Sunday, 26 August 2018

What are some psychological facts that people don't know?

  1. 90% of people between 10–29 years sleep with their phones.
  2. It is possible to die due to a broken heart. It is called as stress cardiomyopathy.
  3. If a person sleeps a lot, then he/she is sad.
  4. Having conversation with a woman gives man improved mental strength.
  5. Intelligent people are more likely to remain faithful while in a relationship.
  6. You have a favourite song? That's because you are emotionally attached to that song.
  7. 1 in 5 people of India are mentally depressed, making it the most depressed country in the world.
  8. Most of us suffer from Phanthom Vibration syndrome. The feeling that your phone is vibrating when it's actually not.
  9. There is a gene that can cause you to be negative most of the time.
  10. It takes only 4 min. to fall in love.
  11. People who easily get distracted are more creative and tend to have more IQ.
  12. 10% of world population is left handed.
  13. The larger your signature, the larger your self esteem.
  14. The smaller your handwriting, the lesser you are open to conversation.
  15. If the crush on someone lasts more than 4 months, it is considered as love.
  16. Wearing red coloured dress makes you desirable to the opposite sex.
  17. Creative people tend to get bored easily.
  18. Eating chocolates reduces stress.
  19. People who give you the best advice are the ones with most problems.
  20. When someone says “ I hate you", they really mean “ you hurt me".
Pardon me! If anything is repetitive.
Source: Google + life experience!
credits: quora

Friday, 24 August 2018

Is the model of the solar system really a vortex?

The model of the solar system is not a vortex, or if it is, I missed that class and someone failed to tell me.
However, there was a model that suggested the vortex as a kind of mechanical explanation of things. Well, I guess it was really a theory aiming at explaining gravitation, but it’s at least a theory astronomically applicable, on the solar system, and it’s vortex-based.
I won’t rephrase this into my own words but shall give you the relevant section from the relevant Wikipedia article without further ado.
Well, almost without further ado, but first, just let us have a look at an illustration of it, shall we? [Theory presented below the image.]

Descartes' vortex theory
Because of his philosophical beliefs, René Descartes proposed in 1644 that no empty space can exist and that space must consequently be filled with matter. The parts of this matter tend to move in straight paths, but because they lie close together, they can not move freely, which according to Descartes implies that every motion is circular, so the aether is filled with vortices. Descartes also distinguishes between different forms and sizes of matter in which rough matter resists the circular movement more strongly than fine matter. Due to centrifugal force, matter tends towards the outer edges of the vortex, which causes a condensation of this matter there. The rough matter cannot follow this movement due to its greater inertia—so due to the pressure of the condensed outer matter those parts will be pushed into the center of the vortex. According to Descartes, this inward pressure is nothing else than gravity. He compared this mechanism with the fact that if a rotating, liquid filled vessel is stopped, the liquid goes on to rotate. Now, if one drops small pieces of light matter (e.g. wood) into the vessel, the pieces move to the middle of the vessel.
Following the basic premises of Descartes, Christiaan Huygens between 1669 and 1690 designed a much more exact vortex model. This model was the first theory of gravitation which was worked out mathematically. He assumed that the aether particles are moving in every direction, but were thrown back at the outer borders of the vortex and this causes (as in the case of Descartes) a greater concentration of fine matter at the outer borders. So also in his model the fine matter presses the rough matter into the center of the vortex. Huygens also found out that the centrifugal force is equal to the force, which acts in the direction of the center of the vortex (centripetal force). He also posited that bodies must consist mostly of empty space so that the aether can penetrate the bodies easily, which is necessary for mass proportionality. He further concluded that the aether moves much faster than the falling bodies. At this time, Newton developed his theory of gravitation which is based on attraction, and although Huygens agreed with the mathematical formalism, he said the model was insufficient due to the lack of a mechanical explanation of the force law. Newton's discovery that gravity obeys the inverse square law surprised Huygens and he tried to take this into account by assuming that the speed of the aether is smaller in greater distance.
Criticism: Newton objected to the theory because drag must lead to noticeable deviations of the orbits which were not observed.
Another problem was that moons often move in different directions, against the direction of the vortex motion. Also, Huygens' explanation of the inverse square law is circular, because this means that the aether obeys Kepler's third law. But a theory of gravitation has to explain those laws and must not presuppose them.
via credits: Quora-
                       David Kahana, physicist unhinged

Thursday, 23 August 2018

What is the center of our solar system and why?

