how fast do we need to go

THX1138 · Post by **THX1138** » Sat Jun 30, 2007 11:59 pm

I've heard of some really far fetched ideas on how to get a spacecraft motoring pretty good and weather this particular idea is possible or not, I have no idea. But i find the most humor in this idea of releasing hydrogen bombs one after the other as kind of a putt - putt - putt method with the goal of reaching 1/10 the speed of light. Where I first saw this idea I do not recall but i do remember the fact being stated that at just 1/10 light speed no one has any idea on how to protect ones ship considering that at that speed even a particle of dust hitting this ship would in effect have the destructive power of a atomic bomb hitting it.

My question, is this true about a particle of dust having that effect at just 1/10th light speed

And as per the topic, how fast do we need to go to even put stelar travel on the drawing board.

BMAONE23 · Post by **BMAONE23** » Sun Jul 01, 2007 12:27 am

The nearest star to our own lies a mere 4.3+-LY away. Light travels at 186,000 miles per second. There are roughly 31,536,000 seconds in a year. So our nearest stellar neighbor lies appx 25 Trillion 222 billion miles away or (25,222,492,800,000 miles away)(2,108,600,398,080,000,000k).
Our fastest space traveller, the currently outbound New Horizons Pluto probe, is travelling at the breakneck speed of 52,000 mph (83600 kph) and has most recently passed Jupiter (it only needs to pass the orbits of Saturn, Uranus, and Neptune before it gets to Pluto and beyond. This part of the journey will take another 9 years at its current speed).
If you were to take that rate of speed and send a probe to our closest stellar neighbor it would take 485,047,938 years to reach it.
If you were to travel at 1/10c (speed of light), the trip would still take 43 years one way, 86 years round trip.
To make interstellar travel viable, and to still have someone alive and working here at missin control that remembers you when you reach your destination, you would likely need to travel at 1/2-3/4c or faster.
As far as the affect of a micrometorid at that speed?????

THX1138 · Post by **THX1138** » Sun Jul 01, 2007 8:51 am

Thanks BMAONE23, imagine that folks. We can travel to our closest neighbor star in a mere 485 million, 47 thousand, 938 years.
That really sucks. Anyone out there have any ideas on the drawing board as to how we might do this a little faster that they would like to share with us here.

makc · Post by **makc** » Sun Jul 01, 2007 2:13 pm

THX1138 wrote:My question, is this true about a particle of dust having that effect at just 1/10th light speed

All I know is that a bird can kill an airplane. But it's not that hard to do the math.

1st, we need the energy of the bomb. According to this page, the most powerful bomb generated 240,000 TJ (2.4e+17 Joules). 2nd, according to this page, shockwave and heat (two most destructive factors) account for 85% of that energy (0.85 * 2.4e+17 ~ 2e+17 Joules). 3rd, this energy goes outwards in all directions, so if your ship has crossection area S, amount of energy it recieves at the distance R is 2e+17*S/(4*pi*R^2) ~ 1.6e+16*S/R^2 Joules. Shuttle have wing a bit smaller than triangular, so I think it is safe to assume area S to be somewhere near 0.3*37*24 ~ 270 m^2. Which means that if you were to put shuttle at 1km distance from the most powerful explosion ever, it would receive approximately 1.6e+16*270/1e+6 ~ 4.3e+12 Joules.

Now, back to our question... I have no idea how much of moving dust particle energy could be consumed by a spacecraft as it passes through it but, assuming it is at least 10%, we now have for 10 gram particle, this equation: 4.3e+12 J = 0.1 * 0.01 kg * (299,792,458 m/s)^2 * (1/sqrt(1 - v^2/(299,792,458 m/s)^2) - 1), or v^2/(299,792,458)^2 ~ 0.0892, or v^2 ~ 8.02e+15, or finally v ~ 8.96e+7 m/s, which is ~ 0.3 of speed of light.

phew... now go check that 8)

THX1138 wrote:Anyone out there have any ideas on the drawing board as to how we might do this a little faster that they would like to share with us here.

We already have 16 pages of discussion of that.

makc · Post by **makc** » Sun Jul 01, 2007 2:34 pm

BMAONE23 wrote:to still have someone alive and working here at missin control that remembers you when you reach your destination, you would likely need to travel at 1/2-3/4c or faster.

I'm sorry but that won't happen. After you will travel at 3/4c for a few years, when you turn your brakes on to orbit an alien star, they will all be dead

craterchains · Post by **craterchains** » Mon Jul 02, 2007 9:03 am

THX1138 wrote:And as per the topic, how fast do we need to go to even put stelar travel on the drawing board.

