 June 2021 (UTC)[reply]

The notion that fundamental physics can be reduced to field equations with some quantization hoopla is also not falsifiable, but has (I think) proved to have some relevance. --Lambiam 08:18, 3 June 2021 (UTC)[reply]

On the contrary, those equations are very falsifiable. The equations make testable predictions about the behavior of things, and those tests will either confirm or refute the results of the equations. For example, the Einstein field equations predict things like gravitational lensing and the precession of the perihelion of Mercury, which are testable and thus falsifiable, while quantum mechanics makes predictions that can be tested via things like the Double-slit experiment and the like. Those theories are very falsifiable. What is not falsifiable is any sort of "what does this mean for the nature of reality" sort of questioning; those lie outside of the realm of science to explain. All science does is make predictions and test the predictions. Philosophers give things meaning. --Jayron 32 13:48, 4 June 2021 (UTC)[reply]

We don't hear much about crystalline spheres anymore, either. ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:26, 2 June 2021 (UTC)[reply]

@Lambiam: Is my question happen to be open question in Physics field? Rizosome (talk) 06:57, 3 June 2021 (UTC)[reply]

No, not in physics, but it is an open question in metaphysics, with connections to the more specific philosophy of space and time and to the question of the fundamental nature of reality as being pondered in ontology. --Lambiam 08:11, 3 June 2021 (UTC)[reply]

Satyendra Nath Bose and Jagadish Chandra Bose[edit]

https://en.wikipedia.org/wiki/Satyendra_Nath_Bose

https://en.wikipedia.org/wiki/Jagadish_Chandra_Bose

In our school text books, it's taught that, they are greatest scientists of all time, and many books wrote that Jagadish Chandra Bose was first to discover life in plants and he invented radio transmission before Guglielmo Marconi.

I want to know, how much recognition they have in scientific world of USA, Europe?

Most people in the Western world who are not into science would not recognize their names, unlike those of Einstein and Darwin. But all physicists would or should know Satyendra Nath Bose – although they may not know much about the person, they would (or should) know that bosons are named after him, and they will know the concept of a Bose–Einstein condensate. As far as I'm aware, Jagadish Chandra Bose has received much less recognition. I question the accuracy of the statement that he was first to discover life in plants; the concept of life traditionally included plants since antiquity. --Lambiam 10:48, 2 June 2021 (UTC)[reply]

Why did the pufferfish go "ÆÜGH"[edit]

A viral internet meme of a pufferfish munching on a carrot caught the eye of 8.7M people, and I was one of them. In the video, we see a pufferfish in a Korean restraunt kitchen being pulled out of its tank. The chef holds the pufferfish, then a few seconds later it gives the pufferfish a carrot strip, we then see the pufferfish bite the carrot strip a couple of times in the chef's hand before the infamous moment where then, the pufferfish lets out the iconic "ÆAUGH". So I was wondering, why did the pufferfish moan after eating a carrot? Was it because it was trying to gasp for air? Or was it because of arousal? Signed by Pink Saffron (talk) 14:26, 2 June 2021 (UTC).[reply]

Like any fish out of water, it is gasping for air. It is distressed. Why would you think it was aroused?--Shantavira|^{feed me} 15:24, 2 June 2021 (UTC)[reply]

No, it's not gasping for air. It's a fish. Fish take in oxygen through their gills, not their mouths. In the water, where (like most fish) they prefer to be, they'll fill up their stomachs with water to protect themselves. The same action sucks in air, if they're being tortured like this. "Arousal"? --jpgordon^{𝄢𝄆 𝄐𝄇} 17:07, 2 June 2021 (UTC)[reply]

Does the pufferfish let out the sound, or did someone add a sound later to match up with the pufferfish's mouth motions to make it look like it was moaning? --Jayron 32 18:08, 2 June 2021 (UTC)[reply]

Yes, the pufferfish lets out the sound. Nobody added the sound, because it was a legitimate clip taken from another video of a tour on a Korean restaurant. Pink Saffron (talk) 18:36, 2 June 2021 (UTC)[reply]

It seems to me that it keeps trying to inflate itself by swallowing more and more air, and begins to emit squawking noises as the air escapes out of its gills and/or stomach. Abductive (reasoning) 19:44, 3 June 2021 (UTC)[reply]

Not specifically about pufferfish, but What Does the Fish Say? quotes a scientist from Griffith University’s Australian Rivers Institute; “An estimated 20 percent of fish species actively make noises to communicate”. Alansplodge (talk) 18:59, 2 June 2021 (UTC)[reply]