The Sun-centered model of the solar system was first proposed more than a thousand years before Copernicus.
What does our Solar System really look like? If we were to somehow fly ourselves above the plane where the Sun and the planets are, what would we see in the center of the Solar System? The answer took a while for astronomers to figure out, leading to a debate between what is known as the geocentric (Earth-centered) model and the heliocentric (Sun-centered model).

Above: The Solar System. Image Credit: NASA

The ancients understood that there were certain bright points that would appear to move among the background stars. While who exactly discovered the "naked-eye" planets (the planets you can see without a telescope) is lost in antiquity, we do know that cultures all over the world spotted them.
The ancient Greeks, for example, considered the planets to include Mercury, Venus, Mars, Jupiter and Saturn — as well as the Moon and the Sun. The Earth was in the center of it all (geocentric), with these planets revolving around it. So important did this become in culture that the days of the week were named after the gods, represented by these seven moving points of light.

Earth is at the center of this model of the universe created by Bartolomeu Velho, a Portuguese cartographer, in 1568. Credit: NASA/Bibliothèque Nationale, Paris

All the same, not every Greek believed that the Earth was in the middle. Aristarchus of Samos, according to NASA, was the first known person to say that the Sun was in the center of the universe. He proposed this in the third century BCE. The idea never really caught on, and lay dormant (as far as we can tell) for several centuries.
Because European scholars relied on Greek sources for their education, for centuries most people followed the teachings of Aristotle and Ptolemy, according to the Galileo Project at Rice University. But there were some things that didn't make sense. For example, Mars occasionally appeared to move backward with respect to the stars before moving forward again. Ptolemy and others explained this using a system called epicycles, which had the planets moving in little circles within their greater orbits. [At left: The retrograde motion of Mars. Credit: NASA]
But by the fifteen and sixteenth centuries, astronomers in Europe were facing other problems, the project added. Eclipse tables were becoming inaccurate, sailors needed to keep track of their position when sailing out of sight of land (which led to a new method to measure longitude, based partly on accurate timepieces), and the calendar dating from the time of Julius Caesar (44 BCE) no longer was accurate in describing the equinox — a problem for officials concerned with the timing of religious holidays, primarily Easter. (The timing problem was later solved by resetting the calendar and instituting more scientifically rigorous leap years.)
While two 15th-century astronomers (Georg Peurbach and Johannes Regiomontanus) had already consulted the Greek texts for scientific errors, the project continued, it was Nicolaus Copernicus who took that understanding and applied it to astronomy. His observations would revolutionize our thinking of the world.
Published in 1543, Copernicus' De Revolutionibus Orbium Coelestium (On the Revolutions of the Heavenly Bodies) outlined the heliocentric universe similar to what we know today. Among his ideas, according toEncyclopedia Britannica, was that the planets' orbits should be plotted with respect to the "fixed point" Sun, that the Earth itself is a planet that turns on an axis, and that when the axis changes directions with respect to the stars, this causes the North Pole star to change over time (which is now known as the precession of the equinoxes.)
Putting the Sun at the center of our Solar System, other astronomers began to realize, simplified the orbits for the planets. And it helped explain what was so weird about Mars. The reason it backs up in the sky is the Earth has a smaller orbit than Mars. When Earth passes by Mars in its orbit, the planet appears to go backwards. Then when Earth finishes the pass, Mars appears to move forwards again.
Other supports for heliocentrism began to emerge as well. Johannes Kepler's rules of motions of the planets (based on work from him and Tycho Brahe) are based on the heliocentric model. And in Isaac Newton's Principia, the scientist described how the motions happen: a force called gravity, which appears to be "inversely proportional to the square of the distance between objects", according to the University of Wisconsin-Madison.

