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Can we violate law of physics in any other planet?

Can we violate law of physics in any other planet?


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Can't there be any way to violates any law of physics? If in our earth we can't violate any law of physics can't we violate in any other planet?


If there is a way to violate a law of nature, it will become a law of nature as soon as it is discovered, studied and formalized into a scientific theory. Therefore, many new discoveries in science do violate (then current) laws of nature, but will not do so for very long. Often there are all sorts of medals and prizes involved too.


Universality of physics

As far as we know, laws of physics seem invariant both across space and time. It's not absolutely certain and taken for granted, there's lots of research probing to try and verify if perhaps something is slightly different far away or long ago, but to our best current knowledge the laws of physics work exactly the same in all faraway stars, because most reasonable changes in fundamental laws or constants of physics would cause some differences that would observable by us.

Our currently known laws of physics aren't final, we know that there are some gaps (mismatch between general relativity and quantum mechanics comes to mind) so there's probably some way to break the laws of physics as we know them. But that's not because we can't do it on earth and might somewhere else, it's because we would find out what the real laws of physics actually are and how they differ from our current understanding.


No.

That's because we believe the laws of physics to be the same everywhere (this itself is a consequence of the law of conservation of momentum, via Noether's theorem). Therefore, if you can't violate the laws of physics as we know them on Earth, you can't violate them elsewhere, too.


Well, it's possible that physics as we know them are somewhat different elsewhere, or on different scales (both microscopic and macroscopic). So if we manipulate our environs in particularly extreme ways, as with the large colliders or extreme lasers, or if we inspect very large structures, we may observe phenomena not predicted by our current laws of physics.

As an example, there are discussions whether acceleration by gravitation on cosmological scales "violates" Newton's Laws of Motion.

Everybody would agree that Newton's Laws are prototypical physics laws, so a deviating behavior is an obvious violation. (This is a standpoint opposing Allure's post.)

But indeed, as tuomas said, these new findings would be incorporated into the ever-evolving corpus of our knowledge of the world and thus become part of new laws which would not be violated anymore according to our knowledge.

The synthesis of these two is probably the following:

  1. Our knowledge of the world is incomplete, and so are the "laws" (actually algorithms for prediction) we derive from it.

  2. Even though this is pure speculation, my gut feeling is that most scientists would not assume that there is a reachable end of discoveries to be made.

  3. Which means that our knowledge will always be incomplete and our predictions will always be wrong somewhere or on some scale or under some certain condition.

  4. And, concluding this and answering your questions: Yes, it will almost certainly and for very principle reasons be possible to "violate" the known, and known to be incomplete, physics somewhere or somehow, given we have developed the means to observe these places or produce these conditions.

A note of caution: Our astronomical observations show that under a wide range of conditions and scales our ideas seem to hold pretty well, so it is virtually excluded that you can float on Mars, or even on some far-away exoplanet, if you cannot do it here. The "violations" will either be very subtle or very hard to produce or very far away (like in the next universe if you survive that wormhole).


Can Astronomy Explain The Biblical Star of Bethlehem?

Bright stars top Christmas trees in Christian homes around much of the world. The faithful sing about the Star of Wonder that guided the wise men to a manger in the little town of Bethlehem, where Jesus was born. They’re commemorating the Star of Bethlehem described by the Evangelist Matthew in the New Testament. Is the star’s biblical description a pious fiction or does it contain some astronomical truth?

To understand the Star of Bethlehem, we need to think like the three wise men. Motivated by this "star in the east," they first traveled to Jerusalem and told King Herod the prophecy that a new ruler of the people of Israel would be born. We also need to think like King Herod, who asked the wise men when the star had appeared, because he and his court, apparently, were unaware of any such star in the sky.

These events present us with our first astronomy puzzle of the first Christmas: How could King Herod’s own advisors have been unaware of a star so bright and obvious that it could have led the wise men to Jerusalem?

Next, in order to reach Bethlehem, the wise men had to travel directly south from Jerusalem somehow that "star in the east . went before them, 'til it came and stood over where the young child was." Now we have our second first-Christmas astronomy puzzle: How can a star "in the east" guide our wise men to the south? The north star guides lost hikers to the north, so shouldn’t a star in the east have led the wise men to the east?

And we have yet a third first-Christmas astronomy puzzle: How does Matthew’s star move "before them," like the tail lights on the snowplow you might follow during a blizzard, and then stop and stand over the manger in Bethlehem, inside of which supposedly lies the infant Jesus?

The adoration of the Magi, after they followed that 'star in the east' to Jesus. Fr Lawrence Lew, O.P.


October 17th: Can the Laws of Physics Change?

Title: Can the Laws of Physics Change?

Podcaster: Stuart Clark

Description: Can the laws of physics change, and if they do what does this mean for our understanding of the Universe?

Bio: Dr Stuart Clark is an award-winning astronomy author and journalist. His books include The Sun Kings, and the highly illustrated Deep Space, and Galaxy. His next book is Big Questions: Universe, from which this podcast is adapted. Stuart is a Fellow of the Royal Astronomical Society, a Visiting Fellow of the University of Hertfordshire, UK, and senior editor for space science at the European Space Agency. He is also a frequent contributor to newspapers, magazines, radio and television programmes. His website is www.stuartclark.com and his Twitter account is @DrStuClark.

