Spaceship Definition and 221 Threads

Suppose I'm an observer out in space and 30 km from me there's another observer, who is static with respect to me. Let's say my name is A and the other is B. We're both far far away from all the cosmical objects that might have a gravitational influence on us. We both notice a spaceship flying...

Yeah, pretty much what the title says. Who has cool ideas for the future of space travel?

When Bell says that the thread in put under "intolerable stress" and breaks, what happens then? Suppose that instead of the thread there is a light rod, which breaks at the point of attachment to the back spacecraft , so it is left sticking out backwards from the front spacecraft .. In the...

Homework Statement A spaceship of frontal area 25 m2 passes through a cloud of interstellar dust at a speed of 1.0x106 m/s. The density of dust is 2.0x10-18 kg/m3. If all the particles of dust that impact on the spaceship stick to it, find the average decelerating force that the impact of the...

Homework Statement A star is 95.0 year lights away from Earth. How much time does it take to a cosmic ship, which moves with speed 0.96 c, to reach the star, if it is measured from a watcher from a) Earth a)ship c)What si the distance of trip, based on the viewer from the ship? Homework...

A spaceship traveling at speed of light close to speed of light (wrt inertial reference frame) sending some data every second on their clock to people who are stationary (wrt inertial reference frame). At what time these people would receive this data on their own clock? Let's say for a second...

Homework Statement You are on Earth as a spaceship flies past at a speed of 0.99c relative to the earth. A high-intensity signal light on the ship blinks on and off, each pulse lasting 2.2 × 10^(−6) s, as measured on the spacecraft . Your laboratory on Earth has a length of 56.4m. How long...

Homework Statement A broken spaceship is located 10 km above the center of a large circular thin sheet of unknown dust. The sheet has a radius of 106km and a density of 7×1011kg/m2. The spaceship and the dust attract each other due to the gravitational force. a) Find the initial acceleration of...

Homework Statement The last of the human race are leaving the earth, after a total nuclear destruction, to reach the only known planet suitable for lives, 2 million light years away from earth. They are traveling on the spaceship ARK, capable of close to speed of light. There is only enough...

For how long will we still be able to communicate with the amazing Voyager 1?

Homework Statement The mass of a spaceship is 10012 kg. The spaceship is at rest. Then one part of the ship with a mass of 1000 kg is ejected and emerges with a speed of 112 m/s. What is the speed of the other part? Homework EquationsThe Attempt at a Solution I tried: pi=pf mivi=mfv2 10012...

Homework Statement A spaceship travels from Earth to the vicinity of the star that is measured by astronomers on Earth to be six light-years away. The spaceship and its occupants have a total rest mass of 32 000 kg. Assume that the spaceship travels at constant velocity. The time taken as...

So recently a friend and I were pondering how much energy would be required to get a 20,000kg spaceship to 99% the speed of light. This arose from us discussing the raw efficiency of antimatter and how much antimatter would be required to fuel a spaceship to 99% C or 296794533.42 m/s. At first...

A given planet has a mass, M = 6.42*10^23 kg, and radius, R = 3.39 * 10^6 m. The gravitational konstant is G = 6.67*10^-11 A spaceship with mass m = 4000 kg is launched from the planets surface. How much energy is needed to send the spaceship to a height h = 100 km above the planets surface?

Say my spacecraft is traveling c, and I'm walking .5 m/s towards the front of the spacecraft . Would that not mean I am traveling faster than light? I'm sure everyone has seen movie where a ship is traveling at the speed of light, while someone is moving about the cabin. I know only photons...

Hello all! I have longed envisaged a new type of space launching device, one that would be reusable and cheap to operate.My idea is to have a large set of concentric circular tubes laid horizontally in some desert or something. The spaceship would use magnetic levitation to float in the tubes...

If I'm traveling on a spaceship at a constant velocity (say 10000 m/s) towards Mars will I feel weightless, or will I feel nearly weightless because I will still be slightly affected by gravity? I know that when astronauts are in the ISS they feel weightless because they are in a constant...

