Double Slit Experiment II

The double slit experiment is based on the wave/particle duality of subatomic particles. What is so amazing about it is that over the years it has produced results that are among the strangest in quantum mechanics. It is the king of quantum weirdness being the strangest in science. The original double silt experiment used photons of light, but later versions used electrons but the results are the same The double slit experiment is actually responsible for starting Quantum Physics.

Over the decades numerous explanations have been proposed to explain the results of what on the surface is a very simple experiment. However resent experiments involving quantum erasure seem to have reduced the possibilities to being the information that is collected making the difference.

What seem to be happening is the in general subatomic particles tend to exist as wave functions that represent multiple possibilities. When specific information is measured about an event those possibilities are reduced to one producing the needed information. A new wave function of multiple possibilities is then produced consistent with that one possibility.

Putting it all together suggests that what we call reality is actually immaterial at its most fundamental level. At its most fundamental level the universe seems to be composed entirely of information. This makes it more like a sophisticated computer program than a world of material objects.

It is more than just the existence of the information the affects the experiment but its ability of it to eventually be accessed by the experimenter. That experimenter is ultimately a human being that is a conscience entity. The information that makes up reality seems to be calculated as need for a conscience entity so as to produce a consistent reality.

This shows that consciousness is a fundamental part of reality. This is not new age thought but what the observation of subatomic particles is actually telling us. It is consistent with the Biblical view of God as creator since the universe would be a result of His consciousness. It is also consistent with the Biblical view of God creating the Universe out of nothing.

Double Slit Experiment in Quantum Mechanics

The double slit experiment a famous some would say infamous experiment in. The experiment requires shooting light or other subatomic particles such as electrons at a screen with two slits in it. Warning things are about to get strange. 

When the double slit experiment is done with pure waves it produces an interference pattern. On the other hand pure particles like bullets would tend to produce two lines behind the slits. However subatomic particles like photons and electrons produce a wave like interference pattern, even when shot one at a time.  It is as though each particle goes through both slits at the same time. 

Even stranger if detectors are put near the slits to check which slit each particle really goes through they produce only the two lines like bullets would. 

Even stranger yet when the detectors are on but the no data is taken the result is a wave like interference pattern suggesting it is the conscience act of observing that actually changes the result.

Such a result is consistent with the Biblical view of God as creator. From a Biblical view point the universe would have resulted from God’s consciousness and so it should not be much of a surprise that we would find such a result.

Additional Reference Video on the Double Slit Experiment of Quantum Physics

Quantum Physics and the Bible.

Since the Bible is the word of God we should expect its view of reality to fit with the reality we see around us. The Bible describes events and ideas that do not fit well with the clock work deterministic universe of Classical Mechanics. The clock work deterministic universe made many of the events in the Bible seem to be impossible. However Quantum Mechanics eliminates this purely deterministic universe. It turns out the Quantum Mechanics is a good fit the Bible and the following examples show why this is the case.

Genesis 1:1, In the beginning God created the heaven and the earth.
Exodus 20:11, For in six days the LORD made heaven and earth, the sea, and all that in them is…
Proverbs16:4, The LORD hath made all things for himself…
Hebrews 11:3, Through faith we understand that the worlds were framed by the word of God, so that things which are seen were not made of things which do appear.

God made every thing from nothing and Quantum Mechanics shows this to be possible. Quantum Mechanics has what are called virtual particles that pop in and out of existence all the time. Wave-particle duality eliminates the idea of particles as solid ball like objects. Particles are exhibiting their wave nature have only a quasi existence where they are essentially every place at once. This alone suggest the Universe could be created out of nothing however the Big Bang is thought to have started with a quantum fluctuation from nothing. Now the Bible does not agree with the Big Bang theory but the point is that Quantum Mechanics supports a creation from nothing.

Colossians 1:17, And he is before all things, and by him all things consist.

