Speed of light
the speed of light in a vaccuum is an accurate result in seconds: 299 792 458 m/s. But who discovered the speed of light, and how did they do it?
Galileo Galilei was the first person to attempt to measure the speed of light, in the early 1600s. Galileo and an assistant each stood on a different hilltop with a known distance between them, the plan was for Galileo to open the shutter of a lamp and then for his assistant to open the shutter of a lamp as soon as he saw the light from Galileo's.
Using the distance between the hilltops and his pulse as a timer, Galileo planned to measure the speed of light. He and his assistant tried this with different distances between them, but no matter how far apart they were, he could measure no difference in the amount of time it took the light to travel.
Galileo concluded that the speed of light was too fast to be measured by this method, and he was correct. We now know the speed of light very precisely, and if Galileo and his assistant were on hilltops one mile apart, light would take 0.0000054 seconds to travel from one person to the other. It is understandable that Galileo was unable to measure this with his pulse!
In 1676 a Danish astronomer named Ole Rømer was studying the orbits of the moons of Jupiter and making tables to predict when eclipses of the moons would occur. He noticed that when Jupiter and Earth are far apart (near conjunction), the eclipses of the moons occurred several minutes later than when Jupiter and the Earth are closer (near opposition.) He reasoned that this could be because of the time light takes to travel from Jupiter to Earth.
Rømer found the maximum variation in timing of these eclipses to be 16.6 minutes. He interpreted this to be the amount of time it takes light to travel across the diameter of Earth's orbit. He didn't actually calculate the speed of light as the diameter of Earth's orbit was not well known in his day. But using his method with the knowledge of distances we have today, we get a value of approximately 301,204.8 km/s for the speed of light. This is only about 0.5% off the modern known value of the speed of light.
In the 1850s, French physicist Jean Foucault measured the speed of light in a laboratory using a light source, a rapidly rotating mirror and a stationary mirror. This method was based on a similar apparatus built by Armand-Hippolyte Fizeau. For the first time the speed of light could be measured on Earth, and the speed of light was measured to very great accuracy.
In the 1970s, interferometry was used to get the most accurate value for the speed of light that had been measured yet: 299,792.4562±0.0011 km/s. Then, in 1983, the meter was redefined in the International System of Units (SI) as the distance traveled by light in vacuum in 1/299,792,458 of a second. As a result, the numerical value of the speed of light (c) in meters per second is now fixed exactly by the definition of the meter. It is always slower in other materials such as water or glass. For most calculations the value 3.00 x 10^5 km/s is used.
#speedoflight
@sciencehub4
the speed of light in a vaccuum is an accurate result in seconds: 299 792 458 m/s. But who discovered the speed of light, and how did they do it?
Galileo Galilei was the first person to attempt to measure the speed of light, in the early 1600s. Galileo and an assistant each stood on a different hilltop with a known distance between them, the plan was for Galileo to open the shutter of a lamp and then for his assistant to open the shutter of a lamp as soon as he saw the light from Galileo's.
Using the distance between the hilltops and his pulse as a timer, Galileo planned to measure the speed of light. He and his assistant tried this with different distances between them, but no matter how far apart they were, he could measure no difference in the amount of time it took the light to travel.
Galileo concluded that the speed of light was too fast to be measured by this method, and he was correct. We now know the speed of light very precisely, and if Galileo and his assistant were on hilltops one mile apart, light would take 0.0000054 seconds to travel from one person to the other. It is understandable that Galileo was unable to measure this with his pulse!
In 1676 a Danish astronomer named Ole Rømer was studying the orbits of the moons of Jupiter and making tables to predict when eclipses of the moons would occur. He noticed that when Jupiter and Earth are far apart (near conjunction), the eclipses of the moons occurred several minutes later than when Jupiter and the Earth are closer (near opposition.) He reasoned that this could be because of the time light takes to travel from Jupiter to Earth.
