401
This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.
402
General Science / Re: How Can I Change the Mind Of A Flat-Earther ?
« on: 05/06/2018 13:25:22 »Re: How Can I Change the Mind Of A Flat-Earther ?Well, you could take that view about anyone who posts here with an incorrect view on a science topic.
But why?
Why would you want to waste your time & energy in converting an unwilling religious fanatic into a being with scientific rational thinking?.........
...........Isn't that Individual allowed/entitled to hold onto his/her/its Faith?
How Fair is it to Force wisdom down someone's throat in the name of Science?
We don’t force anyone to believe correct science, but we do feel it is our duty to explain reality.
The following users thanked this post: Zer0
403
That CAN'T be true! / Re: Rotating earth theory of two high tides a day
« on: 25/05/2018 16:13:22 »Yesterday the Fundy tide was 11m and the buoy in N Gulf of Maine registered 1.98km/hYou claim that a current of 15km/h is required in the Northern part of the Gulf of Maine, but buoy data from this area shows a maximum of 2.34km/h over the first 5 months of this year.At a maximum of 2.34 km / h, what is the height of the tides?
Find the height of the tides of 15 meters, the speed should be 15 km / h?
If this does not happen, I will apologize to everyone for losing my time and yours.
The following users thanked this post: Yusup Hizirov
404
New Theories / Re: Critique of scientific method and will we ever find a theory of everything?
« on: 21/05/2018 14:23:02 »
This isn’t really a question on a science topic but a presentation of a new theory and an alternative to the current scientific method.
As such it will get better coverage in New Theories section
As such it will get better coverage in New Theories section
The following users thanked this post: Paradigmer
405
Physics, Astronomy & Cosmology / Re: Does light have a weight?
« on: 20/05/2018 08:15:44 »There is always a gravitational potential between two objects, though often it is negligible? Can we say that the gravitational potential between two bodies would be the mutual effect they have on each other’s spacetime curvature, i.e., their geodesics?Depends what you are considering.
If so, am I right to think that their mutual gravitational attraction qualifies as an acceleration, and is included in the calculation of the geodesics that they will follow?
In SR the assumption is flat spacetime far away from gravitational influence and small objects far enough apart for the gravitational attraction to be negligible. So non-accelerating motion is possible.
GR considers spacetime under the influence of gravitational forces including bodies where there is significant mutual attraction, so as you say, there will be relative acceleration included.
then am I way off base asking what effect light has 4.24 light years away from an object, over millions of years, multiplied by trillions of stars, combined with the process repeating for billions of years with new stars replacing dying stars? 4.24 ly is distance to nearest star. granted, each photons effect is negligible, but the accumulated effect must amount to something. if we can see a photon, then it must affect an object, however miniscule. surely this must add up to a phenomenal amount of "light pressure"........ and if light has mass as some theorize, could this be the missing mass needed to make the models of the universe work correctly? ..........perhaps this material is not so dark after all. .....EDIT: while I was typing @Kryptid posted the one above, so this is to be read with what he wrote.
There are 2 things to consider, the ability of an object to move and the ability of something to move it.
Elsewhere there is a question about whether a rocket taking off from the moon can change the moon’s orbit and the same principles apply if we consider some examples.
- Starlight falling on the earth is of very low intensity due to inverse square law. However, the earth has a large surface area and so can collect a lot of starlight, but each photon of starlight carries an unbelievably small amount of momentum and the earth’s inertia is phenomenal - even large asteroids won’t kick it off orbit. So the earth does not move.
- a solar sail has a very large surface area, so can collect a lot of photons, it also has a very low mass (inertia) so near a large source of light eg the sun, it will move. As it gets further away the effect diminishes and the drive will stop working, also there comes a point where the sail is equidistant from 2 stars and the pressure from both would cancel out.
- take interstellar dust and gas. Very low mass, easy to move, but small cross sectional area so it won’t collect many photons and even then their momentum is minuscule compared to the inertia of the particles. Yes, over time they might move, but remember, wherever you are in the universe you are surrounded by stars so the net pressure on this interstellar material is zero. Question: would that, over time, lead to any form of gas/dust clumping and can it be detected? Would that clumping force be greater than the ability of gravity from nearby stars to attract the dust/gas, I suspect not.
The following users thanked this post: Bogie_smiles
406
Physics, Astronomy & Cosmology / Re: Does light have a weight?