This verse indicates that the universe is actively maintained by God. The indeterminacy of Quantum Mechanics is expected with intelligent control of the universe. General Intelligent Design is a perfect match to this concept. General Intelligent Design depicts quantum mechanical waves and their collapse as being the result of intelligent agents that determine the states resulting from the waves' collapse. In this case God would be the intelligent agent behind Quantum mechanical waves and their collapse

According to the Bible, Jesus Christ died on the cross to save us of our sin this salvation comes to the individual by acceptance of God’s offer as a free gift. He then rose from the dead on the third day. Following His resurrection Jesus was no longer restricted in space. He could now appear at will where he would and then disappear again.  Even a locked room was not a problem since Jesus appeared to his disciples inside as locked room and then He then disappeared again.

Quantum Mechanics provides a possible scientific description of these events. A particles wave function can have a high probability at one point and a low or non in another. If the waves swap positions then the probabilities would be swapped and a particle which is in the first position will instantly jumps to the other. If a wave function starts with a high probability outside a locked room and a low or zero probability inside a locked room and that wave function changes so that it has a high probability inside a locked room and a low or zero probability outside a locked room then the object would suddenly appear inside the locked room.

If Jesus started out side a locked room His body would have wave function starts with a high probability outside the locked room and a low or zero probability inside the locked room. If He could change His wave function at will; not a stretch since He is God; to a high probability inside a locked room and a low or zero probability outside a locked room then He would suddenly appear inside the locked room. Changing His wave function back again He would then disappear again. This provides a possible scientific description of the post resurrection appearances and disappearances of Jesus. This is just a possible description of how He could do these things and in no way detracts from the miraculous nature of these events.

The existence of the soul and free will have come under attack by two philosophical concepts materialism and determinism. Materialism is the theory that the only reality that exists is physical matter and that everything can be explained in terms of matter physical phenomena including mind, thought, feeling, consciousness and will. Determinism is the doctrine that all events are fully determined by preceding events and conditions including human choices and actions.  As a result of these doctrines freedom of choice is considered illusory. It needs to be realized that modern studied of neurology do allow any consideration of dualism is dealing with the mind / brain issue. Only theories that assume from the start that them mind is nothing but a by product of the brain are allowed consideration so it is no surprise that there conclusion leave not place fore the sole or free will.

Both materialism and determinism fit well classical mechanics but quantum mechanics refutes both ideas. Under quantum mechanics the future position of a particle can not be determined precisely which refutes determinism. Under quantum mechanics particles do not have an exact position and can be everywhere at once which refutes materialism. By refuting materialism and determinism quantum mechanics also refutes the naturalistic view of the mind that is the idea that the mind is nothing but the neuron activity of the brain opening the door to two alternatives dualism and quantum mind theory. Dualism where the mind and brain are totally separate and quantum mind theory which depicts the brain as a quantum computer. Both ideas allow for free will and the possibility of life after death.

Quantum mechanics allows for a new theory of dualism where the mind and brain are separate but connected by quantum entanglement. Quantum mechanics then becomes the means of mind / brain interactions.  Based on this view mind is not limited to the brain thus can have free will and survive the death of the brain.

Quantum mind theory says that the mind results from quantum activity in brain. Basically the brain is seen as quantum computer where quantum indeterminately allows for the possibility of free will. Quantum nonlocality and entanglement allows for the possibility of the mind surviving the death of the brain.

The point is quantum mechanics provides for the possibility of a non materialistic mind. So is there evidence for a quantum mechanical aspect to the brain. Yes: in he synaptic activity in the brain. Calcium ions that trigger exocytosis needs to cross a barrier to the synaptic vesicle and the Calcium ions can not classically cross this barrier. As a result quantum tunneling is needed fore the Calcium ions to cross this barrier but the odds of this occurring are 1 in 10,000,000.  The problem is that the functioning of the brain requires this quantum tunneling to occur on demand. The only way to get quantum tunneling on demand is for the mind to be able to control quantum events.