Today’s sponsor: This episode of � Days of Astronomy” is sponsored by AAVSO. The American Association of Variable Star Observers (AAVSO) is a worldwide, non-profit scientific and educational organization of amateur and professional astronomers interested in stars that change in brightness–variable stars.

Founded in October 1911 to coordinate variable star observations made largely by amateur astronomers for Harvard College Observatory, the AAVSO has grown to become the world leader in variable star astronomy, with members in 45 countries and an archive of over 17 million variable star observations.

As we begin our 99th year, the AAVSO is proud to support excellent education and outreach initiatives like the 365 Days of Astronomy podcast.

CAN THE LAWS OF PHYSICS CHANGE?

Hello I’m Dr Stuart Clark, astronomy author and journalist. Today I’d like to explore the question: Can the laws of physics change?

Science has enjoyed unprecedented success in describing nature with mathematics. The equations derived have become our way of understanding the laws of physics and of predicting the behaviour of physical systems. It seems unlikely that the laws themselves can change, but what about the so-called constants of nature?

There are many constants. They are the values that cannot be derived from theory, and so can only be determined by measurement. They are used in the laws of physics as conversion factors to create exact mathematical relationships between quantities.

Some of the constants are self explanatory, such as the speed of light. Others seem more abstruse, such as the Planck constant, which governs the way nature breaks energy up into small ‘packets’. Despite calling these quantities constants, there has been a creeping suspicion over the last 15 years or so that some of them – particularly the speed of light – may be changing slowly with time.

The universe is bathed in microwaves. Traditional physics explains the almost uniform temperature of this background as a result of a sudden period of exponential expansion early in the Universe’s history – but what drove this inflation is still a mystery. In 1993 physicist John Moffat pointed out that if the speed of light had been higher in the past, photons of light could have travelled much further and so could have equalized the temperature across a much wider expanse of space without the need to invoke inflation.

Astronomers now study distant quasars – early galaxies powered by matter falling into black holes − in the hopes of catching the last vestiges of any change in the speed of light. But we have to be careful when drawing conclusions from the measurement of constants that have units attached to them. The speed of light is measured in units of length and time. If a variation is detected, the researchers cannot be sure whether it is the speed of light that has varied, or the rate at which the clock has ticked, or the length of the ruler. So they concentrate on examining dimensionless constants. Say you measure the ratio of a proton’s mass to an electron’s mass, then the units – kilograms – will cancel out and the resulting constant will simply be a number.

The so-called fine-structure constant is dimensionless. It is obtained by combining the speed of light with the Planck constant and the charge on an electron. It affects the outer structure of each atom, which controls the way an atom’s electrons react with passing light beams. If the speed of light were to change with the passage of time, the fine-structure constant would change also, as would the characteristic pattern of lines produced by atoms.

In 1999, John Webb of the University of New South Wales led a team observing 128 quasars out to 10 billion light years. They collected the quasar light, split it into spectra, looking for the fingerprints of intervening atoms. The spectral lines changed in a way that was consistent with the fine-structure constant having increased slightly during the course of cosmic history, by around 1 part in 100,000 during those 10 billion years.

Numerous groups are trying to verify or disprove this idea because the discovery of changing constants has enormous consequences for our understanding of the Universe. It points to physics beyond Einstein, perhaps even to the elusive ‘theory of everything’.

Most physicists believe that the best candidate for a theory of everything is string theory. This complex mathematical theory replaces particles with strings wiggling in higher dimensions than the three we are directly familiar with. According to string theory, only if all the higher dimensions are taken into account will the value of physical constants remain truly constant.

In the case of gravity, mass in kilograms and distance in metres are equated to a force in newtons by Newton’s ‘gravitational constant’, Big G. This too has been another target for physicists searching for variations in the constants but Big G is difficult to measure accurately.

By 1987, physicists thought Big G was known to an accuracy of 0.013 percent. Improved experiments in 1998 forced this to be re-assessed to a lesser accuracy of just 0.15 percent. The value of Big G is extraordinarily imprecise when compared with the force of electromagnetism, which is known to 2.5 million times greater accuracy. This lack of precision has led to speculation about whether the constant might be changing slowly over time, in effect changing the strength of gravity. Such a variation would gradually change the orbits of stars and planets, affect the sizes of celestial objects, and determine how brightly stars shine.

Measuring the distance of the Moon using lasers from Earth has shown that the value of Big G cannot be changing by more than one part in a million per year. Other physicists search for temporary changes in the strength of gravity brought on by the movement of Earth around its orbit.

This is because Einstein’s theories of relativity rest upon the central tenet that the laws of physics are the same, no matter where or when you are located in the Universe or how you are moving. How to transform what one observer can see into the viewpoint of another is known as the Lorentz transformation but if the constants change, the Lorentz transformation no longer works precisely, and a Lorentz violation is said to have taken place.

String theory allows small Lorentz violations to have taken place in the big bang, imprinting themselves on the fabric of space-time and these could make Big G display a different value over the course of a single year as Earth orbits the Sun and so travels in different directions through space. The obvious way to test for this is to drop objects throughout the year and measure how fast they fall. Comparing measurements taken six months apart should yield the greatest difference because then the Earth is travelling in opposite directions through space. The best place to conduct the experiment is in space, because when an object is in free fall, small gravitational variations can be measured very precisely. A number of missions hoping to pursue this research are currently on the drawing board.