So, as I understand special relativity, when you go close to the speed of light, observers see you "shrink" in the direction of motion, and you see objects as shorter than they were when you were in the same frame, according to L=Lo√1-v2/c2. So suppose I am nearby Earth (in the same reference...

[Mentor's note: This thread is forked from https://www.physicsforums.com/threads/bell-spaceship-paradox-quantitatively.828670/ for discussion of the basic principles behind the spaceship paradox] Suppose the string was replaced by some structure which linked the ships together to make a longer...

Yesterday, I found the time to write a bit further on my SRT FAQ and wanted to give a quantitative analysis of the Bell space-ship paradox on the example of the two rockets accelerating with constant proper acceleration, and I found a problem, I cannot solve. So I took this section out from my...

bcrowell submitted a new PF Insights post What Is the Bell Spaceship Paradox, and How Is It Resolved? Continue reading the Original PF Insights Post.

I couldn't find a relevant forum - that I could recognize, anyway - so, if this is in the wrong place, please feel free to move it to a more appropriate forum. Ennywho, I have a question on terms. Let's say there's a space probe's propulsion system that is currently providing an acceleration...

Homework Statement You plan to take a trip to the moon. Since you do not have a traditional spaceship with rockets, you will need to leave the Earth with enough speed to make it to the moon. Some information that will help during this problem:mearth = 5.9742 x 1024 kg rearth = 6.3781 x 106 m...

Homework Statement A spaceship leaves Earth at time ##t=0## with constant speed ##u##. Its clock is synchronized with the terrestrial one. At time T an earthling reads with an optical telescope the clock inside the spaceship. What value does he read? Homework Equations Lorentz equations. The...

Homework Statement The proper length of a spaceship A is 60 m and the proper length of spaceship B is 120 m. The proper mass of spaceship A is 15000 kg. An observer on Earth watches the two spaceships fly past at a constant speed and determines that they have the same length. If the speed on...

Let's say a spaceship made of a transparent material moving past the Earth in a straight line at a constant speed of 0.99 c, and it's at its minimum distance from Earth. If a light is turned on in the middle of the ship, for an observer on Earth will the light move towards the front of the ship...

Hi, I got this fun idea. Has anyone ever consider that heat radiation could be an efficient propellant for a spaceship? Imagine a spherical spaceship, half of which is hot and with a large emissivity coefficient (say almost 1), and the other half is cold and with low emmisivity. A naive...

I had this though back in collage and asked my professor and he gave me a very short attempt to answer the question then said he was never quite sure about all this relativistic stuff... I didn't get my answer though but I have not forgot my question. Say a spaceship was headed toward the sun...

I believe length contraction always makes more sense when integrated with reminders of relativity of Simultaneity. Let's say the engines are at the back end of each rocket. For the viewer "A" in the initial frame, they begin moving and continue accelerating simultaneously, and clocks next to...

Homework Statement A spaceship is sent to investigate a planet of mass M and radius R. While hanging motionless in space at distance 5R from the center of the planet, the ship fires an instrument package with speed v0 (at angle ##\theta## with the line passing through the spaceship and the...

When a spaceship is moving at 150,000 km/sec and you shine a flashlight forward, both an outside observer and the observer on the ship perceive the beam as traveling at c. I think I understand the reason for that when the light is shined forward, but I am confused in the case where he shines it...

Suppose we launch two ships and move them close to the Sun. They have solar collectors and can absorb a massive amount of energy thanks to their proximity to the Sun. The ships are connected by a 1000 meter long rod of titanium, and each ship's rocket is position opposite the other's, so that...

Let's imagine say, a spaceship is going through space at 99% the speed of light. Relativity says (to my understanding) that as the spaceship increases in speed it's mass will increase and it shall also get slightly shorter. Let's assume that energy isn't a problem, should the spaceship continue...

Homework Statement bob and anna are in two space ships of proper length 100m; anna's ship passes bob's and is moving in the -x dir at v=0.75c. the front of anna's ship and the tail of bob's ship coincide at x=x'=t=t'=0. bob sits at the window in his ship and sees a clock inside anna's ship a)...