This means that the mind must be a result of more than synaptic activity. There needs to be an immaterial aspect to the mind that does not depend on the brain and that controls this quantum tunneling.

As a result quantum mechanics shows the Biblical view of man is possible. It allows for the possibility of free will and the possibility of an eternal soul.

The point is Quantum mechanics allows for possibilities that classical mechanics does not. Consider what a being with total control of quantum phenomenon could do such a being would literally be capable of miracles. For over 200 years the idea of miracles has been criticized. However quantum mechanics shows how miracles could be possible. It is actually powerful support for the truth of the Bible.

The Interpretations of Quantum Physics

The interpretations that follow areeforts to explain what is really going on behind Quantum Mechanics. Each often has unique basic concepts and they are not necessarily mutually exclusive since there is some overlap of concepts.

The thought experiment called Schrödinger's cat involved placing a cat in a sealed box with a vile of poison that would kill the cat if broken, a radioactive material and a gaiter counter set to drop a hammer on the vile of poison if it detects a radiometric decay event. When the cat is later observed it is found to be ether alive or dead and each these interpretation has a different description of the state of the cat before it is observed.

According to the Copenhagen interpretation a quantum particle doesn't exist in any one state but exists in all of it’s possible states at once. Once observed a quantum particle is essentially forced into one of the possible states and that is the state that is actually observed. Since it may be forced into a different state each time is why quantum particles behave erratically. The state of a particle being in all possible states at once is called an object's coherent superposition. When an object is observe the superposition collapses the object is forced into one of the states of its wave function. Schrödinger's cat would be both dead and alive at the same time until actually observed. Ultimately the only thing that really matters are the experimental results it does not really seek to explain what it happening behind the experimental results. Currently it is the most popular interpretation, but it is losing ground.

The consistent histories interpretation works backwards from the result of an experiment and says that only a few possible histories are consistent with quantum mechanics and that Quantum mechanics simply predicts the probabilities of various alternative histories Schrödinger's cat is either alive or dead but not both Quantum mechanics just gives the probability of which it may be. This idea is not very popular because it still doesn't explain how a particle can go through two slits and interfere with itself and it is considered by some to be pretty much the same as Copenhagen.

The Transactional interpretation sees quantum mechanical waves as stand waves in space time that constructively interfere were the particle is and destructively interfere every place else. These waves go both forward and backward in time. There is an "exact canceling" of waves so that is no "net" energy travels backwards in time. In the case of Schrödinger's cat tt is alive until the interference patterns line up in the sample to result in a decay event.

The Bohm interpretation or pilot-wave theory; depicts the quantum wave as guiding the particle. It is totally deterministic and good at explaining quantum phenomenon but requires a large number of hidden variables that can not be directly measured. The hidden variables have the side affect of rendering the interpretation untestable. Schrödinger's cat is alive until one the pilot-waves in the sample to causes a decay event.

The many-worlds interpretation sees the world as constantly splitting off into multiple universes in which every possible quantum event occurs. This fits perfectly with Evolution even the most improbable events occurred in some of these universes. Schrödinger's cat the universe keeps spitting off into each alternative in one the cat lives and in the other dies. They both happen in different quantum universes. There is no evidence for this interpretation since the alterative worlds would be forever out of reach. While quantum interference between adjacent worlds has been suggested, the possible evidence for it. Successful interpretation of single particle interference is not unique to the Many-worlds interpretation. So acceptance of this interpretation is purely philosophical and not scientific since it can not be tested.