Physicists will continue to search for changes in the constants of nature – both long-term and short-term effects – for as long as they believe that string theory is the way to unite gravity with the other forces. By measuring the amount of change, they will be able to home in on the correct version of string theory and understand better its picture of a multi-dimensional Universe.

Newton’s theory of gravity is said to have been inspired by watching an apple fall to the ground earlier, Galileo is said to have dropped objects from tall buildings to discover that all objects fall at the same speed, regardless of their composition or mass. It would therefore be entirely fitting if our next breakthrough in understanding the Universe could come from measuring falling objects in orbit.


Can we violate law of physics in any other planet? - Astronomy

I probably won't get an answer to this one. but entropy says the universe is breaking down. evolution says the universe is getting better! Please explain this.

This idea has been put forward by many people to try to prove that evolution is impossible. However, it is based on a flawed understanding of the second law of thermodynamics, and in fact, the theory of evolution does not contradict any known laws of physics.

The second law of thermodynamics simply says that the entropy of a closed system will tend to increase with time. "Entropy" is a technical term with a precise physical definition, but for most purposes it is okay to think of it as equivalent to "disorder". Therefore, the second law of thermodynamics basically says that the universe as a whole gets more disordered and random as time goes on.

However, the most important part of the second law of thermodynamics is that it only applies to a closed system - one that does not have anything going in or out of it. There is nothing about the second law that prevents one part of a closed system from getting more ordered, as long as another part of the system is getting more disordered.

There are many examples from everyday life that prove it is possible to create order! For example, you'd certainly agree that a person is capable of taking a pile of wood and nails and constructing a building out of it. The wood and nails have become more ordered, but in doing the work required to make the building, the person has generated heat which goes into increasing the overall entropy of the universe.

Or, if you prefer an example that doesn't require conscious human intervention, consider what happens when the weather changes and it gets colder outside. Cold air has less entropy than warm air - basically, it is more "ordered" because the molecules aren't moving around as much and have fewer places they can be. So the entropy in your local part of the universe has decreased, but as long as that is accompanied by an increase in entropy somewhere else, the second law of thermodynamics has not been violated.

That's the general picture - nature is capable of generating order out of disorder on a local level without violating the second law of thermodynamics, and that is all that evolution requires.

The idea of evolution is simply that random genetic mutations will occasionally occur that lead an individual organism to have some trait that is different from that of its predecessors. Now, it is true that these mutations, being random, would probably tend to increase the "entropy" of the population as a whole if they occurred in isolation (i.e., in a closed system). That is, most of the mutations will create individual organisms that are less "ordered" (i.e., less complex) and only some will create individual organisms that are more complex, so overall, the complexity goes down.

However, evolution does not take place in a closed system, but rather requires the existence of outside forces - i.e., natural selection. The idea is that there can be some environmental effect that makes organisms with a particular mutation (one that makes them more "complex") more likely to survive and pass their genes on to the next generation. Thus, as generations go by, the gene pool of the species can get more and more complex, but notice that this can only occur if the gene pool interacts with the outside world. It is through the course of that interaction that some other form of entropy (or disorder) will be generated that increases the entropy of the universe as a whole.

If the above is too esoteric, consider a simple analogy: a poker tournament. In poker, good hands are less likely to be dealt than bad ones - for example, the odds of getting three of a kind are much less than the odds of getting two of a kind. So in a poker tournament, most people will be dealt bad hands and only a few will be lucky enough to be dealt good hands. But it is the people with good hands who will be more likely to win and "survive" to the next round. So the "outside forces" (in this case, the rules of poker) acting on a random distribution (all the poker hands that were dealt) will tend to select out the best, least likely ones.

For further information, the Talk.Origins website has an extensive discussion about the evolution/thermodynamics controversy.

This page was last updated June 27, 2015.

About the Author

Dave Rothstein

Dave is a former graduate student and postdoctoral researcher at Cornell who used infrared and X-ray observations and theoretical computer models to study accreting black holes in our Galaxy. He also did most of the development for the former version of the site.


Astrological answers to astronomical puzzles

Astronomer Michael Molnar points out that “in the east” is a literal translation of the Greek phrase en te anatole, which was a technical term used in Greek mathematical astrology 2,000 years ago. It described, very specifically, a planet that would rise above the eastern horizon just before the Sun would appear. Then, just moments after the planet rises, it disappears in the bright glare of the Sun in the morning sky. Except for a brief moment, no one can see this “star in the east.”

We need a little bit of astronomy background here. In a human lifetime, virtually all the stars remain fixed in their places the stars rise and set every night, but they do not move relative to each other. The stars in the Big Dipper appear year after year always in the same place. But the planets, the Sun, and the Moon wander through the fixed stars in fact, the word planet comes from the Greek word for wandering star. Though the planets, Sun and Moon move along approximately the same path through the background stars, they travel at different speeds, so they often lap each other. When the Sun catches up with a planet, we can’t see the planet, but when the Sun passes far enough beyond it, the planet reappears.

