When Particles Collide (APOD 25 Feb 2008)

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Expand view Topic review: When Particles Collide (APOD 25 Feb 2008)

by iamlucky13 » Fri Sep 19, 2008 1:36 am

The energy in the fuel would not increase, so neither would the thrust.

by BMAONE23 » Wed Sep 17, 2008 2:03 pm

If the Mass of the ship increases as speed reaches C wouldn't also the mass of the fuel increase although it is being used? and couldn't the proportional thrust increase as a result?

by soupphysics » Wed Sep 17, 2008 11:06 am

starnut wrote:While in college (decades ago), I once wrote a computer program using the Special Theory of Relativity, to compute and list the changes (to an outside observer) in a spacecraft's physical attributes as it accelerated constantly at 1g until it reached 99.9% of the speed of light. It would take the spacecraft almost one year to reach that speed. I don't remember how the distance it would travel to reach that speed. During the voyage, its relativistic length would contract and its relativistic mass would increase. One thing I was not sure about when writing the program is whether the steady increase in relativistic mass would require even greater amount of energy to maintain the constant 1g acceleration. The mass of the spacecraft with its fuel does not increase in its proper frame.

Gary
Seen from the ship itself, no energy increase is needed to keep the acc of 1g.

Seen from a stationary (relative to the ship), the acc. would be less and less if the energy was no increased

by soupphysics » Wed Sep 17, 2008 11:03 am

starnut wrote: I don't think that you would be so dismissive of the risk of continually using chemical rockets if we have more accidents like the Challenger and Columbia tragedies. Each time, those accidents resulted in the complete shutdown of the manned space flights by the U.S. for several years while NASA worked to prevent their re-occurrences. We had to depend on the Russians for resupplying the ISS after the Columbia disaster. That is why I am hoping the the LHC or any other particle accelerator would enable us to understand the nature of the gravitational force and a way to control it, like we are able to control electromagnetism.
Irrelevant! This is not what is preventing long space trips and anti gravity isn't either.
starnut wrote: Yes, and each requires corresponding amount of fuel/energy to perform. And you will also need to carry additional fuel for the return trip.
I don't know why you are telling me this, which I obviosly already know. I am the one who told you that this is what you need energy for, and that antigravity doesn't help you.

starnut wrote: I don't think they would be consider "minor" from engineering point of view. And you do need a non-rotating section if you are orbiting a planet and wanting to send out a shuttle craft without stopping the rotating section. Of course, we could put the docking port at the front end like the space station in "2001: A Space Odyssey."

Gary
No, there is no need for rotation while orbiting. Orbiting is the least part of the problem. You can also easily enough dock while rotating if you want to.

by starnut » Wed Sep 17, 2008 4:01 am

While in college (decades ago), I once wrote a computer program using the Special Theory of Relativity, to compute and list the changes (to an outside observer) in a spacecraft's physical attributes as it accelerated constantly at 1g until it reached 99.9% of the speed of light. It would take the spacecraft almost one year to reach that speed. I don't remember how the distance it would travel to reach that speed. During the voyage, its relativistic length would contract and its relativistic mass would increase. One thing I was not sure about when writing the program is whether the steady increase in relativistic mass would require even greater amount of energy to maintain the constant 1g acceleration. The mass of the spacecraft with its fuel does not increase in its proper frame.

Gary

by starnut » Wed Sep 17, 2008 3:26 am

soupphysics wrote:
Still, we go to and from space regularly. It's not the problem, and waiting for anti gravity is not the way, since there is nothing to indicate that it is anywhere close to happening.
I don't think that you would be so dismissive of the risk of continually using chemical rockets if we have more accidents like the Challenger and Columbia tragedies. Each time, those accidents resulted in the complete shutdown of the manned space flights by the U.S. for several years while NASA worked to prevent their re-occurrences. We had to depend on the Russians for resupplying the ISS after the Columbia disaster. That is why I am hoping the the LHC or any other particle accelerator would enable us to understand the nature of the gravitational force and a way to control it, like we are able to control electromagnetism.
soupphysics wrote: Acceleration and deceleration is the same thing.
Yes, and each requires corresponding amount of fuel/energy to perform. And you will also need to carry additional fuel for the return trip.
starnut wrote: Rotating a spaceship to create artificial gravity also creates all kinds of engineering problems, such as maintaining balance when internal loads shift from one side to another and stopping and restarting the rotation in order to do exterior maintenance during spacewalks. Then you need a non-rotating section for navigation, ingress and egress purposes.
soupphysics wrote: Those are minor issues.