With consciousness causes collapse consciousness causes collapses the quantum mechanical waves. It is usually associated with observation. There is some supporting evidence for this though the evidence is not exclusive to this interpretation. It is compatible with General Intelligent Design as well. This supporting evidence comes from the human brain. It turns out that synaptic activity in the brain requires quantum tunneling on demand. This shows some degree of control by the mind of quantum wave functions. Thus view fits well with both New Age / Hinduism, and the Christian world view. With New Age / Hinduism it provides a way for the mind to interact with the world beyond the five senses. With the Christian world view, since God is the ultimate mind it provides a model for his interaction with our world. Schrödinger's cat It would be both alive and dead until observed then the mind of the observer would collapse the wave function choosing one or the other. It is similar to the Copenhagen interpretation in this regard.

General Intelligent Design also known views quantum mechanical waves and their collapse results from intelligent agents that determine the states resulting from the waves' collapse. These intelligent agents could be one or more intelligent beings or mechanisms preprogrammed by an intelligent being. This is supported by evidence of synaptic activity in the brain requiring quantum tunneling on demand showing some degree of intelligent control of quantum wave functions. This interpretation fits well with the Christian world view. The idea of an intelligence controlling the universe at its fundamental level fits well with God as described in the Bible. In the case of Schrödinger's cat, the cat is a live until the controlling intelligent agent decides to cause a decay event to takes place and then the cat dies.

The relationship between the mind and Quantum Mechanics is mentioned here because it provides evidence in support for the last two interpretations consciousness causes collapse and General Intelligent Design. It turns out that the synaptic barriers of dendrite brain cells are too thick for nerve signals to classically cross. This means that nerve signals need to use Quantum tunneling to cross the dendrite synaptic barrier. The odds of the nerve signal tunneling across the dendrite synaptic barrier are 1 chance in 10,000,000, Yet for our brains to function these tunneling events need to occur on demand this is evidence for the mind being able to control quantum phenomenon and against the naturalistic model of the mind as well.

In conclusion there are many ways of interpreting Quantum Mechanics. Acceptance or rejection of each often has more to do with philosophy than science. each fits better with some philosophical views than others and each interpretation differs in how it sees the fundamental nature of reality.

The Quantization in Quantum Mechanics

Quantization is the situation where physical quantities like position, energy and momentum can have only certain discrete values. In free empty space a particle’s position, energy and momentum are continuous. If the particle is bound to a particular area of space can these properties can only have certain discrete values. The energy contained in a given frequency of electromagnetic waves is quantized in that it always has the same value at the same frequency. The electromagnetic energy is found in discrete packet called photons.

The quantization of the energy of an electron inside an atom explains much of the behavior of atoms such as why atoms emit only discrete frequencies of light. An electron that is in a low orbit of an atom can absorb a photon causing the electron  to jump to a higher orbit. The electron then emits a photon jumping back to the lower orbit.

The quantization of space-time is based on several natural units proposed by Max Planck that are based on five universal physical constants: Gravitational constant, Reduced Planck constant, Speed of light in a vacuum, Coulomb constant, and Boltzmann's constant

While most of them have no physical significance two of them Planck Length and Planck Time are the smallest possible measurements of space-time according our current understanding of the laws of Physics because of the  uncertainty principle when a plied to these scales. This suggests that time and space themselves are Quantized.

Planck Length is the smallest measurement of length that has any meaning with in the laws of physics as we understand them today and Planck Length is about 1.616 252 × 10⁻³⁵ m.

Planck Time is the amount of time it takes a photon to cross a Planck Length. It is the smallest measurement of time that has any meaning with in the laws of physics as we understand them today and Planck Time is about 5.391 24 × 10⁻⁴⁴ s,

Quantization requires physical quantities like position, energy and momentum to have discrete values explaining much of what goes on in side atom and based on our current understanding of the laws of physics it suggest that time and space are quantized.

Quantum Physics and Quantum Nonlocality

Quantum Nonlocality: The phenomenon by which measurements made at a subatomic level necessarily refutes the notions of local realism.The basic principle is that particles of matter are not restricted to local interactions. They can have interactions outside their local system with no limit on distance.