« on: 18/05/2018 09:13:44 »I am curious of the difference in definition between propagate and travel, I will look this up next break if I remember.Although I agree with @PmbPhy sometimes I find dictionaries can be less than clear.
Consider a car, you can say it travels, but clearly it does not propagate ie make a new copy, or object.
However, waves do propagate. When you see waves approaching the shore it looks as though the water is moving, this is an illusion. The water does not flow as in a current, but the height of the wave is passed on (propagated, created anew) from one point to another. This is also true of sound and light waves.
sadly, I cannot seem to download the "apparent weight of photons" and I can't figure out how to edit my last post or do the quote thing y'all do.The paper is rather technical, start with wiki.
I’ll send you a pm on editing
.....if all particles with mass emit gravitational wavesBut, they don’t. Only accelerating masses emit gravitational waves and photons are not accelerating.
Also gravitational waves do not behave like em waves, very different properties, very different phenomena.
I might be wrong, but I don't think you can see light from the side, only the photons headed your way. I speculate the photons headed at right angles to ones observation point are "unseen". but nonetheless, very much there. but again, I'm not well educated and might be missing something. ...You are right, only light reaching your retina, or a sensor are detected. However, if you move around a star you can check that light is emitted in all directions.
but if correct, this its a huge volume of unobserved photons, and if they have mass (does mass indicate that they would have gravity? ) then regardless of the inverse square law, this is a tremendously large amount of "material" affecting its environment. However minutely, over millions of years surely this must amount to something, either with the push imparted by a photons velocity, or a pull from the photons mass. multiplied by the amount of estimated stars, makes for quite a wrestling match. .....unless they just canceled each other out. ........ugh. ......No they don’t cancel out, but the critical point is where you say “regardless of the inverse square law”. I’m sorry but you can’t disregard it, it is key to understanding why the force at a distance becomes negligible regardless of how much you start off with.
The following users thanked this post: Zer0
407
That CAN'T be true! / Re: Rotating earth theory of two high tides a day
« on: 16/05/2018 09:49:32 »According to the lunar theory of the tides ...There is very little point quoting lunar theory of tides if you are unable to answer questions about your own theory eg:
Are you able to show in detail how your whirlpool theory accounts for spring and neap tides and their periodicity?What is the height of the tidal hill at the equator?You really are missing the point here. The question is not the height of any bulge, but the periodicity of the variation in heights. This periodicity is, as explained previously, the combined effect of Moon and Sun.
Please show your calculations to explain spring and neap tides and their exact periodicity.
I don’t think you can. Until you do there is very little point in posting more as you are just wasting our time.
The following users thanked this post: Yusup Hizirov
408
Physics, Astronomy & Cosmology / Re: Does light have a weight?
« on: 16/05/2018 08:51:25 »if supposed rock, whether it is falling or at rest, were to undergo total mass to energy conversion, would the energy output not justify the equation? like when two hydrogen atoms fuse to form helium. ..... 1 plus 1 does not quite equal 2, or am I misinformed that there is a small amount of mass that is ' lost ' and the only thing on other side of the equal sign are photons? surely a total conversion would have far more output.Fortunatly the processes in an atomic bomb are very inefficient. For the fusion bomb dropped on Hiroshima it is estimated that the amount of matter converted to energy was about 700 milligrams, less than one-third the mass of a U.S. dime. If the total mass of the bomb had been converted the result would have been earth shattering - literally.
This energy comes from the binding energy that has to be put in if you want to push the components (protons, neutrons) together to make Uranium, split those components apart and you release energy; however the energy you add also adds to the mass so the uranium atom has more mass than the individual components that make it up. The energy released is mainly heat, shockwave, and some radiation, so it’s really a case of energy changing the form it is held in.
if some mass is "lost" during a stars fusion process, does this mean that the universe is losing weight? would this "weight loss" explain why models of the early universe do not work correctly without the addition of more matter then we can account for?The light doesn’t leave the universe, we see some of it, it just gets redistributed.
how much volume is in a.....say 4.24 light year radius sphere? how much volume of photons is that? if they have even the most miniscule amount of mass. ........................The ‘volume’ of photons will depend on the intensity of the source and how long it keeps emitting. As I said earlier and as @PmbPhy says, they don’t have mass in the classical sense but have momentum .