Artist's conception of the Kepler Space Telescope. Credit: NASA/JPL-Caltech

Newton's gravity theory was later supplanted by that of Albert Einstein, who in the early 20th century proposed that gravity is instead a warping of space-time by massive objects. That said, heliocentric calculations guide spacecraft in their orbits today and the model is the best way to describe how the Sun, planets and other objects move.
Universe Today has articles on both the heliocentric model and thegeocentric model, and Astronomy Cast has an episode on the center of the universe.
This post by Elizabeth Howell originally appeared at Universe Today. It has been republished with permission.

source and credits: universetoday

Sunday, 19 August 2018

Can it be that our solar system is an atom? is Bohr model of the atom is probably not correct?

by Ron Kurtus (revised 2 Janaury 2018)

The Bohr model—or solar system model—of the atom describes atoms as consisting of a nucleus with a number of electrons in orbits around that nucleus, similar to a solar system. Because of this, people have speculated that perhaps atoms are like tiny solar systems.

Since our own Solar System consists of a sun in the middle with eight smaller planets rotating around it in their orbits and the element Oxygen has a nucleus and eight smaller electrons rotating around it in their orbits, you could imagine that there is a similarity between the two. Likewise, perhaps our solar system is an atom in some larger entity.
Although recent studies have shown that the Bohr model of the atom is probably not correct—or at least incomplete—the concept of tiny solar systems has captured the imagination of many people.
Questions you may have include:
  • Is it possible that atoms are like tiny solar systems?
  • Is it possible that our solar system is really an atom in a bigger universe?
  • What are some problems with this idea?
This lesson will answer those questions. Useful tool: Units Conversion

Atoms as solar systems

According to the Bohr or solar system model of matter, every atom consists of a nucleus with a certain number of electrons rotating about the nucleus in their orbits. The nucleus is much larger than the electrons. These particles are assumed to be very small spheres or ball-shaped. This is similar to the configuration of a solar system, with a large sun in the center and planets rotating in orbits around the sun.
Is it possible that the atomic level represents a smaller universe of some sort?

Oxygen and our Solar System

Look at the example of the element Oxygen, which consists of a nucleus and 8 electrons in orbit. Our solar system has our Sun and 8 planets in orbit around it. Is it possible that the third electron from the Oxygen nucleus is similar to the third planet from the Sun—our Earth—except on a very small and different scale?
Perhaps there are even tiny little people or animals living on that electron. When they look out through their tiny telescopes at the other atoms and molecules around them, perhaps they think they are looking at the whole Universe. This may be stretching our imagination, but is it a possibility?

Pluto creates an ion

But what about Pluto? It used to be considered a planet, and it does orbit the Sun. However, it is no longer considered a planet and may have been a large asteroid that had captured into orbit by the Sun.
Just as an extra electron in orbit around the Oxygen nucleus would make the atom an ion, so too would the extra asteroid rotating around the Sun make the Solar System a form of "solar ion" or such.

Solar systems as atoms

Following that train of thought, perhaps solar systems are actually "atoms" in a much larger universe. Some stars are very large and some are much smaller than our Sun—just as some atomic nuclei are large and some are small, depending on their atomic number and weight. The rotating galaxies could be like rotating eddies in a liquid or gas.
Since there is this similarity, is it possible that each solar system is really an atom in some physical system?
Atom or Solar System?
Atom or Solar System?
Our solar system could be similar to Oxygen, while others may be like Chlorine, Iron or Uranium. In fact, the Universe we see through our telescopes may be just the collection of billions of atoms that are in a larger Universe.
Perhaps we are even part of the atoms on another gigantic living being!

Problems with idea

There are some problems with the idea of atoms being tiny solar systems. Scientific studies in the area of Quantum Mechanics have shown that at the quantum or atomic level there are added rules of physics that restrict the activities and appearances that are allowed on a larger scale.

Probably not tiny spheres

This theory states that electrons, protons, neutrons and the nucleus are probably not tiny spheres. The most common theory is that electrons are spread out in the form of a cloud. Another theory is that electrons look like tiny strings. Since these particles are too small to be seen in a microscope, what they look like is pure speculation.