And now we need a little bit of astrology background. When the planet reappears again for the first time, and rises in the morning sky just moments before the Sun, for the first time in many months after having been hidden in the Sun’s glare for those many months, that moment is known to astrologers as a heliacal rising. A heliacal rising, that special first reappearance of a planet, is what en te anatole referred to in ancient Greek astrology. In particular, the reappearance of a planet like Jupiter was thought by Greek astrologers to be symbolically significant for anyone born on that day.

Thus, the “star in the east” refers to an astronomical event with supposed astrological significance in the context of ancient Greek astrology.

Was the star visible just briefly before dawn? James Callan, CC BY-NC-SA

What about the star parked directly above the first crèche? The word usually translated as “stood over” comes from the Greek word epano, which also had an important meaning in ancient astrology. It refers to a particular moment when a planet stops moving and changes apparent direction from westward to eastward motion. This occurs when the Earth, which orbits the Sun more quickly than Mars or Jupiter or Saturn, catches up with, or laps, the other planet.

Together, a rare combination of astrological events (the right planet rising before the Sun the Sun being in the right constellation of the zodiac plus a number of other combinations of planetary positions considered important by astrologers) would have suggested to ancient Greek astrologers a regal horoscope and a royal birth.


Which ‘Hints’ Of New Physics Should We Be Paying Attention To?

The April 11, 2017 reconstructed image (left) and a modeled EHT image (right) line up remarkably . [+] well. This is an excellent indication that the model library the Event Horizon Telescope (EHT) collaboration put together can, in fact, model the physics of the matter surrounding these supermassive, rotating, plasma-rich black holes quite successfully.

Huib Jan van Langevelde (EHT Director) on behalf of the EHT Collaboration

Every once in a while — multiple times per year — a new research finding fails to line up with our theoretical expectations. In the fields of physics and astronomy, the laws of nature are known to such incredible precision that anything that fails to align with our predictions isn’t just interesting, it’s a potential revolution. On the particle physics side of the equation, we have the laws of the Standard Model governed by quantum field theory on the astrophysics side, we have the laws of gravity governed by General Relativity.

And yet, from all of our observations and experiments, we occasionally get results that conflict with the combination of those two remarkably successful theories. Either:

  • there’s an error with the experiments or observations,
  • there’s an error with the predictions,
  • there’s a new effect we haven’t anticipated within the Standard Model or General Relativity,
  • or there’s new physics involved.

While it’s tempting to leap to the final possibility, it should be the scientists final resort, as the resiliency and successes of our leading theories has shown they’re not so easy to overturn. Here’s a look at eight potential hints of new physics that have come along with a great deal of hype, but deserve tremendous skepticism.

When two black holes merge, approximately 10% of the smaller one's mass gets converted into . [+] gravitational radiation via Einstein's E = mc^2. In theory, the matter outside of the black holes will be too sparse to create an electromagnetic burst. Only one black hole-black hole merger, the very first one, has ever been associated with an electromagnetic counterpart: a dubious proposition.

1.) Do gamma-ray bursts accompany black hole mergers? On September 14, 2015, the very first gravitational wave signal ever directly detected by humans arrived in the twin LIGO detectors. Indicating a merger of two black holes, one of 36 and one of 29 solar masses, they converted about three solar masses of energy into gravitational radiation. And then, unexpectedly, just 0.4 seconds later, a very small signal arrived in the Fermi GBM instrument: a potential indication of an accompanying electromagnetic signal.

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But with more than 50 additional black hole-black hole mergers, including some that were more massive, no other gamma-ray bursts were seen. The ESA’s Integral satellite, operational at the same time, saw nothing. And these low-magnitude transient events occur in the Fermi GBM data about once or twice per day. The odds of a false positive? 1-in-454, approximately. While researchers are still considering how gamma-ray bursts could accompany black hole-black hole mergers, the evidence that they occur is generally considered flimsy.

Verdict: Probably not, but perhaps rarely.

Most likely explanation: Observational coincidence, or a statistical fluctuation.

The excess of signal in the raw data here, outlined by E. Siegel in red, shows the potential new . [+] discovery now known as the Atomki anomaly. Although it looks like a small difference, it's an incredibly statistically significant result, and has led to a series of new searches for particles of approximately 17 MeV/c^2.

A.J. Krasznahorkay et al., 2016, Phys. Rev. Lett. 116, 042501 E. Siegel (annotation)

2.) Is there a new, low-energy particle called the X17? Just a few years ago, a Hungarian research team reported the possible detection of a new particle: dubbed the X17. When you make an unstable nucleus like Beryllium-8, an important intermediate step in the nuclear fusion process of red giant stars, it has to emit a high-energy photon before decaying back to two Helium-4 nuclei. Occasionally, that photon will spontaneously produce an electron-positron pair, and there will be a particular energy-dependent angle between the electron and the positron.

When they measured the rate of which angles occurred, however, they found a departure from what the Standard Model predicted at large angles. A new particle and a new force were initially proposed as the explanation, but many are doubtful. The direct detection exclusion limits already rule such a particle out, the calibration methods used are dubious, and this is already the fourth claimed “new particle” by this team, with the first three having already been ruled out earlier.

Verdict: Doubtful.

Most likely explanation: Experimental error by the team performing the experiments.

The XENON1T detector is shown here being installed underground in the LNGS facility in Italy. One of . [+] the world's most successfully shielded, low-background detectors, XENON1T was designed to search for dark matter, but is also sensitive to many other processes. That design is paying off, right now, in a big way.