It’s worth looking at the link he gave you. On the same site is a very good article on energy which you should read, you’ll find it helpful.
even at the surface of said sphere, and assuming light is massless, it can still impart inertia, giving everthing at said surface a gentle little push. .....Yes. The voyager spacecraft had to have its course adjusted to allow for the push of photons from the sun. Remember though that the sun is close and big, intensity drops off as inverse square law so at the edge of your 4.24 ly sphere there won’t be any noticable push.
Just a point of forum etiquette. If you post a reply and you want to add to it, but no one else has replied in the meantime, can you modify your post rather than post a series of separate posts. Thanks.
The following users thanked this post: Zer0
409
Technology / Re: What determines when a steel spring develops metal fatigue?
« on: 15/05/2018 10:22:55 »
The best place to start is by finding the Stress Life Cycle curve for the particular steel you are working with.
These usually show the the applied stress S as a proportion of the steel’s ultimate tensile stress Su, against the number of stress cycles to failure. The scale is usually log.
Obviously the applied stresses are in Pa so are dependant on csa rather than mass, but you could easily do the conversions. Also bear in mind that these curves assume no stress concentration points or stress raisers, nor any surface treatments. Although you are probably not too worried about it at the moment, remember that compressive surface stresses increase fatigue load carrying capacity, so compression is better than tension.
These usually show the the applied stress S as a proportion of the steel’s ultimate tensile stress Su, against the number of stress cycles to failure. The scale is usually log.
Obviously the applied stresses are in Pa so are dependant on csa rather than mass, but you could easily do the conversions. Also bear in mind that these curves assume no stress concentration points or stress raisers, nor any surface treatments. Although you are probably not too worried about it at the moment, remember that compressive surface stresses increase fatigue load carrying capacity, so compression is better than tension.
The following users thanked this post: Yahya
410
That CAN'T be true! / Re: Rotating earth theory of two high tides a day
« on: 15/05/2018 08:19:33 »Galileo called the Moon theory of tides, frivolous, sad return to the realm of mystical ravings and preferred to explain the tides, the rotation of the Earth.Galileo made some very insightful discoveries, but he also missed making the connection with many others. If he had followed up on the ‘mystical ravings’ we would now be referring to Galileo’s Laws of Gravity. As it was it was left to Newton to make those insights and understand the effect of moon and gravity.
The tidal calendar existed long before the opening of the tidal wave, compiled by the "poke method", as they are today. As there was also a normal calendar up to Ptolemy and after Ptolemy, and to Copernicus, and after Copernicus.The influence of the Moon on tides was mentioned in Ptolemy's Tetrabiblos as having been derived from ancient observation. Newton recognised the role of the moon and Laplace started the first steps to producing accurate forecasts of tides (not using the inaccurate ‘poke’ methods).
What is the height of the tidal hill at the equator?You really are missing the point here. The question is not the height of any bulge, but the periodicity of the variation in heights. This periodicity is, as explained previously, the combined effect of Moon and Sun.
Please show your calculations to explain spring and neap tides and their exact periodicity.
The following users thanked this post: Yusup Hizirov
411
Physics, Astronomy & Cosmology / Re: How fundamental is time?
« on: 01/05/2018 18:01:50 »
Interesting thoughts.
Do we have the same problem with distance, there is no true origin. All measurements are Δx, Δy or Δz.
Similarly, units are arbitrary.
Do we have the same problem with distance, there is no true origin. All measurements are Δx, Δy or Δz.
Similarly, units are arbitrary.
The following users thanked this post: chiralSPO
412
That CAN'T be true! / Re: Rotating earth theory of two high tides a day
« on: 30/04/2018 17:37:01 »This was moved to new theories, so I thought I would say something.The thread you posted in is in Physics, Astronomy & Cosmology not in the lighter section! It hasn’t been moved.
This is the one that was moved https://www.thenakedscientists.com/forum/index.php?topic=73127.0
You are restricted to the lighter sections
The following users thanked this post: Yusup Hizirov
413
That CAN'T be true! / Re: Rotating earth theory of two high tides a day
« on: 28/04/2018 23:03:49 »The gravity of the moon does not reach the Earth:It does. NIST and others measure the uplift of earth surface and measure gravimetric effect.
There is no data on the fluctuation of tidal forces, if there were fluctuations, then there would be data.it is there if you search for it, but I suspect you won’t want to try and expect to be spoon fed.
