Earth Definition and 1000 Threads

Hi, I have been doing my own personal fusion research for almost a year now and I recently began looking into the various fusion fuel cycles other than D-T and D-D. The cycle that I'm interested in is P-P fusion, I'm aware that this method is inefficient for energy production, however, it seems...

Full disclosure, I am a creationist, but i want to know the finer points about the big bang and the creation of the universe. So we know that the formation of new rock from lava doesn't make them "day zero" rocks, ie they still would be considered aged when we do radiometric dating. So we know...

Greetings, I wonder if someone could please kindly give a physics explanation for the phenomenon of circular star trails when Earth is moving 67 times faster laterally than it is rotating? Thanks very much in advance...

What would happen if the entire Earth was somehow exposed to a massive magnetic field, such as those found near magnetars, like 10^10 teslas, for about 1 second? Would everyone instantly die? What would be the impact of a moving magnetic field vs a stationary magnetic field be? How much time...

Consider an artificial satellite orbiting the Earth and suppose that the atmosphere co-rotates with the Earth. I need to calculate x, y and z components of the atmospheric drag. I know how to calculate the drag in a non-spinning atmosphere and I have all the data to do that, but the Earth’s...

I just recently read about how we got to know the true age of the Earth but I am a bit confused and curious about one thing. The mineral or rock is initially going to be a uranium right? If it is, isn't all of it going to decay at the same rate? I know that a radioactive reaction is spontaneous...

Even if the outer core is convecting and conductive it is still charge neutral, so how can a Magnetic field be generated? Maxwells Equation say there needs to be net charge moving for a Magnetic field to be generated.

Im quite fascinated over how Earth is constantly trying to stabilise itself. What is your most interesting observation or 'happening' about climate change?

I've been messing around with some circle theorems and found that you couldn't possibly take a picture of a full Earth from a single shot. Is this impossible? Is their some math to prove otherwise, I'm really stuck.

Yes I know. Sounds silly. I'm not a physicist, but it occurred to me to wonder: is it possible Earth is a black hole with data encoded in two dimensions on its surface? What would the proofs look like? Discuss.

Homework Statement Calculate the potential energy and kinetic energy of the moon, as well as it's escape velocity. Give the moon's period and angular speed. Consider the Earth to have a mass of 6 x 10^24 kg, the moon to have a mass of 7 x 10^22 kg, and their center separation distance to be 4 x...

Earth may have been born in a huge flare-up of the young sun by Ken Croswell It’s not easy to make Earth. Most of the explanations for how our planet formed have troubling problems. But if a new idea is right, we can thank a hyperactive young sun for Earth’s existence, plus solve a...

Homework Statement Calculate the temperature of the Earth assuming that the Sun and the Earth are black bodies. Assume that Earth is in a steady state as far as energy balance is concerned Homework Equations ##\frac{E}{St} = \sigma T^4## - Stefan-Boltzman law The Attempt at a Solution The...

1. The problem statement, all variables and given/known There is an Earth but the hole is not in the middle but the side.find the period of oscillation Homework Equations Simple harmonic equation.Newton gravitational force The Attempt at a Solution I got GMx/R^3+acc=0 so period of...

I am doing research for my aerospace engineering dissertation to plan a mission to a Jupiter trojan asteroid. I was researching the type of outgoing trajectories used in missions such as JUNO, Galileo and Europa and noticed they all use Earth as a gravity assist in getting to deep space. Surely...

Time to think about what you can personally do to be a good steward of our home Earth. What activities are you doing today? I was hoping I could attend a sister science march in my city, but alas I have a wedding to attend. Instead this morning I will pick up trash I find in my community during...

We know (measured) that a clock on a mountain "ticks" faster than a clock at sea level. At higher altitude, the clock runs even faster. Now, if we go much higher, towards the Sun, on the line between the center of the Earth and the center of the Sun, the clock should begin, at some point, to...

...they land on April 1st. Merry confusion ensues.

Hi. I fear I might not have understood some fundamental concepts about electric power transmission. So we have "neutral" which is brought to Earth potential. Does this mean the electrical circuit from the power plant over highly conductive aluminium cables to my home closes back to the power...

Kansas I have been told has the flattest and biggest flat spot on earth. Any actual data on the size/area and flatness. Is it an outlier in Earth curvature. Most google info was junk. Looking for science data if this is even true. Posted here cos I am not sure if science or junk science.

as i mentioned I am a huge noob in the reals of math and physics, but if anyone can explain things to me as a noob that would be awesome. magnetism had always fascinated me so i think that's where i want to dive into. i am curious about experiments or ideas on a model of the earth, and inert...

I am planning to plot all the observations made by a satellite in two respective grid boxes. One grid located at the equator and one grid located at the mid latitudes... Each grid box will be a 10° x 10° box. However, due to the shape of the Earth the area of each box will indeed not be the...

When I googled it, I wasn't satisfied with the answers from various sites...some sites like universetoday.com gave me a glimpse but it was totally theoretical and based on assumption. Also I would like to know why some planets have retrograde rotation; what might have caused them to and why do...

I'm an empirical sciences student who loves physics. While studying geology I learned that the core of the Earth is considered to be solid and the reason for that is because the pressure is too high. Although according to my calculations g( gravitational field) equals zero and when you go out...

From my understanding: The age of the universe is ~13.8 billion yrs. The age of Earth is ~4.5 billion yrs. The age of the Earth is based on radiometric dating. I understand that the Earth was probably formed by gas and dust clouds ~9.3 billion yrs after the universe was born, but if the gas...

Hello all. I am new here. I have an idea about defending the Earth from meteors using laser beams. I thought about using chemical lasers to burn the meteors. The first phase is that we use gas lasers if possible to create plasma by heating the gas and to use that plasma beam to strike at the...