Do not rotate in orbit

Also, quantum theories state that electrons probably do not rotate around the nucleus in an orbit.
When electric charges move, they create a magnetic field. When the charges change directions, they give off electromagnetic radiation. If electrons rotate in orbits, they would give off such radiation, which they don't. Thus, scientists believe that electrons are stationary in a shell around the nucleus of an atom, perhaps as a cloud. On the other hand, perhaps that radiation rule does not hold when an electron is in an orbit or shell.

Can't be proven

Of course, none of this can ever be proven—at least not in our lifetime. But it shows that there is a lot more to what is around us than we realize. Thinking and speculation on this sort of thing can be fun to do. Science fiction writers have used such speculation to write stories and movies for use to enjoy.
Look beyond what is obvious. Examine similarities and trends in order to draw some conclusions or create a theory. That is what science is all about.


The Bohr or solar system model of the atom states that atoms consist of a nucleus with a number of electrons in orbits around that nucleus, similar to a solar system. People have speculated that perhaps atoms are tiny solar systems. Perhaps our own Solar System is similar to the element Oxygen, which has a nucleus and eight smaller electrons rotating around it in their orbits.
Likewise, perhaps our solar system is an "atom" in some larger entity. Although recent studies have shown that the Bohr model of the atom is probably not correct or is incomplete, the concept of tiny solar systems has captured the imagination of many people.

Friday, 17 August 2018

Top 10 Mind-blowing Facts about Physics

Author: Arun Thakur

The contribution of Physics in unraveling mysteries of the universe and its constituents has been tremendous and greatly remarkable. Discoveries made by the Physicists over the years have helped us a great deal in understanding both micro and macro cosmos. The discoveries, such as Planck’s constant and natural unit of light, have opened the Pandora’s Box around us to reveal other facts as well. Here is a list of top 10 mind blowing facts about Physics that will literally surprise you.

10. Light waves don’t always move in straight lines:

It is generally believed that light waves only move in straight lines. However, as per the recent research in 2010 using computer controlled hologram, it has been proved that light, too, can get twisted into knots. According to the study, when light passes through the hologram, it twists into different shapes, producing multiple knots.

Light waves don’t always move in straight lines - Mind-blowing Facts about Physics

9. Unbelievable hydrogen energy:

It is estimated that Sun burns around 620 million metric tons of hydrogen/second into 616 million metric tons of helium. Out of this total volume, around 4 million tons of mass enters the solar system. Furthermore, only about 3.6 pounds of the mass reaches our earth. Had even 1 percent of the energy produced out of fusion reached us, what would have been the scenario?
Unbelievable hydrogen energy - Mind-blowing Facts about Physics

8.  Human radiations:

As per the recent studies and discoveries in the field of Physics, a nude human body constantly radiates around 1000 watts of heat and absorbs about 900 watts. However, once the person covers his body with clothes, the outflow of the heat flux reduces considerably due to the exterior barrier. The amount of heat outflow from the human body is more than enough in lightning up a 100 watt bulb for some time.

Human radiations - Mind-blowing Facts about Physics

7. Anti-gravity movement:

Water can easily run against the gravitational pull when moving up narrow pipes. The process is described as ‘Capillary Action’. Water moves up in the narrow spaces without any assistance and against the gravitational force. This ability of the liquid proves that gravitational force can’t control the movement of every matter present on earth. At times, other forces (Surface tension, in this case) can defeat it.

Anti-gravity movement - Mind-blowing Facts about Physics

6. Viscous fluids can flow at high speeds:

It is generally believed that viscous fluids can’t flow fast enough like water – a liquid with reduced viscous level. However, some scientists went on to prove that fluids like “Ketchup” can attain high speeds, too, if constantly sheered over a period of time till they attain momentum. Once thrust is achieved, the viscous forces dwindle down considerably and free movement is observed.

