I'm glad someone out there thinks these things through...
BTW, an acquaintance told me of her ILLIAC IV days. With 64 independent processors it was the fastest pre-Cray machine, but sometimes did produce wrong values. Standard practice was to have 3 processors run the same problem and compare the results at the end, deciding that the 3x performance hit was worth it, if the results actually meant something...
In San Francisco, MUNI buse and light rail take the dollar coins. They have bill-for-coin changers near the subway fare gates; you swap a $1 or $5 bill for the corresponding number of dollar coins. It's much easier for a fare gate to deal with a coin than an old, worn bill.
If you think modern dollar coins are heavy, imagine the old Eisenhower or older Liberty coins:).
With one atom of gain medium, you can pump it with one pboton to your high energy level, and dump it with another photon. The two photons do leave the gain "medium" (all one atom of it) coherently, but so what?
even a "relatively low powered 486 laptop had more power than all of the computer technology in use by NASA as a whole during the Apollo era"
I've heard this and am somewhat skeptical. Certainly the compute power in the spacecraft was quite limited; adding power would have added weight and power consumption, and both were on a tight budget. However, trajectory simulation and radar processing computers, taken together, would likely have had more power than a 50 MHz 486. IIRC Michael Collins in his bio said NASA had a "basement full of computers" tracking the spacecraft in flight.
I would not go quite that far, as it could not orbit. It was certainly an essential early step, though. The X-20, or Dyna-Soar, should have been the real space program, but it was cancelled.
We pumped the dye laser with a doubled YAG output (532 nm, green). The dye was usually Rhodamine 690, tuned for power (unless that put us near an electronic resonance, which we didn't want) and, IIRC, it was orange-red. I don't have my notebook handy, and this was 6 - 11 years ago:).
If you're interested in the details, look up papers authored by Peter M. Felker in Chem Abstracts.
In grad student (chemistry) days I ran an apparatus for stimulated, mass-selective Raman spectroscopy of molecular clusters. The Raman pump beam was two colors, generally tuned for power (a watt or two each, depending on tuning). The molecular clusters were formed in a vacuum chamber and we had a quartz window to let the laser light in. If there was a speck of dust on the window at the point the beam entered, the absorption was sufficient to start drilling a hole in the window. The noise was our cue to cut the laser beam before the window was breached (there were dedicated electronic circuits to protect the vacuum chamber's diffusion pumps, but we didn't want to take the risk of failure).
Of course, we spent a lot of time cleaning that window, and for that matter all the optics.
If the interaction lasts 10^-18 s, then by special relativity the neutron couldn't interact with anything more than 0.3 nanometer away, or 3 angstrom. Any chance that the experiment is too fast to see the surroundings?
They do have Elvis' private airliner, a Convair 880 named Lisa Marie after his daughter. Convair's 880 and 990 airliners, though faster than 707s and DC-8s, were low-capacity (5-across seating) gas hogs. Few were sold.
At different points in the show I heard them say the velocity of the foam was 500mph or 700fps (equivalent to 1 sig fig). With a TV camera frame rate of 30 frames/second, the foam would have been in the image for maybe a frame.
(1) If we don't have to arrange for overseas bases, we don't need allies.
(2) This thing brings near-ICBM speed to conventional weapons, or "tactical" nukes.
Some trigger-happy type could take advantage of (1) and (2) to obliterate someone before consulting with other leaders, or ensure they've got the right location. "Shoot first, ask questions later" is bad policy, but this enables it.
And remember, other nations and non-governmental entities could have it. At best, a useless arms race; at worst, a more dangerous world. My vote is to pass.
There were plans for damming the lower Grand Canyon, which at the time was not part of the national park. I seem to remember that the Sierra Club, represented by the late David Brower, horse-traded Glen Canyon Dam for no dams in Grand Canyon.
Oil-lens binoculars? I've heard of oil lens microscope (drop of oil on the slide cover, move the lowest lens in to touch the drop) but not binocular. How and why?
I've noticed this with the red-on-blue Arco logo painted on the pumps, especially at night when illuminated by bluish, flickering mercury lamps. Very annoying. Anyone else?
But the mirror does not have to be a full circle. The Keck duo isn't, and the resolution corresponds to the distance from one mirror far-edge to the other.
Given this, the Shuttle dimension that's critical is the length of the bay, not the width.