3.) Is the XENON experiment finally detecting dark matter? After decades of gradually improving the limits on the cross-section of dark matter with protons and neutrons, the XENON detector — the world’s most sensitive dark matter experiment to date — detected a minuscule but hitherto unexplained signal in 2020. There were definitely a small but significant number of events that were detected above and beyond the expected Standard Model background.

Immediately, fantastic explanations were considered. The neutrino could have a magnetic moment, explaining these events. The Sun could be producing a novel type of (candidate dark matter) particle known as an axion. Or, perhaps in a mundane disappointment, it could have been a tiny amount of tritium in the water, an isotope which has not yet been accounted for, but where the presence of just a few hundred atoms could account for the difference. Astrophysical constraints already disfavor the neutrino and axion hypotheses, but no definitive conclusion as to this signal excess’s nature have yet been reached.

Verdict: Doubtful probably tritium.

Most likely explanation: New effect from an unaccounted-for background.

The best-fit amplitude of an annual modulation signal for a nuclear recoil with sodium iodide. The . [+] DAMA/LIBRA result shows a signal at extreme confidence, but the best attempt to replicate that has instead yielded a null result. The default assumption should be that the DAMA collaboration has an unaccounted for noise artifact.

J. Amaré et al./ANAIS-112 Collaboration, arXiv:2103.01175

4.) Is the DAMA/LIBRA experiment seeing dark matter? We often say that “extraordinary claims require extraordinary evidence,” because basing a revolutionary conclusion on only flimsy evidence is a recipe for scientific disaster. For many years now — well over a decade — the DAMA/LIBRA collaboration has seen an annual pattern in its signal: more events at one time of year, fewer at another, in a cyclical pattern. Despite no other detectors seeing anything of the sort, they have long claimed that this is evidence for dark matter.

But so much about this experiment has been questionable. They’ve never disclosed their raw data or their data pipeline, so their analysis cannot be checked. They perform a dubious annual recalibration at the same time every year, which could cause poorly-analyzed noise to be mistaken for a signal. And, with the first independent replication tests now having occurred, they refute DAMA/LIBRA’s results, as do complementary direct detection efforts. Although the team associated with the experiment (and a few theorists who are speculating wildly) claim dark matter, practically no one else is convinced.

Verdict: No, and this is likely a dishonest, rather than an honest, mistake.

Most likely explanation: Experimental error, as shown by a failed reproduction attempt.

The LHCb collaboration is far less famous than CMS or ATLAS, but the particles and antiparticles . [+] they produce, containing charm and bottom quarks, holds new physics hints that the other detectors cannot probe. Here, the massive detector is shown in its shielded location.

5.) Has the LHCb collaboration broken the Standard Model? The Large Hadron Collider at CERN is famous for two things: colliding the highest-energy particles ever in a laboratory on Earth, and discovering the Higgs boson. Yes, its primary goal is to discover new, fundamental particles. But one of the serendipitous things that comes along with its setup is the ability to create large numbers of unstable, exotic particles, like mesons and baryons that contain bottom (b)-quarks. The LHCb detector, where the “b” stands for that particular quark, produces and detects more of these particles than any other experiment in the world.

Remarkably, when these particles decay, the version that contain b-quarks and the version that contain b-antiquarks have different properties: evidence for a fundamental matter-antimatter asymmetry known as CP-violation. In particular, there’s more CP-violation seen than (we believe) the Standard Model predicts, although there are still uncertainties. Some of these “anomalies” exceed the 5-sigma threshold, and could point towards new physics. This could be important, because CP-violation is one of the key parameters in explaining why our Universe is made of matter, and not antimatter.

Verdict: Uncertain, but is likely a measurement of new parameters associated CP-violation.

Most likely explanation: New effect within the Standard Model, but new physics remains a possibility.

Scheme of the MiniBooNE experiment at Fermilab. A high-intensity beam of accelerated protons is . [+] focused onto a target, producing pions that decay predominantly into muons and muon neutrinos. The resulting neutrino beam is characterized by the MiniBooNE detector.

6.) Is there an ‘extra’ type of neutrino present? According to the Standard Model, there should be three species of neutrino in the Universe: electron, muon, and tau neutrinos. Although they were initially expected to be massless, they were shown to oscillate from one form into another, which is only possible if they’re massive. Similar to how the light quarks mix together, the neutrinos do as well, and measurements of atmospheric neutrinos (produced from cosmic rays) and solar neutrinos (from the Sun) have shown us what the mass differences between these neutrinos are. With only the mass differences, however, we don’t know the absolute masses, nor which neutrino species are heavier or lighter.

But neutrinos from accelerators, as shown from the LSND and MiniBooNE experiments, don’t fit with the other measurements. Do they indicate a fourth type of neutrino, despite the decay of the Z-boson and constraints from Big Bang Nucleosynthesis showing only three, definitively? Could that neutrino be sterile and non-interacting, except for these oscillatory effects? And when the decisive data, either confirming or refuting these results come in (from MicroBooNE, ICARUS, and SBND), will they continue to show evidence for a fourth neutrino, or will things slide back into line with the Standard Model?

Verdict: Unlikely, but new experiments will either confirm or rule out such indications.

Most likely explanation: Experimental error is the safe bet, but new physics remains possible.