Rømer found the maximum variation in timing of these eclipses to be 16.6 minutes. He interpreted this to be the amount of time it takes light to travel across the diameter of Earth's orbit. He didn't actually calculate the speed of light as the diameter of Earth's orbit was not well known in his day. But using his method with the knowledge of distances we have today, we get a value of approximately 301,204.8 km/s for the speed of light. This is only about 0.5% off the modern known value of the speed of light.
In the 1850s, French physicist Jean Foucault measured the speed of light in a laboratory using a light source, a rapidly rotating mirror and a stationary mirror. This method was based on a similar apparatus built by Armand-Hippolyte Fizeau. For the first time the speed of light could be measured on Earth, and the speed of light was measured to very great accuracy.
In the 1970s, interferometry was used to get the most accurate value for the speed of light that had been measured yet: 299,792.4562±0.0011 km/s. Then, in 1983, the meter was redefined in the International System of Units (SI) as the distance traveled by light in vacuum in 1/299,792,458 of a second. As a result, the numerical value of the speed of light (c) in meters per second is now fixed exactly by the definition of the meter. It is always slower in other materials such as water or glass. For most calculations the value 3.00 x 10^5 km/s is used.
#speedoflight
@sciencehub4
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Proofs for existence of God by priests and their counter response from Scientists
1. Cosmological proof. Things move because they are pushed—that is, something sets them into motion. But what is the First Mover or First Cause that set the universe into motion? This
must be God.
2. Teleological proof. Everywhere around us we see objects of
great complexity and sophistication. But every design
eventually requires a designer. The First Designer was God.
3. Ontological proof. God, by definition, is the most perfect being
imaginable. But one can imagine a God that does not exist. But
if God did not exist, he would not be perfect. Therefore he must
exist.
The three of the above proofs showed a flawless in their content in the later scientific experimentation and reasoning .
The cosmological proof decline because when we have a clear shot of gaseous substances they collide with walls in the absence of any external force application.They continue collision through their life time.Conversation law of mass and energy is enough and persuasive reason behind the unimportance of first mover.
The teleological proof have a counter response from the evolution of complexity from simpler life forms through a natural selection and chance ; theory of evolution ......the survival of the fittest.
The ontological argument will collapse up on the amazing reasoning of difference between existence and perfection by Immanuel Kant .
What's your point of view about these ideas .....add your comment on the comment section below
@sciencehub4
1. Cosmological proof. Things move because they are pushed—that is, something sets them into motion. But what is the First Mover or First Cause that set the universe into motion? This
must be God.
2. Teleological proof. Everywhere around us we see objects of
great complexity and sophistication. But every design
eventually requires a designer. The First Designer was God.
3. Ontological proof. God, by definition, is the most perfect being
imaginable. But one can imagine a God that does not exist. But
if God did not exist, he would not be perfect. Therefore he must
exist.
The three of the above proofs showed a flawless in their content in the later scientific experimentation and reasoning .
The cosmological proof decline because when we have a clear shot of gaseous substances they collide with walls in the absence of any external force application.They continue collision through their life time.Conversation law of mass and energy is enough and persuasive reason behind the unimportance of first mover.
The teleological proof have a counter response from the evolution of complexity from simpler life forms through a natural selection and chance ; theory of evolution ......the survival of the fittest.
The ontological argument will collapse up on the amazing reasoning of difference between existence and perfection by Immanuel Kant .
What's your point of view about these ideas .....add your comment on the comment section below
@sciencehub4
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Photoelectric effect
✨photoelectric effect, phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation. The effect is often defined as the ejection of electrons from a metal plate when light falls on it.
✨ In a broader definition, the radiant energy may be infrared, visible, or ultraviolet light, X-rays, or gamma rays; the material may be a solid, liquid, or gas; and the released particles may be ions (electrically charged atoms or molecules) as well as electrons.
✨The phenomenon was fundamentally significant in the development of modern physics because of the puzzling questions it raised about the nature of light—particle versus wavelike behaviour—that were finally resolved by Albert Einstein in 1905.
