White defects are not at all a rare phenomenon. What is rare about Friday's eclipse is the length of the eclipse, 43 hour and 27 minutes, very close to the theoretical record possible and the longest in terms of its duration (the full part will begin on July 22 at 30:28 and end on July 00 at 13:XNUMX), but It is still a few minutes of addition compared to an average deficiency. Solar eclipses can occur up to twice a year, but most of them are partial * A total eclipse occurs once every two to three years on average
Eclipses of the moon or eclipses of the moon, each according to the linguistic layer accepted for it, are not rare, every year there are eclipses, and the wait for full eclipses is not longer than two or three. But the eclipse that will be visible on the night between Friday and Saturday (July 27-28, 2018) is special in that it is the longest eclipse in the 21st century. But there is no reason to worry, full white eclipses, although shorter by a few minutes will occur once every two years on average, and this is not the last eclipse in the 21st century as written elsewhere.
Three factors determine the duration of a lunar eclipse and their combination this time when they are near their peak, has made the eclipse of July 27, 2018 the longest of the entire 21st century. The total duration of the eclipse will be one hour and 43 minutes, just four minutes short of the longest possible calculated duration of a lunar eclipse.
For viewers in Israel, the partial eclipse will begin at 21:14 p.m., the total eclipse will begin at 22:30 p.m., the peak of the eclipse in which the moon is in the deepest part of the Earth's shadow will be at 23:21 p.m., the total eclipse will end at 00:13 a.m. on July 28, and the end of the partial eclipse at 01:19 minutes. All times are according to Israel time.
The first factor that affects the length of the lunar eclipse is the position of the moon relative to the cone of the earth's shadow. If it crosses it above or below the center of the circle (as seen from Earth) the duration of the eclipse is shorter (see figure). If it passes through the center of the shadow cone, it is shadowed longer. As a side effect, the Moon will appear darker than other eclipses because it will pass close to the center of the shadow.
The second factor is the fact that during the eclipse the moon will be close to the farthest point in its orbit (apogee), and will also appear smaller in the sky, so it spends more time in the shadow. It is the combination of these two factors together that makes the current deficiency. According to Kepler's second law, being more distant means that the moon moves at the slowest possible speed, therefore this reason alone adds 5-10 minutes to its stay in the shadow of the earth compared to the eclipse that occurs when the moon is at its closest point to the earth - the perigee, when the moon is also close And moving faster, too.
And finally, additional minutes of eclipse are derived from the fact that the Earth is close to the farthest point from the Sun, which it crossed in early July. When the Earth is far from the Sun, the center of the Earth's shadow cone (umbra) lengthens and expands.
Solar eclipses and lunar eclipses
Since it takes several weeks for the Earth, the Moon and the Sun to move out of their relative positions on an approximately straight line, lunar eclipses usually come in pairs with solar eclipses two weeks before or two weeks after the lunar eclipse and sometimes, like this time, the eclipse season includes three consecutive eclipses. Two weeks before the lunar eclipse, on July 13, a partial solar eclipse occurred that was observed in the vast area between Australia and Atanaktica, and also two weeks after the lunar eclipse, on August 11, another partial solar eclipse will occur, this time in the Arctic Circle area. The last total solar eclipse occurred on August 23, 2017 and was visible from many locations within the US.
To the July 27, 2018 eclipse page on the NASA website
To the eclipse page, as seen from Tel Aviv on the Time and Date website
More of the topic in Hayadan:
7 תגובות
For the sake of scientific accuracy, a summary of the opinion of the scientific community.
The theory of quantum gravity or quantum information (drawn from Bekenstein-Hawking calculations for the entropy of a black hole) is an alternative candidate (but not a complete replacement, at least at the moment) for the dark matter theory. Still not 100% agreed. The theory of quantum information was presented in the past science, the work of 2 Israelis that can be produced from nothing if the positive information balances the negative information.
What stands in the way of full acceptance but much less since the publication of the article in November 2016:
A. A claim that when the equations are worded differently - then their convergence to Newtonian gravity and not general relativity.
In my opinion Lorlind had something to say about this in the lecture: that he could derive the general relativity equation from quantum information theory as an alternative to Einstein's derivation. That is, he goes for equivalence.
B. The time - waiting for feedback from the best physicists, Schwerlind being one of them, whether you agree with his theory or not. He is smart enough to go to conferences in the world, to set foot in centers of influence and to lecture. This is not about hiding.
third. A differentiating experiment. A thought experiment, an observation that will differentiate between the theories.
d. There were claims of inconsistency with general relativity in 2012. The November 2016 article resolved many of them in my opinion.
God. There was also an argument made by Albenzo (?) here against observational results between galaxy clusters. But I don't want to start a war, so in advance I call not to respond to section e. To Albanzo's credit (?) it can be said that he brought up the MOND theory and thanks to his talkback I was exposed to the theory about two years ago.
and. Many, many hundreds, thousands of scientists deal with dark matter. You need to join them, in the sense of attaching them to the work, so that their observations are building blocks for establishing a more generalized quantum gravity theory than general relativity.
What works in favor of the theory:
A. Reproducing all observational results showing dark matter, at galactic and intergalactic levels. I haven't read enough about the mother between galaxy clusters as well. Verlind calculates the observations and explains the dark matter equivalent well in the lecture.
B. simplicity. Ability to quantitatively calculate the results.
third. About 150 groups of scientists are betting that he will be right within two years.
I understand he is also a professor at CERN in the field of HEP. Among them are Lee Smolin and of course Mordechai Milgrom who empirically conceived the idea and the late Jacob Beckenstein who extended the result of general relativity.
d. Maybe the time factor. On the other hand, maybe someone will refute his arguments.
It is worth noting that there was also a critical article by D Dai, D Stojkovic (Springer HEP, Nov 2017)
who said that something in the development in their opinion is flawed
..When properly done, Verlinde's elaborate procedure recovers the standard Newtonian gravity instead of MOND".
Verlind's lecture at the Technion last year, and he mentions Milgrom Mordechai (MOND) from 30 years ago in the variable gravity theory.
https://www.youtube.com/watch?v=nCGlj9Mndjs
Eric Verlind's article on a quantum gravitation explanation for the Israeli Milgrom's theory of variable gravity MOND
The late Yaakov Bekenstein - an article from November 2016. It has 153 citations from leading physicists in the world such as Lee Smolin.
153 works in research centers were carried out on the basis of the article in almost two years.
Today an article was published in Israel about dark matter. Time for a super article
Verlind's theory: Quantum gravity fully explains gravitational variation at galactic, intergalactic, and intergalactic clusters of galaxies without dark matter.
https://scholar.google.co.il/scholar?um=1&ie=UTF-8&lr&q=related:GZhhOAxI8LaFXM:scholar.google.com/
The article itself in a free-to-read version can be found at
https://arxiv.org/pdf/1611.02269.pdf
This is not a fringe theory, but since there are many physicists who deal with dark matter it will take time for it to be fully accepted. Why is there a full admission? Because it does not require dark matter, and Occam's razor principle says that when there are 2 theories and one requires greater complexity than the other, the other is chosen.
Because Verlind gives in the article "Emergent Gravity
and the Dark Universe” complete formulas from general relativity combined with quanta for the main effects that dark matter explains.
Is it possible to witness an eclipse without a telescope and in an urban environment full of light?
Is it possible to witness an eclipse in Israel without a telescope and in an urban environment?
Waiting for the amazing event that happens once every few years. Hope it will be possible to see it all over the country from my home in Nahariya.