Ask any question you want about Physics

originally posted by: greenreflections
I think that one cannot say space-time has a form. It expands arbitrary. When needed, on demand. When the demand is too much, black hole forms))

But do you think idea is plausible?

It doesn't make enough sense to evaluate the plausibility. "on demand" by what? What creates this demand? I think black holes form from a concentration of matter, not from expansion of space, at least for the 3 solar mass and greater black holes we are know about. We haven't yet observed any micro black holes.

You your self, what do you think of origins and what not? Can not be that you simply wait till someone's theory emerges and accepted by scientific community just so you could break it down here for us.

Thanks for your contributing!!

I found this video about what happened before the big bang intriguing as some leading physicists are questioning the big bang theory, or certain aspects of it.

BBC Documentary - What Happened Before the Big Bang

The one man I find myself agreeing with the most in the video is the director of the Canadian research facility, who emphasizes the ultimate goal needs to be to have evidence to support the ideas. I don't see much evidence yet. I see lots of ideas, but the evidence to support them is lacking. Maybe it will come.

I also believe in Newton's flaming laser sword, that what can not be settled by observation or experiment is not worth debating. Yes it's possible our universe could be a "pocket universe" and there could be other "universes" beyond ours, but since we can never observe what's beyond the observable universe I don't see the point in violating Newton's flaming laser sword to discuss them.

I think you'll get more interesting ideas from the physicists who are paid to think about these things, which I'm not. With no evidence to contradict them I keep an open mind and allow that any of them can be right even though they have different, conflicting ideas on origins. The one claim I found most questionable was by Dr. Laura Messini-Houghton who says she has evidence of other universes in the form of CMB anomalies, but as I mentioned in prior posts, even the existence of these anomalies can be debated and the origins of them if they really exist are even more debatable, so it seems like a stretch to say they are evidence of other universes to me. I'm also puzzled how she managed to get specific predictions out of string theory when one of the problems with it has historically been the difficulty of getting specific predictions.

I think this video is worth watching, but sadly of the 6 copies I found on youtube, all 6 are defective in some way. This one and another have a "tunnel vision" effect, and on the other 4 the colors are separated. Maybe you will be able to find a good copy but I didn't so I watched this one. What these scientists are saying about the big bang would have been blasphemy 10-15 years ago; how times change. But some of them might be on the right track. For me personally I'm fine with accepting that there are some things we don't know and may never know, possibly including what happened before the big bang.

a reply to: Arbitrageur

Watched about 4 minutes of the video up to the part about the Hubble universe expansion based on observations of "velocity".

Stopped there with a question.

We know from experience that the clocks used in modern GPS constellations orbiting at a constant velocity in free fall around earth are running faster than they do on Earth. This is because the clocks on Earth run slower as they are lower in the Earths gravity well.

What is a clock? a measure of entropy
Where entropy is zero there is no heat, no wave motion, nothing to measure time.

The local speed of light is (the ancient pi convention 299,7) later refined beyond 92,458 KPHour.
More recently we know the hours are shorter further out the gravity well
of the Earth
of the universe.

This explains the increase in velocity Hubble observed at the beginning of the universe no?

originally posted by: Nochzwei
Lol don't you know that internet is notorious for keeping dogmas alive. what you find on the internet is not necessarily true. but to give you room, put all that you claim in a post with equations and calculations thereof and we will debate them.
when e = mc2 is resolved it phoo phoos the GR hook line and sinker and yet you ignorantf folks embrace it
a reply to: Arbitrageur

you have nothing to bring to the table Nochzwei except repetitive selective hearing and understanding. you ask a question, Arbitrageur does a good job of explaining and giving you an example, then you say "Do a calculation"

im still waiting for some of your calculations... but once again, when I asked you to provide some backup, you simply told me to do more measurements... so... going to actually show us this intellect or is that armchair so comfortable you cannot lean forward with a pen and paper and do some 1+1

This is a similar article written about the T2K beam target, which operates at higher luminocity but lower energy than the LHC, I believe it uses a tungsten window, and the whole system is helium cooled to stop the graphite from melting/shattering.

accelconf.web.cern.ch...

accelconf.web.cern.ch...

the GR in all this is to do with how the high energy particles deposit energy in the target, this is not a magical process, the T2K beam is luminous to burn holes in things.

Doing the simple newtonian physics calculations would not tell you the object would react like it does in reality.

originally posted by: Cauliflower
This explains the increase in velocity Hubble observed at the beginning of the universe no?

Edwin Hubble's observations were limited and he couldn't see near the beginning of the universe as we can today.

Let's look at a chart showing the amount of gravitational time dilation around Earth:

Gravitational time dilation


The gravitational time dilation approaches 696.2 picoseconds per second even at the greatest possible distances, unless I made a math error but that value seems consistent with the chart shown.

Now my answer is another question: How could time dilation of less than 696.2 picoseconds per second explain the apparent average recessional velocity of a z=10 galaxy of ~2.5 times the speed of light? Isn't that "effect" many times larger than your hypothetical "cause" would predict?