Homework Statement If the Earth has a radius of 6 x 10^6 meters, how high above Earth's surface does a geosynchronous satellite have to be, if it has a mass of 100kg and gravity acts on the satellite with a force of 4.23 x 10^8 Newtons? What is its linear speed? (Assume the orbit is circular)...

Crash into the Sun, orbit the Sun, or fly off into space?

Homework Statement A particle of mass m is dropped into a hole drilled straight through the center of the Earth. neglecting rotational effects and friction, show that the particle’s motion is a simple harmonic if it is assumed that the Earth has a uniform mass density. Obtain an expression for...

I'm trying to figure out or find how fast Earth is moving due to the Hubble constant. I'm runnng into two answers and have difficulty understanding either one. --- One answer is a number of kilometers per second per megaparsec. But that's a distance per time unit per distance unit. I don't...

If gravity is as we know a weak force and magnetism is a strong force, would it be possible to use electromagnetism to propel an object fast enough away from the Earth's surface to escape the pull of gravity and at least put an object in orbit. I assume you would need a long horizontal then...

I propose a calculation of the drop X in the horizon that an observer sees due to the curvature of the Earth surface the parameters are: h: the elevation of the observer from the surface of the Earth in km H: the length of the horizon at which the drop is perceived in km R: the radius of the...

Homework Statement If the Earth, with a radius of 6400 km, were collapsed into a sphere of the same mass, having a radius of 10 km, what would be its rotational period? Homework Equations L = Iw The Attempt at a Solution I can solve this if the moment of inertia is given but since it isn't I...

Homework Statement The Earth is about 12.70 km in diameter. The Earth’s average density is about 5.5 grams cubic centimeter. A nucleon (the main constituent of an atomic nucleus) has a mass of about 1.67 x 10⁻²⁷ kilograms. If the Earth’s mass is entirely due to its nucleons, how many nucleons...

Since the planet is only 4.55 BY old, that might be considered a fast start. Some people have found some rocks (3.7 BYA) in Greenland with what they think are indications of life (short article, a bit longer article). The indicators are primarily microscopic hematite tubes (some say, similar...

If we took some of Earth's hardiest extremophile microorganisms and placed them on Mars, what one factor on Mars would be most difficult for them to cope with? too cold, low oxygen, low atmospheric pressure, radiation, lack of liquid water, toxic soil, lack of organic material, acidity Please...

In another forum, the question was raised, "could a ship with 1G acceleration escape the gravity well of a planet with 1G gravity?" A popular response is, if the craft is aerodynamic, it could accelerate laterally until it reached escape velocity and then manage to get to space. I don't...

I've been stuck on this physics problem for several years now. I would be very grateful if someone could explain how to solve this problem. The farthest a human could travel from Earth in one lifetime theoretically is limited only by the acceleration a human can withstand, and the length of...

Ok now I have a strange question. The Earth is spinning continuously at a considerable speed. So if the Earth stopped spinning everything would be thrown by its momentum. But what would happen if for a split second you were no longer caught up in the Earths momentum. For example you are...

The geography of Great Lakes Earth, and the questions that come with it. Pangaea From 250 to 200 million years ago, all the continents had joined together to form a singular landmass called Pangaea. The brown lines presented in the map are mountain ranges varying in height above sea level...

What force keeps our atmosphere spinning with the rotating earth? How can there ever be a calm day?

This maybe a basic question to the educated. I wondered if anyone can describe or show the path the Earth takes not only in relation to orbiting the moving sun but taking into consideration the movement of the milkyway as in rotation and expansion of the universe. Hmm thinking of it as i write...

Motion relative to the CMB rest frame creates a dipole moment in the wavelength of CMB photons in the direction of motion. Observations suggest that the Earth has a motion relative to CMB rest frame of 600 km/s. As indicated in this study, for a spacecraft at a speed we shall dub 'ludicrous...

< Mentor Note -- thread moved to HH from the technical physics forums, so the Homework Help Template is filled out farther down the thread >[/color] The number of rotations of Earth around its own axis in one year as measured by an observer from the sun.

This article has a different spin on how water came to Earth. https://www.newscientist.com/article/2118993-Earth's-water-must-have-arrived-here-earlier-than-we-thought/ The arrival of water on our planet wasn’t a last-minute job. Water came to Earth on icy comets after most of the planet and...

Hi there. I very much enjoy this forum and have been doing so for a while. I have a problem and I am not sure of the explanation I came with. Suppose there is a plane that is nosediving perpendicular to Earth. What will the "passengers" feel? In the first seconds the acceleration will be equal...

Sound pressure waves attenuate pretty quickly. On Earth we can not hear much of what is going on a few kms away, or above, or underground, unless it's some really catastrophic event of huge energy. But the Sun's energy output is hugely immense compared to even the most catastrophic event on...

Homework Statement My homework involves calculating the amount of energy the Earth receives from the Sun in a given year. I actually have the answer, but what I'm confused with is that the calculation says that the Sun "sees the cross section of the Earth, a circle". So in the calculation, we...

Assume that you are commissioned to select three solar system bodies (planets or moons) to deposit a colony of bacteria or microbes of your choice outside (i.e. either on the surface or underground, but not in any man-made enclosure). No resources from Earth (such as food, water, organic...

Ringling Bros. and Barnum & Bailey Circus to End Its 146-Year Run (NY Times) Ringling Bros. closing ‘Greatest Show on Earth’ after 146 years (NY Post) The last performance will be at the Nassau Coliseum on Long Island NY, on May 21. Many years ago (20 or so?) I saw their train passing through...