The dumb questions thread

[steve_bank]

What's the illusion of the waves moving forwards called:

View attachment 14274 They are offset in space and time, same wavelength and amplitude.

OQ: What is it called when overlapping standing (oscillating vertically, but not moving horizontally relative to one another) waves with different horizontal space offsets and maybe wavelengths and time offsets look like they are moving horizontally relative to one another?

It is simply called a propagating wave.

http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/tralon.html

There are two types of waves.

Longitudinal waves like a Slinky or hitting the end of a metal rod with a hammer. Compression waves. Power vector is in the direction of propagation.

EM waves are transverse. The power or Poynting Vector is orthogonal to the direction of propagation.


If it is just on 2d paper it is simple addition. Same if it is multiple electrical signals on a wire. In a mechanical medium superposition should hold at any point in the block. Superposition says at any point in the block amplitude is the sum of the effect of the individual waves.

 

[Kharakov]

Ok, there are 6 standing waves. They aren't moving. They are offset from eachother in time and space, having the same wavelength and amplitude.

What is the name of the illusion of movement when the waves don't move but it looks like they are moving.

These waves aren't changing space offset, they are oscillating with different time and space offsets.

same 6 waves added together/6=

 

[beero1000]

Ok, there are 6 standing waves. They aren't moving. They are offset from eachother in time and space, having the same wavelength and amplitude.

What is the name of the illusion of movement when the waves don't move but it looks like they are moving.

These waves aren't changing space offset, they are oscillating with different time and space offsets.

View attachment 14276

Looks like a variant of the  barberpole illusion to me.

 

[steve_bank]

Ok, there are 6 standing waves. They aren't moving. They are offset from eachother in time and space, having the same wavelength and amplitude.

What is the name of the illusion of movement when the waves don't move but it looks like they are moving.

These waves aren't changing space offset, they are oscillating with different time and space offsets.

View attachment 14276 same 6 waves added together/6= View attachment 14281

It is not an illusion. It is caled superposition for me.

When you say standing waves like on an RF transmission lines it is not stationary, the wave is propagating.

 

[Kharakov]

Below is one of the  standing waves in the above image slowed down. There are 6 of these in the one image, all 6 are combined in the other one (the superposition). My question is... what is the name of the illusion (similar to the barber pole illusion) of waves moving in a direction when they are only oscillating up and down, although they have different time and space offsets?

One of the six waves in the first image:

 

[steve_bank]

Below is one of the  standing waves in the above image slowed down. There are 6 of these in the one image, all 6 are combined in the other one (the superposition). My question is... what is the name of the illusion (similar to the barber pole illusion) of waves moving in a direction when they are only oscillating up and down, although they have different time and space offsets?

One of the six waves in the first image:
View attachment 14287

Relax and watch the wave. You are getting sleepy, your eyes are heavy. Become one with the sacred wave.

 

[barbos]

Ok, there are 6 standing waves. They aren't moving. They are offset from eachother in time and space, having the same wavelength and amplitude.

What is the name of the illusion of movement when the waves don't move but it looks like they are moving.

These waves aren't changing space offset, they are oscillating with different time and space offsets.

View attachment 14276 same 6 waves added together/6= View attachment 14281

This is called "You need to check your oscilloscope triggering"
But if you insist on shorter name then the best I can give you "Stroboscopic effect"

 

[Angry Floof]

/mod

 

[humbleman]

Ok, there are 6 standing waves. They aren't moving. They are offset from eachother in time and space, having the same wavelength and amplitude.

What is the name of the illusion of movement when the waves don't move but it looks like they are moving.

These waves aren't changing space offset, they are oscillating with different time and space offsets.

View attachment 14276 same 6 waves added together/6= View attachment 14281

This is called "You need to check your oscilloscope triggering"
But if you insist on shorter name then the best I can give you "Stroboscopic effect"

Dumb question to new generations.

What is such obsession with illusions created with manipulated images?

 

[humbleman]

What is an eclipse called if it's the Earth eclipsing the sun as seen from the moon? I'm guessing it's still a solar eclipse since the terms solar eclipse and lunar eclipse refer to what is being eclipsed and not what is doing the eclipsing.

A less dumb question: would that not be the coolest, most badass thing to see??

Actually, it is called terrestrial eclipse.

http://news.softpedia.com/news/Lunar-Probe-Captures-Terrestrial-Eclipse-105042.shtml

The Kaguya lunar orbiter, sent by the Japanese Space Agency (JAXA) to collect data from the Moon, sent back amazing new images of a terrestrial eclipse, meaning that the huge sphere of the Earth was observed from a position that placed it directly in front of the Sun. As it came from behind the natural satellite, Kaguya saw the moment in its entire splendor, as our planet closely resembled a giant diamond ring, with the Sun drawing its outer layer.