Good question, , ,

That "drawing board" is a mighty big place that spans hundreds of billions of galaxy's. To move materials just from one star to another would require a speed that would get you and your cargo there in a reasonable amount of time and would also depend on what the cargo was. If that cargo were bananas, you would have about three to four weeks maximum to get the cargo to market. Based on that you can come up with an arbitrary figure for the speed necessary to get you and your cargo there on time. (Before you can only make banana bread with them.)

That tells me that we will need a drive unit that can cross our solar system in about two weeks. We would then need a drive that would allow us to cross from one side of our galaxy to the other in about two weeks also. Then if we wanted to sell those bananas to someone on the other side of the known universe we again would have to be able to do so in about two weeks time.

Bottom line we would need three types of engines to move products about our universe in a timely manner.

Just my two coins worth.
Norval

THX1138 · Post by **THX1138** » Tue Jul 03, 2007 8:13 am

great, on this entire rock not one person as yet has the slightest idea?
We are stuck in rocket mode, crazy.
I've read somewhere that a snail can travel about one mile in 5 days. Now X 250,000 to the moon, 1,250,000 days / a dam snail can make it to the moon. Us 485 million years to another star. I think I'm going to be sick.

makc · Post by **makc** » Tue Jul 03, 2007 9:44 am

THX1138 wrote:I've read somewhere that a snail can travel about one mile in 5 days. Now X 250,000 to the moon, 1,250,000 days / a dam snail can make it to the moon.

snails can't really travel airborne (unless it's downward), neither can they hold their breath for 3000 years.

craterchains · Post by **craterchains** » Tue Jul 03, 2007 5:09 pm

, , , on the other hand if you have a great control over that speed, one could use the intergalactic drive for all three engines. 8)

BMAONE23 · Post by **BMAONE23** » Tue Jul 03, 2007 7:28 pm

I think Mel Brooks got it right in SpaceBalls "Ludicrous Speed" is the way to go

Dark Helmet: No, no, no. Light speed is too slow.
Colonel Sandurz: Light speed is too slow?
Dark Helmet: Yes. We're gonna have go right to... ludicrous speed.
[everybody gasps]
Colonel Sandurz: Ludicrous speed? Sir, we've never gone that fast before. I do'nt know if this ship can take it.
Dark Helmet: What's the matter Colonel Sandurz? Chicken?

craterchains · Post by **craterchains** » Wed Jul 04, 2007 5:21 am

I was just wondering at what speed we would need to be able to reach the nearest galaxy in two weeks time?

harry · Post by **harry** » Thu Jul 26, 2007 10:43 am

Hello All

2 weeks,,,,,,,,,,,Total Recall,,,,,,,,,,the movie

Can someone tell me the scene.

makc · Post by **makc** » Thu Jul 26, 2007 2:59 pm

border control.

craterchains wrote:I was just wondering at what speed we would need to be able to reach the nearest galaxy in two weeks time?

that is easy. 1st you go to wiki and read about "the Large and the Small Magellanic Clouds, whose perigalacticon is at ~180,000 light-years", then you go to google, and calculate that 180,000 ly is 1.7e21 meters (A). if someone were to go there at speed V m/s, it would took him A/V seconds, according to Earth observer. However, due to SRT, in his own opinion, our traveller would make it in just about A * sqrt(1 - (V/c)^2) / V seconds. Two weeks = 2 * 7 * 24 * 60 * 60 ~ 1.2e6 seconds (B). This gives the equation, A * sqrt(1 - (V/c)^2) / V = B, or 1 - (V/c)^2 = (VB/A)^2. Let's substitude (V/c)^2 with Z, then we have 1 - Z = Z*(cB/A)^2, or Z = 1 / (1 + (cB/A)^2). This finally gives us V = c * 0.99999999999997761 if I did the math correctly.

harry · Post by **harry** » Fri Jul 27, 2007 12:04 pm

Hello All

I think the power that is required to drive a space ship to extreme speeds is within the properties of Plasma.

http://www.plasmacenter.cornell.edu/

http://www.electric-cosmos.org/electricplasma.htm

http://plasmascience.net/tpu/EM_forces.html

http://www.lawrencevilleplasmaphysics.c ... s_plan.htm

http://www.plasmas.org/plasma-physics.htm

Have a read of the links and let me know what you think.

I know some people think that plasma is a "dirty word" and omly crank pots use it to smoke the broken arrow.

makc · Post by **makc** » Fri Jul 27, 2007 2:24 pm

some people think that posting tangential links is one step away from spamming

- does anyone here know anyhitng about breeding dogs?
- well, dogs have fleas, right, so here goes a bunch of links about my flea circus.