There is a long history of measuring solid earth tides eg http://www.bidstonobservatory.org.uk/earth-tides/
Or
https://watermark.silverchair.com/125-1-106.pdf?token=AQECAHi208BE49Ooan9kkhW_Ercy7Dm3ZL_9Cf3qfKAc485ysgAAAbIwggGuBgkqhkiG9w0BBwagggGfMIIBmwIBADCCAZQGCSqGSIb3DQEHATAeBglghkgBZQMEAS4wEQQMGT08BWeSTnQp5XrpAgEQgIIBZde8q6N4D3SLR6rpZesye1qyqgozQsoUwU5jFGJX63b283Jpn7glcxhnlUxEe811HvGOWMV3r6fFXM7CHU0BdSDpUvKC8JfebPc63xlRkPqPdtnLFnFLYjI_HFVkKCoX8o3IOec-48mdVr1XP_m104RSVDATU9I_1TpwrAXDnArwfGKsfx6qJhmmBtrwEKjgoRNgjIYuk87CJmuOPimbZ5qR6axPw_Q2ZsPed6lnf4zAZWpcZKs5qvKuGlJxD_O8aKDmyrXXClUKa3N-FEH1L92n9Fkw97ONkIFN3ezNKAuXdTVfDA9DFnXhiOnhb9ocHncJmnlzrohjoYAPjByyUIJ4kArAzqo21LLC5tsCG5mSRj8BI_IWtoWX37FIlV-kI18alfy2Ag6t8lNYGifeP3ZphPPfWkiyl87aquCmA7O6aKuCyKSVfrq6zKUXcpbsfh6TT_kWMHrf-X9J_d8wxDXhWl331A
You could also search for papers from NIST at their Boulder site.
The geostationary satellite of the Earth, acting as part of the Earth, is in zero gravity,It is a common misconception that satellites are in zero gravity, this is not true, if they were they could not maintain an orbit.
at a distance of 35,000 km. from the Earth, and for some reason, is not exposed to the tidal influence of the Moon,
GPS satellites have to have timing corrected for influence of moon which deflects their orbit.
These posts are not only going off topic but are making ridiculous, unscientific suggestion and so will be moved.
You might also answer this question
If you state that the radius is too small, you must have made a calculation in order to reach that conclusion, please show it.To make calculations you need time.We can't look at your calculations unless you post them.
First you need to look at the existing calculations.
If you are saying you have not done the maths, what are you using as the basis of your post?
The following users thanked this post: Yusup Hizirov
414
General Science / Re: Why do wasps sting us?
« on: 23/04/2018 17:35:56 »
The majority of wasp species are solitary and do not sting, it is only the females of social wasps that sting.
Most stings occur in late summer. In the early part of the year social wasps gather protein to feed the brood, eg caterpillars, and are rewarded by a sweet excretion from the lavae. In late summer the brood rearing ends and the sweet substance is no longer available, this is when they go searching for a replacement and get into contact with humans. Most stings are accidental eg inadvertently crushing a wasp, or a panic flap which triggers an attack at the fast movement. Quite often if you sit still a wasp will land on your hand, clean, and leave. It is also true that they don’t like mammal breath, which they view as a threat, combine this with rapid movement and you will get stung.
Whoops, Chris replied while I was typing
Most stings occur in late summer. In the early part of the year social wasps gather protein to feed the brood, eg caterpillars, and are rewarded by a sweet excretion from the lavae. In late summer the brood rearing ends and the sweet substance is no longer available, this is when they go searching for a replacement and get into contact with humans. Most stings are accidental eg inadvertently crushing a wasp, or a panic flap which triggers an attack at the fast movement. Quite often if you sit still a wasp will land on your hand, clean, and leave. It is also true that they don’t like mammal breath, which they view as a threat, combine this with rapid movement and you will get stung.
Whoops, Chris replied while I was typing
415
New Theories / Re: Gravity and Inertia are two sides of same phenomena
« on: 23/04/2018 12:46:19 »
@kpvats
You say “When we try to change state of a body, we are doing so against the coupling strength of the body to its own gravitational field which in turn, is coupled to the uniform state of the body. The body can not escape from its own gravitational field because the field moves with the body. This may be one of the reasons that we do not recognize inertia as body’s own gravity. ”
You might like to look at the motion of charged particles in constant motion vs acceleration, there are some parallels to what you are saying here.