 

[George S]

What is an eclipse called if it's the Earth eclipsing the sun as seen from the moon? I'm guessing it's still a solar eclipse since the terms solar eclipse and lunar eclipse refer to what is being eclipsed and not what is doing the eclipsing.

A less dumb question: would that not be the coolest, most badass thing to see??

Actually, it is called terrestrial eclipse.

http://news.softpedia.com/news/Lunar-Probe-Captures-Terrestrial-Eclipse-105042.shtml

The Kaguya lunar orbiter, sent by the Japanese Space Agency (JAXA) to collect data from the Moon, sent back amazing new images of a terrestrial eclipse, meaning that the huge sphere of the Earth was observed from a position that placed it directly in front of the Sun. As it came from behind the natural satellite, Kaguya saw the moment in its entire splendor, as our planet closely resembled a giant diamond ring, with the Sun drawing its outer layer.

View attachment 14335

Awesome

 

[Angry Floof]

What is an eclipse called if it's the Earth eclipsing the sun as seen from the moon? I'm guessing it's still a solar eclipse since the terms solar eclipse and lunar eclipse refer to what is being eclipsed and not what is doing the eclipsing.

A less dumb question: would that not be the coolest, most badass thing to see??

Actually, it is called terrestrial eclipse.

http://news.softpedia.com/news/Lunar-Probe-Captures-Terrestrial-Eclipse-105042.shtml

The Kaguya lunar orbiter, sent by the Japanese Space Agency (JAXA) to collect data from the Moon, sent back amazing new images of a terrestrial eclipse, meaning that the huge sphere of the Earth was observed from a position that placed it directly in front of the Sun. As it came from behind the natural satellite, Kaguya saw the moment in its entire splendor, as our planet closely resembled a giant diamond ring, with the Sun drawing its outer layer.

View attachment 14335

Amazing!

 

[humbleman]

Actually, it is called terrestrial eclipse.

http://news.softpedia.com/news/Lunar-Probe-Captures-Terrestrial-Eclipse-105042.shtml



View attachment 14335

Amazing!
View attachment 14337

I love it too.

Russian Heterosexual Pride Flag.

 

[humbleman]

I may word this poorly, but this IS the dumb question thread.

As I understand current cosmology, the universe we see around us expanded from an infinitely dense point some 13 billions years ago. It was at that point that space and time as we understand it, began. It would seem to me that we really are not able to describe what was "there" when time began and space started expanding. Yet, it seems physicists, at least some, are boldly stating that the universe came from...NOTHING. I wonder why they make that statement? It might actually be true, but how can they know? I read Kraus' book, A Universe from Nothing where he tries to lay out his ideas for how "nothing" might be unstable. I could take it as conjectural on his part, but a worthwhile thing to consider. But I am pretty sure he calims the universe came from nothing.

How can they know there was actually NOTHING? I realize why they might say there was no space or time, matter/energy, but how can they know it was not some other heretofore unimagined state which we have not yet contemplated much less discovered and certainly have been unable to model mathematically?

Like I said, it's a dumb question so try not to pick apart my understanding so much as, if possible, try to explain why some physicists...Hawking, Kraus to name a few seem to be promoting this idea. It seems the Bord, Guth, Valenkin theorem maintains, in Valenkin's words: 'f someone asks me whether or not the theorem I proved with Borde and Guth implies that the universe had a beginning, I would say that the short answer is “yes”. If you are willing to get into subtleties, then the answer is “No, but…” So, there are ways to get around having a beginning, but then you are forced to have something nearly as special as a beginning.'

It would seem at least they'd hedge their bets and acknowledge they don't know what was there, but explain they are studying the plausibility/possibility of a universe coming, literally, from nothing. It seems to me that there might very well turn out that some other region/realm/state existed/exists that IS outside of time and space and does not contain classic forms of matter/energy and they seem to be prematurely excluding this possibility without really knowing. But they are the experts so what am I missing...what does it mean?

If the question is too involved to explain, at least, point me to a book/website that explains why some physicists are promoting a universe specifically/exactly FROM NOTHING. Thanks

Actually, the Big Bang Theory is not the widely accepted by scientists.

The Big Bang theory fails in almost everything. The simple scenario of a microscopic particle existing in the middle of "nothing", for later "expand" forming stars and galaxies, such is too much for being took seriously.

The common error is that because this theory is the most known, that scientists in their majority are following it. But, such is just propaganda.

At the current moment, the Nebulae theory still is the most accepted.

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

The nebular hypothesis is the most widely accepted model in the field of cosmogony to explain the formation and evolution of the Solar System (as well as other planetary systems). It suggests that the Solar System formed from nebulous material.