✨The effect remains important for research in areas from materials science to astrophysics, as well as forming the basis for a variety of useful devices
@sciencehub4
#photoelectric_effect
✨photoelectric effect, phenomenon in which electrically charged particles are released from or within a material when it absorbs electromagnetic radiation. The effect is often defined as the ejection of electrons from a metal plate when light falls on it.
✨ In a broader definition, the radiant energy may be infrared, visible, or ultraviolet light, X-rays, or gamma rays; the material may be a solid, liquid, or gas; and the released particles may be ions (electrically charged atoms or molecules) as well as electrons.
✨The phenomenon was fundamentally significant in the development of modern physics because of the puzzling questions it raised about the nature of light—particle versus wavelike behaviour—that were finally resolved by Albert Einstein in 1905.
✨The effect remains important for research in areas from materials science to astrophysics, as well as forming the basis for a variety of useful devices
@sciencehub4
#photoelectric_effect
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Scientist who discovered the equation for wave particle nature by combining Einstein's E=mc² and Plank's formula E=hf is ?
Anonymous Quiz
7%
Hoyle
54%
De Broglie
10%
Pauli
30%
Heisenberg
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For any suggestions and promotion contact @Jpassion4me and @code_astrophy
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Find out ur favorite movies in any of genere from this bot @MovieDiskBot
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Jr's ThoughtLab✨
Find out ur favorite movies in any of genere from this bot @MovieDiskBot
For those really interested in this bot please don't forget to do us a favor share this channel for ur colleagues and let's us Advance together😊
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Nuclear fusion
Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles (neutrons or protons).
The difference in mass between the reactants and products is manifested as either the release or the absorption of energy. This difference in mass arises due to the difference in nuclear binding energy between the nuclei before and after the reaction.
Nuclear fusion is the process that powers active or main sequence stars and other high-magnitude stars, where large amounts of energy are released.
@sciencehub4
#nuclear_fusion
Nuclear fusion is a reaction in which two or more atomic nuclei are combined to form one or more different atomic nuclei and subatomic particles (neutrons or protons).
The difference in mass between the reactants and products is manifested as either the release or the absorption of energy. This difference in mass arises due to the difference in nuclear binding energy between the nuclei before and after the reaction.
Nuclear fusion is the process that powers active or main sequence stars and other high-magnitude stars, where large amounts of energy are released.
@sciencehub4
#nuclear_fusion
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Hello everyone ,this channel haven't been posting actively for alot of months ,and as we all know the channel members are declining from time to time ,
but starting from now on we will inform you that we have officially started posting actively .
but starting from now on we will inform you that we have officially started posting actively .
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The Large Hadron Collider (LHC) is the world's largest and highest-energy particle collider. It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and hundreds of universities and laboratories, as well as more than 100 countries.
It lies in a tunnel 27 kilometres (17 miles) in circumference and as deep as 175 metres (574 ft) beneath the France–Switzerland border near Geneva.
@sciencehub4
It lies in a tunnel 27 kilometres (17 miles) in circumference and as deep as 175 metres (574 ft) beneath the France–Switzerland border near Geneva.
@sciencehub4
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Carbon Dating
Carbon-14 (14C) is a naturally occurring radioisotope that is created in the atmosphere by cosmic rays. This
is a continuous process, so more 14C is always being created. As a living organism develops, the relative level of 14C in its body is equal to the concentration of 14C in the atmosphere. When an organism dies, it is no longer ingesting 14C, so the ratio will decline. 14C decays to 14N by a process called beta decay; it gives off energy in this slow process.
After approximately 5,730 years, only one-half of the starting concentration of 14C will have been converted
to 14N. The time it takes for half of the original concentration of an isotope to decay to its more stable form
is called its half-life. Because the half-life of 14C is long, it is used to age formerly living objects, such as fossils. Using the ratio of the 14C concentration found in an object to the amount of 14C detected in the atmosphere, the amount of the isotope that has not yet decayed can be determined.