A cording to Bell's Theorem developed by John Stewart Bell shows that no physical theory of local hidden variables can ever reproduce all of the predictions of Quantum Mechanics. This does leave open the possibility of non-local hidden variables.

The implications are that subatomic particles clearly exhibit non-local behavior showing that our notions of location do not apply at the fundamental levels of reality. Quantum Nonlocality creates a link between the physical and metaphysical.

Quantum Mechanics and Quantum Entanglement

Quantum Entanglement: A phenomenon in which the quantum states of two or more objects have to be described with reference to each other, even though the individual objects may be separated in space. This results in a correlation between the observable physical properties of the systems such that a change in one object causes an instantaneous change in the other.

Special Relativity is generally thought to prevent classical information from being sent faster than light by this means. One reason is that the two particles need to be near each other to become entangled, or they need an intermediate particle, which has to be near one particle and then the other. However this would not prevent sending information faster than light in cases where the sender and receiver were originally near each other and then separated such as s apace ship that leaves Earth and uses such a means for communications.

Quantum entanglement is a quantum effect that has no parallel in Classical mechanics.

Quantum Tunneling of Quantum Mechanics

Quantum tunneling: The process by which a particle gets across a barrier that it can not classically pass.

Quantum Tunneling is related to Wave-particle duality in that it is a result of the wave nature of a particle. The probability of the particle getting through the barrier drops exponentially with the thickness of the barrier.

When the wave comes in contact with the barrier most of it bounces off the carrier but some passes through the barrier; however it decays exponentially with the thickness of the barrier.  Such that the amplitude of the initial wave increases then the amplitude of the wave on the opposite side of the barrier increases. If the barrier thickness increases, the amplitude of the wave on the opposite side of the barrier decreases. If the energy of the initial wave increases, (wavelength decreases) the amplitude of the wave on the opposite side of the barrier increases. If the waves energy greater than that of the barrier tts all passes through the barrier. With a longer wavelength For particles most of them bounce off while a few instantly get through.

In theory Quantum tunneling is valid at the macroscopic but the odds of it occurring are extremely small. There is a non zero probability that you could run you cart into a brick wall an suddenly find yourself safely on the other side. However please don’t try it because the odds of it happening is so small as to be impossible by any reasonable definition.

Tunneling gets subatomic particles across barriers they normally can not cross. The number of particles that gets across the barrier drops exponentially with the barrier thickness. The number of particles that gets across the barrier increases with the energy of the particle. Quantum tunneling is a purely quantum effect. It has no counter part in Classical mechanics. It could theoretically occur on the macroscopic scale but the odds are too small to ever see it happen.

This is an article on the quantum effect known as Superconduction

Superconduction: The property that occurs in certain materials below a characteristic temperature where they have an electrical resistance of exactly zero.

Superconduction was discovered in 1911 but was not understood for years do to the lack of a theory to understand it. When a critical temperature is reached for a particular substance the electrical resistance will suddenly drops to zero.  The basic theory is that at the critical temperature electrons become coupled over a ranger of about 1,000 X the spacing of the conductor’s lattice with a binding energy that is the result of vibration that the electrons cause in the lattice. Called cooper pairs, the coupled electrons effectively becomes a boson and condense into the ground state. The result is that each coupled electron helps the other over come any resistance encountered from the lattice.

The Meissner Effect is where a magnetic field is expelled from a superconductor during the transition to the superconducting state that is caused by electric currents generated near its surface by the applied field. The magnetic field of these currents cancels out the applied magnetic field within the superconductor. This causes the magnetic levitation associated with superconductors.

Superconductivity is a purely quantum effect that has no counter part in classical physics. It’s most commonly known effect is magnetic levitation. It is one of two purely quantum effects that are seen on a macroscopic scale.

Atoms, Their Every Place

Atom: The basic unit of matter that consists of a dense, central positively charged nucleus surrounded by a cloud of negatively charged electrons.