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

Cosmogony (or cosmogeny) is any model concerning the origin of either the cosmos or universe.[1][2] Developing a complete theoretical model has implications in both the philosophy of science and epistemology.

 

[bilby]

Actually, the Big Bang Theory is not the widely accepted by scientists.

The Big Bang theory fails in almost everything. The simple scenario of a microscopic particle existing in the middle of "nothing", for later "expand" forming stars and galaxies, such is too much for being took seriously.

The common error is that because this theory is the most known, that scientists in their majority are following it. But, such is just propaganda.

At the current moment, the Nebulae theory still is the most accepted.

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

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

Cosmogony (or cosmogeny) is any model concerning the origin of either the cosmos or universe.[1][2] Developing a complete theoretical model has implications in both the philosophy of science and epistemology.

You are conflating two totally different questions. The Big Bang Theory concerns the earliest moments of the universe, and seeks to explain the observed expansion of the universe by considering what must have led up to it.

The formation of stars and solar systems is a completely different field; the first stars didn't form until about two hundred million years after the Big Bang, and in the absence of elements heavier than Helium, almost certainly didn't have planets.

Our Solar System formed some 9 billion years after the Big Bang.

Your lack of understanding of the topics on which you do confidently hold forth is staggering.

It's as though someone asked where cars came from, and you derided as fools those people who talk of mining iron ore and processing it into steel, on the basis that cars are made in factories in Detroit.

 

[humbleman]

You are conflating two totally different questions. The Big Bang Theory concerns the earliest moments of the universe, and seeks to explain the observed expansion of the universe by considering what must have led up to it.

The formation of stars and solar systems is a completely different field; the first stars didn't form until about two hundred million years after the Big Bang, and in the absence of elements heavier than Helium, almost certainly didn't have planets.

Our Solar System formed some 9 billion years after the Big Bang.

Your lack of understanding of the topics on which you do confidently hold forth is staggering.

The nebulae theory was born with the thought that the universe always have existed: An existing gigantic nebulae which by some reason started to move. Such was the original idea.

Even when religion is the scientific pioneer saying that the universe was created from what is not visible and just by the word of God, no one with sane mind when idealizing the nebulae theory ever invented a similar idea to the Big Bang.

Hebrews 11

1 Now faith is confidence in what we hope for and assurance about what we do not see. 2 This is what the ancients were commended for.

3 By faith we understand that the universe was formed at God’s command, so that what is seen was not made out of what was visible.

The idea of an "expanding universe is not scientific but religious as well, the bible is again the pioneer.

Isaias 42:5

Thus says God, YHWH, who created the heavens and stretched them out, who spread out the earth and what comes from it, who gives breath to the people on it and spirit to those who walk in it:

The Big Bang theory saying that a super dense microscopic particle which exploded or "expanded" started the universe, is just a bad plagiarism of what the bible says in the books of Hebrews and Isaiah.

In no part of the Big Bang theory is found mentioning a transitional step of the famous microscopic particle becoming a nebulae first to later rotate and start forming stars and galaxies.

In other words, you are believing in the wrong religion.

It is more, the Big Bang theory is so absurd, that look what it claims:

https://prezi.com/t7mqgbnjf5ga/the-big-bang-theory-and-nebular-hypothesis/

Scientists have found evidence that the universe is expanding and galaxies are moving further apart. A way to show this expansion is by visualizing a balloon (representing the universe) with dots (representing galaxies) on it. As the balloon is blown up, the dots move further away from each other.

Is that "the empirical way" the Big Bang can be explained? Ha ha ha ha

What a bunch of idiots.

Look, I will strongly suggest you to buy cheap balloons from the store, and paint dots on the surface.

Start inflating and see the balloon expanding. Tell me, are the whole galaxies of the universe located at the outer surface of the universe? Can you really represent the galaxies on the universe by painting dots in the outer surface of the balloon?

Can't you see that those smart dudes have pulled your legs?

(You better make this discussion short and find the right evidence, otherwise the Big Bang defenders will make the ridiculous again, will cry to moderators and this part of the discussion will also "by magic" be sent to "Elsewhere" section) Lol.

 

[bilby]

The nebulae theory was born with the thought that the universe always have existed. And existing gigantic nebulae which by some reason started to move. Such was the original idea.

Even when religion is the pioneer saying that the universe was created from what is not visible and just by the word of God, no one with sane mind when idealizing the nebulae theory ever invented an idea similar to the Big Bang.

Hebrews 11



The idea of an "expanding universe is not scientific but religious, the bible is again the pioneer.

Isaias 42:5

Thus says God, YHWH, who created the heavens and stretched them out, who spread out the earth and what comes from it, who gives breath to the people on it and spirit to those who walk in it:

The Big Bang theory saying that a super dense microscopic particle which exploded or "expanded" started the universe, is just a bad plagiarism of what the bible says in the books of Hebrews and Isaiah.

