Detecting systems with life

Message boards : SETI@home Science : Detecting systems with life
Message board moderation

To post messages, you must log in.

Previous · 1 · 2 · 3 · Next

AuthorMessage
Profile William Rothamel
Avatar

Send message
Joined: 25 Oct 06
Posts: 3756
Credit: 1,999,735
RAC: 4
United States
Message 1132492 - Posted: 27 Jul 2011, 9:40:29 UTC - in response to Message 1132317.  

What are the other ways of containing a fusion reaction that might allow fusion to power a spaceship other than a tokamak type of arrangement.
ID: 1132492 · Report as offensive
Profile tullio
Volunteer tester

Send message
Joined: 9 Apr 04
Posts: 8797
Credit: 2,930,782
RAC: 1
Italy
Message 1132493 - Posted: 27 Jul 2011, 9:41:21 UTC - in response to Message 1132317.  

There is more than one way of sustaining fusion in a reactor, other than magnets with superconducting coils.

Yes, the inertial confinement approach tried at Livermore National Laboratory, which makes H-bombs. But it uses high powered lasers and is not working yet. It is more an attempt to produce micro H-bomb explosions than producing power.
Tullio
ID: 1132493 · Report as offensive
C Olival

Send message
Joined: 6 Sep 10
Posts: 209
Credit: 10,675
RAC: 0
United States
Message 1132574 - Posted: 27 Jul 2011, 15:02:33 UTC - in response to Message 1132417.  

A trip to the Alpha Centauri system in a craft going 30 light speed, for the experts outthere, how long would such a craft take to reach the Alpha Centauri system? do the math, a mere 4.5 light years away. I m refering to the binary system of Alpha Centauri, A and B. Even Gliese d, do the math.
ID: 1132574 · Report as offensive
Profile Bob DeWoody
Avatar

Send message
Joined: 9 May 10
Posts: 3387
Credit: 4,182,900
RAC: 10
United States
Message 1132917 - Posted: 28 Jul 2011, 9:28:28 UTC - in response to Message 1132574.  

A trip to the Alpha Centauri system in a craft going 30 light speed, for the experts outthere, how long would such a craft take to reach the Alpha Centauri system? do the math, a mere 4.5 light years away. I m refering to the binary system of Alpha Centauri, A and B. Even Gliese d, do the math.

Are you asking 30 times the speed of light or 30% of the speed of light?
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.
ID: 1132917 · Report as offensive
C Olival

Send message
Joined: 6 Sep 10
Posts: 209
Credit: 10,675
RAC: 0
United States
Message 1132973 - Posted: 28 Jul 2011, 14:22:52 UTC - in response to Message 1132917.  

oops sorry, i meant at 30% light speed.
ID: 1132973 · Report as offensive
Profile Gary Charpentier Crowdfunding Project Donor*Special Project $75 donorSpecial Project $250 donor
Volunteer tester
Avatar

Send message
Joined: 25 Dec 00
Posts: 30608
Credit: 53,134,872
RAC: 32
United States
Message 1133004 - Posted: 28 Jul 2011, 15:40:26 UTC - in response to Message 1132973.  

oops sorry, i meant at 30% light speed.

Actually what is more important is the rate of acceleration.

We don't instantly go from zero to 30% light or the reverse when we get to the destination. So you have the time and distance to accelerate at say 1g to your cruise speed, your coasting cruise until it is time to hit the brakes, and your deceleration time which matches your acceleration time. Good estimate but it ignores if the destination star system is moving relative to the sun system.

ID: 1133004 · Report as offensive
C Olival

Send message
Joined: 6 Sep 10
Posts: 209
Credit: 10,675
RAC: 0
United States
Message 1133216 - Posted: 29 Jul 2011, 0:58:43 UTC - in response to Message 1133004.  

thank you for the good information.
ID: 1133216 · Report as offensive
Profile Bob DeWoody
Avatar

Send message
Joined: 9 May 10
Posts: 3387
Credit: 4,182,900
RAC: 10
United States
Message 1133393 - Posted: 29 Jul 2011, 7:50:03 UTC

I haven't done the math but I do know at that rate by the time you got back to earth everyone you knew would be dead.
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.
ID: 1133393 · Report as offensive
Profile Bob DeWoody
Avatar

Send message
Joined: 9 May 10
Posts: 3387
Credit: 4,182,900
RAC: 10
United States
Message 1133395 - Posted: 29 Jul 2011, 7:56:20 UTC

Not allowing for acceleration it would by my calculation take 285 yrs one way.
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.
ID: 1133395 · Report as offensive
Profile Bob DeWoody
Avatar

Send message
Joined: 9 May 10
Posts: 3387
Credit: 4,182,900
RAC: 10
United States
Message 1133449 - Posted: 29 Jul 2011, 12:59:31 UTC

I think now I did some bad math and the time one way at 30% of lightspeed not allowing for acceleration or decelleration would be 15 years for the crew.
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.
ID: 1133449 · Report as offensive
C Olival

Send message
Joined: 6 Sep 10
Posts: 209
Credit: 10,675
RAC: 0
United States
Message 1133736 - Posted: 29 Jul 2011, 23:39:32 UTC - in response to Message 1133449.  