The Rutherford Gold Foil Experiment was suggested by Ernest Rutherford and conducted in 1911 by Hans Geiger and Ernest Marsden. It Involved shooting alpha particles (He nuclei) at a gold foil to observe how they are scattered by the gold on a screen. It probed the structure of the Atom.  

If it were a solid mass few if any alpha particles would get through. If negative electron were embedded in a thin positive mass all of the alpha particles would get through. However most of the alpha particles get through with some being scattered by the small positive nucleus.

Rutherford Conclusion was that the atom is mostly empty space with a small positive nucleus surrounded by electrons scattered through out the surrounding space. In such a model the electron can not stand still since if they did they fall into the nucleus

This problem led to modeling the atom as a solar system called the planetary model with electrons orbiting the nucleus like planets around a star. The problem with the planetary model is that electrons are charged particles and an accelerating charge emits light loosing energy and this would cause the electron to spiral into the nucleus.

The Bohr Atomic Model

Broglie had shown earlier that particles have wave like propertied. Bohr then used this by showed that these waves could be bent into orbits like those expected for an electron with the result that electrons can only occupy those orbits with exactly a whole number of wavelengths. In these orbits the waves are add together with constructive interference. If an orbit has a fractional number of wavelengths the wave would destructively interfere and not persist so an electron can not occupy such an obit. The result is that that electrons jump from orbit to orbit emitting photons when going to a lower orbit and absorbing photons are when going to a higher orbit. It turns out that transitions between the possible electron orbits, matches the spectral lines that are actually observed in hydrogen. This was a major step in development quantum Mechanics.

Further Development

Studying elements other hydrogen included the effects of multiple electrons resulted in the electron orbital five of which are shown above. They are places in an atom where electrons can actually be found. The shapes of these orbitals were originally found mathematically and they have long been viewed as purely mathematical abstractions that were never expected to be seen. Physics students have long been told this however field-emission electron microscopy has changed this.

In conclusion the imaging of actual electron orbitals was a surprise but it vividly shows the accuracy of Quantum Mechanics.

The Quantum Effect know as Superfluids

Superfluid: A liquid that has no viscosity and infinite thermal conductivity.

Superfluids appears as normal liquids but flow without friction past any surface allowing it to continue to circulate over obstructions and through pores in its container do only to its own inertia.

All of the atoms in a superfluid exist in the same quantum state so they all have the same momentum such that if one moves they all move. This allows superfluids to move without friction even through the tiniest of cracks. Superfluid helium will flow up the sides of a jar and over the top.

Superfluity is a purely quantum effect that has no counter part in classical physics. It is one of two purely quantum effects that are seen on a macroscopic scale.

The Principle of Quantum Mechanics called the Heisenberg Uncertainty Principle

The Uncertainty Principle: The principle of Quantum Mechanics that there is a limit on the accuracy of simultaneous measurement of physical quantities like a particle's position and momentum.

The Uncertainty Principle was published by Werner Heisenberg in 1927  it is based on the fact that the light needed to observe a subatomic particle will disturb it making measurements uncertain though it goes way beyond that.

Planck's constant is so small for the uncertainty principle does not show up in the macroscopic world even though it is significant in the subatomic world nut it results in the fact that the more accurately one measures a particle's position the less accurately one can measure its momentum and one measures a particle's momentum the less accurately one can measure its position. This does not happen just because the act of measurement disturbs the system; which it only does sometimes; it is actually related to Wave-particle duality. The same principle applies to other quantities like energy and time.

More recent developments involving the debate between determinism and freewill. The idea is that the uncertainty principle is a possible avenue for allowing for freewill in neurology. The evidence involves quantum, mechanical processes like tunneling being involved in synapse activity.

The Uncertainty Principle shows us that we are limited in our ability to make measurements of the subatomic world. It shows that there are limits to our possible knowledge about the universe.