Viscous fluids can flow at high speeds - Mind-blowing Facts about Physics

5. Gravitational constant:

The standard value of the gravitational constant is 9.8 m/s^2. It must be well known to all the science students that the value is calculated from the free fall of an object at sea level. The point worth noting is that the free fall should be at latitude of 45 degrees from the base level in order to obtain this value than 90 degrees as believed by the most.
Gravitational constant - Mind-blowing Facts about Physics

4. Air current:

The speed of wind near the surface of ocean is much lower than what is observed in the higher altitudes. The reason can be attributed to the friction it receives from the water surface. It is due to this reason that most birds fly at a higher altitude. They manipulate the wind power in order to use least amount of energy on flying.

Air current - Mind-blowing Facts about Physics

3. Universe is a Computer:

On the basis of a paper published by a professor in MIT, the Universe is equivalent to a computer. The figure is roughly equal to 10^120 bits. The number was calculated by him on the basis of the amount of information that can be stored in a volume just before it adopts the properties of a black hole. The information can be equated to absolute entropy of the universe.

Universe is a Computer - Mind-blowing Facts about Physics

2. Mystery of microwave and liquids:

As per the latest researches worldwide, water in the liquid state has the characteristic to enable many new molecular interactions to develop. This helps in enhancing absorption of heat by food items. Due to this property, foods items like burgers become soft enough to be eaten after coming out of microwave ovens.

Mystery of microwave and liquids - Mind-blowing Facts about Physics

1. Ultimate expansion:

It is proved by scientific theories that the universe is constantly expanding. It is expanding at a decent pace and it is believed that galaxies will evaporate in the coming 10^19 to 10^20 years. It has been learnt from a number of theories by different Physicists worldwide that only White Dwarfs (a type of star) would be able to survive as their lifetime is more than 10^32 years.

Ultimate expansion - Mind-blowing Facts about Physics

source: topyaps

Monday, 13 August 2018

How Can We Calculate The Mass Of A Planet?

image credits: creative commons
How do we know the mass of a planet originally appeared on Quora - the knowledge sharing network where compelling questions are answered by people with unique insights.
It's actually pretty cool.
One of the things Sir Isaac Newton is most famous for is his theory of gravity. He established that the pull of gravity between any two objects can be calculated from the mass of the two objects, the square of the distance between them, and a gravitational constant. When you put an apple on a scale, you're actually measuring the force between that apple and the earth. The weight depends on both masses; if the earth was a different mass, the apple would have a different weight on earth.

So, once we've measured the weight of the apple, we can work backward. We can easily convert the weight of the apple to find its mass. And we know the distance between the center of the apple and the center of the earth, because we know how big the earth is (how we first calculated that is another story, though a pretty interesting one). Given all that, the two things we don't know are the mass of the earth and the gravitational constant. If we can find one, we can use Newton's equation to figure out the other.
Enter Henry Cavendish.
Cavendish was a brilliant and wealthy but very shy and eccentric 18th century scientist. He made a number of groundbreaking scientific discoveries, and didn't even bother to publish many of them. But one that he did publish was the gravitational constant. See, gravity means that there is an attractive force between all objects, not just planets and stars. So, if you take a big, heavy, metal ball and place it close to another big, heavy ball, there will be an attractive force between them. When dealing with 350 pound chunks of metal instead of planets, the force is very, very tiny, but it's there. An amateur scientist/clergyman named John Michell invented an impressively delicate apparatus for measuring these tiny forces, and left it to Cavendish when he died. Cavendish, after much trial and error, managed to set up an experiment that used it to accurately measure the force between pairs of metal balls. Knowing that force, the mass of the balls, and the distance between them, Cavendish could accurately calculate the gravitational constant. (In case you're curious, it's 6.67*10^-11 cubic meters per kilogram-second squared).
With that number known, we can solve the mass equation for the whole world. Every time you step on a bathroom scale, you're measuring the mass of the planet. If we know your mass and your distance from the center of the earth, then we can apply Newton's equation of gravity and determine the mass of the planet you're standing on. What's more, once we know the mass of the earth, we can use orbital observations to calculate the mass of the moon and the sun, and we can use those to determine the mass of the other bodies in the solar system. All of which was first made possible by one guy fiddling with a delicate balance in his estate in England 200 years ago.
source:quora via forbes