Interesting, 15 years for astronauts to reach the Alpha Centauri system in a craft at 30 percent light speed. So to Gliese d, looking at 40 to 50 year space mission in such a craft. I could see a craft powered by nuclear pulse fusion doing such missions. That is something that NASA can focus on, nuclear pulse fusion research.
ID: 1133736 · Report as offensive
C Olival

Send message
Joined: 6 Sep 10
Posts: 209
Credit: 10,675
RAC: 0
United States
Message 1133747 - Posted: 29 Jul 2011, 23:51:47 UTC

Question? can the Atacama Large Millimeter/submillimeter Array be used for the detection of radio signals that might be artificialin nature from the cosmos? Basically, can Atacama Large Millimeter/submillimeter Array be used like Arecibo?
ID: 1133747 · Report as offensive
Profile tullio
Volunteer tester

Send message
Joined: 9 Apr 04
Posts: 8797
Credit: 2,930,782
RAC: 1
Italy
Message 1133960 - Posted: 30 Jul 2011, 5:38:26 UTC - in response to Message 1133747.  

All I know is that a key person from the Allen Telescope Array has gone to Atacama. Maybe she can do something.
Tullio
ID: 1133960 · Report as offensive
C Olival

Send message
Joined: 6 Sep 10
Posts: 209
Credit: 10,675
RAC: 0
United States
Message 1136112 - Posted: 5 Aug 2011, 3:03:52 UTC - in response to Message 1133960.  

Allen Array will up and running again
ID: 1136112 · Report as offensive
Profile William Rothamel
Avatar

Send message
Joined: 25 Oct 06
Posts: 3756
Credit: 1,999,735
RAC: 4
United States
Message 1136187 - Posted: 5 Aug 2011, 8:54:07 UTC

Yes, the inertial confinement approach tried at Livermore National Laboratory, which makes H-bombs. But it uses high powered lasers and is not working yet. It is more an attempt to produce micro H-bomb explosions than producing power.
Tullio
____________



I used to canoe on the lake there in the Livermore valley. I have seen the TV show on the "Cold Fusion" project going on there. I hate to think that such a prestigious Laboratory would be doing anything that was not scientifically sound---but then there was PEAR at Princeton and JB Rhine and Parapsychology at Duke.

The cold fusion project there gives me that funny feeling. What do you think ?

The lasers were supposed to be turned on last summer.
ID: 1136187 · Report as offensive
Profile tullio
Volunteer tester

Send message
Joined: 9 Apr 04
Posts: 8797
Credit: 2,930,782
RAC: 1
Italy
Message 1136230 - Posted: 5 Aug 2011, 13:22:59 UTC - in response to Message 1136187.  

I don't think Livermore is looking into cold fusion.On June 24 there was an article on the NYTimes titled "Fusion experiment faces new hurdles".Its main point is that tritium used in the experiments can pollute the environment and cause lung cancer if inhaled. This was also the worry of the Nuclear Regulatory Commission about a sizable number of fission reactors in the USA. Tritium cannot be used as an explosive material but if you inhale it you are dead.
Tullio
ID: 1136230 · Report as offensive
Profile William Rothamel
Avatar

Send message
Joined: 25 Oct 06
Posts: 3756
Credit: 1,999,735
RAC: 4
United States
Message 1136238 - Posted: 5 Aug 2011, 13:55:07 UTC - in response to Message 1136230.  

Tritium is what makes your watch glow at night. It is also used in some medical applications. I think that we used to burn it in our power plant at the university where I worked by putting it into the #6 fuel oil tanks that fired the power plant at the time.

Radon gas can also cause lung cancer--it was fairly common in basements in New Jerseysince much of the state sits over the Redding Tongue of uranium rich rock.
ID: 1136238 · Report as offensive
Profile tullio
Volunteer tester

Send message
Joined: 9 Apr 04
Posts: 8797
Credit: 2,930,782
RAC: 1
Italy
Message 1136245 - Posted: 5 Aug 2011, 14:26:20 UTC - in response to Message 1136238.  


Radon gas can also cause lung cancer--it was fairly common in basements in New Jerseysince much of the state sits over the Redding Tongue of uranium rich rock.

I know. But in Badgastein, Austria, you can go into old mine tunnels to make "Radon baths". I am not joking, it was also on advertisement leaflets for that skiing resort (but only downhill runs, not my cross-country, so I did not return there).
Tullio
ID: 1136245 · Report as offensive
Profile Darrell Benvenuto
Avatar

Send message
Joined: 14 Oct 00
Posts: 23
Credit: 17,457,177
RAC: 58
United States
Message 1136254 - Posted: 5 Aug 2011, 14:38:32 UTC - in response to Message 1133449.  

I think now I did some bad math and the time one way at 30% of lightspeed not allowing for acceleration or decelleration would be 15 years for the crew.

It's actually pretty good that it would be doable in the lifespan of a single crew. Otherwise (for further-away destinations) we have to go to the model of large "generation ships", where you actually have children born and raised in space, the parents dying of old age, etc., and the highly-trained (by then) children taking their place, etc., etc., until the round trip was completed. And of course, with time dilation, even more years would have passed on Earth by the time the ship returned... the argument always was that by the time any such ship made it back from its long, isolated journey, odds were that we'd have developed a level of tech sufficient to make the round trip much faster.
ID: 1136254 · Report as offensive
C Olival

Send message
Joined: 6 Sep 10
Posts: 209
Credit: 10,675
RAC: 0
United States
Message 1137224 - Posted: 7 Aug 2011, 14:47:52 UTC - in response to Message 1129330.  

Interesting, i wonder too if the Voyager probes ever looked back at Earth for a spectral analysis.
ID: 1137224 · Report as offensive
Previous · 1 · 2 · 3 · Next

Message boards : SETI@home Science : Detecting systems with life


 
©2024 University of California
 
SETI@home and Astropulse are funded by grants from the National Science Foundation, NASA, and donations from SETI@home volunteers. AstroPulse is funded in part by the NSF through grant AST-0307956.