You don't really need a non-rotating section.

You can let the the whole ship rotate, once it's done accelerating, and doesn't need much navigation for the rest of the trip, until accelerating to a stop again.

The shop would likely be accelerating for a very long time, maybe close to half the way, before "decelerating". During acceleration, you have gravity, due to the acceleration, so in that case, you don't need any rotation at all.
I don't think they would be consider "minor" from engineering point of view. And you do need a non-rotating section if you are orbiting a planet and wanting to send out a shuttle craft without stopping the rotating section. Of course, we could put the docking port at the front end like the space station in "2001: A Space Odyssey."

Gary

by BMAONE23 » Tue Sep 16, 2008 7:40 pm

http://www.daviddarling.info/encycloped ... craft.html
It could also work outside the solar system thanks to time dialation

by soupphysics » Tue Sep 16, 2008 5:25 pm

BMAONE23 wrote:The best solution, in my book, is to create an engine that produces a constant 1G thrust. Susatined 1G supplies the gravity and constant thrust supplies the speed. You would simply need to shut down the engines at the 1/2 way point, thruster turn the ship 180deg and then fire up the engines again. The constant 1G breaking thrust would again provide the gravity while slowly breaking to your destination. The trick is that the engines would need to be electrical as opposed to chemical.
right, that is a good solution for traveling within our solar system.

But to other stars, 1 g is too little

by BMAONE23 » Tue Sep 16, 2008 5:14 pm

The best solution, in my book, is to create an engine that produces a constant 1G thrust. Susatined 1G supplies the gravity and constant thrust supplies the speed. You would simply need to shut down the engines at the 1/2 way point, thruster turn the ship 180deg and then fire up the engines again. The constant 1G breaking thrust would again provide the gravity while slowly breaking to your destination. The trick is that the engines would need to be electrical as opposed to chemical.

by soupphysics » Tue Sep 16, 2008 3:35 pm

starnut wrote: Remember what happened to the space shuttles Challenger and Columbia? Using chemical rockets to leave the Earth and atmospheric braking to return is too dangerous and inefficient. It also takes far too long to get the shuttle ready for the next flight. Better to be able to control gravity to take off and land gently. We can also use gravity control for air travels.
Still, we go to and from space regularly. It's not the problem, and waiting for anti gravity is not the way, since there is nothing to indicate that it is anywhere close to happening.
starnut wrote: Accelerating to near light speed is not the only problem. Decelerating when reaching your destination is another problem that also requires a lot of energy. Then there is the time dilation problem.
Acceleration and deceleration is the same thing.
starnut wrote: Rotating a spaceship to create artificial gravity also creates all kinds of engineering problems, such as maintaining balance when internal loads shift from one side to another and stopping and restarting the rotation in order to do exterior maintenance during spacewalks. Then you need a non-rotating section for navigation, ingress and egress purposes.

Gary
Those are minor issues.

You don't really need a non-rotating section.

You can let the the whole ship rotate, once it's done accelerating, and doesn't need much navigation for the rest of the trip, until accelerating to a stop again.

The shop would likely be accelerating for a very long time, maybe close to half the way, before "decelerating". During acceleration, you have gravity, due to the acceleration, so in that case, you don't need any rotation at all.

by starnut » Tue Sep 16, 2008 2:43 am

soupphysics wrote:
Actually gravity is not what is preventing long term space travel. It's not a huge problem to go into space.

It's the unimaginable huge distances that prevent it the long trips and the energy needed to accelerate to close to light speed, and even at that speed, it is some very long trips.

Artificial gravity on a space ship is not a problem either. It can be created by rotation (centripetal force).
Remember what happened to the space shuttles Challenger and Columbia? Using chemical rockets to leave the Earth and atmospheric braking to return is too dangerous and inefficient. It also takes far too long to get the shuttle ready for the next flight. Better to be able to control gravity to take off and land gently. We can also use gravity control for air travels.