Homework Statement Anna is born in a spaceship, Bob is born on Earth (at the same time t=t'=0) just as Anna's spaceship passes Earth at 0.9c (EVENT A) Planet Z is 45 ly away at rest in Bob's frame. Anna flies past plant Z (event B) Meanwhile, Carl was born at the same time (t=t'=t''=0) on a...

Homework Statement Imagine a 50kg vehicle located at the origin. We wish to navigate this vehicle by means of applying directed force. From the point (-2000,16000,0)m, you set a course directly back to the origin. A force of 10N is applied in the appropriate direction for 5 seconds. 5...

Would a spaceship that is half reflective ( the stern ) and half flat-black ( the bow) be propelled through space just by the ambient radiation from stars and the CMBR?

dear friends, days ago on a physics forum I saw this interesting question regarding fixed power and speed of a spaceship. After thinking for a while I came up with my answer but I am not really sure its correct.So please tell me what you think the answer is. The question is: imagine there are...

Suppose I have a spaceship that can accelerate to c in one month of acceleration/deceleration of month and I want to travel to Andromeda. From my frame of reference wouldn't my total travel time be two months?

Hello to everyone! I cane across this problem and since I have no training in SR I can't solve it on my own, That is why I would very mutch apprecitate any help I could get. The problem: A photon and a spaceship simultaneously start at planet A and the travel in paralal towards planet B. The...

Homework Statement A spaceship has traveled for 14 years at an average speed of 90% of the speed of light. Its round trip from Earth has taken 14 years according to clocks on the ship. (a) How long has the journey taken according to Earth clocks? Homework Equations t = t’ / (1-v2/c2)-1/2The...

Hello Folks. I am writing a Sci-Fi Tale set in the late 22nd century and I need some Help designing some aspects of the ship in my story. I started asking advice for this story in a different thread but seeing as how the topic as become more specific I figured it deserved a dedicated thread...

Homework Statement A spaceship travels from Earth to a star that is 6 light years away. The spaceship takes 2.5 years to reach the star in its frame. Calculate the velocity of the spaceship. Homework Equations x=\frac{x_0}{γ}, t=γt_0 The Attempt at a Solution I guess I have to...

Homework Statement The position of a spaceship is (3 + t, 2 + ln(t), 7 - \frac{4}{t^2 + 1}) and the coordinates of the space station are (6, 4, 9). The captain wants the spaceship to coast into the space station. When should the engines be turned off? Homework Equations r' = (1, \frac{1}{t}...

I'm sticking my neck out because I just worked this out and may regret this post later. The spaceship paradox arises because the expansion scalar of the 'Bell' congruence is always positive, implying that the thread will break, even when the ships are not separating. For this vector field...

I appologize for any spelling or grammar errors. Please take into account that English isn't my first language and that I haven't finished my English course yet, since I'm 14 years old. My Question (which I suppose is very dumb): Imagine there is a manned spacecraft traveling through deep...

why not launch space ships with a sort of magnetic rail system so that you don't have to launch fuel with you a ship coated in resin would survive the atmosphere and because of its elevated location on a mountain the atmosphere would already be much thinner the length of the rail is a slight...

Given the above setup in this image, there is a fast spinning massive flywheel inside a spaceship. The flywheel is only connected via a lock to a spring. What would happen if the retractable steel wall moves towards the steel ball (purple) which is connected to the fly wheel, so the steel...

Homework Statement A spaceship of mass 2.30×106kg is cruising at a speed of 5.50×106m/s when the antimatter reactor fails, blowing the ship into three pieces. One section, having a mass of 5.20×105kg , is blown straight backward with a speed of 2.30×106m/s . A second piece, with mass...

This is another version of bell’s spaceship paradox. Consider two spaceships A & A’ separated by a distance L, and are tied by a non elastic thread. They are on earth. This time the two spaceships are not moving instead I'm moving. I’m in a distant planet and i starts to accelerate and reach at...