Friday, 10 August 2018

Different Branches Of Physics

Science is about studying the natural world in a disciplined way. It allows us to find evidence with the help of experiment and develops new technologies, medicines and much more that makes the human life significantly simpler. On the other hand, Science has basically been divided into 3 types – Chemistry, Physics and Biology. Among all, we are going to explore the different branches of Physics. Yes, Physics – the branch of natural science, that deals with the study of motion, gravitation, space, energy, time and much more. Honestly, learning physics is essential as it is used in regular day to day existence.
Different Branches Of Physics
Today, this subject has been divided into various branches. Among all, below are the 7 different branches of physics:
1. Optics
2. Modern Physics
3. Classical Mechanics
4. Nuclear Physics
5. Electromagnetism
6. Astrophysics
7. Thermodynamic.
The branch of physics deals with the behaviors and the properties of light, Optics usually describes the behaviors of electromagnetic radiations (EMR) like ultraviolet- (UV) is an electromagnetic radiation with a wavelength from 10 nm to 400 nm, infrared light (IR), is an electromagnetic radiation (EMR) with  a wavelengths  extends from 700 nm to 1000000 nm etc. Today, Optics has three major branches. Geometrical optics, it is a physics deals with the study of light as rays. Physical optics is the study of light as waves and the last one, Quantum optics is the study of light as particles.
Modern Physics
Modern physics is a branch of physics focuses on the theory of relativity and quantum mechanics. The pioneer of this physics is the founder of the theory of relativity – the greatest physicist - Albert Einstein and the founder of quantum theory- Max Planck. Remember, quantum mechanics deals with the behavior of smallest particles, whereas the theory of relativity deals with the relationship between electromagnetism and mechanics.
the theory of relativity and quantum mechanics
Classical Mechanics
Classical Mechanics is a branch a physics, that deals with the energy, force, gravitation and so on. This branch of physics is named after the most influential scientist of all time, Sir Isaac Newton and his laws of motion. Therefore, this branch is known as the “Newtonian mechanics”. Classical Mechanics studies the motion of macroscopic objects as well as the cosmic entities such as Stars, Galaxies, Planets and also the behaviors of solid, liquid, gas and many more.
Nuclear Physics
Nuclear physics deals with the study of the protons and neutrons (its constituents and interactions) at the center of an atom. Nuclear physics helps reveal atomic weapons, atomic power,  nuclear medicine ion implantation in material engineering designing and a great deal more. However, Atomic Physics, on the other hand, deals with atoms in isolation.
the protons and neutrons
Electromagnetism is a study of electromagnetic force (existence of electricity) like light, electric fields, magnetic fields and so on. The two aspect of this physics is “electricity” and “magnetism”. Remember, electricity is the form of energy borne by elementary particles like the electron. Electromagnetism is considered as one of the most powerful physics, in light of the fact that electromagnetic force is encountered in day to day existence. For example Lightning in the sky during a thunderstorm is an electrostatic discharge.
The branch of natural science, Astrophysics deals with the study of astronomical objects like Stars, Galaxies, Planets, Comets and other celestial bodies. This physics likewise to focus on the laws and theories, interpretation as well as astronomical observations. Astrophysics apply many another discipline of physics such as electromagnetism, thermodynamic, relativity, nuclear physics, quantum mechanics and much more.
Astrophysics is all about astronomical object
The branch of physics, Thermodynamic deals with the study of physical qualities which includes temperature, energy, and entropy. Remember, the laws of thermodynamic control interactions of almost everything in this universe today.