Accelerating to near light speed is not the only problem. Decelerating when reaching your destination is another problem that also requires a lot of energy. Then there is the time dilation problem.

Rotating a spaceship to create artificial gravity also creates all kinds of engineering problems, such as maintaining balance when internal loads shift from one side to another and stopping and restarting the rotation in order to do exterior maintenance during spacewalks. Then you need a non-rotating section for navigation, ingress and egress purposes.

Gary

Re: LHC results

by soupphysics » Mon Sep 15, 2008 7:06 pm

GOD wrote:
bystander wrote:It will be interesting to see what new answers the LHC will provide. Evidence of WIMPs, Higgs bosons, supersymmetry, gravitons????? Even more interesting, what new questions will be asked?
They are going to discover that quarks don't exist; that what they thought was a single "quark" is really a soup of many, many newly discovered smaller particles. This will lead the scientists to understand that "dark matter" is really "very, very tiny matter".

The most important new questions will be related to their discovery of the nature of different realities of vibrational frequencies. Scientists will prove that the vibrational reality in which humans reside, emanates from a higher vibrational reality. I understand many of you do not understand this yet.
That doesn't really change the existence of quarks. It just changes the definition of a quark or actually just explains what a quark exactly is.

by soupphysics » Mon Sep 15, 2008 6:59 pm

starnut wrote:One thing I hope that discoveries from the LHC and other future particle colliders will lead is better understanding how the gravitational force is created. Until we learn if this fundamental force can be controlled by some artificial means, long-term space travel will remain very difficult to attain. We need to find a way to neutralize the gravitational force around a spacecraft on a planet or moon so it can lift off the surface without so much energy and to create artificial gravity inside the spacecraft for people on long space travels. Otherwise, long space voyages will remain just a pipe dream.
Actually gravity is not what is preventing long term space travel. It's not a huge problem to go into space.

It's the unimaginable huge distances that prevent it the long trips and the energy needed to accelerate to close to light speed, and even at that speed, it is some very long trips.

Artificial gravity on a space ship is not a problem either. It can be created by rotation (centripetal force).

Re: The God Particle (higgs boson)

by emc » Sat Sep 13, 2008 12:49 am

iamlucky13 wrote:Sorry about the misquote EMC. Interestingly, the IEDAB didn't actually say we're all dead. It just said the earth had been destroyed. Draw you own conclusions. :lol:
No prob

Thanks for clarifying IEDAB's position. Sounds a little bit political though. :wink:

I'm holding with being dead if the earth is destroyed. And still a little disappointed with my outcome.

Re: The God Particle (higgs boson)

by iamlucky13 » Fri Sep 12, 2008 11:33 pm

Sorry about the misquote EMC. Interestingly, the IEDAB didn't actually say we're all dead. It just said the earth had been destroyed. Draw you own conclusions. :lol:
bystander wrote:The God Particle (higgs boson)

http://ngm.nationalgeographic.com/2008/ ... nteractive

How can you create a particle with 100 to 200 times the mass of a proton by smashing two protons together?
Mass-energy equivalence and the fact that matter can "condense" out of high energy environments. The collisions occur at 14 TeV. This is equivalent to about 15000 times the mass of a proton.

The more puzzling question is how can a particle that gives mass to a proton have 100 to 200 times as much mass as the particle? I've heard this explained in a reasonable manner before, but I've forgotten the answer.

The God Particle (higgs boson)

by bystander » Fri Sep 12, 2008 4:06 pm

The God Particle (higgs boson)

http://ngm.nationalgeographic.com/2008/ ... nteractive

How can you create a particle with 100 to 200 times the mass of a proton by smashing two protons together?

by emc » Thu Sep 11, 2008 7:52 pm

iamlucky13 wrote:
emc wrote:"The world breathed a sigh of relief as our predicted demise - at 5pm - came and went with not even a whimper, let alone a bang."
Geeze...for something as important as this you can't trust the media. Go to an authoratative source:

http://qntm.org/?board

Or better yet, recognize it with your own eyes:

http://www.cyriak.co.uk/lhc/lhc-webcams.html

Billions of people around the world are still in denial because of the mainstream media, saying things like "but they haven't even started colliding particles yet." Oh yeah smarty-pants? Then how come the IEDAB is reporting the world has been destroyed?
So according to the IEDAB we are all dead... interesting... I had much higher hopes for after-life... I'm still at work. :(

But you know... you can't really trust things with ED in the name... never know whats to be expectED from EDs.