@sciencehub4
Carbon-14 (14C) is a naturally occurring radioisotope that is created in the atmosphere by cosmic rays. This
is a continuous process, so more 14C is always being created. As a living organism develops, the relative level of 14C in its body is equal to the concentration of 14C in the atmosphere. When an organism dies, it is no longer ingesting 14C, so the ratio will decline. 14C decays to 14N by a process called beta decay; it gives off energy in this slow process.
After approximately 5,730 years, only one-half of the starting concentration of 14C will have been converted
to 14N. The time it takes for half of the original concentration of an isotope to decay to its more stable form
is called its half-life. Because the half-life of 14C is long, it is used to age formerly living objects, such as fossils. Using the ratio of the 14C concentration found in an object to the amount of 14C detected in the atmosphere, the amount of the isotope that has not yet decayed can be determined.
@sciencehub4
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Are we living in flat or round shaped earth ?
As we all have a different mindsets , similarity we believe on different inferences to arrive us at a conclusion that we assume to be true ,possibly in our perspectives .But this would rather leads to different conclusions for specific things , disagreement would follow at last. It's obviously known that we won't go to something better with out agreement.So everyone should have facts that's acceptable every where unlike of myth.
As far as we concerned there's still myth acceptable , specially by uneducated society , although science is what matters and which provides plausible knowledge about our universe.
Are we living in a flat earth or spherical shaped earth ?
Aristotle , a Greek philosopher concerned with these two good arguments for believing that the Earth was a round ball rather than a flat plate. First, he realized that eclipses of the moon were caused by the Earth coming between the sun and the moon. The Earth’s shadow on the moon was always round, which would be true only if the Earth was spherical. If the Earth had been a flat disk, the shadow would have been elongated and elliptical, unless the eclipse always occurred at a time when the sun was directly above the center of the disk.
Second ,Greeks knew from their travels that the Pole Star appeared lower in the sky when viewed in the south than it did in more northerly regions. From the difference in the apparent position of the Pole Star in Egypt and Greece, Aristotle even quoted an estimate that the distance around the Earth was four hundred thousand stadia. It is not known exactly what length a stadium was, but it may have been about two hundred yards. This would make
Aristotle’s estimate about twice the currently accepted figure.
They also have third reason not to believe earth as flat plate. "For why
else does one first see the sails of a ship coming over the horizon and only later
see the hull?"
@sciencehub4
As we all have a different mindsets , similarity we believe on different inferences to arrive us at a conclusion that we assume to be true ,possibly in our perspectives .But this would rather leads to different conclusions for specific things , disagreement would follow at last. It's obviously known that we won't go to something better with out agreement.So everyone should have facts that's acceptable every where unlike of myth.
As far as we concerned there's still myth acceptable , specially by uneducated society , although science is what matters and which provides plausible knowledge about our universe.
Are we living in a flat earth or spherical shaped earth ?
Aristotle , a Greek philosopher concerned with these two good arguments for believing that the Earth was a round ball rather than a flat plate. First, he realized that eclipses of the moon were caused by the Earth coming between the sun and the moon. The Earth’s shadow on the moon was always round, which would be true only if the Earth was spherical. If the Earth had been a flat disk, the shadow would have been elongated and elliptical, unless the eclipse always occurred at a time when the sun was directly above the center of the disk.
Second ,Greeks knew from their travels that the Pole Star appeared lower in the sky when viewed in the south than it did in more northerly regions. From the difference in the apparent position of the Pole Star in Egypt and Greece, Aristotle even quoted an estimate that the distance around the Earth was four hundred thousand stadia. It is not known exactly what length a stadium was, but it may have been about two hundred yards. This would make
Aristotle’s estimate about twice the currently accepted figure.
They also have third reason not to believe earth as flat plate. "For why
else does one first see the sails of a ship coming over the horizon and only later
see the hull?"
@sciencehub4
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Who introduced telescope for the first time?
Anonymous Quiz
57%
Galileo Galilei
24%
Hans lippershey
16%
Johannes Kepler
2%
Nicholas Copernicus