In no part of the Big Bang theory the mention of a transitional step of the famous microscopic particle becoming a nebulae first to later rotate and start forming stars stars and galaxies is not found.

In other words, you are believing in the wrong religion.

It is more, the Big Bang theory is so absurd, that look what it is claiming:

https://prezi.com/t7mqgbnjf5ga/the-big-bang-theory-and-nebular-hypothesis/

Scientists have found evidence that the universe is expanding and galaxies are moving further apart. A way to show this expansion is by visualizing a balloon (representing the universe) with dots (representing galaxies) on it. As the balloon is blown up, the dots move further away from each other.

Is that "the empirical way" the Big Bang can be explained? Ha ha ha ha

What a bunch of idiots.

Look, I will strongly suggest you to buy cheap balloons from the store, and paint dots on the surface.

Start the input of air and see the balloon expanding. Tell me, are the whole galaxies of the universe located at the outer surface of the universe? Can you really represent the galaxies on the universe painted in the outer surface of the balloon?

Can't you see that those smart dudes have pulled your legs?

You were better a few messages ago when you didn't participate in a discussion where surely you don't know what are you talking about... or better to say, where you seem to know a lot aboput the Big Bang theory but nothing about physics.












No ridiculous microscopic particle expanding forming galaxies ever crossed the main of sane people.

I very rarely put anyone on 'ignore', because I feel that even those with whom I disagree often say things that are informative, interesting, amusing, or inspiring.

You appear to be the rare exception.

 

[humbleman]

I very rarely put anyone on 'ignore', because I feel that even those with whom I disagree often say things that are informative, interesting, amusing, or inspiring.

You appear to be the rare exception.

Sure, just buy the balloon as it was suggested.

Do not pain dots but paint galaxies on the surface of the balloon.

Inflate the balloon and the painted "galaxies" will separate one from another at the same time they will become greater in size the more air you put inside the balloon. Ha ha ha ha...

In real life, in our physical universe, do the galaxies get "bigger" because the expanding universe? What is the rate of the "expansion " of galaxies due to the fast expansion of space... as seen in the painted galaxies on the surface of the balloon?

With such ideas of yours, you must put in ignore to yourself... lol.

Again, can't you see that those dudes from the Big Bang theory have pulled your legs?

 

[steve_bank]

bilby stated it simply and correctly, the BB is an attempt to explain observation.

When I took astronomy in the 70s it was the 'missing mass' of the universe. Depending on a number the universe was expanding, forever, oscillatory, or a one time out and back event.

The BB does not offer ultimate origins, it does not explain what led up to the BB.In a show I watched on cosmology the result of a simulation was shown. It was good enough to get to galaxies, crudely. Simulation starting at the BB particle level takes a lot of time even on fast computers.

It is good science that explains most or all of what we see, but I have some issues. The BB has come to be a modern secular creation myth of sorts. I'd like to see universe qualified as 'observable universe' . It bugs me when I see it presented as fact not theory in science shows. The BB is a theory that extrapolates back in time that can never be experimentally validated.

Well, I knew there was a creationist lurking in humbleman. In the 90s the Vatican allowed for evolution as a part of god's plan, why not the BB? Genesis says god created everything, it does not say how. Perhaps the B run repeatedly is god's Monte Carlo tool.Yes the BB is a fallacy. Based on ancient texts of unknown origin we must believe an ill defined super-being of unknown origin winked the universe into existence...yea that's it. Yo ho ho.

 

[George S]

If there ever was the state of nothing at all, no time nor space nor energy nor mass, it was apparently unstable since there is something now.
We can call the transition from nothing to something a natural miracle. That is, nothing (according to natural "law") can come from nothing.
Even if a containing universe is the case, it, too, appeared contradicting natural "law."
Even if a powerful alien -- a god to us -- who created our universe his universe is unexplained.*
Even if there is an infinite stack of containing universes, that stack appeared in defiance of nature.
If there was the state of empty spacetime and the Heisenberg uncertainty principle applies, that is Krauss's universe from nothing. But the origin of spacetime is the new unexplained.
There must be at least one something that just is. No why. Just because.
Relativity is a very accurate model of the large aggregates of matter behave. It works, bitches. Shrodinger's equation is a very accurate model of behavior of the very small, including massless photons.
Yet they do not agree with each other for a small region with a huge mass like the conditions from t=0 to t=0.0000000000000000000000001 seconds. That gap in knowledge is why physicists search for a Theory of Everything -- a model that combines Quantum Mechanics with Relativity..

Why is there something rather than nothing? Just because.

* Jewish and Christian theology propose a containing universe named Heaven with an alien named YHVH, who made ours.