source: urbanpro

Gravitational Waves Could Help Find Secret Alien Worlds

By Kelly Oakes

a close up of food: Photo Illustration by The Daily Beast© Provided by The Daily Beast Photo Illustration by The Daily Beast
When physicists announced the first direct detection of gravitational waves in 2016, the discovery sent ripples through the scientific community. Gravitational waves—wrinkles in the fabric of space-time that make space itself stretch as they pass through it—were predicted by Albert Einstein over 100 years ago.
Now, in a pre-print article published on arxiv, a group of researchers have their sights set on using gravitational waves to solve that other big problem in astronomy: finding alien planets.
The exoplanets they think they could find would be un-Earth-like, with huge masses, orbiting close to their stars, and years that last about an hour or less. In other words, these planets would be unlikely to support life.
Still, the technique is promising as another tool in our exoplanet-hunting arsenal that could find planets we’ve so far been unable to detect at all.
Video: NASA: Gravitational Waves Likely Indicated Birth Of A Black Hole (GeoBeats)
Video player from: Oath (Privacy Policy)

“Even weak signals could also be detected if the sources are close enough to the Earth,” José Ademir Sales de Lima, one of the authors of the paper, at the University of São Paulo, Brazil, told the Daily Beast.
Lima and his colleagues decided to look at binary systems— double star systems, or a star and a planet—in our own galaxy. They realized that “a special class of exoplanets, the ones with ultra-short periods” could cause gravitational waves strong enough for us to see, he said.
It’s not just mass that affects how strong a gravitational signal an object can make. The shorter period an exoplanet has—that is, the faster it travels around its star—the stronger the gravitational waves it creates. And Lima and his colleagues think that the next generation of detectors could sense gravitational waves coming from exoplanets that travel around their star in an hour or less—as long as they’re close enough to Earth.
Current exoplanet-finding methods have some significant blind spots. The transit method, used by NASA’s Kepler mission and responsible for the majority of planet detections to date, requires a planet to orbit in front of its star.
Slideshow: Spectacular photos from space (Microsoft ICE)

Researchers see the traveling speck as proof of an exoplanet’s existence. If a star has a planet that doesn’t cross in front of it from our vantage point, however, we can’t see it, which means we can’t prove its existence.
“While I suspect that detectable systems would be extremely rare, interestingly these systems might have orbital inclinations that would be much less favourable to traditional exoplanet search methods,” Martin Hendry, a professor of gravitational astrophysics and cosmology at the University of Glasgow, told The Daily Beast.
So far, using our normal methods, we’ve found a handful of planets that fit this description. They tend to be gas giants many times the mass of Jupiter and orbit close in to their star, characteristics that have earned them the nickname “hot Jupiters.”
The gravitational waves we’ve seen since 2016 have been made by incredibly massive objects—typically, black holes and super dense neutron stars – as they interact. But, technically, anything with  mass can make gravitational waves; most are just far too small to detect.
Today’s state-of-the-art gravitational wave experiments, LIGO and Virgo, consist of large ground-based detectors that use lasers to measure incredibly small changes in space. LIGO is made of two 4km-long L-shaped detectors on either side of the US, with one in Hanford, Washington State, and the other in Livingston, Louisiana. Virgo is similar and sits near Pisa, Italy.
Related Video: Gravitational waves (Agence France-Presse)
Gravitational waves

Gravitational waves get weaker the further away they travel from their source, so we could only detect the merging of those faraway black holes because they were so massive and started off with such a strong signal. By the time the first gravitational waves (created during a merger of two black holes 1.3 billion light years away) reached Earth, the amount they stretched space by at our detectors was a fraction of the diameter of a proton.
We’re still a couple of decades out from actually measuring any planets’ gravitational waves. LISA, a space-based detector being developed by NASA and ESA, is not due to launch until 2034. “The possibility that some extreme exoplanetary systems could be gravitational-wave sources accessible to spaceborne detectors such as LISA is an intriguing one,” Hendry said, adding that gravitational waves could make a useful add-on to other search methods.
Gravitational waves from exoplanets would also have a unique feature we’ve not yet seen from any other source: Unlike in the collision of two black holes, the signal from exoplanets would not be a one-time event. They would continually emit gravitational waves as long as the planet kept orbiting its star.
“This class of binary systems is very suitable for continued observation,” Lima said. In other words, however long it takes us to build the detectors to measure those signals, they’ll be there waiting for us.