BTW - The quote you list is not mine... sorry I thought that the <<"___">> was an indication of quoting another resource. The quoted sentence actually comes from the link I list below the text. http://www.news.com.au/heraldsun/story/ ... 63,00.html Don't want to be getting crEDit for stuff I didn't say.

THANKS for the funnies! 8)

by iamlucky13 » Thu Sep 11, 2008 7:30 pm

emc wrote:"The world breathed a sigh of relief as our predicted demise - at 5pm - came and went with not even a whimper, let alone a bang."
Geeze...for something as important as this you can't trust the media. Go to an authoratative source:

http://qntm.org/?board

Or better yet, recognize it with your own eyes:

http://www.cyriak.co.uk/lhc/lhc-webcams.html

Billions of people around the world are still in denial because of the mainstream media, saying things like "but they haven't even started colliding particles yet." Oh yeah smarty-pants? Then how come the IEDAB is reporting the world has been destroyed?

by emc » Thu Sep 11, 2008 3:08 pm

The race is on...

Image

http://www.eetimes.com/news/latest/show ... =210601016

<<"Both Fermi and CERN are looking for the Higgs bosun using similar methods of accelerating particle beams to near the speed of light, then colliding them with a force almost as powerful as the Big Bang. Whereas CERN will use high-intensity proton beams, Fermilab's DZero project is using one beam of protons and one beam of anti-protons.">>

by emc » Wed Sep 10, 2008 11:10 am

<<"The world breathed a sigh of relief as our predicted demise - at 5pm - came and went with not even a whimper, let alone a bang.">>
http://www.news.com.au/heraldsun/story/ ... 63,00.html

Image
-------------------------------------------
<<"The Large Hadron Collider fired its first beam around the machine's full track at 10:28 AM local time (1:36 AM Pacific time).

No actual atoms were smashed today -- that won't start for weeks -- and no results are expected for months, at the earliest. Still, like first light in a telescope, the first beam in the particle accelerator is a landmark moment for a program that has spanned more than 20 years and involved tens of thousands of scientists.">>

http://blog.wired.com/wiredscience/2008 ... -circ.html

Image

by emc » Tue Sep 09, 2008 10:41 pm

Image

More news on CERN's LHC power up tomorrow...

http://afp.google.com/article/ALeqM5jaO ... iNCVi6Rsmw

by Hans Kanitschar » Tue Sep 09, 2008 8:12 pm

jesusfreak16 wrote:It would probably be Andromeda.
(but I'm not sure)
Thanks jesusfreak16. It must be Andromeda. See the beautiful links BMAONE23 sent me in his/her answer. Hans

by Hans Kanitschar » Tue Sep 09, 2008 8:10 pm

BMAONE23 wrote:It sits with Andromeda
Oriented just below it in these APOD's http://antwrp.gsfc.nasa.gov/apod/ap080124.html
http://antwrp.gsfc.nasa.gov/apod/ap070721.html
and below left in this spectacular comparative image
http://antwrp.gsfc.nasa.gov/apod/ap061228.html
BMAONE23, THANKS a lot for these phantastic links! Now it is clear: the huge galaxy in todays foto must be Andromeda. Really great!
Hans

by emc » Tue Sep 09, 2008 7:18 pm

by BMAONE23 » Tue Sep 09, 2008 5:16 pm

It sits with Andromeda
Oriented just below it in these APOD's http://antwrp.gsfc.nasa.gov/apod/ap080124.html
http://antwrp.gsfc.nasa.gov/apod/ap070721.html
and below left in this spectacular comparative image
http://antwrp.gsfc.nasa.gov/apod/ap061228.html

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