Something else to consider, is that the time dilation differential from Earth's gravity at extragalactic distances is practically a flat line at around 696 picoseconds per second. We are looking for an explanation of the Hubble constant which shows an increasing effect with distance, so a relatively flat line at 696 picoseconds per second can't explain the Hubble constant.

a reply to: Arbitrageur

Your chart stops at the Lagrange point balancing between the gravity well of the Earth and the much larger gravity well of "our Sun".

www.space.com...

I know I kind of skipped ahead in the lesson beyond the French Revolution with the pi thing.

In 1772 physicists were obviously aware that there was a superposition of gravitational wells which makes the problem more difficult.

Its a little like chess there are more possible chess games of length less than 40 moves than there are electrons in the universe.

So my question would be how can we reliably make sense of observations that are the result of gravitational lensing by such a complex superposition of gravity wells?

That would have been the question in1772 and we have acquired a lot more higher resolution data since then.
Maybe if I stare at the wallpaper another 20 years I will have a better answer than a five year old.

Unless you can put equations and calculations in a post, it would be pointless debating. Other than that, you can be my guest and believe the internet and embrace GR all you want and wallow in your ignorance. I shall never subscribe to GR.
a reply to: ErosA433

originally posted by: Cauliflower
Your chart stops at the Lagrange point balancing between the gravity well of the Earth and the much larger gravity well of "our Sun".

Even if you consider other gravity wells, you won't get an explanation of the Hubble constant merely by considering gravity wells.

So my question would be how can we reliably make sense of observations that are the result of gravitational lensing by such a complex superposition of gravity wells?

It depends on how you define "reliably". There are some accuracy issues. This paper points out that methods used to determine weak gravitational lensing are only accurate to within a few percent, but the accuracy desired for future work is much greater, on the order of 0.1%.

Weak Gravitational Lensing

In the KSB method, the ellipticity is derived from quadrupole moments weighted by a Gaussian function. This method has been used by many authors but it is not sufficiently accurate for future surveys...

To prepare for the next generation of wide-field surveys, a wide range of shear estimation methods have been compared blindly in the Shear Testing Program (STEP) ([29, 56]). Several methods have achieved an accuracy of a few percent. However, the accuracy required for future surveys is of the order of 0.1%.

That would have been the question in1772 and we have acquired a lot more higher resolution data since then.
Maybe if I stare at the wallpaper another 20 years I will have a better answer than a five year old.

I don't think they knew anything about gravitational lensing in 1772.

originally posted by: Nochzwei
Unless you can put equations and calculations in a post, it would be pointless debating.

So re-typing the equations shown in a link to a post here has some magical effect that makes the re-typed equation worth debating, while the original of the exact same thing is not? Surely you can't be serious.

Other than that, you can be my guest and believe the internet and embrace GR all you want and wallow in your ignorance. I shall never subscribe to GR.

General Relativity has nothing to do with the internet. General relativity and mainstream science were well communicated before the internet existed. The internet has however given cranks a greater voice because the communication channels for cranks were limited prior to the internet.

originally posted by: [post=20040560]Arbitrageur

So re-typing the equations shown in a link to a post here has some magical effect that makes the re-typed equation worth debating, while the original of the exact same thing is not? Surely you can't be serious.

Other than that, you can be my guest and believe the internet and embrace GR all you want and wallow in your ignorance. I shall never subscribe to GR.

General Relativity has nothing to do with the internet. General relativity and mainstream science were well communicated before the internet existed. The internet has however given cranks a greater voice because the communication channels for cranks were limited prior to the internet.
Am quite serious But am no crank. Get it.

are there any experiments thats actually prove Niels Bohr's prediction about the quantum leap?

I understand that mathematically it appears to be so and that based upon the quantum leap they believe this is why we see different colors

...but i was just curious if anyone has ever created an experiment to prove definitively that the quantum leap is in fact the reason for this?

thanks in advance for any responses

a reply to: disk4
Not just experiments. Practical applications.
photoelectric effect
again

originally posted by: Phage
a reply to: disk4
Not just experiments. Practical applications.
photoelectric effect
again

A mass spectrometer is a great example of a practical application.

a reply to: Nochzwei

Nietzsche weighed in on this *process* back in the 1800's

The mechanistic world is imagined only as sight and touch imagine a world (as "moved") - so as to be calculable Thus causal unities are invented

In other words math is the formulaic response to the stimulus of a real problem in the sight and touch world.

The problem is that you chose a subset when you "move" the real world observation into a calculable form.

Simple example, I just ran an intermediate calculation in my head that a 5 year old would quickly understand.
Notice this intermediate integer series is not as intuitively obvious as the real number set that inspired it?

1,1,1,3,1,3,1,3,5,1,5,3,1,3,5,5,1,5,3,1,5,3,5,7

Copying and pasting excrement without a clear understanding of the original problem is losing the chess game in the opening. Like losing your Queen in Jabberwocky when its not the red Queen of hearts.

a reply to: Nochzwei


Am still waiting for your predictions on the candle experiment... like you said, if you can write something down, ill entertain it... actually... iv already entertained it.

You think i got my schooling from the internet... thats cute.

a reply to: Arbitrageur

I don't think they knew anything about gravitational lensing in 1772.