The Muon g-2 electromagnet at Fermilab, ready to receive a beam of muon particles. This experiment . [+] began in 2017 and will take data for a total of 3 years, reducing the uncertainties significantly. While a total of 5-sigma significance may be reached, the theoretical calculations must account for every effect and interaction of matter that's possible in order to ensure we're measuring a robust difference between theory and experiment.

7.) Does the Muon g-2 experiment break the Standard Model? This one is both highly contentious and also brand new. Years ago, physicists attempted to measure the magnetic moment of the muon to incredible precision, and got a value. As theory raced to catch up, they calculated (and, where calculations were impossible, inferred based on other experimental data) what that value ought to be. A tension emerged, and Fermilab’s Muon g-2 experiment returned their first major results, showing a strong discrepancy between theory and experiment. As always, “new physics” and a broken Standard Model were all over the headlines.

The experiment was sound, their errors were well-quantified, and the discrepancy appears to be real. But this time, it appears that the theory might be the problem. Without the ability to calculate the expected value, the theory team relied on indirect data from other experiments. Meanwhile, a different theoretical technique has recently emerged, and their calculations match the experimental values (within the errors), not the mainstream theory calculation. Better experimental data is coming, but the theoretical discrepancy is rightfully at the center of this latest controversy.

Verdict: Undecided the biggest uncertainties are theoretical and must be resolved independent of experiment.

Most likely explanation: Error with the theoretical calculations, but new physics remains a possibility.

Modern measurement tensions from the distance ladder (red) with early signal data from the CMB and . [+] BAO (blue) shown for contrast. It is plausible that the early signal method is correct and there's a fundamental flaw with the distance ladder it's plausible that there's a small-scale error biasing the early signal method and the distance ladder is correct, or that both groups are right and some form of new physics (shown at top) is the culprit. But right now, we cannot be sure.

8.) Do the two different measurements for the expanding Universe show the way to new physics? If you want to know how fast the Universe is expanding, there are two general ways to go about measuring it. One is to measure objects close by and determine how far away they are, then find those objects more distantly along with other observational indicators, then find those other indicators farther out along with rare but bright events, and so on, out to the edges of the Universe. The other is to start at the Big Bang and find an early, imprinted signal, and then measure how that signal evolves as the Universe evolves.

These two methods are sound, robust, and have many ways to measure them. The problem is that each method gives an answer that disagrees with the other. The first method, in units of km/s/Mpc, gives 74 (with an uncertainty of just 2%), while the second gives 67 (with an uncertainty of just 1%). We know it’s not a calibration error, and we know it’s not a measurement inaccuracy. Is it a clue of new physics, and if so, what’s the culprit? Or is there some sort of unidentified error that, once we figure it out, will cause everything to fall back into line?

Verdict: The different measurements of the two general techniques are difficult to reconcile, but more study is needed.

Most likely explanation: Unknown, which is exciting for new physics possibilities.

Optical starlight polarization data (white lines) trace out the cumulative effects of the magnetic . [+] fields in interstellar dust within the Milky Way along the line-of-sight. The hot dust emits radiation (orange), while linear structures can be seen oriented along the magnetic field lines from neutral hydrogen emission (blue). This is a relatively new way to characterize polarized dust and magnetic fields in the neutral interstellar medium.

Clark et al., Physical Review Letters, Volume 115, Issue 24, id.241302 (2015)

We must always remember just how much established data, evidence, and agreement between measurement and theory there is before we can ever hope to revolutionize our scientific understanding of how things work in the Universe. It isn’t just the results from any new study that need to be examined, but rather the full suite of evidence at hand. A single observation or measurement must be taken as just one component of all the data that’s been gathered we must reckon with the cumulative set of information that we have, not just the one anomalous finding.

Nevertheless, science is, by its nature, an inherently experimental endeavor. If we find something that our theories cannot explain, and that finding is robustly replicated and significant enough, we must look to a potential fault with the theory. If we’re both good and lucky, one of these experimental results may point the way towards a new understanding that supersedes, or even revolutionizes, the way we make sense of our reality. Right now, we have many indications — some very compelling, others less so — that a paradigm-shifting discovery may be within our grasp. These anomalies may, in fact, turn out to be harbingers of a scientific revolution. But more often than not, these anomalies turn out to be errors, miscalculations, miscalibrations, or oversights.

Will any of our current “hints” turn out to be something more? Only time, and more inquiry into the nature of reality itself, will ever be able to reveal a closer approximation of the Universe’s ultimate truths.


How the laws of physics constrain the size of alien raindrops

The swirling clouds of Jupiter, captured by NASA’s Juno spacecraft, could release semisolid ammonia slushballs of precipitation. New work suggests that any liquid rain on Jupiter would be similar in some ways to rain on any other cloudy world.

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Whether they’re made of methane on Saturn’s moon Titan or iron on the exoplanet WASP 76b, alien raindrops behave similarly across the Milky Way. They are always close to the same size, regardless of the liquid they’re made of or the atmosphere they fall in, according to the first generalized physical model of alien rain.

“You can get raindrops out of lots of things,” says planetary scientist Kaitlyn Loftus of Harvard University, who published new equations for what happens to a falling raindrop after it has left a cloud in the April Journal of Geophysical Research: Planets. Previous studies have looked at rain in specific cases, like the water cycle on Earth or methane rain on Saturn’s moon Titan (SN: 3/12/15). But this is the first study to consider rain made from any liquid.