You say “When we try to change state of a body, we are doing so against the coupling strength of the body to its own gravitational field which in turn, is coupled to the uniform state of the body. The body can not escape from its own gravitational field because the field moves with the body. This may be one of the reasons that we do not recognize inertia as body’s own gravity. ”
You might like to look at the motion of charged particles in constant motion vs acceleration, there are some parallels to what you are saying here.
The following users thanked this post: kpvats
417
New Theories / Re: Ok, lets rumble, I challenge the world.
« on: 18/04/2018 08:34:33 »
@Thebox @atbsphotography
These long quotes in the last few posts use up a lot of bandwidth and make the threads hard to follow. Please edit your quotes to the specific point you are answering.
Thank you
These long quotes in the last few posts use up a lot of bandwidth and make the threads hard to follow. Please edit your quotes to the specific point you are answering.
Thank you
The following users thanked this post: atbsphotography
418
Physics, Astronomy & Cosmology / Re: What is a tensor?
« on: 17/04/2018 15:37:42 »
@PmbPhy and @jeffreyH understand tensors and will give you very sound answers with no waffle, but as @Bill S says, perhaps you need to step back a bit.
Vector is a simple tensor rank 1. Examples can be a force+direction or speed+direction.
Tensors aren’t limited to these values because a tensor is just an array of numerical values that can be used to describe the state or properties of a material or point in space.
Let’s take a simple example of stress. Stress, like pressure is defined as force per unit area and a material can support different forces applied in different directions. Imagine a cube of material with forces acting on it in three dimensions, the stresses on the cube can be obtained and stress state can be represented by 9 components - 3 for each face, force component and 2 components for the area of the face. Hence a second rank tensor.
Stress, strain, thermal conductivity, magnetic susceptibility and electrical permittivity are all second rank tensors, piezoelectricity is described by a third rank tensor, elasticity of single crystals is described by fourth rank tensor.
So very useful, particularly when you add the transformations and operations that @PmbPhy and @jeffreyH mention.
So ,if in any medium (or apparently also even in a vacuum) any point is associated with more than one force , these forces can be represented by vectors and they are called tensors when they all originate and combine at this one point....Let’s start by forgetting medium, vacuum, forces, and combining at one point.
Vector is a simple tensor rank 1. Examples can be a force+direction or speed+direction.
Tensors aren’t limited to these values because a tensor is just an array of numerical values that can be used to describe the state or properties of a material or point in space.
Let’s take a simple example of stress. Stress, like pressure is defined as force per unit area and a material can support different forces applied in different directions. Imagine a cube of material with forces acting on it in three dimensions, the stresses on the cube can be obtained and stress state can be represented by 9 components - 3 for each face, force component and 2 components for the area of the face. Hence a second rank tensor.
Stress, strain, thermal conductivity, magnetic susceptibility and electrical permittivity are all second rank tensors, piezoelectricity is described by a third rank tensor, elasticity of single crystals is described by fourth rank tensor.
So very useful, particularly when you add the transformations and operations that @PmbPhy and @jeffreyH mention.
The following users thanked this post: Bill S
419
New Theories / Re: What is space?
« on: 14/04/2018 10:12:18 »Why relative motion is not necessary?I think you are forgetting gravitational effects. I know you know, because we’ve discussed before.
Here is a different point of view, with more details:As it says in the link “None of this is really a contradiction between general relativity and quantum mechanics. ”
https://physics.stackexchange.com/questions/387/a-list-of-inconveniences-between-quantum-mechanics-and-general-relativity
The following users thanked this post: nilak
420
Physics, Astronomy & Cosmology / Re: Could 3 comet fragments 65m yrs ago cause the same results as Chilxulub impacts?
« on: 13/04/2018 18:34:24 »No one talks about that possibility. Why? Is it illogical?Lots of people talk about it, but not on this thread which is about something else.
Does 1 asteroid traveling at X speed have the same impact force as 3, 1/3 sized objects travelling at 3X speed?The energy is the same but its distribution will be different.
Basic Force equation says yes, but does material makeup and the fact that less material is lost on contact with the atmosphere change that?
Smaller lumps are more likely to burn up on entry giving lots of downward heat, as in a nuclear air burst. If the entry points are widely spread then the heat will be dissipated over a wider area giving less overall effect. There will also be significant shockwaves flattening trees etc.
A single lump which loses mass on entry might have sufficient remaining mass to kick up a significant dust cloud and and create a nuclear winter.
Useful to note that the nucleus of a comet is mainly ice and frozen gas with a small amount of solid material.
The following users thanked this post: Xen