In 1919 Arthur Eddington was able to prove light from the sun bent in the moons gravitational well during an eclipse.
They used a simple reed tube scope without glass optics to mimic what would have been available to the ancient civilizations.

They also made more accurate measurements of the gravitational bending with a more modern telescope.

The ancients may have known the approximate speed of light although that wasn't published till the transits of Venus correlations LOL. If they also understood the effect of gravity on light from simple solar observations they may have theorized a more global effect.

Its universally understood that looking off in any direction from Earth we are looking back in time at light sources that no longer exist. About 1830, the Hungarian mathematician János Bolyai and the Russian mathematician Nikolai Ivanovich Lobachevsky separately published treatises on hyperbolic geometry. Non euclidean math theories were likely entertained long before they were published. So even the *choice* for the shape of the cosmic chess board may have ancient sources.

So again by using a specific 20th century term "gravitational lensing" I've headed down the rabbit hole.

physicsworld.com...

Quasar is a modern term also. When the observed redshift of quasars is interpreted in terms of Hubble's law, it is inferred that quasars are very distant objects. When the red shift is attributed to the light climbing out of the gravity well of a black hole you get an entirely different correlation.

I'm amazed you personally aren't put off by the black matter kludge of the big bang theory.

originally posted by: Cauliflower
In 1919 Arthur Eddington was able to prove light from the sun bent in the moons gravitational well during an eclipse.

That´s interesting! Can you toss me a link on further reading on that aspect? So far I have thought that the 1919 result was just the starlight bending near Sun. It would be lovely to read about what else they did there, especially what they did with simple instruments.

a reply to: Pirvonen

I went looking for a write up of the original experiment this morning.
Of course it was starlight being bent around the suns gravity well, the moons gravity well would have been too weak to measure with primitive tools except by inference..
The primitive tubes Eddington used were aluminum and underwent thermal expansion which made the observations inaccurate. You will need to find an abstract of the experiment that includes the description of those aluminum tubes without glass optics, they do exist.

originally posted by: ErosA433
a reply to: Nochzwei


Am still waiting for your predictions on the candle experiment... like you said, if you can write something down, ill entertain it... actually... iv already entertained it.

You think i got my schooling from the internet... thats cute.

Iv already said can't give a quantitative prediction as of yet.

a reply to: Nochzwei


Yeah sure, so when you can, then we can entertain your theory... so until that time, presenting your idea as anything other than anecdotes is not at all a discussion of science, physics or anything else. Discuss them by all means, but if you cannot back up your statements, then supplying misleading information in a thread about answering physics questions is not at all helpful for those involved.

Plus we already proved with absolute certitude that your observation is misinterpreted and simply not supported at all by any observations two of us have now made

a reply to: Nochzwei
If you're serious then explain why a link to a formula can't be debated, but if the same formula is re-typed in a post here, it can be debated. Also keep in mind that some formulae contain symbols that are difficult to duplicate here.

originally posted by: Cauliflower
They used a simple reed tube scope without glass optics to mimic what would have been available to the ancient civilizations.

I went looking for a write up of the original experiment this morning.
Of course it was starlight being bent around the suns gravity well, the moons gravity well would have been too weak to measure with primitive tools except by inference..
The primitive tubes Eddington used were aluminum and underwent thermal expansion which made the observations inaccurate. You will need to find an abstract of the experiment that includes the description of those aluminum tubes without glass optics, they do exist.

"mimic what would have been available to the ancient civilizations." What? At times scientists attempt to duplicate ancient methods for that specific purpose but to apply such a statement in this case seems absurd. And "without glass optics"? So what is the 13 inch piece of glass used for, decoration?

Here's the description of the telescope from Eddington's 1920 book (page 114 of the pdf):
archive.org...


The book contains a photograph of the two telescopes used at the other expedition at Sobral (see below), but on page 117 he says the telescope his expedition used at Principe was similar to the one on the left, where it appears to have a 13 inch piece of glass as the objective lens in the front, matching his description. The opening in the other telescope is 4 inches, and we can't see the glass in that one but it also had optics.



However among your wildly inaccurate and zany claims exist some truths. There was some concern about whether the tubes of the telescopes could flex, so that was one of many potential sources of error. Another source of error was caused by the mirror sitting in front of the telescope getting distorted as it heated up from absorbing solar radiation, and there are other sources of error.

There's no shortage of drama in the stories told about efforts to test Einstein's eclipse predictions, so I don't see any need to add such fiction about mimicking what ancient civilizations would have had. However, there is no shortage of competing myths about the 1919 expeditions, as discussed in this paper, though I don't think the author discusses any "ancient civilizations" myths:

Not Only Because of Theory: Dyson, Eddington and the Competing Myths of the 1919 Eclipse Expedition

True or false; all we have ever 'seen' (or 'touched' too?) are photons?

All, or most of our understanding, knowledge, comprehension of the world is transported to our awareness, via photons; I think this is why it is so difficult to know and comprehend what photons are and how they exist, because they are the only way we know anything else; its like how the mind cant truly see itself, though at the same time in a way the mind mostly only sees itself.