“They are proposing something that can be applied to any planet,” says astronomer Tristan Guillot of the Observatory of the Côte d’Azur in Nice, France. “That’s really cool, because this is something that’s needed, really, to understand what’s going on” in the atmospheres of other worlds.

Comprehending how clouds and precipitation form are important for grasping another world’s climate. Cloud cover can either heat or cool a planet’s surface, and raindrops help transport chemical elements and energy around the atmosphere.

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Clouds are complicated (SN: 3/5/21). Despite lots of data on earthly clouds, scientists don’t really understand how they grow and evolve.

Raindrops, though, are governed by a few simple physical laws. Falling droplets of liquid tend to default to similar shapes, regardless of the properties of the liquid. The rate at which that droplet evaporates is set by its surface area.

“This is basically fluid mechanics and thermodynamics, which we understand very well,” Loftus says.

She and Harvard planetary scientist Robin Wordsworth considered rain in a variety of different forms, including water on early Earth, ancient Mars and a gaseous exoplanet called K2 18b that may host clouds of water vapor (SN: 9/11/19). The pair also considered Titan’s methane rain, ammonia “mushballs” on Jupiter and iron rain on the ultrahot gas giant exoplanet WASP 76b (SN: 3/11/20). “All these different condensables behave similarly, [because] they’re governed by similar equations,” she says.

The team found that worlds with higher gravity tend to produce smaller raindrops. Still, all the raindrops studied fall within a fairly narrow size range, from about a tenth of a millimeter to a few millimeters in radius. Much bigger than that, and raindrops break apart as they fall, Loftus and Wordsworth found. Much smaller, and they’ll evaporate before hitting the ground (for planets that have a solid surface), keeping their moisture in the atmosphere.

Eventually the researchers would like to extend the study to solid precipitation like snowflakes and hail, although the math there will be more complicated. “That adage that every snowflake is unique is true,” Loftus says.

The work is a first step toward understanding precipitation in general, says astronomer Björn Benneke of the University of Montreal, who discovered water vapor in the atmosphere of K2 18b but was not involved in the new study. “That’s what we are all striving for,” he says. “To develop a kind of global understanding of how atmospheres and planets work, and not just be completely Earth-centric.”

Questions or comments on this article? E-mail us at [email protected]

Editor's Note:

This story was updated on April 19, 2021, to correct that falling droplets of liquid tend to default to similar shapes, not to teardrops, and that the researchers considered rain on ancient, not modern, Mars. The caption was also updated to clarify that Jupiter's ammonia slushballs are semisolid.

A version of this article appears in the May 8, 2021 issue of Science News.

Citations

K. Loftus and R. D. Wordsworth. The physics of falling raindrops in diverse planetary atmospheres. JGR Planets, Volume 126, Issue 4, April 2021. doi:10.1029/2020JE006653.

About Lisa Grossman

Lisa Grossman is the astronomy writer. She has a degree in astronomy from Cornell University and a graduate certificate in science writing from University of California, Santa Cruz. She lives near Boston.


How the laws of physics constrain the size of alien raindrops

Whether they’re made of methane on Saturn’s moon Titan or iron on the exoplanet WASP 76b, alien raindrops behave similarly across the Milky Way. They are always close to the same size, regardless of the liquid they’re made of or the atmosphere they fall in, according to the first generalized physical model of alien rain.

“You can get raindrops out of lots of things,” says planetary scientist Kaitlyn Loftus of Harvard University, who published new equations for what happens to a falling raindrop after it has left a cloud in the April Journal of Geophysical Research: Planets. Previous studies have looked at rain in specific cases, like the water cycle on Earth or methane rain on Saturn’s moon Titan (SN: 3/12/15). But this is the first study to consider rain made from any liquid.

“They are proposing something that can be applied to any planet,” says astronomer Tristan Guillot of the Observatory of the Côte d’Azur in Nice, France. “That’s really cool, because this is something that’s needed, really, to understand what’s going on” in the atmospheres of other worlds.

Comprehending how clouds and precipitation form are important for grasping another world’s climate. Cloud cover can either heat or cool a planet’s surface, and raindrops help transport chemical elements and energy around the atmosphere.

Clouds are complicated (SN: 3/5/21). Despite lots of data on earthly clouds, scientists don’t really understand how they grow and evolve.

Raindrops, though, are governed by a few simple physical laws. Falling droplets of liquid tend to default to similar shapes, regardless of the properties of the liquid. The rate at which that droplet evaporates is set by its surface area.

“This is basically fluid mechanics and thermodynamics, which we understand very well,” Loftus says.

She and Harvard planetary scientist Robin Wordsworth considered rain in a variety of different forms, including water on early Earth, ancient Mars and a gaseous exoplanet called K2 18b that may host clouds of water vapor (SN: 9/11/19). The pair also considered Titan’s methane rain, ammonia “mushballs” on Jupiter and iron rain on the ultrahot gas giant exoplanet WASP 76b (SN: 3/11/20). “All these different condensables behave similarly, [because] they’re governed by similar equations,” she says.

