Comments on: How is the hubble space telescope able to see back in time? http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/ Thu, 17 May 2012 20:27:41 +0000 http://wordpress.org/?v=2.7 hourly 1 By: nathaniel a http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/comment-page-1/#comment-1656 nathaniel a Tue, 23 Jun 2009 12:56:29 +0000 http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/#comment-1656 Ummm.. not an answer, but maybe someone can enlighten. If the light here coming from there is a year old, then wouldn't we be technically be looking into the future with the Hubble? Since the light here is of what already happened... If we look 73 trillion miles away, we'll be looking at what we wont see here until 500 years right? Ummm.. not an answer, but maybe someone can enlighten. If the light here coming from there is a year old, then wouldn’t we be technically be looking into the future with the Hubble? Since the light here is of what already happened… If we look 73 trillion miles away, we’ll be looking at what we wont see here until 500 years right?

]]> By: Steven http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/comment-page-1/#comment-1655 Steven Sat, 20 Jun 2009 22:08:21 +0000 http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/#comment-1655 Every time you look at the sun you are looking 8 minutes into the past. Because it takes TIME for the light to reach our eyes. If the sun were to explode we wouldn't know at that exact moment, only 8 minutes later would we know. Every time you look at the sun you are looking 8 minutes into the past. Because it takes TIME for the light to reach our eyes. If the sun were to explode we wouldn’t know at that exact moment, only 8 minutes later would we know.

]]> By: Billy Butthead http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/comment-page-1/#comment-1654 Billy Butthead Thu, 18 Jun 2009 02:53:39 +0000 http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/#comment-1654 The same as you do when you look at something,even the person in the room with you,you are seeing them as they were billionths of a second in the past,the farther they are away the farther back in time they are. The same as you do when you look at something,even the person in the room with you,you are seeing them as they were billionths of a second in the past,the farther they are away the farther back in time they are.

]]> By: dammit249 http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/comment-page-1/#comment-1653 dammit249 Tue, 16 Jun 2009 03:56:00 +0000 http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/#comment-1653 Look up in the sky at night, if you're lucky enough to be in a light-pollution free area, you'll see stars. Now every single star you see are actually their image from years, if not millions of years in the past. The most distant a star is, the oldest its image is. You just made yourself litteraly looking back in time! Look up in the sky at night, if you’re lucky enough to be in a light-pollution free area, you’ll see stars.
Now every single star you see are actually their image from years, if not millions of years in the past. The most distant a star is, the oldest its image is.
You just made yourself litteraly looking back in time!

]]> By: Boatman1 http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/comment-page-1/#comment-1652 Boatman1 Sat, 13 Jun 2009 18:37:53 +0000 http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/#comment-1652 You don't believe it-- well OK. BUT it is true-- From a dark sky site away from the city if you know exactly where to look and have GOOD vision, you can see the Andromeda Galaxy 2.5 MILLION light years away-- or as it was 2.5 million years ago. You don’t believe it– well OK.

BUT it is true–

From a dark sky site away from the city if you know exactly where to look and have GOOD vision, you can see the Andromeda Galaxy 2.5 MILLION light years away– or as it was 2.5 million years ago.

]]> By: mellowfellow http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/comment-page-1/#comment-1651 mellowfellow Fri, 12 Jun 2009 19:57:37 +0000 http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/#comment-1651 no , i dont believe it no , i dont believe it

]]> By: It's That Guy http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/comment-page-1/#comment-1650 It's That Guy Fri, 12 Jun 2009 05:24:36 +0000 http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/#comment-1650 If you look at something 7 trillion miles away, you are seeing it a year ago. It takes a year for light to travel 7 trillion miles, so the light you are seeing left the place a year ago. When we look at the sun, 93 million miles away, we are seeing it 8 minutes ago. So the farther away something is, the longer ago we are seeing it. The Hubble Telescope can see right out to the edge of the universe. In fact, we can tell how old the universe is by how far away the farthest thing we can see is. It's been expanding since the Big Bang, so however far away the 'edge' is, divided by the speed of light, that's how old the universe is. If you look at something 7 trillion miles away, you are seeing it a year ago. It takes a year for light to travel 7 trillion miles, so the light you are seeing left the place a year ago. When we look at the sun, 93 million miles away, we are seeing it 8 minutes ago.

So the farther away something is, the longer ago we are seeing it. The Hubble Telescope can see right out to the edge of the universe. In fact, we can tell how old the universe is by how far away the farthest thing we can see is. It’s been expanding since the Big Bang, so however far away the ‘edge’ is, divided by the speed of light, that’s how old the universe is.

]]> By: Silent http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/comment-page-1/#comment-1649 Silent Tue, 09 Jun 2009 22:06:00 +0000 http://www.telescopebuyingguide.com/blog/how-is-the-hubble-space-telescope-able-to-see-back-in-time/#comment-1649 When you (or the HST) see something, it's because light has traveled from that object to your eye. Maybe that object generated the light (like a star, or a light bulb) or maybe light from somewhere else reflected off of it. But light doesn't travel instantaneously. It's incredibly fast, but it does take time to get where it's going. Light travels at about 300,000 kilometers per second. So if you're looking at an object that's 300,000 kilometers away, it's taken one second for that light to get to you. If it took a whole year for the light to get to you, the object would be at a distance astronomers call a "light-year". Because the light from the object originated one year ago, you'd be seeing the object as it was one year ago. You'd have to wait another year to see it as it is today. So, if another galaxy is something like 13 billion light-years away, the light you're seeing from it started its journey 13 billion years ago. In this way, you can sort of see into the past. I know it's a little counter-intuitive. This is because we're used to dealing with distances measured in meters or miles, distances which light can cover in a time so short we perceive it as instantaneous. But even the closest star, apart from our own Sun, is around 4 light-years away. When you (or the HST) see something, it’s because light has traveled from that object to your eye. Maybe that object generated the light (like a star, or a light bulb) or maybe light from somewhere else reflected off of it.

But light doesn’t travel instantaneously. It’s incredibly fast, but it does take time to get where it’s going. Light travels at about 300,000 kilometers per second. So if you’re looking at an object that’s 300,000 kilometers away, it’s taken one second for that light to get to you.

If it took a whole year for the light to get to you, the object would be at a distance astronomers call a “light-year”. Because the light from the object originated one year ago, you’d be seeing the object as it was one year ago. You’d have to wait another year to see it as it is today.

So, if another galaxy is something like 13 billion light-years away, the light you’re seeing from it started its journey 13 billion years ago. In this way, you can sort of see into the past.

I know it’s a little counter-intuitive. This is because we’re used to dealing with distances measured in meters or miles, distances which light can cover in a time so short we perceive it as instantaneous. But even the closest star, apart from our own Sun, is around 4 light-years away.

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