Slashdot Mirror
I'm glad someone out there thinks these things through...
BTW, an acquaintance told me of her ILLIAC IV days. With 64 independent processors it was the fastest pre-Cray machine, but sometimes did produce wrong values. Standard practice was to have 3 processors run the same problem and compare the results at the end, deciding that the 3x performance hit was worth it, if the results actually meant something...
In San Francisco, MUNI buse and light rail take the dollar coins. They have bill-for-coin changers near the subway fare gates; you swap a $1 or $5 bill for the corresponding number of dollar coins. It's much easier for a fare gate to deal with a coin than an old, worn bill.
:).
If you think modern dollar coins are heavy, imagine the old Eisenhower or older Liberty coins
B-52's: Taking the 'Fun' Out of 'Fundamentalism' since 1952
1956
With one atom of gain medium, you can pump it with one pboton to your high energy level, and dump it with another photon. The two photons do leave the gain "medium" (all one atom of it) coherently, but so what?
xylene
We pumped the dye laser with a doubled YAG output (532 nm, green). The dye was usually Rhodamine 690, tuned for power (unless that put us near an electronic resonance, which we didn't want) and, IIRC, it was orange-red. I don't have my notebook handy, and this was 6 - 11 years ago :).
If you're interested in the details, look up papers authored by Peter M. Felker in Chem Abstracts.
In grad student (chemistry) days I ran an apparatus for stimulated, mass-selective Raman spectroscopy of molecular clusters. The Raman pump beam was two colors, generally tuned for power (a watt or two each, depending on tuning). The molecular clusters were formed in a vacuum chamber and we had a quartz window to let the laser light in. If there was a speck of dust on the window at the point the beam entered, the absorption was sufficient to start drilling a hole in the window. The noise was our cue to cut the laser beam before the window was breached (there were dedicated electronic circuits to protect the vacuum chamber's diffusion pumps, but we didn't want to take the risk of failure).
Of course, we spent a lot of time cleaning that window, and for that matter all the optics.
If the interaction lasts 10^-18 s, then by special relativity the neutron couldn't interact with anything more than 0.3 nanometer away, or 3 angstrom. Any chance that the experiment is too fast to see the surroundings?
I'm curious...how did your first computer affect your life?
Well, since then I've needed stronger and stronger eyeglasses...
Another interesting machine was a computer created by a student of the Wisconsin uni in the 50s/60s
:)
Not just any student, Gene Amdahl! It was part of his Ph.D. in EE.
Museum volunteer since, uh, hey Dag, when did I start...
At different points in the show I heard them say the velocity of the foam was 500mph or 700fps (equivalent to 1 sig fig). With a TV camera frame rate of 30 frames/second, the foam would have been in the image for maybe a frame.
(1) If we don't have to arrange for overseas bases, we don't need allies.
(2) This thing brings near-ICBM speed to conventional weapons, or "tactical" nukes.
Some trigger-happy type could take advantage of (1) and (2) to obliterate someone before consulting with other leaders, or ensure they've got the right location. "Shoot first, ask questions later" is bad policy, but this enables it.
And remember, other nations and non-governmental entities could have it. At best, a useless arms race; at worst, a more dangerous world. My vote is to pass.
BP of hydrogen is 20.28K; MP is 13.81K.
Never Say Never Again
Here are links to photos of how the valley looked.
There were plans for damming the lower Grand Canyon, which at the time was not part of the national park. I seem to remember that the Sierra Club, represented by the late David Brower, horse-traded Glen Canyon Dam for no dams in Grand Canyon.
There's a little black spot on the sun today.... :)
Oil-lens binoculars? I've heard of oil lens microscope (drop of oil on the slide cover, move the lowest lens in to touch the drop) but not binocular. How and why?
The LAST thing one of these "random University professors" would do is buy Plutonium on the black market.
Of course; could you imagine putting this on a research grant?
Name: Plutonium
Qty: 100g
Vendor: mumble
:)
I've noticed this with the red-on-blue Arco logo painted on the pumps, especially at night when illuminated by bluish, flickering mercury lamps. Very annoying. Anyone else?
a telescope diameter of roughly 5 meters
But the mirror does not have to be a full circle. The Keck duo isn't, and the resolution corresponds to the distance from one mirror far-edge to the other.
Given this, the Shuttle dimension that's critical is the length of the bay, not the width.