The team found that worlds with higher gravity tend to produce smaller raindrops. Still, all the raindrops studied fall within a fairly narrow size range, from about a tenth of a millimeter to a few millimeters in radius. Much bigger than that, and raindrops break apart as they fall, Loftus and Wordsworth found. Much smaller, and they’ll evaporate before hitting the ground (for planets that have a solid surface), keeping their moisture in the atmosphere.

Eventually the researchers would like to extend the study to solid precipitation like snowflakes and hail, although the math there will be more complicated. “That adage that every snowflake is unique is true,” Loftus says.

The work is a first step toward understanding precipitation in general, says astronomer Björn Benneke of the University of Montreal, who discovered water vapor in the atmosphere of K2 18b but was not involved in the new study. “That’s what we are all striving for,” he says. “To develop a kind of global understanding of how atmospheres and planets work, and not just be completely Earth-centric.”


1 Answer 1

Let's take a look at how a planet is defined. According to IAU, it is

  1. is in orbit around the Sun,
  2. has sufficient mass to assume hydrostatic equilibrium (a nearly round shape), and
  3. has "cleared the neighborhood" around its orbit.

As you can see, the size of the object is not relevant, although it somehow relates to the object's mass in 2.

Why is Mercury considered a planet at 15329km in circumference when Callisto is not at 15144km?

As we saw before, the size doesn't matter. Callisto does not fulfill the first requirement to be a planet - it is not in orbit around the sun, but is a satellite of Jupiter. This means that it isn't a planet, but a moon.

Pluto is 7232 km in circumference. If it was once a planet, why not Callisto?

Pluto was considered to be a planet because it was a relatively large body orbiting the sun - unlike Callisto, which was orbiting another planet. However, in 2006, Pluto was deprived the status of planet when the IAU set up the definition above. Pluto is now considered a dwarf planet which fulfills every requirement except 3. and is not a satellite of another planet.


Newton's three laws of motion, also found in "The Principia," govern how the motion of physical objects change. They define the fundamental relationship between the acceleration of an object and the forces acting upon it.

  • First Rule: An object will remain at rest or in a uniform state of motion unless that state is changed by an external force.
  • Second Rule: Force is equal to the change in momentum (mass times velocity) over time. In other words, the rate of change is directly proportional to the amount of force applied.
  • Third Rule: For every action in nature there is an equal and opposite reaction.

Together, these three principles that Newton outlined form the basis of classical mechanics, which describes how bodies behave physically under the influence of outside forces.


PH-111: Space, Astronomy and Our Universe (1C)

“Space, Astronomy, and our Universe” discusses topics related to space and astronomy, beginning with our planet and our Moon, and extending to stars, galaxies, and the Universe as a whole. This course will explore physical processes and laws that govern the motion and evolution of all objects in the Universe, including planets, stars and galaxies.

Academic programs for which this course serves as a requirement or an elective:

General Education Outcomes: Below is a listing of General Education Outcome(s) that this course supports.

Communicate effectively in various forms

Use analytical reasoning to identify issues or problems and evaluate evidence in order to make informed decisions

Reason quantitatively as required in various fields of interest and in everyday life

Course-specific student learning outcomes:

Demonstrate an understanding of the nature, scope, and evolution of the Universe, and where the Earth and Solar System fit in.

Demonstrate an understanding of and use some crucial astronomical quantities.

Describe appropriate physical laws. 

Demonstrate an understanding of the notion that physical laws and processes are universal, that the world is knowable, and that we are coming to know it through observations, experiments, and theory (the nature of progress in science).

Describe the scientific method. 

Explain the meaning of uncertainty in science. 

Relate some subjects from physics (e.g., gravity and electromagnetic radiation) to astronomy.

Use mathematics to solve simple problems involving physical laws.

Describe topics related to the history of astronomy and the evolution of scientific ideas (science as a cultural process). 

Show familiarity with the night sky and demonstrate an understanding of how its appearance changes with time and position on Earth.

Program-specific outcomes

Other program outcomes (if applicable).

Work collaboratively to accomplish learning objectives

Methods by which student learning will be assessed and evaluated describe the types of methods to be employed note whether certain methods are required for all sections:

Available evaluation methods include: Classroom quizzes and tests, homework sets, portfolio assessment, classroom attendance and participation, laboratory performance and reports, and term papers for WI sections.

Academic Integrity policy (department or College):
Academic honesty is expected of all students. Any violation of academic integrity is taken extremely seriously. All assignments and projects must be the original work of the student or teammates. Plagiarism will not be tolerated. Any questions regarding academic integrity should be brought to the attention of the instructor. The following is the Queensborough Community College Policy on Academic Integrity: "It is the official policy of the College that all acts or attempted acts that are violations of Academic Integrity be reported to the Office of Student Affairs. At the faculty member's discretion and with the concurrence of the student or students involved, some cases though reported to the Office of Student Affairs may be resolved within the confines of the course and department. The instructor has the authority to adjust the offender's grade as deemed appropriate, including assigning an F to the assignment or exercise or, in more serious cases, an F to the student for the entire course." Read the University's policy on Academic Integrity opens in a new window (PDF).

Disabilities
Any student who feels that he or she may need an accommodation based upon the impact of a disability should contact the office of Services for Students with Disabilities in Science Building, Room S-132, 718-631-6257, to coordinate reasonable accommodations for students with documented disabilities. You can visit the Services for Students with Disabilities website.