The Quantum Mechanics Principle Heisenberg Uncertainty Principle

The Uncertainty Principle: The principle of Quantum Mechanics that there is a limit on the accuracy of simultaneous measurement of physical quantities like a particle's position and momentum.

The Uncertainty Principle which was published by Werner Heisenberg in 1927 was based on the fact that the light needed to observe a subatomic particle will disturb it making measurements uncertain though it goes beyond that.

Planck's constant is too small for the uncertainty principle to show up in the macroscopic world but it is significant in the subatomic world nut it results in the fact that the more accurately one measures a particle's position the less accurately one can measure its momentum and one measures a particle's momentum the less accurately one can measure its position. This does not happen just because the act of measurement disturbs the system; which it only does sometimes; it is actually related to Wave-particle duality. The same principle applies to other quantities like energy and time.

There has been a more recent development involving the debate between determinism and freewill. The idea is that the uncertainty principle is a possible avenue for allowing for freewill in neurology. The evidence involves quantum, mechanical processes like tunneling being involved in synapse activity.

The Uncertainty Principle shows us that we are limited in our ability to make measurements of the subatomic world. It shows that there are limits to our possible knowledge about the universe.

The Principle of Wave-particle duality from Quantum Mechanics

Wave-Particle Duality is the fact that light and matter exhibit the properties of both waves and particles. This is a key concept of quantum mechanics.

Subatomic particles have a dual nature that is some times they act like particles, exhibiting properties like scattering and at other times they behave as waves, exhibiting properties like interference and diffraction.

The photoelectric effect is the situation where photons of light eject electrons from a sheet of metal like interacting partials are supposed to behave. The Davission-Germer experiment is an experiment in which an electron beam is aimed a nickel crystal in whith the resulting scattering has peeks and valise do to diffraction.

The wave length of a particle's wave is l = h / p.  Where l is the wave length, p is momentum and  h is Planck's constant  Now this relationship is just the first part of wave particle duality. The actual wave function is denoted by Y (Psi).  While the exact formula varies with the situation, the wave function is always a complex number. It is related to the probability of finding the particle at a given point in pace.

The probability of finding a partial at a given point in space is denoted by |Y(x)|² also denoted by Y* Y  where the complex number is  Y = A + iB and the complex conjugate: Y* = A – iB The over all space the probability density = 1.

In conclusion matter behaves as both particles and waves. The wave nature is related to the probability of finding a particle at a given location at a given time.

Space is Not Nothing

Space is the three dimensional extent in which objects and events occur, with a relative position to other objects and events. In a more general sense space can refer to an nth dimensional hyper-volume. 

Space is often illustrated by 3 lines representing the three spacial dimensions. They are the axis of a 3d graph. In 3d space you can move in 3 directions forwards and backwards; up and down and left to right. General Relativity depicts space and time as a fabric that can be warped, bent, twisted, stretched and contracted. Quantum Mechanics describes subatomic particles coming and going even in a vacuum. Space is not empty, it is not nothing. Yes I know this is a double negative however empty space is normally thought of as nothing but it is something.

Basic SI unit – meter (m) which is the distance traveled by light in a vacuum in 1/299,792,458 of a second.

The most common methods of measuring space are rulers but odometers are another common way of measuring distance and there by space. Other methods include bouncing light, radio waves, or sound off of an object using the return time to measure distance. These include radar and sonar. Parallax uses geometry to measure distance it is used in Astronomy and land surveying.

Distance and position must be measured according to some standard. The standard has to be a chosen point in space. The point is selected by ether convenience or convention with out such a starting point determining distance and position is impossible..

Space is one of the three main parts of the Universe space, time and mass. Relativity shows them to be inter-related with space and time are so interrelated that they form a single entity.  Intern mass warps space-time forming gravity and motion of mass contracts both space and time.

In conclusion based on common experience space is basically where you are. You are at a particular point in space relative to other objects. Physics however has shown it to be a lot more. It is a fundamental part of the universe.