Nereid · Post by **Nereid** » Fri Jul 27, 2007 11:27 pm

makc is right, harry ... your post seems to have the same relevance with the topic of this thread as dog breeding.

Or perhaps less, in that it conflates mainstream science with crackpottery, with the implication that they are in some sense equivalent.

So, I'll ask you - again? - to please stop using the Asterisk Cafe as a vehicle to promote a-scientific (and anti-science) ideas.

harry · Post by **harry** » Sat Jul 28, 2007 1:10 am

Neried

You have got to be joking.

What science are we talking about.

Are we talking about science that you want to control.

You have proved a point, that HISTORY does not repeat itself, but Man repeats history.

I'm not selling the links or even promoting them.

Explain to me what you think about PLASMA.

and please leave the Dogs at home.

THX1138 · Post by **THX1138** » Sat Jul 28, 2007 7:53 am

Excuse me, I posted the original question “ how fast do we need to go “ Then ask if anyone, anywhere, has any idea as to how we might get our interstellar space program out of 1st gear running at a slow idle and not one person posts any kind of idea whatsoever. Then one person “Harry” at least has the intestinal fortitude to post a possible / NO MATTER HOW FAR-FETCHED / Idea. Plasma I.E. Plasma propulsion I suppose?
And then gets a hard time for doing so? This is not happening! Is it really?
Not to mention, who of any of us can tell the future? If so please tell me the next lotto numbers for the California lottery tomorrow please.
Can any of you state with certainty, absolute certainty, that 100 years from now there will not be plasma powered engines. if so how about 1000 years from now
Thank you Harry for having the b... to at least post some kind of hope for something to get us out of rocket mode, they are just a wee bit to slow for my liking / 800 plus million years to the nearest star / too slow.

I never met a weapon I didn’t like ( Ronald Regan ) 1989

makc · Post by **makc** » Sat Jul 28, 2007 8:10 am

THX1138 wrote:My question, is this true about a particle of dust having that effect at just 1/10th light speed

And as per the topic, how fast do we need to go to even put stelar travel on the drawing board.

THX1138, just to be clear, is this post a response your question was aimed at, yes or no?

P.s.: if you really think harry is "having a hard time" here, mind you, he's not; there are plenty examples, check this 50+ pages thread for one. After countless times Nereid asked him not to bring non-scientific material up, he continues to do that without any action taken against him. I almost admire him, I never managed to piss on the rules as long as he does without getting banned on some board =)

craterchains · Post by **craterchains** » Sat Jul 28, 2007 4:37 pm

Now this could get interesting, , ,

After all, we are just looking for knowledge and wisdom, the truth, which I think science is all about.

It is not about big brother (sister) and their censorship against the mainstream of theories.

A "Coffee Shop" is just that, so screw the names on the papers and their methodologies of politicaly correct ways of doing research ! ! !

Norval

makc · Post by **makc** » Sat Jul 28, 2007 5:16 pm

craterchains wrote:screw the names on the papers and their methodologies of politicaly correct ways of doing research

You know, I would totally agree with you, if you had posted on youtube video of "plasma propelled" or whatever, capable of flying at 0.999+ c, engine test, and linked us to it. For now, it is those politically correct idiots who fly Hubble telescope in orbit, or men on moon.

P.s.: somewhat related, btw.

THX1138 · Post by **THX1138** » Sun Jul 29, 2007 1:09 am

I had no idea about this situation with Harry, my apologies to all concerned. All I can say is that I was happy to of gotten some kind of answer even though in all actuality it was not the original question on this post. If someone would like to start a new thread on possible alternatives to our current propulsion methods I would be more than happy to indulge myself in their proposed ideas.
I myself am not going to start that thread / question “ future propulsion methods “ Have a nice day all.

I never met a weapon I didn’t like ( Ronald Regan ) 1989

makc · Post by **makc** » Sun Jul 29, 2007 5:41 am

THX1138 wrote:If someone would like to start a new thread...

cough, cough... IIRC it went to discussing warp drives at some point... here is nice post on subject:

Doum wrote:For information.

http://www.daviddarling.info/encycloped ... cepts.html

This is a good place to see what is the best the human can hope to do on maximum speed for traveling deep into space. Some might get close to the light speed (Bussard ramjet.). Some can reach 10% the light speed (Daedalus project.).

I don't know about credibility of the link, but it surely covers more than we can hope to discuss here 8)

THX1138 · Post by **THX1138** » Sun Jul 29, 2007 8:52 am

way cool site makc, thanks alot.

craterchains · Post by **craterchains** » Tue Jul 31, 2007 10:22 am

, , , ahhhhh yes, Dr. David Darling , , ,

Starship Asterisk*

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